Wastewater treatment methods and equipment

Abstract

Various aspects of the present invention relate to a wastewater treatment method (200) and a wastewater treatment plant (1) for treating wastewater. The wastewater treatment method (200) includes receiving wastewater to be treated. The wastewater is supplied to an electrocoagulation unit (91) to cause solid matter suspended in the wastewater to aggregate. The wastewater is supplied from the electrocoagulation unit (91) to a mechanical filtration device (15). The mechanical filtration device (15) includes a static filter bag (75) for filtering the aggregated solid matter from the electrocoagulation unit (91). The static filter bag (75) consists of a plurality of mechanical filter elements (71), each having one or more filter units (73). The treated wastewater is discharged. Alternatively or additionally, the wastewater treatment method (200) may include introducing a coagulant into the wastewater. The wastewater treatment plant (1) may include a chemical agent system (97) for introducing the coagulant.

Description

Technical Field

[0001] This disclosure relates to wastewater treatment methods and apparatus. Various aspects of the invention relate to wastewater treatment methods and wastewater treatment plants. Wastewater may, for example, comprise industrial wastewater and / or municipal wastewater. The wastewater treatment methods and apparatus can also be used to treat wastewater in water reuse applications. Background Technology

[0002] Bioreactors are known for their use in the biological filtration of wastewater. A bioreactor may, for example, contain a filter medium that supports a community of microorganisms that transform organic matter present in the wastewater, thereby performing biological filtration. The bioreactor may be configured to support aerobic or anaerobic microorganisms for biological filtration. The filter medium may comprise multiple biofilter elements that can be circulated within the bioreactor (a so-called moving bed bioreactor).

[0003] The inventors have recognized that, in this context, movement of biofilter elements within a bioreactor can generate solid particles suspended in the wastewater. Movement of the biofilter elements can cause material to be removed, for example, when the biofilter elements come into contact with each other and / or with the sidewalls of the bioreactor. The removed material may contain clumps of accumulated waste and / or dead microorganisms filtered from the wastewater. The size of the removed solid particles may be relatively small, less than 5 μm in diameter. The inventors have determined that additional filtration can be performed to remove at least some of the solid particles discharged from the bioreactor. If the biofilter elements are in a static bed, such as a submerged aerated bed, it has been recognized that material can detach from the surface of the biofilter elements. This can cause solid matter, for example, to settle into the wastewater as suspended particles. Other forms of biofiltration can result in the introduction of particles and waste into the wastewater.

[0004] The purpose of this invention is to address one or more drawbacks associated with the prior art. Summary of the Invention

[0005] Various aspects and embodiments of the present invention provide a wastewater treatment method and a wastewater treatment plant, as described in the appended claims.

[0006] According to another aspect of the present invention, a wastewater treatment method is provided for treating wastewater, the wastewater treatment method comprising:

[0007] Receive wastewater awaiting treatment;

[0008] The wastewater is supplied to an electrocoagulation unit to cause the solids suspended in the wastewater to aggregate.

[0009] The wastewater is supplied from the electrocoagulation unit to a mechanical filtration device, wherein the mechanical filtration device includes a static filter bag for filtering aggregated solids from the electrocoagulation unit, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0010] Discharge the treated wastewater.

[0011] The method involves agglomerating solids suspended in wastewater. The electrocoagulation unit is located upstream of the mechanical filtration device. The agglomerated material is supplied from the electrocoagulation unit to the mechanical filtration device. The agglomerated material can be suspended in the wastewater introduced into the mechanical filtration device.

[0012] The mechanical filtration device comprises multiple mechanical filter elements. These mechanical filter elements form a static filter bag that mechanically filters wastewater as it passes through the device. The device may include a filter tank forming a filter chamber in which the mechanical filter elements are disposed. Each filter unit, or each filter cell, formed within each mechanical filter element has an open cell structure. Wastewater can flow into this filter unit or each filter unit. The mechanical filtration is achieved by promoting the settling of particles within the filter unit or each filter unit.

[0013] Alternatively, or additionally, the electrocoagulation unit may be incorporated into the mechanical filtration device. Solid matter (typically particles) can aggregate within the mechanical filtration device, thereby helping to ensure that the aggregated solid matter remains intact. The electrocoagulation unit may include one or more electrodes to support the electrochemical process. The one or more electrodes may be disposed within the mechanical filtration device, for example, inside a filter chamber where the static filter bag is formed. The one or more electrodes may be at least partially surrounded by the mechanical filter element forming the static filter bag. The one or more electrodes may be sacrificial. By aggregating solid matter (typically particles) within the mechanical filtration device, the decomposition or degradation of the aggregated material can be reduced. The at least one electrocoagulation unit may allow material to aggregate directly into the static filter bag.

[0014] The method may include supplying wastewater to a bioreactor for biofiltration. Wastewater discharged from the bioreactor may be discharged to an electrocoagulation unit to aggregate solid waste suspended in the wastewater discharged from the bioreactor. The electrocoagulation unit may be located downstream of the bioreactor. The bioreactor may include a biofilter medium for biofiltration of the wastewater. The biofilter medium may include multiple biofilter elements for supporting a community of microorganisms on the surface of the biofilter medium for biofiltration of the wastewater. The biofilter elements may circulate within the bioreactor, i.e., forming a moving bed biofilter. Alternatively, the biofilter elements may be static within the bioreactor, i.e., forming a static bed biofilter. The bioreactor may, for example, include or consist of a trickle filter. The method may include introducing air into the bioreactor to form a (submerged) static bed biofilter comprising multiple biofilter elements. Air may be introduced into the biofilter medium in the trickle filter. Other types of bioreactors may be considered. For example, the bioreactor may not contain a biofilter medium.

[0015] The method may include introducing a coagulant into wastewater to form flocs. At least some of the flocs may be suspended in the wastewater. At least one chemical agent system may be provided to introduce the coagulant into the wastewater. The wastewater may be supplied to the mechanical filtration device to filter the flocs suspended in the wastewater. The mechanical filtration device may be located downstream of at least one chemical agent system. The coagulant may be introduced upstream or downstream of the bioreactor. In one variation, a first chemical agent system may be located upstream of the bioreactor; and a second chemical agent system may be located downstream of the bioreactor. The coagulant may be introduced in liquid or solid form, such as comprising granules or powder.

[0016] In at least some embodiments, the wastewater flow rate through the mechanical filtration device is substantially constant. The method may include performing a single mechanical filtration of the wastewater within the mechanical filtration device (i.e., the wastewater passes through the mechanical filtration device once). Alternatively, the method may include performing multiple mechanical filtrations of the wastewater within the mechanical filtration device (i.e., the wastewater passes through the mechanical filtration device multiple times). A conduit may be provided to allow the wastewater to be recirculated through the mechanical filtration device.

[0017] The method may include establishing a flow rate per unit cross-sectional area of ​​the static filter bag formed in the mechanical filtration device within the range of 0.1 m³ / m² / h to 19 m³ / m² / h; 5 m³ / m² / h to 19 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h.

[0018] At least one water pump may be provided for pumping wastewater through a mechanical filtration device. The wastewater treatment method may include pumping wastewater discharged from the bioreactor to the mechanical filtration device. The at least one water pump may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter pack in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

[0019] The at least one water pump may be located downstream of the bioreactor. The at least one water pump may be located upstream of the mechanical filtration device. The at least one water pump may be located between the bioreactor and the mechanical filtration device. Alternatively or additionally, the at least one water pump may be located downstream of the mechanical filtration device.

[0020] The method may include using an electrocoagulation unit to coagulate particles in wastewater. Alternatively or additionally, the method may include using a chemical agent system to introduce a coagulant into the wastewater. The chemical agent system and / or the electrocoagulation unit may be located between the bioreactor and the mechanical filtration device. One or more of the at least one water pump may be located between the bioreactor and the chemical agent system; and / or between the bioreactor and the electrocoagulation unit.

[0021] The at least one pump may include or consist of a first pump. The first pump may be located upstream of the chemical agent system and / or the electrocoagulation unit. The first pump may be located between the bioreactor and the chemical agent system; and / or between the bioreactor and the electrocoagulation unit. The bioreactor may be located on the suction side of the first pump. The chemical agent system and / or the electrocoagulation unit may be located on the pressure side of the first pump. The method may include coagulating particles in wastewater downstream of the first pump. The method may include using the first pump to pump wastewater discharged from the bioreactor to the chemical agent system and / or the electrocoagulation unit.

[0022] Alternatively or additionally, the at least one pump may include or consist of a second pump. The second pump may be located downstream of the chemical agent system and / or the electrocoagulation unit. The second pump may be located between the chemical agent system and / or the electrocoagulation unit and the mechanical filtration device. The chemical agent system and / or the electrocoagulation unit may be located on the suction side of the first pump. The mechanical filtration device is located on the pressure side of the second pump. The second pump is operable to pump wastewater discharged from the chemical agent system and / or the electrocoagulation unit to the mechanical filtration device. The method may include using the mechanical filtration device to filter coagulated particles from the wastewater after treatment by the chemical agent system and / or the electrocoagulation unit.

[0023] Alternatively or additionally, the at least one water pump may comprise or consist of a water pump located downstream of the mechanical filtration device. The at least one water pump may comprise or consist of a third water pump. The mechanical filtration device may be located on the suction side of the water pump.

[0024] Alternatively, or additionally, one or more water pumps may be located upstream of the bioreactor. The bioreactor may be located on the pressure side of one or more water pumps.

[0025] According to another aspect of the present invention, a wastewater treatment method is provided for treating wastewater, the wastewater treatment method comprising:

[0026] Receive wastewater awaiting treatment;

[0027] At least one chemical agent system is used to introduce a coagulant into the wastewater to form flocs;

[0028] The wastewater is supplied to a mechanical filtration device located downstream of the at least one chemical agent system, wherein the mechanical filtration device comprises a static filter bag that filters the flocs suspended in the wastewater, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0029] Discharge the treated wastewater.

[0030] The coagulant is introduced into the wastewater upstream of the mechanical filtration device. The coagulant causes flocs to form in the wastewater. The flocs may comprise loosely aggregated particles or soft flakes, or be composed of them. At least some of the flocs may be suspended in the wastewater. The mechanical filtration device filters at least some of the flocs from the wastewater.

[0031] The coagulant causes dissolved phosphates in the wastewater to be released from the solution and form particles. The static filter bag of the mechanical filtration device filters particles or flocs containing or composed of phosphates. The coagulant can be ferric chloride or polyaluminum sulfate (PAC). The coagulant causes particles containing or composed of phosphates to aggregate and form flocs. At least some of the flocs can be suspended in the wastewater. The static filter bag of the mechanical filtration device filters the flocs from the wastewater. The coagulant can be introduced in liquid or solid form, such as comprising particles or powder.

[0032] The coagulant may comprise, or be composed of, organic or inorganic chemical substances or a polymer matrix. The coagulant may comprise, or be composed of, one or more of the following: ferric sulfate, ferric chloride, ferrous sulfate, aluminum sulfate and aluminum chloride or polyaluminium chloride (PAM), activated silica, bentonite, and metal hydroxides having a polymer structure, natural flocculants (e.g., starch derivatives, Moringa polysaccharides, and alginate or seaweed), and synthetic flocculants (e.g., polyacrylamide, polyethyleneimine, polyamines, polydiallyl dimethyl ammonium chloride (Poly DADMACs) and polytannates, polyamide-amines, polyamines, and polyethylene oxide).

[0033] After the coagulant is introduced, the wastewater can be retained for a period of time to allow floc formation. For example, the wastewater can be contained in a tank for a sustained period of time. This retention time can be predetermined, for example, depending on the volume of wastewater to which the coagulant is added. After the retention time, the wastewater can be supplied to the mechanical filtration device to remove the flocs suspended in the wastewater.

[0034] The detention time may be, for example, 10 to 40 minutes, 10 to 30 minutes, or 20 to 40 minutes. The detention time may be longer than 40 minutes.

[0035] The wastewater treatment method may include mixing a coagulant with the wastewater.

[0036] Wastewater can be retained in a settling tank to allow for floc formation. At least some of the flocs can settle out of the suspension in the settling tank. Wastewater can be supplied directly from the settling tank to the mechanical filtration equipment.

[0037] The coagulant can be introduced into the wastewater upstream of the settling tank or can be directly introduced into the wastewater of the settling tank.

[0038] Wastewater can be supplied to a tubular flocculant located upstream of the mechanical filtration equipment. The coagulant can be introduced into the wastewater supplied to the tubular flocculant. The coagulant can be introduced into the wastewater upstream of the tubular flocculant or directly into the tubular flocculant. The tubular flocculant may, for example, comprise a coiled flocculant.

[0039] Wastewater discharged from the tubular flocculant can be introduced into the sedimentation tank or the mechanical filtration equipment.

[0040] The wastewater treatment method may include supplying wastewater to a bioreactor for biological filtration. The bioreactor may be located upstream of the mechanical filtration equipment.

[0041] The bioreactor may include a biofilter medium for biofiltration of wastewater. The biofilter medium may include multiple biofilter elements for supporting microbial communities on its surface to biofilter the wastewater. The biofilter elements may circulate within the bioreactor, forming a moving bed biofilter. Alternatively, the biofilter elements may be static within the bioreactor, forming a static bed biofilter. The bioreactor may, for example, include or consist of a trickle filter. Air may be introduced into the biofilter medium in the trickle filter. A pump may be provided for introducing air into the bioreactor to form a (submerged) static bed biofilter comprising multiple biofilter elements. Other types of bioreactors are also possible. For example, the bioreactor may not contain a biofilter medium.

[0042] The static filter pack filters solid waste discharged from the bioreactor. This solid waste may be suspended in the wastewater discharged from the bioreactor. Circulation of the biofilter element can cause the solid waste to be removed from the biofilter element into the suspension in the wastewater. For example, the static filter pack can filter solid waste removed from the biofilter element in the bioreactor.

[0043] The at least one chemical agent system may be located downstream of the bioreactor. The method may include introducing the flocculant into the wastewater discharged from the bioreactor.

[0044] Alternatively or additionally, the at least one chemical agent system may introduce the coagulant into the mechanical filtration device, for example, into a filter chamber in which the static filter pack is formed. The at least one chemical agent system may introduce the coagulant directly into the filter chamber or directly into the filter chamber at the inlet.

[0045] At least some of the solid waste accumulated in the mechanical filtration device can be introduced into the bioreactor. At least some of the solid waste removed from the mechanical filtration element can be directly introduced into the bioreactor or upstream of the bioreactor.

[0046] The wastewater treatment plant may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter bag formed in the mechanical filtration device within the range of 0.11 m³ / m² / h to 19 m³ / m² / h. The wastewater treatment plant may include at least one pump for pumping wastewater through the mechanical filtration device. The at least one pump may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter bag formed in the mechanical filtration device within the range of 0.1 m³ / m² / h to 19 m³ / m² / h; 5 m³ / m² / h to 19 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h.

[0047] The wastewater treatment plant may include at least one pump for pumping wastewater via the mechanical filtration equipment. This at least one pump may, for example, be configured to establish a flow rate per unit cross-sectional area of ​​the static filter pack in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

[0048] The at least one water pump may be located downstream of the bioreactor. The at least one water pump may be located upstream of the mechanical filtration device. The at least one water pump may be located between the bioreactor and the mechanical filtration device.

[0049] As described herein, the wastewater treatment plant includes a chemical agent system. Alternatively, or additionally, the wastewater treatment plant may include an electrocoagulation unit. The chemical agent system and / or the electrocoagulation unit may be located between the bioreactor and the mechanical filtration equipment. One or more of the at least one water pump may be located between the bioreactor and the chemical agent system; and / or between the bioreactor and the electrocoagulation unit.

[0050] The at least one pump may include or consist of a first pump. The first pump may be located upstream of the chemical agent system and / or the electrocoagulation unit. The first pump may be located between the bioreactor and the chemical agent system; and / or between the bioreactor and the electrocoagulation unit. The bioreactor may be located on the suction side of the first pump. The chemical agent system and / or the electrocoagulation unit may be located on the pressure side of the first pump. The first pump is operable to pump wastewater discharged from the bioreactor to the chemical agent system and / or the electrocoagulation unit.

[0051] Alternatively or additionally, the at least one pump may include or consist of a second pump. The second pump may be located downstream of the chemical agent system and / or the electrocoagulation unit. The second pump may be located between the chemical agent system and / or the electrocoagulation unit and the mechanical filtration device. The chemical agent system and / or the electrocoagulation unit may be located on the suction side of the first pump. The mechanical filtration device is located on the pressure side of the second pump. The second pump is operable to pump wastewater discharged from the chemical agent system and / or the electrocoagulation unit to the mechanical filtration device.

[0052] Alternatively or additionally, the at least one water pump may comprise or consist of a water pump located downstream of the mechanical filtration device. The at least one water pump may comprise or consist of a third water pump. The mechanical filtration device may be located on the suction side of the water pump.

[0053] Alternatively, or additionally, one or more water pumps may be located upstream of the bioreactor. The bioreactor may be located on the pressure side of one or more water pumps.

[0054] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0055] An inlet for receiving wastewater to be treated;

[0056] An electrocoagulation unit is used to aggregate solids suspended in the wastewater.

[0057] A mechanical filtration device, disposed downstream of the electrocoagulation unit, wherein the mechanical filtration device includes a static filter bag for filtering aggregated solids discharged from the electrocoagulation unit and suspended in the wastewater, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0058] An outlet used to discharge treated wastewater.

[0059] The wastewater treatment plant may include a bioreactor for biological filtration of wastewater. The electrocoagulation unit may be configured to aggregate solid waste suspended in the wastewater discharged from the bioreactor.

[0060] The wastewater treatment plant may include at least one chemical agent system for introducing a flocculant into the wastewater to form flocs. At least some of the flocs may be suspended in the wastewater. The mechanical filtration device may be located downstream of at least one chemical agent system. In use, wastewater may be supplied to the mechanical filtration device to filter the flocs suspended in the wastewater. The chemical agent system may be located upstream or downstream of the bioreactor. In one variation, a first chemical agent system may be located upstream of the bioreactor, and a second chemical agent system may be located downstream of the bioreactor.

[0061] Alternatively, or additionally, the at least one electrocoagulation unit may be integrated into the mechanical filtration device. For example, the at least one electrocoagulation unit may be disposed within the filtration chamber, wherein the mechanical filtration elements form a static filter bag within the filtration chamber. The at least one electrocoagulation unit may be at least partially surrounded by the mechanical filtration elements within the static filter bag. The at least one electrocoagulation unit allows material to directly aggregate into the static filter bag.

[0062] At least one water pump may be provided for pumping wastewater through a mechanical filtration device. The at least one water pump may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter bag in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

[0063] The at least one water pump may be located downstream of the bioreactor. The at least one water pump may be located upstream of the mechanical filtration device. The at least one water pump may be located between the bioreactor and the mechanical filtration device.

[0064] One or more of at least one water pump may be disposed between the bioreactor and the electrocoagulation unit. Alternatively or additionally, one or more of the at least one water pump may be disposed between the electrocoagulation unit and the mechanical filtration device.

[0065] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0066] An inlet for receiving wastewater to be treated;

[0067] An electrocoagulation unit is used to aggregate solids suspended in the wastewater.

[0068] A mechanical filtration device comprising a static filter bag for filtering aggregated solids suspended in the wastewater, wherein the static filter bag comprises a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0069] An outlet for discharging treated wastewater. The at least one electrocoagulation unit may be integrated into the mechanical filtration device. The at least one electrocoagulation unit may be spaced apart from the static filter pack, for example, above or below the static filter pack. Alternatively, the at least one electrocoagulation unit may be at least partially surrounded by the mechanical filter elements in the static filter pack.

[0070] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0071] An inlet for receiving wastewater to be treated;

[0072] At least one chemical agent system for introducing a coagulant into the wastewater to form flocs;

[0073] A mechanical filtration device, disposed downstream of the at least one chemical agent system, wherein the mechanical filtration device comprises a static filter bag that filters the flocs suspended in the wastewater, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0074] An outlet used to discharge treated wastewater.

[0075] At least some of the flocs formed by the coagulant can be suspended in the wastewater. In use, the mechanical filtration device can be operated to filter the flocs suspended in the wastewater. The coagulant can be introduced in liquid or solid form, for example, comprising granules or powder.

[0076] In use, at least one chemical agent system may introduce a coagulant to release phosphates dissolved in the wastewater from the solution and form particles. The static filter pack of the mechanical filtration device may filter at least some particles containing or composed of phosphates. The coagulant is a chemical substance, such as ferric chloride or polyaluminum sulfate (PAC).

[0077] The coagulant may comprise, or be composed of, organic or inorganic chemical substances or a polymer matrix. The coagulant may comprise, or be composed of, one or more of the following: ferric sulfate, ferric chloride, ferrous sulfate, aluminum sulfate and aluminum chloride or polyaluminium chloride (PAM), activated silica, bentonite, and metal hydroxides having a polymer structure, natural flocculants (e.g., starch derivatives, Moringa polysaccharides, and alginate or seaweed), and synthetic flocculants (e.g., polyacrylamide, polyethyleneimine, polyamines, polydiallyl dimethyl ammonium chloride (Poly DADMACs) and polytannates, polyamide-amines, polyamines, and polyethylene oxide).

[0078] In use, the coagulant causes particles containing or composed of phosphates to aggregate and form flocs. At least some of these flocs remain suspended in the wastewater. The static filter bag of the mechanical filtration device filters these flocs from the wastewater.

[0079] The wastewater treatment plant may be configured to retain wastewater for a specified period of time to allow floc formation in the wastewater. The wastewater treatment plant may be configured to supply the wastewater to the mechanical filtration equipment after the retention period ends. This retention period may be predetermined, for example, depending on the volume of wastewater added. The retention period may be, for example, in the range of 10 to 40 minutes.

[0080] The wastewater treatment plant may include a settling tank for retaining wastewater before it is supplied to the mechanical filtration equipment. Wastewater from the settling tank may be supplied directly to the mechanical filtration equipment. The outlet of the settling tank may be directly connected to the inlet of the mechanical filtration equipment. The settling tank may be referred to as a downstream settling tank.

[0081] The at least one chemical agent system can be configured to introduce the coagulant into the wastewater upstream of the settling tank or to introduce the coagulant directly into the wastewater of the settling tank.

[0082] The wastewater treatment plant may include a bioreactor for biological filtration of wastewater. The bioreactor may be located upstream of the mechanical filtration equipment. The method may include supplying wastewater to a settling tank to settle solids. The settling tank may be located upstream of the bioreactor. The method may include supplying wastewater from the settling tank to the bioreactor. The settling tank may be referred to as an upstream settling tank.

[0083] The wastewater treatment plant may include a tubular flocculant for introducing a coagulant into the wastewater. The tubular flocculant may include a coil pipe flocculator. The tubular flocculant may be located upstream of the mechanical filtration equipment. The tubular flocculant may be configured to directly introduce wastewater into the settling tank or the mechanical filtration equipment.

[0084] The bioreactor may include a biofilter medium for biofiltration of wastewater. The biofilter medium may include multiple biofilter elements for supporting microbial communities on its surface to biofilter the wastewater. The biofilter elements may circulate within the bioreactor, forming a moving bed biofilter. Alternatively, the biofilter elements may be static within the bioreactor, forming a static bed biofilter. The bioreactor may, for example, include or consist of a trickle filter. Air may be introduced into the biofilter medium in the trickle filter. A pump may be provided for introducing air into the bioreactor to form a (submerged) static bed biofilter comprising multiple biofilter elements. Other types of bioreactors are also possible. For example, the bioreactor may not contain a biofilter medium.

[0085] The wastewater treatment plant may include means for circulating biological filter elements within a bioreactor during filtration to remove retained waste.

[0086] The static filter pack in the mechanical filtration device is operable to filter solid waste discharged from the bioreactor. The solid waste can be removed from the surface of the biofilter elements in the bioreactor. Solid waste can be removed when the biofilter elements in the moving bed come into contact with each other. Solid waste can be removed when the biofilter elements form a static bed biofilter. Other mechanical, hydraulic, or biological methods can remove solid waste from the biofilter elements. The solid waste may be suspended in the wastewater discharged from the bioreactor.

[0087] The at least one chemical agent system may be located downstream of the bioreactor. The at least one chemical agent system may be configured to introduce the flocculant into the wastewater discharged from the bioreactor. The flocculant may also be introduced into the wastewater upstream of the mechanical filtration device.

[0088] The wastewater treatment plant may include a return line for returning at least some of the solid waste accumulated in the mechanical filtration equipment to the bioreactor or upstream of the bioreactor.

[0089] The return line can be directly connected to the bioreactor or connected upstream of the bioreactor.

[0090] The wastewater treatment plant may include at least one pump for pumping wastewater through the mechanical filtration device. The at least one pump may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter bag formed in the mechanical filtration device within the range of 0.1 m³ / m² / h to 19 m³ / m² / h; 5 m³ / m² / h to 19 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h.

[0091] The wastewater treatment method may include pumping wastewater discharged from the bioreactor to the mechanical filtration device. At least one pump may be provided for pumping the wastewater through the mechanical filtration device. This at least one pump may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter pack in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

[0092] The at least one water pump may be located downstream of the bioreactor. The at least one water pump may be located upstream of the mechanical filtration device. The at least one water pump may be located between the bioreactor and the mechanical filtration device.

[0093] One or more of the at least one water pump may be disposed between the bioreactor and the electrocoagulation unit. Alternatively or additionally, one or more of the at least one water pump may be disposed between the electrocoagulation unit and the mechanical filtration device.

[0094] According to one aspect of the present invention, a wastewater treatment method is provided for treating wastewater, the wastewater treatment method comprising:

[0095] Receive wastewater awaiting treatment;

[0096] The wastewater is supplied to a bioreactor containing a biofiltering medium for biofiltration of the wastewater. The biofiltering medium includes multiple biofiltering elements for supporting a community of microorganisms. The biofiltering elements circulate within the bioreactor during filtration, and the circulation of the biofiltering elements causes solid waste to be removed from the biofiltering elements and suspended in the wastewater.

[0097] Wastewater discharged from the bioreactor is supplied to a mechanical filtration device located downstream of the bioreactor. This mechanical filtration device includes a static filter bag for filtering solid waste removed from the biofiltration elements in the bioreactor and suspended in the wastewater. The static filter bag contains multiple mechanical filter elements, each having one or more filter units.

[0098] Discharge the treated wastewater.

[0099] It is recognized that the operation of a bioreactor generates solid waste, such as solid particles or flocs, or is composed of them. Flocs discharged from the bioreactor may contain flocculent clumps. As the biofilter media circulates within the bioreactor, the solid waste is removed from the surface of the biofilter media. In particular, the biofilter media come into contact with each other, resulting in the removal of solid waste. The removed solid waste may be suspended in the wastewater discharged from the bioreactor, for example, as solid particles. It has been determined that mechanical filtration devices comprising static filter bags formed by multiple mechanical filter elements are particularly effective in removing solid waste suspended in the wastewater discharged from the bioreactor. At least in some embodiments, it has been determined that a combination of a bioreactor and a mechanical filtration device in series is particularly effective in wastewater treatment. The wastewater may be, for example, industrial wastewater or municipal wastewater.

[0100] The bioreactor can be anaerobic or aerobic. Anaerobic bioreactors are configured to support anaerobic microorganisms. Aerobic bioreactors are configured to support aerobic microorganisms. For example, an aerobic bioreactor may be configured to introduce air into the wastewater to support aerobic microorganisms.

[0101] Each of the mechanical filter elements has one or more filter units. The structure of the mechanical filter element is referred to herein as an open structure. The filter element is non-porous. The sidewalls of each filter unit are non-porous. Each of the one or more filter units contains pores formed in the mechanical filter element. The filter element may be molded, for example, from a plastic material.

[0102] The cross-sectional area of ​​the filter unit or each filter unit may be in the range of one (1) to ten (10) square millimeters; or one (1) to five (5) square millimeters. The length of the filter unit may be greater than or equal to five (5) millimeters, six (6) millimeters or eight (8) millimeters. The mechanical filter element may have negative buoyancy, neutral buoyancy or positive buoyancy.

[0103] The wastewater treatment method may include supplying wastewater to a settling tank located upstream of the bioreactor to settle solids. Wastewater from the settling tank may be supplied to the bioreactor.

[0104] The wastewater treatment method may include introducing pressurized fluid into the bioreactor to circulate the biofilter media within the bioreactor. The fluid may be a liquid or a gas. The wastewater treatment method may also include introducing pressurized air into the bioreactor to circulate the biofilter media within the bioreactor. Alternatively, or additionally, a mechanical agitator may be used to circulate the biofilter media within the bioreactor. The mechanical agitator may include, for example, one or more rotating components.

[0105] The wastewater treatment method may include periodically cleaning the mechanical filtration equipment to remove solid waste accumulated in the static filter pack. Cleaning the mechanical filtration equipment may include breaking the static filter pack to remove solid waste accumulated in the mechanical filter elements. The method may include breaking the static filter pack after closing at least one of the mechanical filtration equipment inlet for receiving wastewater from the bioreactor and the mechanical filtration equipment outlet for discharging treated wastewater from the mechanical filtration equipment. The cleaning may include breaking the static filter pack within a predetermined time period.

[0106] One or more mechanical cleaning components can be used to disrupt the static filter pack. These components may be driven by an electric motor or similar device. For example, the mechanical cleaning components may rotate within the mechanical filtration apparatus. Alternatively, or additionally, fluid may be introduced into the mechanical filtration apparatus to disrupt the static filter pack. The fluid may be a liquid or a gas. The fluid may be introduced at a pressure greater than atmospheric pressure. The fluid may be air. An air pump may be provided to supply pressurized air to the mechanical filtration apparatus.

[0107] The wastewater treatment method may include opening the waste outlet of a mechanical filtration device to discharge at least some wastewater from the mechanical filtration device and solid waste removed from the mechanical filter elements. The waste outlet of the mechanical filtration device may be opened after the static filter pack has been destroyed within a predetermined time period.

[0108] The wastewater treatment method may include recycling at least some of the wastewater through a bioreactor. At least some solid waste removed from the mechanical filter elements of the mechanical filtration device may be reintroduced upstream of the bioreactor. Therefore, solid waste accumulated in the mechanical filtration device can undergo further biological filtration. Solid waste removed from the mechanical filter elements may be directly introduced into the bioreactor. Alternatively, solid waste removed from the mechanical filter elements may be introduced upstream of the bioreactor, for example, into a settling tank (if present in the system).

[0109] The removed solid waste is preferably transported together with the wastewater discharged from the mechanical filtration device. Alternatively, or additionally, the removed solid waste may be transported together with a separate liquid supply, such as a cleaning solution.

[0110] The wastewater treatment method may include using an electrocoagulation unit to aggregate substances suspended in the wastewater. The electrocoagulation unit may be located upstream of the mechanical filtration device. The aggregated substances may be suspended in the wastewater introduced into the mechanical filtration device. In at least some embodiments, the mechanical filtration device is operable to remove the aggregated substances from the wastewater.

[0111] The electrocoagulation unit may be located downstream of the bioreactor. The electrocoagulation unit is operable to aggregate solid waste removed from the biofiltration element in the bioreactor. The aggregated material can then be removed by the mechanical filtration device.

[0112] The wastewater treatment plant may include at least one chemical agent system for introducing a flocculant into the wastewater upstream of the mechanical filtration equipment. The flocculant causes floc formation in the wastewater. This at least one chemical agent system may be located downstream of the bioreactor. In use, the flocculant causes dissolved phosphates in the wastewater to release from solution and form particles. The static filter bag of the mechanical filtration equipment may be configured to filter particles or aggregates formed by the flocculant. The flocculant may be ferric chloride or polyaluminum sulfate (PAC). Particles containing or composed of phosphates may aggregate. In use, particles containing or composed of phosphates may aggregate to form flocs. At least some of the flocs may be suspended in the wastewater. The static filter bag of the mechanical filtration equipment is configured to filter flocs from the wastewater.

[0113] The wastewater treatment plant may include at least one pump for pumping wastewater discharged from the bioreactor to the mechanical filtration device. The at least one pump may be configured to pump the wastewater through the mechanical filtration device. The at least one pump may be configured to establish a flow rate per unit cross-sectional area of ​​the static filter pack in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

[0114] The at least one water pump may be located downstream of the bioreactor. The at least one water pump may be located upstream of the mechanical filtration device. The at least one water pump may be located between the bioreactor and the mechanical filtration device.

[0115] As described herein, a chemical agent system and / or an electrocoagulation unit may be disposed between the bioreactor and the mechanical filtration device. One or more of the at least one water pump may be disposed between the bioreactor and the chemical agent system; and / or between the bioreactor and the electrocoagulation unit.

[0116] The at least one pump may include or consist of a first pump. The first pump may be located upstream of the chemical agent system and / or the electrocoagulation unit. The first pump may be located between the bioreactor and the chemical agent system; and / or between the bioreactor and the electrocoagulation unit. The bioreactor may be located on the suction side of the first pump. The chemical agent system and / or the electrocoagulation unit may be located on the pressure side of the first pump. The first pump is operable to pump wastewater discharged from the bioreactor to the chemical agent system and / or the electrocoagulation unit.

[0117] Alternatively or additionally, the at least one pump may include or consist of a second pump. The second pump may be located downstream of the chemical agent system and / or the electrocoagulation unit. The second pump may be located between the chemical agent system and / or the electrocoagulation unit and the mechanical filtration device. The chemical agent system and / or the electrocoagulation unit may be located on the suction side of the first pump. The mechanical filtration device is located on the pressure side of the second pump. The second pump is operable to pump wastewater discharged from the chemical agent system and / or the electrocoagulation unit to the mechanical filtration device.

[0118] Alternatively or additionally, the at least one water pump may comprise or consist of a water pump located downstream of the mechanical filtration device. The at least one water pump may comprise or consist of a third water pump. The mechanical filtration device may be located on the suction side of the water pump.

[0119] According to another aspect of the present invention, a wastewater treatment method is provided for treating wastewater, the wastewater treatment method comprising:

[0120] Receive wastewater awaiting treatment;

[0121] The wastewater is supplied to a bioreactor containing a biofiltering medium for biofiltration of the wastewater. The biofiltering medium includes multiple biofiltering elements for supporting a community of microorganisms. The biofiltering elements circulate within the bioreactor during filtration, and the circulation of the biofiltering elements causes solid waste to be removed from the biofiltering elements and suspended in the wastewater.

[0122] Wastewater discharged from the bioreactor is supplied to an electrocoagulation unit to aggregate solid waste removed from the biofiltration elements in the bioreactor; and

[0123] Discharge the treated wastewater.

[0124] Wastewater containing aggregated solid waste can be supplied to a mechanical filtration device. The mechanical filtration device can be of the type described herein. For example, the mechanical filtration device may include a static filter bag for filtering solid waste removed from the biofilter elements in the bioreactor and suspended in the wastewater. The static filter bag contains multiple mechanical filter elements, each having one or more filter units. The treated wastewater can be discharged from the mechanical filtration device.

[0125] The microorganisms can be aerobic or anaerobic. The biofilter element can circulate continuously within the bioreactor to maintain suitable environmental conditions to support the microorganisms within the bioreactor.

[0126] According to another aspect of the present invention, a wastewater treatment method is provided for treating wastewater, the wastewater treatment method comprising:

[0127] Receive wastewater awaiting treatment;

[0128] The wastewater is supplied to an electrocoagulation unit to cause the solids suspended in the wastewater to aggregate.

[0129] The wastewater is supplied from the electrocoagulation unit to a mechanical filtration device, wherein the mechanical filtration device includes a static filter bag for filtering aggregated solids from the electrocoagulation unit, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0130] Discharge the treated wastewater.

[0131] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0132] An inlet for receiving wastewater to be treated;

[0133] A bioreactor comprising a biofilter medium for biofiltering the wastewater, the biofilter medium being adapted to support a microbial community, the bioreactor including means for circulating the biofilter medium within the bioreactor during filtration; and

[0134] A mechanical filtration device, disposed downstream of the bioreactor, comprising a static filter bag for filtering solid waste removed from the biofiltration elements in the bioreactor and suspended in the wastewater, the static filter bag comprising a plurality of mechanical filter elements, each having one or more filter units; and

[0135] An outlet used to discharge treated wastewater.

[0136] Microorganisms can be aerobic, anaerobic, or hypoxic.

[0137] Each of the mechanical filter elements comprises one or more filter units. The mechanical filter element is non-porous. The sidewalls of each filter unit are non-porous. Each of the one or more filter units contains pores formed within the mechanical filter element. The mechanical filter element may, for example, be molded from a plastic material.

[0138] The wastewater treatment plant may include a settling tank for promoting the settling of solids suspended in the wastewater, the settling tank being located upstream of the bioreactor.

[0139] The wastewater treatment plant may include a pressurized air supply for introducing pressurized air into the bioreactor to circulate the biofilter media within the bioreactor. The wastewater treatment plant may also include an air pump for generating the pressurized air supply.

[0140] The wastewater treatment plant may include means for disrupting static filter media in the mechanical filtration apparatus to remove solid waste accumulated in the porous filter medium. The disruption means may include mechanical components or agitation mechanisms for disrupting the static filter media. Alternatively, or additionally, the disruption means may include a pump or compressor for supplying pressurized fluid to the mechanical filtration apparatus. The fluid may comprise liquid or gas. The pump or compressor may supply pressurized air to the mechanical filtration apparatus.

[0141] The wastewater treatment plant may include one or more valves for closing at least one of the following: the inlet of the mechanical filter; and the outlet of the mechanical filter. At least one of the mechanical filter inlet and / or mechanical filter outlet may be closed when the static filter pack is destroyed for cleaning.

[0142] The wastewater treatment plant may include a pump for introducing pressurized air or liquid into the mechanical filtration device to disrupt the static filter pack. Alternatively, or additionally, the wastewater treatment plant may include a mechanical agitator for disrupting the static filter pack.

[0143] The wastewater treatment plant may include a mechanical filtration equipment waste outlet, operable to discharge at least some of the wastewater from the mechanical filtration equipment.

[0144] The wastewater treatment plant may include a return line configured to recirculate at least some wastewater and / or accumulated waste from the mechanical filtration equipment back into the wastewater treatment plant upstream of the bioreactor. The return line may be connected to the bioreactor to recirculate wastewater and / or accumulated waste from the mechanical filtration equipment into the bioreactor. The return line may also be connected to a settling tank to recirculate wastewater from the mechanical filtration equipment into the settling tank upstream of the bioreactor. Water from the settling tank may then be discharged into the bioreactor.

[0145] The wastewater treatment plant may include an electrocoagulation unit to aggregate substances suspended in the wastewater.

[0146] The electrocoagulation unit may be located upstream of the mechanical filtration device. In use, the aggregated material is suspended in the wastewater, which is then introduced into the mechanical filtration device.

[0147] The electrocoagulation unit may be located downstream of the bioreactor. In use, the electrocoagulation unit is operated to aggregate solid waste suspended in the wastewater discharged from the bioreactor.

[0148] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0149] An inlet for receiving wastewater to be treated;

[0150] A bioreactor comprising a biofilter medium for biofiltering the wastewater, the biofilter medium being adapted to support a microbial community, the bioreactor including means for circulating the biofilter medium within the bioreactor during filtration; and

[0151] An electrocoagulation unit is located downstream of the bioreactor and is configured to aggregate substances suspended in the wastewater discharged from the bioreactor.

[0152] The wastewater treatment plant may include mechanical filtration equipment of the type described herein. Aggregated solid waste may be supplied to the mechanical filtration equipment. The mechanical filtration equipment may include static filter bags for filtering solid waste removed from the biofilter elements in the bioreactor and suspended in the wastewater. The static filter bags contain multiple mechanical filter elements, each having one or more filter units. The treated wastewater may be discharged from the mechanical filtration equipment.

[0153] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0154] An inlet for receiving wastewater to be treated;

[0155] An electrocoagulation unit is used to aggregate solids suspended in the wastewater.

[0156] A mechanical filtration device, disposed downstream of the electrocoagulation unit, wherein the mechanical filtration device includes a static filter bag for filtering aggregated solids discharged from the electrocoagulation unit and suspended in the wastewater, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and

[0157] An outlet used to discharge treated wastewater.

[0158] According to another aspect of the present invention, a wastewater treatment method is provided for treating wastewater, the wastewater treatment method comprising:

[0159] Receive wastewater awaiting treatment;

[0160] The wastewater is supplied to a first filtration device, which includes a storage tank for receiving the wastewater.

[0161] A second filtration device is used to filter at least some of the wastewater in the storage tank. The second filtration device includes a static filter bag for filtering solid waste suspended in the wastewater. The static filter bag includes a plurality of mechanical filter elements, each of which has one or more filter units.

[0162] Wastewater from the storage tank of the first filtration device is supplied to the second filtration device for filtration, and the wastewater filtered by the second filtration device is returned to the storage tank of the first filtration device; and

[0163] The wastewater is filtered in the storage tank using the first filtration device, and the wastewater treated by the first filtration device is discharged.

[0164] The second filtration device filters the wastewater in the storage tank of the first filtration device. The second filtration device can thereby reduce the filtration load on the first filtration device. The second filtration device can be selectively connected to the first filtration device. One or more control valves can be used to control the supply of wastewater from the storage tank to the second filtration device and / or from the second filtration device to the first filtration device.

[0165] The wastewater treatment method may include biological filtration of the wastewater. A bioreactor containing biological filter media may be used for biological filtration. The bioreactor may be located upstream of the first filtration device. The method may include supplying the wastewater filtered by the bioreactor to the storage tank of the first filtration device.

[0166] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0167] An inlet for receiving wastewater to be treated;

[0168] A first filtration device is used to filter wastewater received at the inlet, the first filtration device including a storage tank for receiving wastewater;

[0169] The second filtration device includes a static filter bag for filtering solid waste suspended in the wastewater, the static filter bag containing a plurality of mechanical filter elements, each mechanical filter element having one or more filter units;

[0170] The second filtration device includes a filtration inlet for receiving wastewater from the storage tank of the first filtration device and a filtration outlet for returning the filtered wastewater to the storage tank; and

[0171] The outlet is used to discharge the treated wastewater from the first filtration device.

[0172] The wastewater treatment plant may include a bioreactor containing a biofilter medium for biologically filtering wastewater. The bioreactor may be located upstream of the first filtration unit. Wastewater filtered by the bioreactor may be supplied to the storage tank of the first filtration unit.

[0173] The first filtration device may include a filter element for filtering wastewater. The filter element may include a mesh, cloth, screen, etc.

[0174] The second filtration device is used to filter wastewater in the storage tank of the first filtration device. The second filtration device can thereby reduce the filtration load on the first filtration device. The second filtration device can be selectively connected to the first filtration device. One or more control valves can be used to control the supply of wastewater from the storage tank to the second filtration device and / or from the second filtration device to the first filtration device.

[0175] According to another aspect of the present invention, a wastewater treatment plant for treating wastewater is provided, the wastewater treatment plant comprising:

[0176] A settling tank for promoting the settling of debris, the settling tank having a settling tank inlet for receiving the wastewater and a settling tank outlet for discharging the wastewater from the settling tank;

[0177] A first filtration device is located downstream of the sedimentation tank, and wastewater discharged from the sedimentation tank is supplied to the first filtration device.

[0178] A second filtration device is used to filter wastewater in the settling tank. The second filtration device includes a static filter bag for filtering solid waste suspended in the wastewater. The static filter bag includes a plurality of mechanical filter elements, each of which has one or more filter units.

[0179] The second filtration device includes a filtration inlet for receiving wastewater from the settling tank and a filtration outlet for returning the filtered wastewater to the settling tank.

[0180] Within the scope of this application, it is expressly indicated that the various aspects, embodiments, examples, and alternatives listed in the foregoing paragraphs, claims, and / or the following description and drawings, particularly the various features therein, may be employed independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or by any combination of methods, unless these features are incompatible. The applicant reserves the right to amend any initially filed claim or accordingly file any new claim, including the right to amend any initially filed claim to reference and / or incorporate any feature of any other claim, even if the claim was not initially filed in this manner. Attached Figure Description

[0181] One or more embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings, wherein:

[0182] Figure 1 A schematic diagram of a water treatment plant according to an embodiment of the present invention is shown;

[0183] Figure 2A It shows Figure 1 A perspective view of the mechanical filter elements used in the filtration equipment of the water treatment plant shown.

[0184] Figure 2B It shows Figure 2A End view of the mechanical filter element shown;

[0185] Figure 2C It shows Figure 2A A perspective view of a variant of the mechanical filter element shown;

[0186] Figure 3 An example is shown. Figure 1 The diagram shows the first flow chart of the wastewater treatment plant's operation.

[0187] Figure 4 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown;

[0188] Figure 5 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown;

[0189] Figure 6 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown;

[0190] Figure 7 An example is shown. Figure 6 The second flow chart of the wastewater treatment plant operation is shown.

[0191] Figure 8A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown, the water treatment plant comprising first and second chemical agent systems;

[0192] Figure 9A A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown, the water treatment plant comprising three chemical agent systems;

[0193] Figure 9B Another embodiment of the invention is shown. Figure 9A A schematic diagram of a variant of the water treatment plant shown;

[0194] Figure 9C An illustration is shown according to another embodiment of the present invention. Figure 9A The illustration shows a variant of the water treatment plant that incorporates a tubular flocculant.

[0195] Figure 10 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown, the water treatment plant comprising first and second water pumps;

[0196] Figure 11 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown, the water treatment plant comprising a water pump disposed between a bioreactor and a chemical agent system;

[0197] Figure 12 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown, in which a chemical agent system is replaced by an electrocoagulation unit;

[0198] Figure 13 A schematic diagram of another embodiment of a water treatment plant according to the present invention is shown, the water treatment plant comprising downstream filtration equipment and mechanical filtration equipment;

[0199] Figure 14 A schematic diagram of a trickling filter for a water treatment plant or water treatment process according to one or more embodiments of the present invention is shown; and

[0200] Figures 15A to 15E An example of a filter tank suitable for a mechanical filtration device according to the present invention is shown. Detailed Implementation

[0201] This document describes a method and apparatus for treating wastewater according to embodiments of the present invention with reference to the accompanying drawings. The wastewater in this embodiment is municipal wastewater. Alternatively or additionally, the wastewater treatment plant and wastewater treatment method can be used to treat industrial wastewater.

[0202] Wastewater treatment plant 1 according to an embodiment of the present invention will now be described. Wastewater treatment plant 1 is a municipal wastewater treatment plant configured to clean municipal wastewater. As described herein, wastewater treatment plant 1 employs physical and biological methods to clean wastewater. Wastewater treatment plant 1 may also optionally use chemical methods to clean wastewater. Wastewater treatment plant 1 cleans wastewater to remove contaminants or toxins that, if released, could lead to environmental degradation. Wastewater treatment plant 1 may also remove dissolved nutrients, such as nitrogen, to reduce or prevent eutrophication of waterways. Nitrogen can be removed by a denitrification process to convert ammonia into nitrates. In some embodiments, wastewater treatment plant 1 can be used to treat industrial wastewater that is more toxic than municipal wastewater. Wastewater treatment plant 1 may include pretreatment facilities (not shown) or posttreatment facilities, for example, suitable for treating industrial wastewater to remove toxins.

[0203] like Figure 1 As shown, wastewater treatment plant 1 includes a wastewater inlet 3, a wastewater outlet 5, and a waste outlet 7. Wastewater inlet 3 is configured to receive incoming wastewater. Wastewater outlet 5 is configured to discharge wastewater treated by wastewater treatment plant 1. Waste outlet 7 discharges waste removed from the wastewater. Waste discharged from wastewater treatment plant 1 through waste outlet 7 may be further treated. Alternatively, at least some waste may be recycled through wastewater treatment plant 1 for further treatment.

[0204] Wastewater treatment plant 1 includes a settling tank 11, a bioreactor 13, a mechanical filtration device 15, and at least one air pump 17. As described herein, the bioreactor 13 is provided for biological filtration of wastewater. The bioreactor 13 in this embodiment is a moving bed bioreactor, but other types of bioreactors are also contemplated. The mechanical filtration device 15 is provided for mechanical filtration to remove particles suspended in the wastewater discharged from the bioreactor 13. The settling tank 11, bioreactor 13, and mechanical filtration device 15 are connected in series. Wastewater passes sequentially through the settling tank 11, the bioreactor 13, and the mechanical filtration device 15. Specifically, the inflowing wastewater is introduced into the settling tank 11 for primary settling. The wastewater discharged from the settling tank 11 is introduced into the bioreactor 13 for biological filtration. The wastewater discharged from the bioreactor 13 is introduced into the mechanical filtration device 15 for mechanical filtration. The wastewater is discharged from the wastewater treatment plant 1 after passing through the mechanical filtration device 15. One or more pumps (not shown) may be provided to pump the wastewater through the wastewater treatment plant 1. At least one air pump 17 is provided to supply air to the bioreactor 13 and the mechanical filtration device 15 at a pressure greater than atmospheric pressure. In this embodiment, the wastewater treatment plant 1 includes a single air pump 17 and is provided with first and second control valves 19-1, 19-2 to control the supply of pressurized air to at least one of the bioreactor 13 and the mechanical filtration device 15, respectively. The wastewater treatment plant 1 includes an electronic control unit ECU 1, which includes at least one electronic processor 21 and a system memory 23. The electronic control unit ECU 1 is configured to control the operation of the wastewater treatment plant 1 according to the methods described herein. The electronic control unit ECU 1 is configured to control the operation of the first and second control valves 19-1, 19-2 to control the supply of pressurized air from the air pump 17 to the bioreactor 13 and the mechanical filtration device 15. In a variant, separate air pumps 17 may be provided to supply air to the bioreactor 13 and the mechanical filtration device 15, respectively.

[0205] The settling tank 11 includes at least one settling tank inlet 31, at least one settling tank outlet 33, and at least one settling tank waste outlet 35. For example... Figure 1As shown, at least one settling tank inlet 31 and at least one settling tank outlet 33 are located in the upper region of the settling tank 11. At least one settling tank waste outlet 35 is located in the lower region of the settling tank 11. The settling tank inlet 31 is in fluid communication with the wastewater inlet 3 of the wastewater treatment plant 1. In operation, incoming wastewater is introduced into the settling tank 11 through at least one settling tank inlet 31. Solid matter settles from the wastewater and settles to the bottom of the settling tank 11. Wastewater is discharged from the settling tank 11 through at least one settling tank outlet 33 to the bioreactor 13. The settling tank 11 thus serves as a pre-filter for the bioreactor 13. At least one settling tank waste valve 37 is provided to control the discharge of solids and waste through the settling tank waste outlet 35. Waste discharged from at least one settling tank 11 is typically in the form of sludge. At least one settling tank waste valve 37 is selectively opened to discharge accumulated waste. Waste discharged from at least one settling tank 11 is sent to a waste disposal facility or for further treatment. ECU1 is configured to control the operation of at least one settling tank waste valve 37. A wastewater control valve (not shown) may optionally be configured to control the discharge of wastewater from settling tank 11 through at least one settling tank outlet 33.

[0206] Bioreactor 13 includes at least one bioreactor inlet 41, at least one bioreactor outlet 43, and at least one bioreactor air inlet 45. At least one bioreactor inlet 41 is in fluid communication with at least one settling tank outlet 33. In use, wastewater from settling tank 11 is introduced into bioreactor 13 through at least one bioreactor inlet 41. At least one bioreactor inlet 41 is located in the lower region of bioreactor 13; and at least one bioreactor outlet 43 is located in the upper region of bioreactor 13. This arrangement is suitable for bioreactor 13 in this embodiment, where an upward flow of wastewater is established. If bioreactor 13 is configured to establish a downward flow of wastewater, the relative positions of at least one bioreactor inlet 41 and at least one bioreactor outlet 43 can be reversed. Bioreactor 13 performs biological filtration of wastewater. Specifically, bioreactor 13 includes a biofiltration chamber 47 containing a biofilter medium 49 for performing biological filtration of wastewater. The biofilter medium 49 includes a plurality of biofilter elements 51. The inner and outer surfaces of the biofilter elements 51 are adapted to support a microbial community. Microorganisms effectively transform organic matter present in wastewater. In this embodiment, the open-cell form of the biofilter element 51 provides an increased surface area to support the microorganisms. The microorganisms in this embodiment are aerobic. In a variant, the bioreactor 13 may be configured to support anaerobic or anoxic microorganisms. A biofilm may form on the surface of the biofilter element 51. Other types of bioreactors 13 are contemplated. For example, the bioreactor 13 may comprise a static bed bioreactor 13. The bioreactor 13 may, for example, comprise a submerged aerated filter (SAF). The biofilter element 51 forms a continuously aerated bed. The biofilter element 51 is at least substantially static in the bed. The biofilter element 51 may be held in place by one or more screens. The submerged aerated filter may comprise an integrated settling tank, for example, in the form of a settling chamber formed before the outlet of the submerged aerated filter. In a variant, the bioreactor 13 may not contain a biological filter media. For example, activated sludge from downstream of the bioreactor 13 may be reintroduced into the bioreactor 13. Activated sludge can be directly introduced into bioreactor 13 or upstream of bioreactor 13.

[0207] Bioreactor 13 is configured to facilitate the biological treatment of wastewater. During filtration, the biofilter media 49 actively circulates within the biofilter chamber 47. The biofilter element 51 moves continuously within the bioreactor 13 (a so-called moving bed bioreactor). Fluid can be introduced under pressure into the biofilter chamber 47 to circulate the biofilter media 49. The circulation of the biofilter media 49... Figure 1The flow is represented by a curve, with arrows indicating the direction of flow. The fluid can be a liquid or a gas. In this embodiment, pressurized air is introduced into the biofilter chamber 47 to circulate the biofilter media 49 within the biofilter chamber 47. An air pump 17 is configured to supply pressurized air to at least one bioreactor air inlet 45. In a variant, a separate air pump may be provided to supply pressurized air to the bioreactor 13. A first control valve 19-1 is configured to control the supply of pressurized air to at least one bioreactor air inlet 45. Alternatively, or additionally, a mechanical agitator, for example, comprising one or more rotating components, may be provided to circulate the biofilter media 49 within the biofilter chamber 47. For example, if the bioreactor 13 is configured to support anaerobic microorganisms, the use of an agitation mechanism may be suitable.

[0208] Bioreactor 13 includes a biofilter medium 49 comprising a plurality of biofilter elements 51. The filter medium 49 typically occupies at least 30% (by volume) of the filter chamber. The filter medium 49 may occupy 70% (by volume) of the filter chamber. In this embodiment, the filter medium 49 occupies approximately 50% (by volume) of the filter chamber. The biofilter elements 51 support a community of microorganisms (microbes) that decompose waste. Influent enters the biofilter chamber 47 for treatment. The biofilter elements 51 serve as a biological carrier supporting the community of microorganisms (microbes). The microorganisms (microbes) typically form a biofilm on at least a portion of the surface of the biofilter element 51. An aeration grid (not shown) may be provided to introduce air into the biofilter chamber 47. The aeration grid may, for example, comprise one or more tubular members having a plurality of holes through which air is introduced into the biofilter chamber 47. In use, an air pump 17 may supply pressurized air to the aeration grid. The aeration grid is typically located in the lower portion of the biofilter chamber 47. Air causes the biofilter element 51 to move within the biofilter chamber 47 (forming a moving bed), thereby promoting contact with waste. Introducing air into the biofilter chamber 47 also introduces oxygen into the biofilter chamber 47 to promote aerobic activity. A screen (not shown) is provided at the bioreactor outlet 43 to retain the biofilter element 51 within the biofilter chamber 47.

[0209] The biofilter media 49 preferably circulates continuously within the biofilter chamber 47 during filtration. It is recognized that circulation of the biofilter elements 49 within the biofilter chamber 47 allows solid matter to be removed from the biofilter elements 49. Circulation of the biofilter media 49 brings the biofilter elements 51 into contact with each other, and this allows solid matter to be removed from the surface of the biofilter elements 51 or from the open cells of the biofilter elements 51. The solid matter removed from the biofilter elements 51 may be in the form of flocs or flocculent mass. The removed solid matter may, for example, contain flocs. The removed solid matter may contain or consist of solid particles with a diameter less than or equal to ten (10) micrometers (i.e., ≤10 µm) and potentially less than or equal to five (5) micrometers (i.e., ≤5 µm). The solid particles removed from the biofilter elements 51 include suspended solid particles.

[0210] Following biological filtration, wastewater is discharged from bioreactor 13 through at least one bioreactor outlet 43 and introduced into mechanical filtration device 15. Mechanical filtration device 15 is configured to mechanically filter the wastewater to remove at least some suspended solid particles from the wastewater discharged from bioreactor 13. Mechanical filtration device 15 includes a mechanical filter tank 60, at least one mechanical filter inlet 61, at least one mechanical filter outlet 63, at least one mechanical filter air inlet 65, and at least one mechanical filter waste outlet 67. At least one mechanical filter inlet 61 is in fluid communication with at least one bioreactor outlet 43. In use, wastewater from bioreactor 13 is introduced into mechanical filtration device 15 through at least one mechanical filter inlet 61. At least one mechanical filter inlet 61 is located in the lower region of mechanical filtration device 15; and at least one mechanical filter outlet 63 is located in the upper region of mechanical filtration device 15. This arrangement is suitable for mechanical filtration device 15 in this embodiment, where an upward flow of wastewater is established. If mechanical filtration device 15 is configured to establish a downward flow of wastewater, the relative positions of at least one mechanical filter inlet 61 and at least one mechanical filter outlet 63 can be reversed. Mechanical filtration device 15 mechanically filters wastewater. Specifically, mechanical filtration device 15 includes a mechanical filtration chamber 70 containing mechanical filter media 69 for mechanically filtering the wastewater. Wastewater supplied to mechanical filtration device 15 is filtered by mechanical filter media 69 to remove at least some solid particles suspended in the wastewater supplied from bioreactor 13. The treated wastewater is discharged from mechanical filtration device 15 through at least one mechanical filtration outlet 63.

[0211] The mechanical filter medium 69 includes a plurality of mechanical filter elements 71. In this embodiment, the mechanical filter elements 71 include an open structure. Figure 2A and Figure 2BA schematic representation of one of the mechanical filter elements 71 is shown. Figure 2C A perspective view of a variant of one of the mechanical filter elements 71 is shown. Figure 2C The dimensions of the mechanical filter element 71 are shown by way of example. The tolerance for the dimensions shown is ±1 mm. The inner wall thickness of the mechanical filter element 71 is about 0.75 mm to 1 mm. A plurality of external ribs are formed around the outer periphery of the mechanical filter element 71. The radial length of the ribs is about 0.5 mm to 1 mm. It should be understood that mechanical filter elements 71 of different sizes can be used in the wastewater treatment plant 1 described herein. The mechanical filter element 71 has a non-porous structure, and each mechanical filter element comprises one or more filter units 73. The mechanical filter element 71 includes walls (inner and outer) forming one or more filter units 73. The walls are impermeable and prevent liquid from flowing between adjacent filter units 73. Each of the one or more filter units 73 has a substantially uniform profile along the length of the mechanical filter element 71. The one or more filter units 73 are open at each end. In this embodiment, each of the filter units 73 has a cross-sectional area ranging from one (1) to five (5) square millimeters and a length greater than or equal to six (6) millimeters. A static filter bag 75, composed of a porous filter medium 69, is formed within the mechanical filter chamber 70. In this embodiment, the mechanical filter element 71 has positive buoyancy in water. The mechanical filter element 71 floats in the wastewater within the mechanical filter chamber 70 and forms the static filter bag 75 in the upper region of the mechanical filter chamber 70. In a variant, the mechanical filter element 71 may have negative buoyancy and may form the static filter bag 75 in the lower region of the mechanical filter chamber 70. The mechanical filter element 71 effectively filters by promoting the settling of solid particles suspended in the wastewater. The solid particles settle within the filter unit 73 and on the surface of the mechanical filter element 71. In this embodiment, the mechanical filter element 71 is formed by extruding a polymer. Other techniques may be used to form the mechanical filter element 71.

[0212] The mechanical filter 15 is cleaned periodically to remove solids accumulated in the mechanical filter chamber. Cleaning the mechanical filter 15 includes closing at least one mechanical filter inlet 61 and at least one mechanical filter outlet 63. The mechanical filter waste outlet 67 is closed during the cleaning operation and then opened to empty (or drain) the mechanical filter 15. In this embodiment, a mechanical filter inlet valve 77 is provided for opening and closing at least one mechanical filter inlet 61; and a mechanical filter outlet valve 79 is provided for opening and closing at least one mechanical filter outlet 63. A mechanical filter waste valve 81 is provided for opening and closing the mechanical filter waste outlet 67. Both the mechanical filter inlet valve 77 and the mechanical filter outlet valve 79 are closed to close the mechanical filter inlet 61 and the mechanical filter outlet 63. The mechanical filter waste valve 81 is also closed to close the mechanical filter waste outlet 67.

[0213] Then, the second control valve 19-2 is opened to supply pressurized air to the mechanical filter chamber 70. The pressurized air is introduced into the mechanical filter chamber 70, breaking the static filter bag 75 and agitating the mechanical filter element 71. The mechanical filter device 15 may be open to the atmosphere or may have an exhaust port (not shown). Accumulated waste is thus removed from the mechanical filter element 71. The pressurized air supply continues for a predetermined period of time. This period of time can be determined, for example, by empirical analysis. Then, the mechanical filter waste valve 81 is opened to open the mechanical filter waste outlet 67, allowing wastewater to be discharged from the mechanical filter chamber 70. After the mechanical filter waste outlet 67 is opened, the pressurized air supply may optionally continue. A portion of the wastewater discharged from the mechanical filter chamber 70 may be recycled for further treatment within the wastewater treatment plant 1. In this embodiment, a waste return line 83 is provided for recycling wastewater discharged from the mechanical filter device 15. A waste control valve 85 may optionally be provided to control the supply of wastewater to the waste return line 83. In this embodiment, a portion of the waste accumulated in the mechanical filtration chamber 70 is returned to the settling tank 11 or the bioreactor 13. Therefore, a portion of the waste can be recycled through the wastewater treatment plant 1. A portion of the wastewater discharged from the mechanical filtration chamber 70 can optionally be sent to a waste disposal facility or undergo further treatment.

[0214] After the mechanical filter chamber 70 has been emptied, close the mechanical filter waste valve 81 to close the mechanical filter waste outlet 67. Stop the supply of pressurized air to the mechanical filter chamber 70 by closing the second control valve 19-2. Then open at least one mechanical filter inlet 61 and at least one mechanical filter outlet 63 to re-establish wastewater flow through the mechanical filter device 15.

[0215] In use, the mechanical filter element 71 forms a static filter bag 75, operable to filter solids from wastewater. The mechanical filter element 71 may have positive buoyancy, negative buoyancy, or neutral buoyancy. The mechanical filter element 71 has an openwork structure that provides high retention capacity. The flow rate per unit cross-sectional area of ​​the static filter bag 75 may be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. It is recognized that these flow rates per unit cross-sectional area are particularly effective for removing flocs (also known as flocculent clumps) from wastewater. Flocs comprise, or are composed of, loosely aggregated particles or soft flakes. In at least some embodiments, the flocs may settle within or outside the filter unit 73 of the mechanical filter element 71. The relatively low flow rate through the static filter bag 75 helps to reduce or avoid floc disruption. Higher flow rates can potentially cause certain types of flocs to break down or disintegrate into smaller flocs or individual particles. In at least some embodiments, the wastewater treatment plant 1 is able to capture very fine particles suspended in the wastewater. The treated water from the mechanical filtration device 15 can be discharged from the wastewater treatment plant 1 or sent to a receiving watercourse. Alternatively, the treated water can be sent downstream for further treatment. The mechanical filtration device 15 can be used as a pre-filter for downstream treatment systems. The filtrate discharged from the mechanical filtration device 15 can be subjected to mechanical and / or biological filtration downstream of the water treatment plant 1.

[0216] Figure 3The first flowchart 100 illustrates the operation of wastewater treatment plant 1. Wastewater to be treated is received by wastewater treatment plant 1 as inflow (block 105). Optionally, the wastewater is introduced into settling tank 11 to promote the settling of solids (block 110). The wastewater is discharged from settling tank 11 into bioreactor 13 (block 115). Bioreactor 13 performs biological filtration on the wastewater, and the biologically filtered water is discharged from the bioreactor (block 120). Movement of the biological filtration elements causes the generation of solid particles, which may contain flocs or consist of flocs, introduced into the suspension in the wastewater discharged from bioreactor 13. Wastewater is supplied from bioreactor 13 to mechanical filtration device 15 (block 125). The wastewater discharged from bioreactor 13 typically contains particles suspended in the wastewater. These particles may aggregate to form flocs suspended in the wastewater. These flocs may be formed from loosely aggregated particles. Mechanical filtration unit 15 mechanically filters wastewater to remove at least some suspended solid particles (block 130). The treated wastewater (effluent) is discharged from mechanical filtration unit 15 (block 135). Mechanical filtration unit 15 is cleaned periodically (block 140). Cleaning involves breaking up static filter bags 75, for example, by introducing a fluid such as air (block 145). Accumulated solid waste is removed from the static filter bags and discharged from mechanical filtration unit 15 (block 150). At least some of the solid waste from mechanical filtration unit 15 is returned through waste return line 83 and passes again through bioreactor 13 (block 155). The process continues (block 160).

[0217] The wastewater treatment plant 1 in the above embodiments has been described with reference to each of the primary sedimentation tank 11, bioreactor 13, and mechanical filtration device 15. This is merely illustrative, and the wastewater treatment plant 1 may include more than one primary sedimentation tank 11, bioreactor 13, and mechanical filtration device 15. For example, one or more bioreactors 13 may be provided. Multiple bioreactors 13 may be provided in parallel or in series. One or more primary sedimentation tanks 11 may be located upstream of one or more bioreactors 13. Multiple primary sedimentation tanks 11 may be connected in parallel or in series upstream of bioreactors 13. One or more tertiary sedimentation tanks 20 may be located downstream of one or more bioreactors 13. Multiple tertiary sedimentation tanks 20 may be connected in parallel or in series downstream of bioreactors 13. Pumps (not shown) may be provided for pumping accumulated waste from the wastewater treatment plant 1, for example, pumping accumulated waste from the primary sedimentation tank 11 and / or tertiary sedimentation tank 20.

[0218] The wastewater treatment plant 1 in the above embodiments is described with reference to a bioreactor 13 comprising a moving bed bioreactor (MBBR). Other types of bioreactors 13 may be considered for use in the wastewater treatment plant 1. The bioreactor 13 may be configured to perform aerobic, anaerobic, or anoxic biological filtration of wastewater. Aerobic biological filtration is carried out by microorganisms (microorganisms) that require oxygen. Anaerobic biological filtration is carried out by microorganisms (microorganisms) that require little or no oxygen (<0.5 mg / L or <0.2 mg / L). Anoxic biological filtration is carried out by microorganisms (microorganisms) that release bound oxygen (nitrite / nitrate, etc.), thereby reducing or avoiding the need to introduce air to aerate the wastewater.

[0219] As described above, a portion of the accumulated waste can be reintroduced into bioreactor 13 in the form of activated sludge. Activated sludge contains a high concentration of microorganisms, including bacteria, protozoa, and fungi, and exists as loose clumps of fine particles. These clumps can be kept suspended by agitation (anaerobic system) or by using air (aerobic system) to remove organic matter from the wastewater. This process is commonly referred to as recirculated activated sludge (RAS).

[0220] Bioreactor 13 may include integrated immobilized membrane activated sludge (IFAS). The process is similar to the moving bed bioreactor (MBBR) described herein. Activated sludge, for example, accumulated in a tertiary settling tank, is introduced into a filter chamber containing filter media. Both the filter media and the activated sludge may be present in the same filter chamber. The filter chamber may include an anoxic zone and an aerobic zone. Activated sludge may be introduced into the anoxic zone; and a moving bed bioreactor may be established in the aerobic zone, for example by introducing air to agitate the filter media.

[0221] Bioreactor 13 may comprise a sequencing batch reactor (SBR) that sequentially utilizes aerobic and anaerobic processes over time. The SBR can perform nitrification and denitrification. A stable and constant inflow rate is supplied to the filter chamber. The filter chamber is aerated to promote aerobic reactions. The air supply is then stopped to promote settling. The water in the filter chamber is subsequently decanted as effluent. The remaining waste in the filter chamber is then discharged into a waste collection system. The process may be used in conjunction with chemical flocculants to remove phosphates. Additional biological treatment may be performed on the wastewater discharged from the filter.

[0222] Bioreactor 13 may include a membrane bioreactor (MBR). A membrane bioreactor combines biological treatment with membrane filtration. In an MBR system, organic matter in wastewater is decomposed by microorganisms. The treated water then passes through a membrane filter to remove any remaining suspended solids and microorganisms. Thus, the highly treated effluent can be reused or discharged into the environment.

[0223] Bioreactor 13 may include a submerged aerated filter (SAF). The biofilter element may be maintained in a static bed submerged in the wastewater. The biofilter element is aerated to promote aerobic biological filtration.

[0224] Other types of mechanical and / or biological filtration can be used to filter wastewater. For example, wastewater can be filtered using: (i) dissolved air flotation (DAF), which brings particles to the water surface to facilitate removal, for example, by overflow; or (ii) a lamella separator in the form of an inclined plate, which slows the liquid flow and promotes the settling of particles for collection and removal by a sludge pump.

[0225] The mechanical filtration device 15 of type 1 described herein can be installed upstream of the bioreactor 13. For example, the mechanical filtration device 15 can be installed between the primary settling tank 11 and the bioreactor 13.

[0226] Now refer to Figure 4 Variations of the wastewater treatment plant 1 according to the above embodiment are described. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to embodiments of the present invention and the reference numerals. Figure 1 Differences between the described embodiments.

[0227] Wastewater treatment plant 1 includes a primary settling tank 11, a bioreactor 13, and a mechanical filtration device 15. Wastewater treatment plant 1 may optionally include a tertiary settling tank 20. The tertiary settling tank 20 may be located between the bioreactor 13 and the mechanical filtration device 15. Wastewater treatment plant 1 also includes a primary screen 9 located upstream of the primary settling tank 11. The primary screen 9 is configured to filter relatively large debris and detritus from the influent supplied to wastewater treatment plant 1. The primary screen 9 includes multiple pores through which wastewater passes to remove debris. For example, the primary screen 9 may include a screen, mesh, or membrane. After being filtered by the primary screen 9, the wastewater is introduced into the primary settling tank 11. At least some of the debris that passed through the primary screen 9 settles out of the suspension in the primary settling tank 11. Waste accumulated in the primary settling tank 11 is discharged into the waste disposal system through the primary settling tank waste outlet 11a. A valve (represented by a valve symbol) may be installed at the waste outlet 11a of the primary settling tank.

[0228] Bioreactor 13 may comprise a moving bed bioreactor (MBBR) of the type described herein. In this embodiment, bioreactor 13 comprises a static bed bioreactor 13. Bioreactor 13 may, for example, comprise a submerged aerated filter (SAF). Biofilter elements 51 form a continuously aerated bed. Biofilter elements 51 are at least substantially static in the bed. Biofilter elements 51 may be held in place by one or more screens. The submerged aerated filter may comprise an integrated settling tank, for example in the form of a settling chamber formed before the outlet of the submerged aerated filter. In one variant, bioreactor 13 may not comprise a biological filter media. For example, activated sludge from downstream of bioreactor 13 may be reintroduced into bioreactor 13. Activated sludge may be introduced directly into bioreactor 13 or upstream of bioreactor 13. Other types of bioreactor 13 may be considered.

[0229] Mechanical filtration device 15 is configured to mechanically filter wastewater to remove at least some suspended solid particles from wastewater discharged from bioreactor 13. Mechanical filtration device 15 includes a mechanical filter tank 60, at least one mechanical filter inlet 61, at least one mechanical filter outlet 63, at least one mechanical filter air inlet 65, and at least one mechanical filter waste outlet 67. At least one mechanical filter inlet 61 is in fluid communication with at least one bioreactor outlet 43. In use, wastewater from bioreactor 13 is introduced into mechanical filtration device 15 through at least one mechanical filter inlet 61. At least one mechanical filter inlet 61 is preferably located in the lower region of mechanical filtration device 15; and at least one mechanical filter outlet 63 is preferably located in the upper region of mechanical filtration device 15. Mechanical filtration device 15 filters wastewater supplied from bioreactor 13. Mechanical filter chamber 70 includes mechanical filter media 69 for mechanically filtering wastewater. Mechanical filter media 69 includes a plurality of mechanical filter elements 71 of the type described herein. Mechanical filter elements 71 form a static filter bag 75, which is suitable for filtering particles and matter suspended in water as it flows through the mechanical filtration device 15. The mechanical filter elements 71 have an open structure to promote the sedimentation of suspended particles within the static filter bag 75. Each mechanical filter element 71 has one or more filter units 73. Wastewater is filtered by mechanical filter media 69 to remove at least some solid particles suspended in the wastewater supplied from the bioreactor 13. The treated wastewater (effluent) is discharged from the mechanical filtration device 15 through at least one mechanical filter outlet 63.

[0230] The mechanical filter 15 is cleaned periodically to remove solids accumulated in the mechanical filter chamber 70. Cleaning the mechanical filter 15 may include closing at least one mechanical filter inlet 61 and / or at least one mechanical filter outlet 63. The mechanical filter waste outlet 67 is closed during filtration operations and opened during cleaning operations to empty (or drain) the mechanical filter canister 60. An air supply duct is provided to supply air to the air inlet 65, which in turn enters the mechanical filter chamber 70. The air introduced into the mechanical filter chamber 70 agitates the mechanical filter element 71, disrupting the static filter pack. By agitating the mechanical filter element 71, waste and debris accumulated in one or more filter units 73 formed in the mechanical filter element 71 are removed. The removed waste can be discharged into the waste disposal system through the mechanical filter waste outlet 67. Air may be pumped into the mechanical filter canister 60 by an air pump (not shown) to agitate the mechanical filter element 71 during cleaning operations. Alternatively, or additionally, air may be drawn into the mechanical filter chamber 70 through the air supply duct. A one-way valve may be provided on the air supply duct. When the mechanical filter waste outlet 67 is opened, the water in the mechanical filter chamber 70 can be drained, causing the pressure in the mechanical filter chamber 70 to decrease to below atmospheric pressure. This reduced pressure allows air to be drawn into the mechanical filter chamber 70 through the air supply duct. As the mechanical filter tank 60 is emptied, air is drawn into the lower portion of the mechanical filter chamber 70 and agitates the mechanical filter element 71. Other techniques can be used to clean the mechanical filter apparatus 15. For example, the mechanical filter element 71 can be backwashed to remove trapped debris. Backwash liquid, such as water, can be introduced into the mechanical filter chamber 70 to clean the mechanical filter element 71. The backwash liquid can be discharged into the waste. Alternatively, at least some of the backwash liquid can be returned to the wastewater treatment plant 1 for further treatment. For example, the backwash liquid can be introduced into the bioreactor 13. In each embodiment of the wastewater treatment plant 1 described herein, the same cleaning process can be used to clean the mechanical filter apparatus 15.

[0231] A portion of the wastewater discharged from the mechanical filtration chamber 70 can be recycled for further treatment within the wastewater treatment plant 1. In this embodiment, a waste return line 83 is provided for recycling wastewater discharged from the mechanical filtration device 15. A waste control valve 85 may be optionally provided to control the supply of waste to the waste return line 83. In this embodiment, a portion of the waste from the mechanical filtration chamber 70 is recycled to the bioreactor 13. The waste recycled from the mechanical filtration device 15 is typically in the form of sludge (containing or composed of settled solid matter). The waste can be introduced into the bioreactor 13 through the bioreactor inlet 41 or a separate inlet. At least some of the waste is thus recycled through the bioreactor 13 and the mechanical filtration device 15. A portion of the waste discharged from the mechanical filtration chamber 70 can be sent downstream of the waste or waste treatment plant 1 for further treatment.

[0232] In use, the mechanical filter element 71 forms a static filter bag 75, operable to filter solids from wastewater. The mechanical filter element 71 may have positive buoyancy, negative buoyancy, or neutral buoyancy. The mechanical filter element 71 has an openwork structure that provides high retention capacity. The flow rate per unit cross-sectional area of ​​the static filter bag 75 may be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. It is recognized that these flow rates per unit cross-sectional area are particularly effective for removing flocs (also known as flocculent clumps) from wastewater. Flocs comprise, or are composed of, loosely aggregated particles or soft flakes. In at least some embodiments, the flocs may settle within or outside the filter unit 73 of the mechanical filter element 71. The relatively low flow rate through the static filter bag 75 helps reduce or avoid floc disruption. Higher flow rates can potentially cause certain types of flocs to break down or disintegrate into smaller flocs or individual particles. In at least some embodiments, the wastewater treatment plant 1 is able to capture very fine particles suspended in the wastewater. The treated water from the mechanical filtration device 15 can be discharged from the wastewater treatment plant 1 or sent to a receiving watercourse. Alternatively, the treated water can be sent downstream for further treatment.

[0233] Now refer to Figure 5 Description based on Figure 4 Another variation of the wastewater treatment plant 1 shown in the embodiment. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to this embodiment and the reference numerals. Figure 4 Differences between the described embodiments.

[0234] Bioreactor 13 may be a moving bed bioreactor or a static bed bioreactor. For example, bioreactor 13 may include a submerged aerated filter (SAF). In this embodiment, bioreactor 13 does not include a biofilter element. Bioreactor 13 may be an activated sludge bioreactor. Other types of bioreactor 13 may be considered.

[0235] In this embodiment, the wastewater treatment plant 1 includes at least one tertiary settling tank 111. The tertiary settling tank 111 is located downstream of the bioreactor 13 and upstream of the mechanical filtration device 15. The tertiary settling tank 111 includes at least one tertiary settling tank inlet 131, which is in fluid communication with at least one bioreactor outlet 43. In use, wastewater from the bioreactor 13 is introduced into the tertiary settling tank 111. The tertiary settling tank 111 includes at least one tertiary settling tank outlet 133 and at least one tertiary settling tank waste outlet 135. Figure 5As shown, at least one tertiary settling tank inlet 131 and at least one tertiary settling tank outlet 133 are located in the upper region of the tertiary settling tank 111. At least one tertiary settling tank waste outlet 135 is located in the lower region of the tertiary settling tank 111. In use, water treated by the bioreactor 13 enters the tertiary settling tank 111 through at least one tertiary settling tank inlet 131. Solid matter settles from the wastewater and settles to the bottom of the tertiary settling tank 111. Wastewater is discharged from the tertiary settling tank 111 through at least one tertiary settling tank outlet 133 to the mechanical filtration device 15. At least one settling tank waste valve 137 is provided for controlling the discharge of solids and waste through the tertiary settling tank waste outlet 35. Waste discharged from at least one settling tank 11 is typically in the form of sludge. At least one settling tank waste valve 37 is selectively opened to discharge accumulated waste. Waste discharged from at least one tertiary settling tank 111 may be sent to a waste disposal facility or used for further treatment. A portion of the waste discharged from at least one tertiary settling tank 111 may be recycled to the bioreactor 13 for treatment. Optionally, a wastewater control valve (not shown) may be provided to control the discharge of wastewater from the tertiary settling tank 111 through at least one settling tank outlet 33.

[0236] In use, the mechanical filter element 71 forms a static filter bag 75, operable to filter solids from wastewater. The mechanical filter element 71 may have positive buoyancy, negative buoyancy, or neutral buoyancy. The mechanical filter element 71 has an openwork structure that provides high retention capacity. The flow rate per unit cross-sectional area of ​​the static filter bag 75 may be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. It is recognized that these flow rates per unit cross-sectional area are particularly effective for removing flocs (also known as flocculent clumps) from wastewater. Flocs comprise, or are composed of, loosely aggregated particles or soft flakes. In at least some embodiments, the flocs may settle within or outside the filter unit 73 of the mechanical filter element 71. The relatively low flow rate through the static filter bag 75 helps reduce or avoid floc disruption. Higher flow rates can potentially cause certain types of flocs to break down or disintegrate into smaller flocs or individual particles. In at least some embodiments, the wastewater treatment plant 1 is able to capture very fine particles suspended in the wastewater. The treated water from the mechanical filtration device 15 can be discharged from the wastewater treatment plant 1 or sent to a receiving watercourse. Alternatively, the treated water can be sent downstream for further treatment.

[0237] Now refer to Figure 6Another embodiment of wastewater treatment plant 1 is described. In this embodiment, the same reference numerals are used for the same features. The description herein focuses on the differences between this embodiment of wastewater treatment plant 1 and the foregoing embodiments described herein.

[0238] The wastewater treatment plant 1 in this embodiment includes an electrocoagulation unit 91. The electrocoagulation unit 91 uses an electrochemical process to remove suspended, emulsified, or dissolved contaminants from wastewater. The electrocoagulation unit 91 supplies an electric current to the wastewater to cause the suspended matter in the wastewater to aggregate. The electrocoagulation unit 91 performs an electrochemical process that uses a charge flow to remove suspended, emulsified, or dissolved contaminants from the wastewater. The electrocoagulation unit 91 generates a charge flow directly into the wastewater to release metal ions from the sacrificial anode, which causes contaminant aggregation for capture within the mechanical filtration device 15. The electrocoagulation unit 91 may include one or more sacrificial electrodes (not shown) to support the electrochemical process. The electrocoagulation unit 91 is operable to cause the suspended matter in the wastewater to aggregate. Particles suspended in the wastewater may aggregate or agglomerate to form flocs (also called flocculent clumps). The formed flocs comprise, or consist of, loosely aggregated particles or soft flakes. The electrocoagulation unit 91 is located downstream of the bioreactor 13. The electrocoagulation unit 91 is located upstream of the mechanical filtration device 15. For example... Figure 3 As shown, an electrocoagulation unit 91 is disposed between a bioreactor 13 and a mechanical filtration device 15. The electrocoagulation unit 91 includes an electrocoagulation unit inlet 93 and an electrocoagulation unit outlet 95. The electrocoagulation unit inlet 93 is connected to at least one bioreactor outlet 43 of the bioreactor 13. Wastewater filtered by the bioreactor 13 is supplied to the electrocoagulation unit 91. The electrocoagulation unit outlet 95 is connected to at least one mechanical filtration inlet 61. Wastewater treated by the electrocoagulation unit 91 is supplied to the mechanical filtration device 15. In use, the electrocoagulation unit 91 is operable to agglomerate solid waste removed from the biofiltration elements in the bioreactor 13. The agglomerated material from the electrocoagulation unit 91 is suspended in the wastewater, which is introduced into the mechanical filtration device 15 disposed downstream therefrom. The mechanical filtration device 15 of the type described herein effectively mechanically filters the wastewater from the electrocoagulation unit 91.

[0239] In use, the electrocoagulation unit 91 is operable to remove phosphates from wastewater. The electrocoagulation unit 91 can cause phosphates to be released from the solution as solid particles in the wastewater (i.e., sedimentation). The electrocoagulation unit 91 can also cause other compounds to be released from the solution as solid particles in the wastewater (i.e., sedimentation). For example, ultrafiltration or reverse osmosis can be used to remove solid particles. However, it has been determined that the mechanical filtration device 15 described herein can also effectively filter solid particles produced by the operation of the electrocoagulation unit 91. The mechanical filtration device 15 is positioned downstream of the electrocoagulation unit 91 to remove at least some solid particles by mechanical filtration. The combination of the electrocoagulation unit 91 and the mechanical filtration device 15 is considered to be independently patentable. This combination has particular applications in wastewater treatment processes. However, other applications are also contemplated.

[0240] Figure 7 The second flowchart 200 illustrates the operation of wastewater treatment plant 1. Wastewater to be treated is received by wastewater treatment plant 1 as inflow (block 205). Optionally, the wastewater is introduced into settling tank 11 to promote the settling of solids (block 210). The wastewater is discharged from settling tank 11 into bioreactor 13 (block 215). Bioreactor 13 performs biological filtration on the wastewater, and the biologically filtered water is discharged from the bioreactor (block 220). Movement of the biological filtration elements causes the generation of solid particles, which may contain flocs or consist of flocs, introduced into the suspension in the wastewater discharged from bioreactor 13. Wastewater is supplied from bioreactor 13 to electrocoagulation unit 91 (block 225). Electrocoagulation unit 91 is operable to aggregate the suspended solid particles (block 230). Alternatively, or additionally, electrocoagulation unit 91 may cause phosphate dissolved in the wastewater to be released from the solution and form particles. The phosphate particles can then aggregate, and the resulting aggregated particles can be suspended in the wastewater. The treated wastewater is discharged from the electrocoagulation unit 91 (block 235). The wastewater is supplied from the electrocoagulation unit 91 to the mechanical filtration unit 15 (block 240). The mechanical filtration unit 15 mechanically filters the wastewater to remove at least some of the suspended solid particles (block 245). The treated wastewater (effluent) is discharged from the mechanical filtration unit 15 (block 250). The mechanical filtration unit 15 is cleaned periodically (block 255). Cleaning involves breaking the static filter pack 75, for example, by introducing a pressurized fluid such as air (block 260). Accumulated solid waste is removed from the static filter pack and discharged from the mechanical filtration unit 15 (block 265). At least some of the solid waste from the mechanical filtration unit 15 is returned through the waste return line 83 and passed again through the bioreactor 13 (block 270). The process continues (block 275).

[0241] Wastewater treatment plant 1 has been described with reference to electrocoagulation unit 91. Alternatively, or additionally, wastewater treatment plant 1 may include at least one chemical agent system 97 for introducing a (chemical) coagulant into the wastewater. Chemical agent system 97 may be disposed between bioreactor 13 and mechanical filtration device 15. Chemical agent system 97 is configured to introduce a dose of coagulant into the wastewater. The coagulant may be introduced into the wastewater continuously or intermittently. The coagulant is positively charged and neutralizes solid particles suspended in the wastewater stream. In use, the coagulant promotes the aggregation or agglomeration of particles suspended in the wastewater. The coagulant may also cause dissolved compounds, such as phosphates, to be released from solution to form particles. The aggregated particles may form flocs (also called flocculent clumps), comprising or composed of loosely aggregated particles or flakes. At least some of the flocs are suspended in the wastewater. In this embodiment, the coagulant is a chemical substance, such as ferric chloride or polyaluminum sulfate (PAC). The coagulant causes dissolved phosphates in the wastewater to be released from the solution and form particles. These particles are released from the solution and aggregate. A chemical agent system 97 can replace the electrocoagulation unit 91. In this arrangement, the chemical agent system 97 is located downstream of the bioreactor 13 and upstream of the mechanical filtration device 15. The chemical agent system 97 is positioned between the bioreactor 13 and the mechanical filtration device 15. The chemical agent system 97 is configured to supply coagulant to the wastewater discharged from the bioreactor 13. The formation of chemical flocs (retention time) is a function of the volume of wastewater added, but a retention time of 10 to 40 minutes is suitable. The water is agitated to disperse the coagulant. The mixed water is stabilized, and at least some particles form together or aggregate, subsequently being released from the suspension (flocculation) for collection.

[0242] The coagulant may comprise, or be composed of, organic or inorganic chemical substances or a polymer matrix. Suitable coagulants include ferric sulfate, ferric chloride, ferrous sulfate, aluminum sulfate and aluminum chloride or polyaluminium chloride (PAM), activated silica, bentonite, and metal hydroxides with polymer structures, natural flocculants (e.g., starch derivatives, Moringa oleifera polysaccharides, and alginate or seaweed), and synthetic flocculants (e.g., polyacrylamide, polyethyleneimine, polyamines, polydiallyl dimethyl ammonium chloride (Poly DADMACs) and polytannates, polyamide-amines, polyamines, and polyethylene oxide). The chemical agent system 97 may be configured to introduce one or more of these coagulants into the wastewater.

[0243] Wastewater is supplied from bioreactor 13 to chemical agent system 97. A flocculant is introduced into the wastewater, causing suspended solid particles to aggregate. In at least some embodiments, the flocculant can release phosphate dissolved in the wastewater from the solution and form particles. The phosphate particles can aggregate to form flocs suspended in the wastewater. The treated wastewater is discharged to mechanical filtration device 15. Mechanical filtration device 15 mechanically filters the wastewater to remove at least some of the suspended solid particles and / or flocs. The treated wastewater (effluent) is discharged from mechanical filtration device 15.

[0244] In use, the static filter bag 75 formed by the mechanical filter element 71 effectively filters flocs suspended in wastewater. The mechanical filter element 71 has an open structure that provides high retention capacity. In at least some embodiments, the flow rate per unit cross-sectional area of ​​the static filter bag 75 may be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. It has been recognized that these flow rates per unit cross-sectional area are particularly effective for removing flocs from wastewater. Flocs may settle within or outside the filter unit 73 of the mechanical filter element 71. The relatively low flow rate through the static filter bag 75 helps to reduce or avoid floc breakage. Higher flow rates can potentially cause certain types of flocs to break down or disintegrate into smaller flocs or individual particles.

[0245] The coagulation and flocculation processes produce particles that need to be captured. The mechanical filtration device 15 described herein can effectively perform this operation. At least in some embodiments, this can be done without the need for a settling tank and / or large amounts of water for backwashing or cleaning the filter screen. The perforated structure of the mechanical filter element 71 is adapted to retain softer flocs within the filtration unit. The mechanical filter element 71 has a high retention capacity for waste accumulation without forming barriers (floc buildup) that water cannot then penetrate.

[0246] Now refer to Figure 8 describe Figure 6 The wastewater treatment plant 1 shown is a variant of the one described above. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to an embodiment of the present invention, and the one shown in the reference numerals. Figure 6 Differences between the described embodiments.

[0247] Wastewater treatment plant 1 includes a primary filter 9, a primary settling tank 11, a bioreactor 13, and a mechanical filtration device 15. Wastewater treatment plant 1 may optionally include a tertiary settling tank 20. The tertiary settling tank 20 may be located between the bioreactor 13 and the mechanical filtration device 15. In this embodiment, the bioreactor 13 includes a moving bed bioreactor (MBBR). Other types of bioreactors 13 may be considered. It should be understood that one or more of the primary settling tank 11, bioreactor 13, and mechanical filtration device 15 may comprise civil installations, for example, in the form of concrete tanks, steel tanks, or glass fiber reinforced polymer (GFRP) tanks.

[0248] The wastewater treatment plant 1 in this embodiment includes a first chemical agent system 97-1 and a second chemical agent system 97-2. The first chemical agent system 97-1 is located upstream of the bioreactor 13; the second chemical agent system 97-2 is located downstream of the bioreactor 13. In this embodiment, the first chemical agent system 97-1 is located between the primary settling tank 11 and the bioreactor 13; and the second chemical agent system 97-2 is located between the bioreactor 13 and the mechanical filtration device 15. The first and second chemical agent systems 97-1 and 97-2 are configured to introduce a coagulant into the wastewater. The coagulant can cause one or more dissolved compounds, such as phosphates, to be released from solution and form particles. Alternatively, or additionally, microbial clumps on the biofiltration elements can be removed, thereby introducing more particles into the wastewater. The coagulant promotes the aggregation or agglomeration of particles suspended in the wastewater. The coagulant can promote the aggregation of particles in the wastewater, for example, the formation of flocs. Wastewater treatment plant 1 can be modified to replace at least one of the first and second chemical agent systems 97-1, 97-2 with one or more electrocoagulation units 91 of the type described herein.

[0249] Mechanical filtration device 15 is configured to mechanically filter wastewater to remove at least some suspended solid particles from wastewater discharged from bioreactor 13. Mechanical filtration device 15 includes a mechanical filter tank 60, at least one mechanical filter inlet 61, at least one mechanical filter outlet 63, at least one mechanical filter air inlet 65, and at least one mechanical filter waste outlet 67. At least one mechanical filter inlet 61 is in fluid communication with at least one bioreactor outlet 43. In use, wastewater from bioreactor 13 is introduced into mechanical filtration device 15 through at least one mechanical filter inlet 61. At least one mechanical filter inlet 61 is preferably located in the lower region of mechanical filtration device 15; and at least one mechanical filter outlet 63 is preferably located in the upper region of mechanical filtration device 15. Mechanical filtration device 15 filters wastewater supplied from bioreactor 13. Mechanical filter chamber 70 includes mechanical filter media 69 for mechanically filtering wastewater. Mechanical filter media 69 includes a plurality of mechanical filter elements 71 of the type described herein. Mechanical filter elements 71 form a static filter bag 75, which is suitable for filtering particles and matter suspended in water as it flows through the mechanical filtration device 15. The mechanical filter elements 71 have an open structure to promote the sedimentation of suspended particles within the static filter bag 75. Each mechanical filter element 71 has one or more filter units 73. Wastewater is filtered by mechanical filter media 69 to remove at least some solid particles suspended in the wastewater supplied from the bioreactor 13. The treated wastewater (effluent) is discharged from the mechanical filtration device 15 through at least one mechanical filter outlet 63.

[0250] The mechanical filter 15 is cleaned periodically to remove solids accumulated in the mechanical filter chamber 70. Cleaning of the mechanical filter 15 is performed using the methods described herein. A portion of the wastewater discharged from the mechanical filter chamber 70 can be recycled for further treatment within the wastewater treatment plant 1. In this embodiment, a waste return line 83 is provided for recycling the wastewater discharged from the mechanical filter 15. A waste control valve 85 may be optionally provided to control the supply of waste to the waste return line 83. In this embodiment, a portion of the waste from the mechanical filter chamber 70 is recycled to the bioreactor 13. The waste recycled from the mechanical filter 15 is typically in the form of sludge (containing or composed of settled solid matter). The waste can be introduced into the bioreactor 13 through the bioreactor inlet 41 or a separate inlet. A portion of the waste discharged from the mechanical filter chamber 70 can be sent downstream of the waste or waste treatment plant 1 for further treatment.

[0251] In use, the mechanical filter element 71 forms a static filter bag 75, operable to filter solids from wastewater. The mechanical filter element 71 may have positive buoyancy, negative buoyancy, or neutral buoyancy. The mechanical filter element 71 has an openwork structure that provides high retention capacity. The flow rate per unit cross-sectional area of ​​the static filter bag 75 may be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. It is recognized that these flow rates per unit cross-sectional area are particularly effective for removing flocs (also known as flocculent clumps) from wastewater. Flocs comprise, or are composed of, loosely aggregated particles or soft flakes. In at least some embodiments, the flocs may settle within or outside the filter unit 73 of the mechanical filter element 71. The relatively low flow rate through the static filter bag 75 helps reduce or avoid floc breakage. Higher flow rates can potentially cause certain types of flocs to break down or disintegrate into smaller flocs or individual particles. Treated water from the mechanical filtration unit 15 can be discharged from the wastewater treatment plant 1 or sent to the receiving watercourse. Alternatively, the treated water can be sent downstream for further treatment.

[0252] Now refer to Figure 9A describe Figure 8 The wastewater treatment plant 1 shown is a variant of the wastewater treatment plant 1. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to this embodiment and the reference numerals. Figure 8 Differences between the described embodiments.

[0253] Wastewater treatment plant 1 includes a primary filter 9, a primary settling tank 11, a bioreactor 13, and a mechanical filtration device 15. Wastewater treatment plant 1 may optionally include a tertiary settling tank 20. The tertiary settling tank 20 may be located between the bioreactor 13 and the mechanical filtration device 15. In this embodiment, the bioreactor 13 includes a moving bed bioreactor (MBBR). Other types of bioreactors 13 are also possible. For example, the bioreactor 13 may include a submerged aerated filter (SAF) of the type described herein.

[0254] Wastewater treatment plant 1 includes a first chemical agent system 97-1, a second chemical agent system 97-2, and a third chemical agent system 97. The first chemical agent system 97-1 is located upstream of bioreactor 13. In this embodiment, the first chemical agent system 97-1 is located between the primary settling tank 11 and the bioreactor 13. The second and third chemical agent systems 97-2 and 97-3 are located downstream of bioreactor 13. The second chemical agent system 97-2 is located between bioreactor 13 and tertiary settling tank 20. The third chemical agent system 97-3 is located between tertiary settling tank 20 and mechanical filtration equipment 15. Each of the first, second, and third chemical agent systems 97-1, 97-2, and 97-3 is configured to introduce a coagulant into the wastewater. The coagulant can cause one or more dissolved compounds, such as phosphates, to be released from solution and form particles. The coagulant promotes the aggregation or agglomeration of particles suspended in the wastewater. The coagulant can promote the aggregation of particles in the wastewater, for example, the formation of flocs. Wastewater treatment plant 1 can be modified to replace at least one of the first, second, and third chemical agent systems 97-1, 97-2, and 97-3 with one or more electrocoagulation units 91 of the type described herein. Alternatively, or additionally, one or more of the first, second, and third chemical agent systems 97-1, 97-2, and 97-3 in wastewater treatment plant 1 may be omitted. For example, the first chemical agent system 97-1 and / or the third chemical agent system 97-3 may be omitted.

[0255] The operation of the wastewater treatment plant 1 according to this embodiment is consistent with other embodiments described herein. The mechanical filtration device 15 is operable to filter particulate matter and flocs from the wastewater. The flow rate per unit cross-sectional area of ​​the static filter bag 75 can be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. The mechanical filter medium 69 can have positive buoyancy, neutral buoyancy, or negative buoyancy. In this embodiment, the mechanical filter medium 69 has positive buoyancy.

[0256] Wastewater treatment plant 1 as described herein can be a sewage treatment plant 1. The wastewater to be treated is in the form of sewage. Wastewater treatment plant 1 as described herein can be a municipal sewage treatment plant 1 used for treating municipal wastewater. For example, sewage treatment plant 1 can treat 1.2 million liters of wastewater per day. Wastewater treatment plant 1 should be able to treat wastewater to meet discharge permits in order to maintain compliance with legal regulations. Discharge permits typically include limits for pollutants, including biochemical oxygen demand (BOD), total suspended solids (TSS), phosphate (P), nitrate (N), and ammonia in the form of ammonia nitrogen (NH3 / N). When receiving water for treatment, discharge permits are set by the water utility; when discharging into the environment, discharge permits are set by a statutory body. Removal of macronutrients such as phosphates and nitrates is particularly important because these nutrients can have a negative impact on receiving waterways.

[0257] As described herein, the flow rate per unit cross-sectional area of ​​the mechanical filter media 69 affects wastewater filtration. The retention capacity of the mechanical filtration device 15 depends on the volume of the mechanical filter media 69 in the mechanical filter tank 60. To facilitate cleaning of the mechanical filter media 69, the filter media 69 preferably occupies about 40% to 60% of the volume of the mechanical filter chamber 70. In a preferred embodiment, the filter media 69 occupies about 50% of the volume of the mechanical filter chamber 70.

[0258] The mechanical filtration device 15 may include mechanical filter canisters 60 of different sizes. The mechanical filter canister 60 may comprise or be composed of a cylindrical portion having a circular cross-section. The mechanical filter canister 60 may have different cross-sections, such as polygonal, rectangular, or square. The mechanical filter canister 60 may be oriented such that its central longitudinal axis extends vertically or horizontally. A mechanical filter chamber 70 formed within the mechanical filter canister 60 has a height (h) and a width (w). When the mechanical filter canister 60 comprises or is composed of a cylindrical portion, the width (w) corresponds to the diameter of the cylindrical portion, and the height (h) corresponds to the height of the cylindrical portion (i.e., excluding any tapered or curved ends). The ratio of the height (h) to the width (w) of the mechanical filter canister 60 is preferably between 1.5 (inclusive) and 2 (inclusive). The ratio of the height (h) to the width (w) of the mechanical filter canister 60 is preferably between 1.75 (inclusive) and 2 (inclusive). It has been determined that a mechanical filter canister 60 with a height (h) to width (w) ratio is particularly effective if the mechanical filter media 69 occupies between 40% and 60% of the volume of the mechanical filter chamber 70. A mechanical filter canister 60 having a height (h) approximately twice its width (w) and containing filter media 69 occupying 50% of its volume is particularly preferred. The depth of the filter bag formed by the mechanical filter media 69 in the mechanical filter chamber 70 is preferably approximately equal to the width (w) of the mechanical filter canister 60.

[0259] Now refer to Figure 9B describe Figure 9A The wastewater treatment plant 1 shown is a variant of the one described above. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to an embodiment of the present invention, and the one shown in the reference numerals. Figure 9A Differences between the described embodiments.

[0260] Wastewater treatment plant 1 includes a primary filter 9, a primary settling tank 11, a bioreactor 13, and a mechanical filtration device 15. Wastewater treatment plant 1 may include a tertiary settling tank 20. The tertiary settling tank 20 is disposed between the bioreactor 13 and the mechanical filtration device 15. In this embodiment, the bioreactor 13 includes a moving bed bioreactor (MBBR). Other types of bioreactor 13 are contemplated. For example, the bioreactor 13 may include a submerged aerated filter (SAF) of the type described herein. In a variant, the primary settling tank 11 may be omitted.

[0261] Wastewater treatment plant 1 includes a first chemical agent system 97-1 and a second chemical agent system 97-2. Both the first and second chemical agent systems 97-1 and 97-2 are configured to introduce a coagulant into the wastewater. The coagulant can cause one or more dissolved compounds, such as phosphates, to be released from solution and form particles. The coagulant promotes the aggregation or agglomeration of particles suspended in the wastewater. The coagulant can promote the aggregation of particles in the wastewater, for example, the formation of flocs. Wastewater treatment plant 1 can be modified to replace at least one of the first and second chemical agent systems 97-1 and 97-2 with one or more electrocoagulation units 91 of the type described herein. Wastewater treatment plant 1 may optionally include a third chemical agent system (not shown) disposed between a tertiary settling tank 20 and a mechanical filtration device 15.

[0262] The first chemical agent system 97-1 is located upstream of the bioreactor 13. In this embodiment, the first chemical agent system 97-1 is located between the primary settling tank 11 and the bioreactor 13. The first chemical agent system 97-1 can be optionally omitted. For example, wastewater can be supplied directly from the primary settling tank 11 to the bioreactor 13.

[0263] The second chemical agent system 97-2 is located downstream of the bioreactor 13. In this embodiment, the second chemical agent system 97-2 is located between the bioreactor 13 and the tertiary sedimentation tank 20. Figure 9AAs shown, a tertiary settling tank 20 is located immediately downstream of a second chemical agent system 97-2. The second chemical agent system 97-2 is configured to introduce a coagulant into the wastewater. A mixture containing wastewater and coagulant is introduced into the tertiary settling tank 20. In a variant, the second chemical agent system 97-2 may be configured to introduce the coagulant directly into the tertiary settling tank 20. The tertiary settling tank 20 reduces the wastewater flow rate. It has been found that this condition promotes floc formation in the wastewater. The tertiary settling tank 20 can be used as a flocculation tank where particles in the wastewater can aggregate to form flocs. The tertiary settling tank 20 can increase the wastewater retention time. A longer retention time can promote floc formation in the wastewater. The tertiary settling tank 20 can be used as a sedimentation tank to promote the settling of particles and flocs. Flocs and particles in the wastewater may desuspension and settle in the tertiary settling tank 20. The tertiary settling tank 20 can be a multi-layer tank (e.g., two, three, or more layers). This multi-stage sedimentation tank can form a meandering flow path along which wastewater flows to promote sedimentation. Other types of tertiary sedimentation tanks 20 can also be used, such as radial flow tanks. At least a portion of the flocs and / or particles suspended in the wastewater can settle in the tertiary sedimentation tank 20. The waste collected in the tertiary sedimentation tank 20 can be sent to a waste disposal facility or for further treatment.

[0264] Mechanical filtration equipment 15 is installed immediately downstream of the tertiary sedimentation tank 20. For example... Figure 9B As shown, wastewater is supplied directly from the tertiary sedimentation tank 20 to the mechanical filtration device 15. The mechanical filtration device 15 is operable to filter particulate matter and flocs from the wastewater. The flow rate per unit cross-sectional area of ​​the static filter bag 75 can be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. The mechanical filter medium 69 can have positive buoyancy, neutral buoyancy, or negative buoyancy. In this embodiment, the mechanical filter medium 69 has positive buoyancy.

[0265] Figure 9B The variant of wastewater treatment plant 1 shown is in Figure 9C As shown in the image. Figure 9BThe illustrated embodiment includes a three-stage settling tank 20 disposed between a bioreactor 13 and a mechanical filtration device 15. A second chemical agent system 97-2 is configured to introduce a coagulant into the wastewater to promote floc formation in the three-stage settling tank 20. The wastewater treatment plant 1 is modified to include a tubular flocculant 18. The tubular flocculant 18 may, for example, comprise a coiled flocculant 18. The tubular flocculant 18 may define a helical fluid channel (or meandering fluid channel) through which wastewater flows. The second chemical agent system 97-2 is configured to introduce the coagulant directly into the tubular flocculant 18 or directly into an adjacent upstream location of the tubular flocculant 18. The flow of wastewater through the tubular flocculant 19 promotes the mixing of the coagulant, thereby promoting floc formation. In the illustrated arrangement, the tubular flocculant 18 is disposed between the bioreactor 13 and the three-stage settling tank 20. The second chemical agent system 97-2 is configured to introduce a coagulant into a tubular flocculant 18. The outlet of the tubular flocculant 18 is connected to a secondary or tertiary settling tank 20. The tertiary settling tank 20 is directly connected to a mechanical filtration device 15.

[0266] The tertiary settling tank 20 increases the residence time of wastewater discharged from the tubular flocculant 18. A longer residence time promotes floc formation in the wastewater. The tertiary settling tank 20 can function as a sedimentation tank, promoting the settling of particles and flocs. Flocs and particles in the wastewater may desuspension and settle in the tertiary settling tank 20. The tertiary settling tank 20 can be a multi-layer tank (e.g., two, three, or more layers). This multi-layer tank can form a meandering flow path along which the wastewater flows to promote settling. Other types of tertiary settling tanks 20 can also be used, such as radial flow tanks. At least a portion of the flocs and / or particles suspended in the wastewater can settle in the tertiary settling tank 20. Waste collected in the tertiary settling tank 20 can be sent to a waste disposal facility or further treated.

[0267] Mechanical filtration unit 15 is located immediately downstream of the tertiary settling tank 20. Wastewater discharged from the tertiary settling tank 20 is supplied to the mechanical filtration unit 15. Figure 9B As shown, wastewater is supplied directly from the tertiary sedimentation tank 20 to the mechanical filtration device 15. The mechanical filtration device 15 is operable to filter particulate matter and flocs from the wastewater. The operation of the mechanical filtration device 15 includes one or more methods described herein.

[0268] In the above example, the tubular flocculant 18 is positioned between the bioreactor 13 and the tertiary settling tank 20. Wastewater discharged from the bioreactor 13 is introduced into the tubular flocculant 18. The tubular flocculant 18 can be used in place of the tertiary settling tank 20, or in conjunction with it. For example, the tertiary settling tank 20 can be omitted. The outlet of the tubular flocculant 18 can be directly connected to the mechanical filtration device 15.

[0269] Now refer to Figure 10 describe Figure 8 The wastewater treatment plant 1 shown is a variant of the wastewater treatment plant 1. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to this embodiment and the reference numerals. Figure 8 Differences between the described embodiments.

[0270] Wastewater treatment plant 1 includes a primary filter 9, a primary settling tank 11, a bioreactor 13, and a mechanical filtration device 15. Wastewater treatment plant 1 may optionally include a tertiary settling tank 20. The tertiary settling tank 20 may be located between the bioreactor 13 and the mechanical filtration device 15. In this embodiment, the bioreactor 13 includes a moving bed bioreactor (MBBR). Other types of bioreactors 13 may be considered. It should be understood that one or more of the primary settling tank 11, bioreactor 13, and mechanical filtration device 15 may comprise civil installations, for example, in the form of concrete tanks, steel tanks, or glass fiber reinforced polymer (GFRP) tanks.

[0271] The wastewater treatment plant 1 in this embodiment includes a first chemical agent system 97-1 and a second chemical agent system 97-2. The first chemical agent system 97-1 is located upstream of the bioreactor 13; the second chemical agent system 97-2 is located downstream of the bioreactor 13. In this embodiment, the first chemical agent system 97-1 is located between the primary settling tank 11 and the bioreactor 13; and the second chemical agent system 97-2 is located between the bioreactor 13 and the mechanical filtration device 15. The first and second chemical agent systems 97-1 and 97-2 are configured to introduce a coagulant into the wastewater. The coagulant can cause one or more dissolved compounds, such as phosphates, to be released from solution and form particles. Alternatively, or additionally, microbial clumps on the biofiltration elements can be removed, thereby introducing more particles into the wastewater. The coagulant promotes the aggregation or agglomeration of particles suspended in the wastewater. The coagulant can promote the aggregation of particles in the wastewater, for example, the formation of flocs. Wastewater treatment plant 1 can be modified to replace at least one of the first and second chemical agent systems 97-1, 97-2 with one or more electrocoagulation units 91 of the type described herein. For example, the first chemical agent system 97-1 can be replaced by one or more electrocoagulation units 91. Alternatively, or additionally, the second chemical agent system 97-2 can be replaced by one or more electrocoagulation units 91. Wastewater treatment plant 1 according to this embodiment can be modified to omit the first chemical agent system 97-1 located upstream of bioreactor 13.

[0272] Mechanical filtration device 15 is configured to mechanically filter wastewater to remove at least some suspended solid particles from wastewater discharged from bioreactor 13. Mechanical filtration device 15 includes a mechanical filter tank 60, at least one mechanical filter inlet 61, at least one mechanical filter outlet 63, at least one mechanical filter air inlet 65, and at least one mechanical filter waste outlet 67. At least one mechanical filter inlet 61 is in fluid communication with at least one bioreactor outlet 43. In use, wastewater from bioreactor 13 is introduced into mechanical filtration device 15 through at least one mechanical filter inlet 61. At least one mechanical filter inlet 61 is preferably located in the lower region of mechanical filtration device 15; and at least one mechanical filter outlet 63 is preferably located in the upper region of mechanical filtration device 15. Mechanical filtration device 15 filters wastewater supplied from bioreactor 13. Mechanical filter chamber 70 includes mechanical filter media 69 for mechanically filtering wastewater. Mechanical filter media 69 includes a plurality of mechanical filter elements 71 of the type described herein. Mechanical filter elements 71 form a static filter bag 75, which is suitable for filtering particles and matter suspended in water as it flows through the mechanical filtration device 15. The mechanical filter elements 71 have an open structure to promote the sedimentation of suspended particles within the static filter bag 75. Each mechanical filter element 71 has one or more filter units 73. Wastewater is filtered by mechanical filter media 69 to remove at least some solid particles suspended in the wastewater supplied from the bioreactor 13. The treated wastewater (effluent) is discharged from the mechanical filtration device 15 through at least one mechanical filter outlet 63.

[0273] In this embodiment, the wastewater treatment plant 1 includes at least one water pump 99-n. Each water pump 99-n includes a suction side (inlet side) and a pressure side (outlet side). At least one water pump 99-n is configured to pump water through a mechanical filtration device 15. At least one water pump 99-n is disposed between the bioreactor 13 and the mechanical filtration device 15. A first water pump 99-1 may be disposed between the bioreactor 13 and a second chemical agent system 97-2. Alternatively, or additionally, a second water pump 99-2 may be disposed between the second chemical agent system 97-1 and the mechanical filtration device 15. It should be understood that one or more water pumps may also be disposed upstream of the bioreactor 13. A flow control valve (not located in...) may be provided. Figure 10 (As shown in the figure) to control the wastewater supplied to the mechanical filtration device 15.

[0274] exist Figure 10In the illustrated arrangement, a first water pump 99-1 is positioned between the bioreactor 13 and the second chemical agent system 97-2; and a second water pump 99-2 is positioned between the second chemical agent system 97-1 and the mechanical filtration device 15. The first water pump 99-1 pumps water discharged from the bioreactor 13 to the second chemical agent system 97-2. The second chemical agent system 97-2 introduces a flocculant into the wastewater upstream of the second water pump 99-2. The flocculant promotes the coagulation or aggregation of particles suspended in the wastewater, which is then pumped by the second water pump 99-2 to the mechanical filtration device 15.

[0275] The mechanical filter 15 is cleaned periodically to remove solids accumulated in the mechanical filter chamber 70. The cleaning of the mechanical filter 15 is performed using the methods described herein.

[0276] In use, the first water pump 99-1 and the second water pump 99-2 are used to pump water to the mechanical filtration device 15. In use, the mechanical filter element 71 forms a static filter bag 75, which is operable to filter solids from wastewater. The mechanical filter element 71 may have positive buoyancy, negative buoyancy, or neutral buoyancy. The mechanical filter element 71 has an openwork structure that provides high retention capacity. The flow rate per unit cross-sectional area of ​​the static filter bag 75 may be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. The first water pump 99-1 and / or the second water pump 99-2 may be configured to establish a desired flow rate per unit cross-sectional area through the static filter bag 75. Flocs suspended in the wastewater can settle inside or outside the filter unit 73 of the mechanical filter element 71. The treated water from the mechanical filtration device 15 can be discharged from the wastewater treatment plant 1 or sent to a receiving watercourse. Alternatively, the treated water can be sent downstream for further treatment.

[0277] In the above embodiments, at least one of the first water pump 99-1 and the second water pump 99-2 is disposed between the bioreactor 13 and the mechanical filtration device 15. Alternatively, or additionally, one or more water pumps 99-n may be disposed downstream of the mechanical filtration device 15. For example, a third water pump 99-3 may be optionally disposed downstream of the mechanical filtration device 15. The mechanical filtration device 15 may be disposed on the suction side of the third water pump 99-3. In use, the third water pump 99-3 can be used to draw water through the mechanical filtration device 15. The first water pump 99-1 and / or the second water pump 99-2 can be omitted from this arrangement.

[0278] Now refer to Figure 11 describe Figure 10A variant of the wastewater treatment plant 1 shown. The same reference numerals are used for the same components. Wastewater treatment plant 1 in this embodiment includes at least one pump 99-n disposed between the bioreactor 13 and the second chemical agent system 97-2. In the illustrated arrangement, wastewater treatment plant 1 includes a first pump 99-1 disposed between the bioreactor 13 and the second chemical agent system 97-2. The second pump 99-2 is omitted in this embodiment. The operation of wastewater treatment plant 1 is similar to other embodiments described herein. The flow rate per unit cross-sectional area of ​​the static filter bag 75 corresponds to one or more operating ranges in other embodiments described herein. The first pump 99-1 is configured to establish the desired flow rate per unit cross-sectional area through the static filter bag 75. Wastewater can be supplied directly from the second chemical agent system 97-2 to the mechanical filtration device 15. This helps retain flocs fed into the mechanical filtration device 15. This may facilitate the mechanical filtration device 15 in filtering the wastewater to remove particles. Wastewater treatment plant 1 may optionally include a third water pump 99-3 located downstream of mechanical filtration equipment 15 (not in...). Figure 11 (as shown in the image).

[0279] Now refer to Figure 12 describe Figure 10 Another variation of the wastewater treatment plant 1 shown. The same reference numerals are used for the same components. As described herein, one or more chemical agent systems 97-n can be replaced by an electrocoagulation unit 91. Figure 12 In the illustrated arrangement, the second chemical agent system 97-2 is used in combination with an electrocoagulation unit 91 of the type described herein. The chemical agent system 97-1 is connected in series with the electrocoagulation unit 91. In this embodiment, the electrocoagulation unit 91 is located downstream of the second chemical agent system 97-2. The electrocoagulation unit 91 is located between the second chemical agent system 97-2 and the mechanical filtration device 15. In use, the second chemical agent system 97-2 introduces a coagulant into the wastewater supplied from the bioreactor 13. The wastewater then passes through the electrocoagulation unit 91 and is supplied to the mechanical filtration device 15.

[0280] Wastewater treatment plant 1 is illustrated as having a first water pump 99-1 and a second water pump 99-2. It should be understood that at least one of the first water pump 99-1 and the second water pump 99-2 may be omitted. For example, the first water pump 99-1 or the second water pump 99-2 may be omitted. The flow rate per unit cross-sectional area of ​​the static filter pack 75 coincides with one or more operating ranges of other embodiments described herein. The first water pump 99-1 and / or the second water pump 99-2 are configured to establish the desired flow rate per unit cross-sectional area through the static filter pack 75. The operation of wastewater treatment plant 1 is similar to other embodiments described herein. In use, the electrocoagulation unit 91 is used to promote the coagulation of particles in the wastewater. The wastewater and the coagulated particles are supplied to the mechanical filtration device 15. The mechanical filtration device 15 is operable to filter the coagulated particles from the wastewater. In this embodiment, the wastewater from the electrocoagulation unit 91 is supplied directly to the mechanical filtration device 15. The water pump may optionally be located between the electrocoagulation unit 91 and the mechanical filtration device 15.

[0281] In one variant, electrocoagulation unit 91 may replace the second chemical agent system 97-2. Electrocoagulation unit 91 may be positioned between bioreactor 13 and mechanical filtration device 15. In use, wastewater is supplied from bioreactor 13 to electrocoagulation unit 91. The wastewater is then supplied from electrocoagulation unit 91 to mechanical filtration device 15.

[0282] exist Figure 12 In the arrangement shown, the first chemical agent system 97-1 is located upstream of the bioreactor 13, and the electrocoagulation unit 91 is located downstream of the bioreactor 13. This arrangement can be reversed, i.e., the electrocoagulation unit 91 can be located upstream of the bioreactor 13. Alternatively, the first electrocoagulation unit 91 can be located upstream of the bioreactor 13, and the second electrocoagulation unit 91 can be located downstream of the bioreactor 13.

[0283] Now refer to Figure 13 describe Figure 8 The wastewater treatment plant 1 shown is a variant of the wastewater treatment plant 1. The same reference numerals are used for the same components. This description focuses on the wastewater treatment plant 1 according to this embodiment and the reference numerals. Figure 8 Differences between the described embodiments.

[0284] Wastewater treatment plant 1 includes a primary filter 9, a primary settling tank 11, a bioreactor 13, a downstream filtration unit 14, and a mechanical filtration unit 15. Wastewater treatment plant 1 may optionally include a tertiary settling tank 20. The tertiary settling tank 20 may be located between the bioreactor 13 and the mechanical filtration unit 15. In this embodiment, the bioreactor 13 includes a moving bed bioreactor (MBBR). Other types of bioreactors 13 may be considered. For example, the bioreactor 13 may include a submerged aerated filter (SAF) of the type described herein.

[0285] Wastewater treatment plant 1 includes a first chemical agent system 97-1 and a second chemical agent system 97-2. The first chemical agent system 97-1 is located upstream of bioreactor 13. In this embodiment, the first chemical agent system 97-1 is located between the primary settling tank 11 and the bioreactor 13. The second chemical agent system 97-2 is located downstream of bioreactor 13. The second chemical agent system 97-2 is located between bioreactor 13 and downstream filtration equipment 14. The first and second chemical agent systems 97-1 and 97-2 are each configured to introduce a coagulant into the wastewater. The coagulant can cause one or more dissolved compounds, such as phosphates, to be released from solution and form particles. The coagulant promotes the aggregation or agglomeration of particles suspended in the wastewater. The coagulant can promote the aggregation of particles in the wastewater, for example, the formation of flocs. Wastewater treatment plant 1 can be modified to replace at least one of the first and second chemical agent systems 97-1 and 97-2 with one or more electrocoagulation units 91 of the type described herein. Alternatively, or additionally, one or more of the first and second chemical agent systems 97-1, 97-2 in wastewater treatment plant 1 may be omitted. For example, the first chemical agent system 97-1 and / or the second chemical agent system 97-2 may be omitted.

[0286] Downstream filtration device 14 is located downstream of bioreactor 13. Downstream filtration device 14 is used to filter particles from the wastewater discharged from bioreactor 13. Downstream filtration device 14 may include, for example, a cloth filter or a mesh filter. In this embodiment, downstream filtration device 14 may also employ other types of filters. Downstream filtration device 14 includes a storage tank 14A and a filter element 14B. In this embodiment, storage tank 14A is integrated into downstream filtration device 14. In a variant, storage tank 14A may be separate from downstream filtration device 14. Wastewater discharged from bioreactor 13 is introduced into storage tank 14A before flowing through filter element 14B. In this embodiment, a second chemical agent system 97-2 introduces a chemical flocculant into the wastewater located between bioreactor 13 and downstream filtration device 14. The chemical flocculant promotes floc formation in the wastewater. Filter element 14B is configured to filter flocs from the wastewater. Filter element 14B may be, for example, in the form of a filter screen or sieve.

[0287] Mechanical filtration device 15 is configured to filter wastewater in storage tank 14A of downstream filtration device 14. Wastewater in storage tank 14A is supplied to inlet 61 of mechanical filtration device 15. Wastewater can be supplied to mechanical filtration device 15 by gravity feeding. Alternatively, a pump (not shown) can be used to pump wastewater to mechanical filtration device 15. Mechanical filtration device 15 can be located on the pressure side or suction side of the pump. The operation of mechanical filtration device 15 is consistent with other embodiments described herein. In use, mechanical filtration device 15 filters particulate matter and flocs from the wastewater. Wastewater filtered by mechanical filtration device 15 is returned to storage tank 14A of downstream filtration device 14. The wastewater is then filtered through filter element 14B before being discharged from wastewater treatment plant 1. Mechanical filtration device 15 is cleaned periodically, for example by backwashing. Waste generated by mechanical filtration device 15 is discharged into waste line 83 via waste outlet 67. This waste can be returned to wastewater treatment plant 1 for further treatment.

[0288] Mechanical filtration device 15 can be selectively connected to downstream filtration device 14. For example, if it is determined that downstream filtration device 14 is overloaded, or the wastewater requires further filtration, mechanical filtration device 15 can be connected to downstream filtration device 14A. Mechanical filtration inlet valve 77 is used to open and close at least one mechanical filtration inlet 61; simultaneously, a mechanical filtration outlet valve 79 is provided to open and close at least one mechanical filtration outlet 63. Opening mechanical filtration inlet valve 77 and mechanical filtration outlet valve 79 connects mechanical filtration device 15 to the storage tank 14A of downstream filtration device 14. Mechanical filtration waste valve 81 is used to open and close mechanical filtration waste outlet 67. Closing mechanical filtration inlet valve 77 and outlet valve 79 disconnects mechanical filtration device 15 from downstream filtration device 14.

[0289] The operation of the wastewater treatment plant 1 according to this embodiment is consistent with other embodiments described herein. The mechanical filtration device 15 is operable to filter particulate matter and flocs from the wastewater. The flow rate per unit cross-sectional area of ​​the static filter bag 75 can be less than 20 m³ / m² / h (excluding 20 m³ / m² / h), for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. The mechanical filter medium 69 can have positive buoyancy, neutral buoyancy, or negative buoyancy. In this embodiment, the mechanical filter medium 69 has positive buoyancy.

[0290] Figure 13A variant of the illustrated wastewater treatment plant 1 may utilize a mechanical filtration device 15 to filter wastewater in a settling tank (e.g., settling tank 13). Wastewater in settling tank 13 may be supplied to the mechanical filtration device 15 for filtration. Filtered wastewater may be returned from the mechanical filtration device 15 to settling tank 13. At least one mechanical filtration inlet 61 and at least one mechanical filtration outlet 63 may be connected to settling tank 13 for wastewater reception and return. The mechanical filtration device 15 may reduce the filtration load of another filtration device located downstream of settling tank 13. The use of the mechanical filtration device 15 to filter wastewater contained in settling tank 11 can be applied to any of the embodiments described herein.

[0291] Wastewater treatment plant 1 includes a bioreactor 13 for biological filtration of wastewater. Different types of bioreactors 13 are suitable for wastewater treatment plant 1. As described herein, bioreactor 13 may include a moving bed filter or a static bed filter. Furthermore, wastewater may be pumped through bioreactor 13. Bioreactor 13 may employ gravity feeding. Bioreactor 13 may, for example, include one or more trickle filters 13 or be composed of them. Figure 13 The illustration shows a trickle filter 13 suitable for use as a bioreactor 13 in a wastewater treatment plant 1 according to one or more embodiments described herein. The trickle filter 13 is configured to biologically filter the wastewater. The trickle filter 13 includes a biological filtration chamber 47 containing a biological filter medium 49 for biologically filtering the wastewater. The filter chamber 47 may have a circular pool structure. Wastewater is sprayed onto the upper surface of the biological filter medium 49 in the filter chamber 47.

[0292] Wastewater can be sprayed, for example, from one or more nozzles onto the top of the biological filter media 49. In an illustrated configuration, one or more nozzles are positioned on an arm supported above the biological filter media 49. This arm can be rotated to distribute the wastewater over a larger area. The wastewater drips (or permeates) downwards through the biological filter media 49 and undergoes biological filtration. The wastewater flows downwards through the biological filter media 49, in... Figure 14 The diagram is illustrated by a series of meandering arrows. Filtered wastewater is discharged through outlet 43. Air can be optionally introduced into the biological filter media 49 to promote aerobic treatment. In the illustrated configuration, an air pump 17 is provided to introduce air into the bottom of the biological filter media 49. The air travels upward through the biological filter media 49, as... Figure 14 A series of dashed arrows illustrate this. It should be understood that in one or more embodiments described herein, the trickle filter 13 can be used as a bioreactor 13.

[0293] Figure 15AThe first mechanical filter tank 60A is shown by way of example. The first mechanical filter tank 60 includes a cylindrical portion. The first mechanical filter tank 60 includes a mechanical filter inlet 61, a mechanical filter outlet 63, and a mechanical filter waste outlet 67. The diameter of the cylindrical portion of the first mechanical filter tank 60A is 1.2 m.

[0294] Figure 15B The second mechanical filter tank 60B is shown as an example. The second mechanical filter tank 60B includes a cylindrical portion. The second mechanical filter tank 60B includes a mechanical filter inlet 61, a mechanical filter outlet 63, and a mechanical filter waste outlet 67. The diameter of the cylindrical portion of the first mechanical filter tank 60B is 0.9 m.

[0295] Figure 15C The third mechanical filter tank 60C is shown as an example. The third mechanical filter tank 60C includes a cylindrical portion. The third mechanical filter tank 60C includes a mechanical filter inlet 61, a mechanical filter outlet 63, and a mechanical filter waste outlet 67. The diameter of the cylindrical portion of the third mechanical filter tank 60C is 0.75 m.

[0296] Figure 15D The fourth mechanical filter tank 60D is shown as an example. The fourth mechanical filter tank 60D includes a cylindrical portion. The fourth mechanical filter tank 60D includes a mechanical filter inlet 61, a mechanical filter outlet 63, and a mechanical filter waste outlet 67. The diameter of the cylindrical portion of the fourth mechanical filter tank 60D is 0.6 m.

[0297] Figure 15E The fifth mechanical filter tank 60E is shown as an example. The fourth mechanical filter tank 60 includes a cylindrical portion. The fourth mechanical filter tank 60E includes a mechanical filter inlet 61, a mechanical filter outlet 63, and a mechanical filter waste outlet 67. The diameter of the cylindrical portion of the fourth mechanical filter tank 60E is 0.5 m.

[0298] The size of the mechanical filtration device 15 depends on the flow rate of the wastewater to be treated. Wastewater treatment plant 1 can be a wastewater treatment plant configured to treat sewage. Wastewater is typically defined by population equivalent (PE), which represents a certain volume of wastewater per person (typically limited to 150 to 180 liters per day). The treated water from wastewater treatment plant 1 must meet certain standards (defined in BSEN 12566-3 in the UK). These standards may define thresholds for one or more of the following: biochemical oxygen demand (BOD), suspended solids (SS), and ammonia (NH4-N) content. The BOD threshold may be defined as 20 mg / L (BOD < 20 mg / L). The suspended solids threshold may be defined as less than 30 mg / L (SS < 30 mg / L). The ammonia threshold may be defined as less than 20 mg / L. Requirements may also apply to other contaminants such as nitrates and phosphates.

[0299] Table A below outlines the operating parameters for a small-scale (sewage) project. Wastewater treatment plant 1 includes at least one mechanical filtration device 15 of the type described herein for mechanically filtering the wastewater discharged from bioreactor 13. The table outlines the number and dimensions (diameter φ) of the mechanical filtration devices 15 in wastewater treatment plant 1. In this example, wastewater treatment plant 1 includes a single mechanical filtration device 15 with a diameter of 0.6 m.

[0300]

[0301] Table A

[0302] Table B below summarizes the operating parameters for a range of small-scale (sewage) projects. Wastewater treatment plant 1 includes at least one mechanical filtration device 15 of the type described herein for mechanically filtering the wastewater discharged from bioreactor 13. The table summarizes the number and dimensions (diameter φ) of the mechanical filtration devices 15 in wastewater treatment plant 1.

[0303]

[0304] Table B

[0305] Table C below summarizes the operating parameters of a large-scale (sewage) treatment plant. Wastewater treatment plant 1 includes at least one mechanical filtration device 15 of the type described herein for mechanically filtering the wastewater discharged from bioreactor 13. The table summarizes the number and size (diameter φ) of the mechanical filtration devices 15 in wastewater treatment plant 1. In this example, wastewater treatment plant 1 includes a single mechanical filtration device 15 with a diameter of 0.6 m.

[0306]

[0307] Table C

[0308] It should be understood that various changes and modifications can be made to this invention without departing from the scope of this application.

[0309] First flowchart marking

[0310]

[0311] Second flowchart marking

[0312]

Claims

1. A wastewater treatment method for treating wastewater, the wastewater treatment method comprising: Receive wastewater awaiting treatment; The wastewater is supplied to an electrocoagulation unit to cause the solids suspended in the wastewater to aggregate. The wastewater is supplied from the electrocoagulation unit to a mechanical filtration device, wherein the mechanical filtration device includes a static filter bag for filtering aggregated solids from the electrocoagulation unit, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and Discharge the treated wastewater.

2. The wastewater treatment method according to claim 1, comprising: The wastewater is supplied to a bioreactor for biological filtration; and Wastewater discharged from the bioreactor is supplied to the electrocoagulation unit to cause solid waste suspended in the wastewater discharged from the bioreactor to aggregate.

3. The wastewater treatment method according to claim 1 or claim 2, comprising: introducing a coagulant to form flocs in the wastewater; and The wastewater is supplied to the mechanical filtration device to filter the flocs suspended in the wastewater, the mechanical filtration device being located downstream of at least one chemical agent system.

4. A wastewater treatment method for treating wastewater, the wastewater treatment method comprising: Receive wastewater awaiting treatment; At least one chemical agent system is used to introduce a coagulant into the wastewater to form flocs; The wastewater is supplied to a mechanical filtration device located downstream of the at least one chemical agent system, wherein the mechanical filtration device comprises a static filter bag that filters the flocs suspended in the wastewater, the static filter bag comprising a plurality of mechanical filter elements, each mechanical filter element having one or more filter units; and Discharge the treated wastewater.

5. The wastewater treatment method according to claim 3 or claim 4, wherein the coagulant causes phosphate dissolved in the wastewater to be released from the solution and form particles, and the static filter bag of the mechanical filtration device filters the particles formed by the coagulant.

6. The wastewater treatment method according to claim 5, wherein the coagulant causes the particles containing or composed of phosphates to aggregate and form flocs suspended in the wastewater, and the static filter bag of the mechanical filtration device filters the flocs from the wastewater.

7. The wastewater treatment method according to any one of claims 3 to 6, wherein, After the coagulant is introduced, the wastewater is retained for a period of time to allow the flocs to form in the wastewater; After the retention period, the wastewater is supplied to the mechanical filtration equipment to remove the flocs suspended in the wastewater.

8. The wastewater treatment method according to claim 7, wherein the wastewater is retained in a settling tank to allow the formation of the flocs.

9. The wastewater treatment method according to claim 8, wherein the coagulant may be introduced into the wastewater upstream of the settling tank or directly into the wastewater of the settling tank.

10. The wastewater treatment method according to any one of claims 3 to 9, wherein wastewater is supplied to a tubular flocculant disposed upstream of the mechanical filtration device, and the flocculant is introduced into the wastewater supplied to the tubular flocculant.

11. The wastewater treatment method according to claim 10, wherein the wastewater discharged from the tubular flocculant is introduced into the sedimentation tank or the mechanical filtration device.

12. The wastewater treatment method according to any one of claims 4 to 11, comprising: The wastewater is supplied to a bioreactor for biological filtration, the bioreactor being located upstream of the mechanical filtration equipment.

13. The wastewater treatment method according to claim 2 or claim 12, wherein the bioreactor comprises a biofilter medium for biofiltering the wastewater, the biofilter medium comprising a plurality of biofilter elements, the biofilter elements being used to support a community of microorganisms on the surface of the biofilter medium for biofiltering the wastewater.

14. The wastewater treatment method of claim 13, wherein the biofilter element circulates within the bioreactor during filtration, and the circulation of the biofilter element causes solid waste to be removed from the biofilter element and become suspended solids in the wastewater.

15. The wastewater treatment method according to claim 13 or claim 14, wherein the static filter bag filters solid waste removed from the biofilter element in the bioreactor and suspended in the wastewater discharged from the bioreactor.

16. The wastewater treatment method according to claim 2 or any one of claims 12 to 15, wherein the at least one chemical agent system is disposed downstream of the bioreactor, the method comprising introducing the coagulant into the wastewater discharged from the bioreactor.

17. The wastewater treatment method according to claim 2 or any one of claims 12 to 16, comprising introducing at least some of the solid waste accumulated in the mechanical filtration device into the bioreactor.

18. The wastewater treatment method of claim 17, wherein at least some of the solid waste removed from the mechanical filter element is directly introduced into the bioreactor or upstream of the bioreactor.

19. The wastewater treatment method according to any one of the preceding claims, comprising: the flow rate per unit cross-sectional area of ​​the static filter bag formed in the mechanical filtration device is in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

20. A wastewater treatment method for treating wastewater, the wastewater treatment method comprising: Receive wastewater awaiting treatment; The wastewater is supplied to a bioreactor containing a biofilter medium for biofiltration of the wastewater. The biofilter medium includes a plurality of biofilter elements for supporting a community of microorganisms on the surface of the wastewater in the biofilter medium. During filtration, the biofilter elements circulate within the bioreactor, and the circulation of the biofilter elements causes solid waste to be removed from the biofilter elements and suspended in the wastewater. Wastewater discharged from the bioreactor is supplied to the electrocoagulation unit to aggregate solid waste removed from the biofiltration element in the bioreactor; as well as Discharge the treated wastewater.

21. A wastewater treatment plant for treating wastewater, the wastewater treatment plant comprising: An inlet for receiving wastewater to be treated; An electrocoagulation unit is used to aggregate solids suspended in the wastewater. A mechanical filtration device is disposed downstream of the electrocoagulation unit, wherein the mechanical filtration device includes a static filter bag for filtering aggregated solids discharged from the electrocoagulation unit and suspended in the wastewater, and the static filter bag includes a plurality of mechanical filter elements, each of which has one or more filter units. as well as An outlet used to discharge treated wastewater.

22. The wastewater treatment plant according to claim 21, comprising: Bioreactors are used for the biological filtration of wastewater. The electrocoagulation unit is configured to aggregate solid waste suspended in wastewater discharged from the bioreactor.

23. The wastewater treatment plant according to claim 21 or claim 22, comprising: at least one chemical agent system for introducing a coagulant into the wastewater to form flocs; The mechanical filtration device is located downstream of the at least one chemical agent system, wherein... In use, the wastewater is supplied to the mechanical filtration equipment to filter the flocs suspended in the wastewater.

24. A wastewater treatment plant for treating wastewater, the wastewater treatment plant comprising: An inlet for receiving wastewater to be treated; At least one chemical agent system for introducing a coagulant into the wastewater to form flocs suspended in the wastewater; A mechanical filtration device is disposed downstream of the at least one chemical agent system, wherein the mechanical filtration device includes a static filter bag that filters the flocs suspended in the wastewater, and the static filter bag includes a plurality of mechanical filter elements, each of which has one or more filter units. as well as An outlet used to discharge treated wastewater.

25. The wastewater treatment plant according to claim 23 or claim 24, wherein, In use, the at least one chemical agent system introduces the coagulant to release phosphate dissolved in the wastewater from the solution and form particles, and the static filter bag of the mechanical filtration device is configured to filter the particles formed by the coagulant.

26. The wastewater treatment plant according to claim 25, wherein, In use, the coagulant causes the particles containing or composed of phosphates to aggregate and form flocs suspended in the wastewater, and the static filter bag of the mechanical filtration device filters the flocs from the wastewater.

27. The wastewater treatment plant according to any one of claims 23 to 26, wherein the wastewater treatment plant is configured to retain the wastewater for a period of time to allow the flocs to form in the wastewater; and after the period of retention ends, to supply the wastewater to the mechanical filtration device.

28. The wastewater treatment plant according to any one of claims 23 to 27, comprising a first settling tank for retaining the wastewater before supplying it to the mechanical filtration equipment.

29. The wastewater treatment plant according to claim 28, wherein the at least one chemical agent system may be configured to introduce the coagulant into the wastewater upstream of the settling tank or to introduce the coagulant directly into the wastewater of the settling tank.

30. The wastewater treatment plant according to any one of claims 23 to 29, comprising a tubular flocculant for introducing the coagulant into the wastewater, the tubular flocculant being disposed upstream of the mechanical filtration equipment.

31. The wastewater treatment plant according to claim 30, wherein the tubular flocculant is configured to directly introduce wastewater into the sedimentation tank or the mechanical filtration device.

32. The wastewater treatment plant according to any one of claims 21 to 31, comprising: A bioreactor for biological filtration of the wastewater, the bioreactor being located upstream of the mechanical filtration equipment.

33. The wastewater treatment plant according to claim 22 or claim 32, wherein the bioreactor comprises a biofilter medium for biofiltering the wastewater, the biofilter medium comprising a plurality of biofilter elements for supporting a community of microorganisms on the surface of the biofilter medium for biofiltering the wastewater.

34. The wastewater treatment plant of claim 33, comprising means for circulating the biofilter element within the bioreactor during filtration to remove retained waste.

35. The wastewater treatment plant according to claim 33 or claim 34, wherein the static filter pack is configured to filter solid waste removed from the biofilter element in the bioreactor and suspended in the wastewater discharged from the bioreactor.

36. The wastewater treatment plant according to claim 22 or any one of claims 24 to 35, wherein the at least one chemical agent system is disposed downstream of the bioreactor, the at least one chemical agent system being configured to introduce the coagulant into the wastewater discharged from the bioreactor.

37. The wastewater treatment plant according to claim 22 or any one of claims 24 to 36, comprising a return line for returning at least some of the solid waste accumulated in the mechanical filtration equipment to the bioreactor.

38. The wastewater treatment plant according to claim 37, wherein the return pipeline is directly connected to the bioreactor or connected upstream of the bioreactor.

39. The wastewater treatment plant according to any one of claims 21 to 38, comprising at least one pump for pumping wastewater through the mechanical filtration apparatus, wherein the at least one pump is configured to establish a flow rate per unit cross-sectional area of ​​the static filter bag formed in the mechanical filtration apparatus in the range of 0.1 m³ / m² / h to 19 m³ / m² / h.

40. A wastewater treatment plant for treating wastewater, the wastewater treatment plant comprising: An inlet for receiving wastewater to be treated; A bioreactor comprising a biofilter medium for biofiltering the wastewater, the biofilter medium being adapted to support a microbial community, the bioreactor including means for circulating the biofilter medium within the bioreactor during filtration; and An electrocoagulation unit is located downstream of the bioreactor and is configured to aggregate substances suspended in the wastewater discharged from the bioreactor.

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