Apparatus for microbial wastewater treatment

Abstract

The invention relates to a method for microbiologically treating an aqueous liquid comprising biodegradable substrate in a plant comprising (i) a bioreactor containing biomass sludge and (ii) a biomass separator separate from the bioreactor and comprising one or more inclined plate settlers, wherein the biomass separator has a footprint A of 0.5 to 30 m 2 and the one or more inclined plate settlers comprise a total number n of inclined plate elements which together provide a total projected surface area (PSA) and a total projected surface area ratio (PSAR) calculated as follows: - PSAR = PSA / A, psa i denotes the total projected surface area of inclined plate element i in m 2 and wherein PSAR ≥ 2.8 + 0.17A. The plant for operating the method of the invention can achieve solid-liquid separation at very high fluid flow rates in the biomass separator without compromising separation efficiency and without substantially increasing the overall footprint of the plant. The invention also provides a plant for microbiologically treating an aqueous liquid comprising biodegradable substrate.

Description

Technical Field

[0001] This invention relates to a method for microbial treatment of an aqueous liquid containing a biodegradable substrate in an apparatus comprising (i) a bioreactor containing biomass sludge and (ii) a biomass separator separate from the bioreactor, the biomass separator comprising one or more inclined plate settling tanks, wherein the method comprises:

[0002] • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator;

[0003] • In one or more inclined plate settlers, the treated fluid is separated into a liquid phase with reduced biomass content and a fluid phase rich in biomass;

[0004] • Remove the liquid phase with reduced biomass content from the one or more inclined plate settlers; and

[0005] • At least a portion of the biomass-rich fluid phase is returned from the bottom of the biomass separator to the bioreactor.

[0006] The present invention further relates to an apparatus that can be used to perform such a method. Background Technology

[0007] Anaerobic treatment of fluids / wastewater is typically carried out in a bioreactor, where (particulate) anaerobic biomass converts organic pollutants into biogas, which consists primarily of methane and carbon dioxide. Typically, such bioreactors are equipped with devices to separate the generated biogas from the treated fluid and to separate the biomass from the degassed fluid.

[0008] WO 2010 / 036107 describes a purifier for purifying wastewater, the purifier comprising a reaction chamber (24), the reaction chamber comprising a fermentation chamber (25), and a settling device (2) mounted above the fermentation chamber (25) for a fluid containing liquid, gas, and particulate material, the settling device comprising:

[0009] • A settling chamber (3) is configured to be filled with the fluid;

[0010] • A liquid outlet (5) for discharging liquid from the settling chamber, the liquid outlet (5) being arranged so as to be close to the liquid level (30) during operation;

[0011] • A fluid inlet (6) is configured to supply the fluid into the settling chamber (3) and is located at a substantially the same level as the liquid outlet (5);

[0012] • Particulate material separation device (7); and

[0013] • Sludge outlet (8) from the settling chamber (3)

[0014] The inlet (6) includes a gas separation device (4) for separating gas from the fluid. The gas separation device (4) includes a row of inclined plates (13) arranged in an overlapping and parallel manner, with their longitudinal axes at an angle to the horizontal plane, such that the fluid supplied through the inlet (6) flows downward along these inclined plates, while light particles of air bubbles (34) and / or particulate material contained in the liquid are collected on the underside of one or more of these plates (13), flow upward and leave the gas separation device (4) at the inlet (6).

[0015] WO 2007 / 078195 describes a method for anaerobic treatment of wastewater using a sludge bed system, comprising feeding wastewater and optionally recirculated water into the lower part of an upflow reactor (containing primarily particulate biomass) to generate biogas during treatment, allowing the resulting gas / liquid / solid mixture to pass upward and separating the gas and solids from the liquid in a three-phase separator to produce an anaerobic effluent drawn from the top of the separator. An improvement includes separating the solids from the liquid in the separator, wherein, above the separation of the gas and liquid phases, a tilted plate, tube, or other tilted internal component is installed in the body of the three-phase separator to increase the effective settling surface.

[0016] WO 2012 / 005592 describes a purifier (100) for purifying wastewater, the purifier comprising:

[0017] • A reaction vessel (10) for fluids, the reaction vessel having a reaction chamber (11) and a bottom (12);

[0018] • A downer (14) having a top end (91) and a bottom end (92), wherein the top end of the downer is connected to a fluid collector (13) to collect fluid from the reaction vessel (10), and the downer is arranged to deliver the fluid toward the bottom (12) of the reaction vessel.

[0019] • A solid separation device (20) arranged to separate solids from liquids, the solid separation device including a fluid inlet (72) arranged to introduce fluid into the solid separation device and a liquid outlet (56) arranged to remove separated liquids from the solid separation device;

[0020] The solid separation device (20) is characterized in that its fluid inlet is connected to the bottom end (92) of the descending bed, and the solid separation device is located inside the reaction vessel, on or near the bottom (12) of the reaction vessel.

[0021] Recirculating the microbially treated fluid at high flow rates in the separation unit is beneficial for the hydraulic conditions in the bioreactor because it allows for better mixing in the lower part of the bioreactor and higher upward liquid flow rates, thus preventing the accumulation of poor-quality anaerobic biomass. This recirculation back to the bioreactor can also be used to dilute biodegradable substrate to non-toxic concentrations, thereby creating better conditions for anaerobic fermentation.

[0022] To increase fluid recirculation capacity, larger or additional separation units are required. Larger bioreactors, especially those with a larger footprint (covered surface area), may be needed to accommodate these larger or additional separation units. This leads to higher capital costs and operational challenges, such as achieving good mixing between the fluid and biomass in the expanded bioreactor. To achieve the latter, even higher fluid recirculation flow rates may be required, necessitating further increases in the size and / or number of separation units.

[0023] It is known to place the separation device outside the bioreactor. WO 2020 / 038959 describes a method for treating an aqueous fluid containing biodegradable organic matter in an apparatus comprising an upflow bioreactor (1) containing a sludge bed (the sludge bed comprising biomass), an external separator (2), and a conditioning tank (12), wherein the method includes

[0024] • The aqueous fluid is treated in the regulating tank (12); thereafter

[0025] • An aqueous fluid from the regulating tank (12) is fed into the lower part of the bioreactor, so that the fed fluid comes into contact with the biomass, thereby forming biogas from the biodegradable organic matter;

[0026] • The fluid that has been in contact with the biomass is extracted from the top of the bioreactor; the extracted fluid contains biomass.

[0027] • An aqueous fluid containing biomass drawn from the top of the bioreactor is fed into the external separator (2), which includes a separation chamber with a side-sloping internal structure, wherein the aqueous fluid containing biomass is separated into a liquid phase (which has a reduced biomass content or is substantially free of biomass) and a biomass-rich fluid phase.

[0028] • Returning the biomass-rich fluid phase from the external separator to the bioreactor; and

[0029] • A portion of the liquid phase with reduced biomass content or essentially no biomass is returned from the external separator (2) to the regulating tank (12).

[0030] EP-A 1 134 194 describes a method for retaining biomass in an anaerobic sludge blanket reactor, wherein a solids separator (through which water from a bioreactor flows) is pressurized and biomass is deposited under elevated pressure. The method is characterized in that the average residence time of water flowing through the solids separator is less than or equal to the ratio of the gas retention capacity of the water in the solids separator to the gas production through the biomass. Summary of the Invention

[0031] The inventors of this invention have developed a method for treating aqueous liquids containing biodegradable substrates in an apparatus comprising (i) a bioreactor containing biomass sludge and (ii) a biomass separator separate from the reactor and comprising one or more inclined plate settling tanks. The apparatus for operating the method of this invention can achieve solid-liquid separation in the biomass separator at very high fluid flow rates without compromising separation efficiency and substantially without increasing the overall footprint of the apparatus.

[0032] More specifically, the inventors have developed a method for microbial treatment of aqueous liquids containing biodegradable substrates in an apparatus comprising (i) a bioreactor containing biomass sludge and (ii) a biomass separator separate from the bioreactor and comprising one or more inclined plate settling tanks, the method comprising:

[0033] • Introduce the aqueous liquid containing the biodegradable substrate into the bioreactor;

[0034] • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator;

[0035] • In one or more inclined plate settlers, the treated fluid is separated into a liquid phase with reduced biomass content and a fluid phase rich in biomass;

[0036] • Remove the liquid phase with reduced biomass content from the one or more inclined plate settlers; and

[0037] • At least a portion of the biomass-rich fluid phase is transferred from the lower part of the biomass separator to the bioreactor;

[0038] or

[0039] • A mixture of an aqueous liquid containing a biodegradable substrate and at least a portion of a biomass-rich fluid phase generated by the one or more inclined plate settlers is introduced into the bioreactor, wherein the mixture is (i) generated by introducing the aqueous liquid containing a biodegradable substrate into the lower part of the biomass separator and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase or (ii) generated by introducing both the aqueous liquid containing a biodegradable substrate and at least a portion of the biomass-rich fluid phase into a mixing unit and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase;

[0040] • Transfer the mixture of the aqueous liquid and at least a portion of the fluid phase to the bioreactor;

[0041] • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator;

[0042] • In one or more inclined plate settlers, the treated fluid is separated into a liquid phase with reduced biomass content and a fluid phase rich in biomass;

[0043] • Remove the liquid phase with reduced biomass content from the one or more inclined plate settlers;

[0044] The biomass separator has a capacity of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the device or unit onto the horizontal surface; and

[0045] The one or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows:

[0046] -

[0047] -PSAR = PSA / A

[0048] psa i The tilting plate element i is represented by m 2 The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and

[0049] Where PSAR ≥ 2.8 + 0.17A.

[0050] By employing a biomass separator separate from the bioreactor, the treatment conditions in the bioreactor and the separation conditions in the biomass separator can be optimized separately. Furthermore, by ensuring a high total projected surface area ratio (PSAR) provided by one or more inclined plate settlers in the biomass separator, efficient solid-liquid separation with high fluid flow rates can be achieved in a biomass separator with a small footprint (relative to the bioreactor's footprint).

[0051] The present invention also provides an apparatus for microbial treatment of aqueous liquids containing biodegradable substrates, wherein the apparatus includes

[0052] • Bioreactor (1), the bioreactor comprising:

[0053] - An inlet (4) for a flow containing a biomass-rich fluid phase; and

[0054] - An outlet (5) for the treated liquid, located at the top of the bioreactor;

[0055] • A biomass separator (2) separate from the bioreactor, the biomass separator comprising:

[0056] - An inlet (6) located at the top of the biomass separator for containing a stream of treated liquid, the inlet for the treated liquid being fluidly connected to the outlet (5) of the bioreactor.

[0057] - One or more inclined plate settlers (7) located below the inlet (6), each inclined plate settler having an outlet (8) for a liquid phase with reduced biomass content;

[0058] • An outlet (9) for biomass-rich fluid located at the lower part of the biomass separator below one or more inclined plate settlers, the outlet (9) being fluidly connected to the inlet (4) of the bioreactor or the inlet (20) of the mixing unit (19), the mixing unit including an outlet (21) fluidly connected to the inlet (4) of the bioreactor;

[0059] The bioreactor, the lower part of the biomass separator, or the mixing unit includes an inlet (3) for an aqueous liquid containing a biodegradable substrate; and

[0060] The biomass separator has a capacity of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the device or unit onto the horizontal surface; and

[0061] The one or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows:

[0062] -

[0063] -PSAR = PSA / A

[0064] psa i The tilting plate element i is represented by m 2 The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and

[0065] Where PSAR ≥ 2.8 + 0.17A. Detailed Implementation

[0066] Therefore, a first aspect of the present invention relates to a method for microbial treatment of an aqueous liquid containing a biodegradable substrate in an apparatus comprising (i) a bioreactor containing biomass sludge and (ii) a biomass separator separate from the bioreactor and comprising one or more inclined plate settling tanks, the method comprising:

[0067] • Introduce the aqueous liquid containing the biodegradable substrate into the bioreactor;

[0068] • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator;

[0069] • In one or more inclined plate settlers, the treated fluid is separated into a liquid phase with reduced biomass content and a fluid phase rich in biomass;

[0070] • Remove the liquid phase with reduced biomass content from the one or more inclined plate settlers; and

[0071] • At least a portion of the biomass-rich fluid phase is transferred from the lower part of the biomass separator to the bioreactor;

[0072] or

[0073] • A mixture of an aqueous liquid containing a biodegradable substrate and at least a portion of a biomass-rich fluid phase generated by the one or more inclined plate settlers is introduced into the bioreactor, wherein the mixture is (i) generated by introducing the aqueous liquid containing a biodegradable substrate into the lower part of the biomass separator and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase or (ii) generated by introducing both the aqueous liquid containing a biodegradable substrate and at least a portion of the biomass-rich fluid phase into a mixing unit and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase;

[0074] • Transfer the mixture of the aqueous liquid and at least a portion of the fluid phase to the bioreactor;

[0075] • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator;

[0076] • In one or more inclined plate settlers, the treated fluid is separated into a liquid phase with reduced biomass content and a fluid phase rich in biomass;

[0077] • Remove the liquid phase with reduced biomass content from the one or more inclined plate settlers;

[0078] The biomass separator has a capacity of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the device or unit onto the horizontal surface; and

[0079] The one or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows:

[0080] -

[0081] -PSAR = PSA / A

[0082] psa i The tilting plate element i is represented by m 2 The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and

[0083] Where PSAR ≥ 2.8 + 0.17A.

[0084] Unless otherwise stated, the term "or" as used herein is defined as "and / or".

[0085] Unless otherwise stated, the term "a / an" as used herein is defined as "at least one / an".

[0086] As used herein, the term "biodegradable substrate" refers to any organic matter that can be chemically oxidized, as determined by a chemical oxygen demand (COD) test (as described in ISO 6060:1989). The content of organic matter is usually expressed in gCOD, which is the number of grams of oxygen consumed in the oxidation of the organic matter.

[0087] As used in this article, the term "biomass" refers to non-dissolved organic matter, including living microorganisms.

[0088] As used in this article, "biomass sludge" refers to a semi-solid slurry with a high biomass content.

[0089] As used herein, the term "biogas" refers to gases (e.g., methane, carbon dioxide, and mixtures of such gases) produced in the methods of the present invention, for example by the anaerobic digestion of biodegradable substrates by biomass.

[0090] As used herein, the term "inclined plate settler" refers to an apparatus comprising one or more inclined plate elements. For example, an inclined plate settler may comprise two or more inclined plate elements in the form of a rectangular plate or an open-topped cone (circular, triangular, rectangular, or hexagonal). Inclined plate settlers can be used for both solid-liquid and gas-liquid separation. For solid-liquid separation, untreated feed liquid flows upward between the inclined plate elements. During this time, solids settle onto the plate elements and slide downward. A clarified liquid is generated above the inclined plate elements, which is then pumped away. Below the inclined plate elements, the separated particles can be collected as sludge, which can also be pumped away. For gas-liquid separation, untreated feed liquid flows downward between the inclined plate elements. During this time, bubbles accumulate below the plate elements and rise upward. A degassed liquid is generated below the inclined plate elements, which is then pumped away. Above the inclined plate elements, the separated bubbles can form a gas phase, which can also be pumped away. Inclined plate settlers may also include one or more inclined plate elements forming a spiral channel, as described in WO 2020 / 260354.

[0091] As used herein, the term "total projected surface area" refers to the horizontal component of the surface area of ​​an inclined plate element. When the inclined plate element is a rectangular plate or an open-topped cone, the total projected surface area is equal to the surface area covered by the vertical projection of the inclined plate element onto a horizontal, flat surface. When the inclined plate element forms a spiral channel, and the spiral rotation exceeds 360°, the total surface area can exceed the surface area covered by its vertical projection.

[0092] As used herein in relation to a device or unit, the term "footprint" refers to the horizontal surface area covered by the vertical projection of the device or unit onto a horizontal surface. Therefore, the footprint of a vertical cylinder is equal to the surface area of ​​the circular cross-section of the cylinder.

[0093] Unless otherwise noted, whenever terms such as “above,” “below,” “upper,” “middle,” or “lower” are used in this document, they refer to the location of the device during its operation.

[0094] As used herein, the term "upper part" refers to the upper half, especially the upper third, and more particularly the upper quarter of a unit. The term "lower part" refers to the lower half, especially the lower third, and more particularly the lower quarter of a unit.

[0095] Unless otherwise specified, the term "nearby" as used herein means at a relative height of no more than + / -15%, and in particular no more than + / -10%, from a reference point. Relative height is the distance from the bottom divided by the total height of the cell (the height difference between the bottom and the top).

[0096] The requirement of PSAR ≥ 2.8 + 0.17A means that the minimum PSAR of one or more inclined plate settlers depends on the footprint of the biomass separator. This dependence is illustrated in the table below for cylindrical biomass separators of different diameters. These separators are equipped with inclined plate settlers containing multiple rectangular plates (plate spacing: 8 cm, plate thickness: 8 mm). The plate angle (30°–80°), width (0.3–4.0 m), and length (0.4–3.0 m) of the rectangular plates are chosen to maximize the total projected surface area achieved by a single settler within the footprint of the cylindrical biomass separator. In practice, such maximum utilization cannot be achieved because additional space is required to enclose the open sides of the inclined plate settlers and allow the device to be assembled within the cylinder. Due to the rectangular form of the inclined plate settlers, open spaces are left between the inner side of the cylinder and the four sides of the settler, allowing fluid to flow through the settling device and subsequently into its lower end. The following indicates how many of these settlers are needed to meet the above PSAR requirement.

[0097]

[0098] This table clearly shows that, in order to achieve the minimum PSAR, a stack of at least two tilting plate settlers is required.

[0099] According to a particularly preferred embodiment, the bioreactor used according to the present invention is a granular sludge bed (GSB) reactor. In a typical GSB reactor, wastewater is introduced into the lower part of the bioreactor and flows upward through a granular sludge bed containing microorganisms that decompose organic substrates present in the wastewater, thereby forming biogas.

[0100] The method of the present invention can be suitably used for microbial treatment of different types of aqueous liquids containing biodegradable substrates. Preferably, the aqueous liquid containing biodegradable substrates is wastewater. Examples of wastewater that can be suitably treated are wastewater from the production of dairy products or dairy ingredients (e.g., cheese), pulp and paper, agricultural products (e.g., sugar, starch, vegetable oil), fermented beverages (e.g., wine, beer), biofuels, petrochemical products, or chemicals.

[0101] In the method of the present invention, the aqueous liquid containing the biodegradable substrate is preferably at least 10 m... 3 A flow rate of / h, more preferably 20-1000m³ / h 3 / h of flow rate is processed.

[0102] The aqueous liquid containing a biodegradable substrate preferably contains at least 90 wt.%, more preferably at least 95 wt.%, and most preferably at least 98 wt.% of water.

[0103] The total organic matter content of the aqueous liquid containing the biodegradable substrate preferably exceeds 0.1 g COD / L, more preferably it is in the range of 0.5-100 g COD / L, and most preferably it is in the range of 1.5-25 g COD / L.

[0104] The biomass present in the bioreactor contains active microorganisms capable of converting at least a portion of the biodegradable substrate into biogas. Examples of microorganisms that can be used include bacteria and archaea. Preferably, the microorganisms used are anaerobic microorganisms. According to a particularly preferred embodiment, the biomass contains one or more species of methanogenic bacteria or methanogenic archaea.

[0105] According to another preferred embodiment, the active microorganisms used in the method of the present invention grow in aggregates, commonly referred to as "granular biomass".

[0106] The bioreactor used in the method of the present invention is preferably operated under anaerobic conditions. Preferably, the average redox potential of the fluid contained in the bioreactor is not less than -200 mV, more preferably not less than -300 mV. The "redox potential" can be suitably determined by a redox electrode, as described in "2580 Redox Potential (ORP), Standard Methods For the Examination of Water and Waste Water" (published online: August 27, 2018, revised: July 19, 2021).

[0107] The fluid in the bioreactor is preferably maintained at a temperature in the range of 10°C to 40°C, more preferably 20°C to 39°C.

[0108] The pH of the fluid in the bioreactor is preferably maintained in the range of 6 to 8, more preferably 6.8 to 7.5.

[0109] In a preferred embodiment, biogas is produced at a rate of m³ / s. 3 The bioreactor contains a fluid that is generated at a rate of at least 80 L / h. More preferably, biogas is generated at a rate of [missing information - likely a specific concentration or flow rate]. 3 The fluid contained in the bioreactor is generated at a rate of at least 80-1250 L / h.

[0110] The biogas produced in the method of the present invention preferably contains at least 50 wt.%, more preferably at least 65 wt.%, of methane.

[0111] According to a particularly preferred embodiment, the bioreactor does not include a solid-liquid separator. The absence of any solid-liquid separators in the bioreactor provides the advantage that these separators can be cleaned without having to remove the biomass from the bioreactor.

[0112] The biomass separator used in the method of the present invention can be located outside the bioreactor, or it can be located inside the bioreactor as a separate unit. Preferably, the biomass separator is located outside the bioreactor.

[0113] In the method of the present invention, the biomass separator is preferably operated under anaerobic conditions. Preferably, the average redox potential of the fluid contained in the biomass separator is less than -200 mV, more preferably less than -300 mV.

[0114] According to a particularly preferred embodiment, the volume of the biomass separator is significantly smaller than the volume of the bioreactor. Preferably, the volume of the bioreactor is at least 3 times, more preferably 4 to 25 times, and most preferably 5 to 15 times, the volume of the biomass separator.

[0115] According to another preferred embodiment, the footprint of the biomass separator is significantly smaller than that of the bioreactor. Preferably, the footprint of the bioreactor is at least 3 times, more preferably 4-25 times, and most preferably 5 to 15 times that of the biomass separator.

[0116] The biomass separator of this invention is a vertically elongated device. Typically, the biomass separator has a length exceeding 1m. -1 More preferably 2 to 30m -1 And the optimal selection is 2 to 12m. -1 Height: Ratio of floor area to total floor area.

[0117] Preferably, at least a portion of the liquid phase with reduced biomass content is not recycled to the bioreactor or biomass separator. More preferably, none of the liquid phase with reduced biomass content is recycled to the bioreactor or biomass separator.

[0118] In one embodiment of the invention, the inclined plate elements of one or more inclined plate settlers are composed of rectangular plates. The projected surface area (psa) of each plate i is... i It can be calculated as follows:

[0119] psa i =l i ×w i ×cos(Θ i )

[0120] in

[0121] l i The length of inclined plate I, expressed in meters;

[0122] w i The width of the inclined plate I, expressed in meters;

[0123] Θ i This indicates the inclination of the inclined plate i.

[0124] The separation efficiency of the inclined plate settler, including the rectangular plate, increases with the length of the plate, although no actual efficiency improvement is achieved when the plate length exceeds 3m. Therefore, the length of the inclined plate (l) i Preferably, it is in the range of 0.4 to 3m, more preferably 0.6 to 2.5m, and most preferably 0.8 to 2m.

[0125] Width of the inclined plate (w) i Preferably, it is in the range of 0.3 to 7 m, more preferably 0.6 to 6 m, and most preferably 1 to 5 m.

[0126] Inclination of the inclined plate (Θ) iPreferably, the angle is in the range of 30° to 80°, more preferably in the range of 40° to 70°, and most preferably in the range of 45° to 65°.

[0127] In another embodiment of the invention, the inclined plate element of one or more inclined plate settlers is composed of a tapered tube in the form of open-topped cones stacked one on top of the other. The distance between the outer edge and the inner edge of the cone is preferably in the range of 0.3 to 7 m, more preferably in the range of 0.6 to 6 m, and most preferably in the range of 1 to 5 m.

[0128] The half-angle of the cone (the angle between the cone surface and the cone axis) is preferably in the range of 30° to 80°, more preferably in the range of 40° to 70°, and most preferably in the range of 45° to 65°.

[0129] In yet another embodiment of the invention, the inclined plate elements in one or more inclined plate settlers form a helical channel. According to a preferred embodiment, this type of inclined plate settler includes:

[0130] • At least two concentric shells that include an outermost shell and an innermost shell and define at least one concentric cavity;

[0131] • One or more spiral channels formed in at least one concentric cavity;

[0132] • A fluid inlet for receiving fluid, located at the lower part of the one or more helical channels;

[0133] • A solids outlet for discharging solids contained in the fluid, the solids outlet being located at the bottom of the separation device; and

[0134] • A liquid outlet for discharging the liquid contained in the fluid, the liquid outlet being located at the top of the one or more spiral channels.

[0135] The total projected surface area of ​​the inclined plate settling tank, including the spiral channel, is calculated as follows:

[0136]

[0137] psa i This represents the total projected surface area of ​​a single channel.

[0138] The average spacing between the inclined plate elements of the inclined plate settler is preferably in the range of 2 to 18 cm, more preferably 4 to 14 cm, and most preferably 8 to 12 cm.

[0139] Biomass separators typically occupy an area of ​​1 to 22 square meters. 2 More preferably 1.5 to 15m 2 Within the range.

[0140] For effective separation to be achieved in a biomass separator, space must be available around one or more inclined plate settlers to allow sufficient, preferably non-turbulent, downward flow. Preferably, 20%–60% of the cross-sectional surface area of ​​the portion of the biomass separator containing one or more inclined plate settlers is available for downward flow.

[0141] The total projected surface area ratio (PSAR) provided by one or more inclined plate settlers preferably satisfies the following condition: PSAR ≥ 3.2 + 0.17A.

[0142] More preferably, PSAR satisfies the following condition: PSAR ≥ 3.5 + 0.17A.

[0143] Most preferably, PSAR satisfies the following condition: 4 + 0.17A ≤ PSAR ≤ 25 + 0.17A.

[0144] The one or more inclined plate settlers used according to the present invention preferably include at least 4, more preferably at least 5, and most preferably 6 to 30 inclined plate elements.

[0145] The biomass separator used in the method of the present invention preferably comprises two or more inclined plate settling tanks stacked one on top of the other. Using stacked settling tanks offers the advantages of efficient utilization of the biomass separator's volume and the separator providing a high projected inclined plate surface area / m². 2 Area occupied. Therefore, in a preferred embodiment, the biomass separator includes at least two, more preferably two to fifteen, and most preferably three to five stacked inclined plate settlers.

[0146] In the case of a biomass separator comprising two or more inclined plate settlers, the liquid phase with reduced biomass content removed from each settler can be suitably combined into a single flow. This can occur inside or outside the biomass separator.

[0147] The biomass-rich fluid phase is preferably collected near the bottom of the biomass separator.

[0148] In an advantageous embodiment of the invention, an aqueous liquid containing a biodegradable substrate is directly introduced into the bioreactor. Preferably, the aqueous liquid is introduced into the lower part of the bioreactor. By introducing the aqueous liquid containing the biodegradable substrate into the lower part of the bioreactor, an upward flow of biomass sludge through the bioreactor is generated, thereby maximizing biomass / substrate contact. The performance of the bioreactor strongly depends on the efficient distribution of the inflow of the aqueous liquid containing the biodegradable substrate. Therefore, in a preferred embodiment, when introducing the aqueous liquid containing the biodegradable substrate, the aqueous liquid is uniformly distributed below the biomass sludge.

[0149] In another advantageous embodiment, the method of the invention includes introducing a mixture of an aqueous liquid containing a biodegradable substrate and at least a portion of a biomass-rich fluid phase produced by one or more inclined plate settlers into a bioreactor, wherein the mixture is produced by introducing the aqueous liquid containing the biodegradable substrate into the lower part of a biomass separator and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase. As will be explained below, introducing the aqueous liquid into the lower part of the biomass separator provides the advantage that the biomass separator can additionally function as a conditioning tank.

[0150] According to a particularly preferred embodiment of the invention, the biomass separator employed in this embodiment includes a conditioning chamber located below one or more inclined plate biomass separators. An aqueous liquid containing biodegradable substrate is introduced into the conditioning chamber, where it is mixed with a biomass-rich fluid phase, after which the mixture of the aqueous liquid and the fluid phase is transferred to the bioreactor. By employing such a conditioning chamber, fluctuations in the inflow of the aqueous liquid containing biodegradable substrate into the bioreactor, as well as undesirable fluctuations in the quality of the fluid stream treated in the bioreactor, can be minimized. Furthermore, the presence of the conditioning chamber below one or more inclined plate settling tanks at the lower end of the biomass separator significantly reduces the risk of blockage of the conduit connecting the lower end of the biomass separator to the bioreactor.

[0151] The mixture of aqueous liquid and fluid phase is preferably transferred from the conditioning chamber to the lower part of the bioreactor. Introducing the mixture into the lower part of the bioreactor creates an upward flow of biomass sludge through the bioreactor. As mentioned above, the performance of the bioreactor strongly depends on the efficient distribution of the inflow containing biodegradable substrate. Therefore, in a preferred embodiment, the mixture of aqueous liquid and fluid phase is uniformly distributed beneath the biomass sludge upon introduction.

[0152] Preferably, the volume of the regulating chamber accounts for 5%-25% of the total volume of the biomass separator, more preferably 10%-15%.

[0153] In another advantageous embodiment, the method of the invention includes introducing a mixture of an aqueous liquid containing a biodegradable substrate and at least a portion of a biomass-rich fluid phase produced by one or more inclined plate setters into a bioreactor. This mixture is generated by introducing both the aqueous liquid containing the biodegradable substrate and at least a portion of the fluid phase into a mixing unit and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase. The mixture of the aqueous liquid and the fluid phase is then transferred to the lower part of the bioreactor, preferably the bioreactor. Introducing the mixture into the lower part of the bioreactor creates an upward flow of biomass sludge through the bioreactor. In a preferred embodiment, the mixture of the aqueous liquid and the fluid phase is uniformly distributed beneath the biomass sludge during introduction.

[0154] The mixing unit used in this embodiment can take the form of a simple tube, a static mixer, a mixing chamber, or a mixing container.

[0155] In a particularly preferred embodiment of the method according to the invention, the highest outlet of one or more inclined plate settlers is located at 20%-90%, more preferably 40%-85%, and most preferably 60%-80% of the height of the fluid column inside the biomass separator.

[0156] In another preferred embodiment of the method of the present invention, the lowest inlet of one or more inclined plate settlers is located at 1%-67%, more preferably 2%-25%, and most preferably 2.5%-20% of the height of the fluid column inside the biomass separator.

[0157] The distance between the highest outlet of one or more inclined plate settlers and the lowest inlet of one or more inclined plate settlers is preferably in the range of 10% to 85% of the height of the fluid column in the biomass separator, more preferably in the range of 15% to 70%, and most preferably in the range of 25% to 55%.

[0158] According to a preferred embodiment, the biomass separator is at least 22m 3 / h / m 2 At a flow rate of at least 33m, more preferably at a flow rate of at least 33m 3 / h / m 2 The optimal flow rate is 44-440 m. 3 / h / m 2 The operation is carried out at a flow rate of [specific value]. Here, the flow rate is calculated by dividing the flow rate of the treated fluid through the biomass separator by the floor area of ​​the biomass separator.

[0159] According to a particularly preferred embodiment, at least 20m 3 / h / m 2 At a flow rate of at least 30m, more preferably at a flow rate of at least 30m 3 / h / m 2At a flow rate of 40-200m, the optimal value is preferred. 3 / h / m 2 The biomass separator is operated at a flow rate to produce a liquid with a reduced biomass content. Here, the flow rate is calculated by dividing the flow rate of the liquid with reduced biomass content through the biomass separator by the floor area of ​​the biomass separator.

[0160] The bioreactor and biomass separator are preferably operated with very similar fluid levels. Preferably, the difference in fluid levels between the bioreactor and the biomass separator does not exceed 5%, more preferably not exceeding 1%. Here, "fluid level" refers to the absolute height of the fluid column.

[0161] The bioreactor and the biomass separator are preferably placed on the same horizontal surface. Therefore, the height of the fluid column in the bioreactor and the height of the fluid column in the biomass separator are preferably no more than 5%, more preferably no more than 1%.

[0162] Typically, the height of the fluid column in the bioreactor is in the range of 5 to 28 m, more preferably 10 to 24 m.

[0163] In the method of this invention, the microbial transformation of the biodegradable substrate is typically accompanied by microbial growth and an increase in biomass. To maintain constant conditions in the bioreactor, it is preferable to remove the biomass at a rate comparable to the rate at which additional biomass is produced within the bioreactor. Therefore, in a preferred embodiment, a portion of the biomass-rich fluid phase obtained from the separation unit is returned to the bioreactor and another portion is discarded.

[0164] In the method of the present invention, the generated biogas rises to the top of the bioreactor and is released from the fluid into the top space of the reactor.

[0165] The treated fluid transferred to the biomass separator typically also contains some biogas. In a preferred embodiment, the downward flow velocity in the biomass separator is low enough to allow the biogas to rise to the top of the separator. By using the upper part of the biomass separator as a gas / liquid separator, the loss of biogas through the outflow with a liquid phase having reduced biomass content is effectively minimized. In this way, biogas interference with biomass separation in one or more inclined plate settlers is also avoided.

[0166] Separation of biogas in the upper part of the bioreactor and / or the upper part of the biomass separator can be assisted by a gas-liquid separator installed below the fluid surface (above one or more inclined plate settlers) in the upper part of the bioreactor and / or the upper part of the biomass separator. Preferably, gas-liquid separation is achieved without using a gas-liquid separator.

[0167] If one or more gas-liquid separators are used to separate biogas, it is preferable to install these separators in a biomass separator rather than in a bioreactor. This allows for the cleaning of these separators without the need to remove the biomass from the bioreactor. Examples of gas-liquid separators that can be used include inclined plate settlers and cyclone separators.

[0168] In another advantageous embodiment of the invention, both the bioreactor and the biomass separator include a top space filled with biogas, and the top spaces of the bioreactor and the biomass separator are connected by a gas conduction, and the method includes removing biogas from either the top space of the bioreactor or the top space of the biomass separator.

[0169] As explained above, in order to achieve maximum separation efficiency in a biomass separator, it is advantageous to generate a tangential downward flow in the upper part of the biomass separator. This can be achieved, for example, by employing a biomass separator in the form of a vertical cylinder, and by introducing the treated fluid horizontally into the upper part of the biomass separator at an angle of less than 20°, more preferably less than 10°, relative to the inner wall of the separator.

[0170] The equipment used in the method of the present invention may include more than one bioreactor and / or more than one biomass separator.

[0171] In an embodiment of the invention, the apparatus includes a bioreactor connected to two or more biomass separators. In this arrangement, treated fluid is transferred from the top of the bioreactor to the top of the two or more biomass separators, and a flow containing a biomass-rich fluid phase is transferred from the one or more biomass separators to the bioreactor. The PSAR of this arrangement is calculated by first calculating the total projected surface area of ​​the combination of separators and dividing it by the combined floor area of ​​the two or more biomass separators. The flow rate operating the combination of two or more biomass separators is calculated by dividing the combined flow rate through the two or more biomass separators by the total floor area of ​​the two or more biomass separators.

[0172] In another embodiment, the apparatus includes two or more bioreactors connected to a single biomass separator. In this arrangement, treated fluid is transferred from the top of the two or more bioreactors to the top of the single biomass separator, and a flow containing a biomass-rich fluid phase is transferred from the biomass separator to the two or more bioreactors.

[0173] Preferably, the method of the present invention is operated in the apparatus described below.

[0174] Another aspect of the invention relates to an apparatus for microbial treatment of aqueous liquids containing biodegradable substrates, wherein the apparatus includes...

[0175] • Bioreactor (1), the bioreactor comprising:

[0176] - An inlet (4) for a flow containing a biomass-rich fluid phase; and

[0177] - An outlet (5) for the treated liquid, located at the top of the bioreactor;

[0178] • A biomass separator (2) separate from the bioreactor, the biomass separator comprising:

[0179] - An inlet (6) located at the top of the biomass separator for containing a stream of treated liquid, the inlet for the treated liquid being fluidly connected to the outlet (5) of the bioreactor.

[0180] - One or more inclined plate settlers (7) located below the inlet (6), each inclined plate settler having an outlet (8) for a liquid phase with reduced biomass content;

[0181] • An outlet (9) for biomass-rich fluid located at the lower part of the biomass separator below one or more inclined plate settlers, the outlet (9) being fluidly connected to the inlet (4) of the bioreactor or the inlet (20) of the mixing unit (19), the mixing unit including an outlet (21) fluidly connected to the inlet (4) of the bioreactor;

[0182] The bioreactor, the lower part of the biomass separator, or the mixing unit includes an inlet (3) for an aqueous liquid containing a biodegradable substrate; and

[0183] The biomass separator has a capacity of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the device or unit onto the horizontal surface; and

[0184] The one or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows:

[0185] -

[0186] -PSAR = PSA / A

[0187] psa i The tilting plate element i is represented by m 2The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and

[0188] Where PSAR ≥ 2.8 + 0.17A.

[0189] Preferred embodiments of the device according to the present invention have been described above.

[0190] According to a particularly preferred embodiment, the bioreactor of the device of the present invention is a granular sludge bed (GSB) reactor.

[0191] The biomass separator is preferably positioned adjacent to the bioreactor.

[0192] Preferably, the bioreactor and the biomass separator are mounted on the same horizontal surface.

[0193] Preferably, the height difference between the bioreactor and the biomass separator is no more than 20%, more preferably no more than 10%.

[0194] According to a preferred embodiment, the bioreactor includes an influent distribution system (22) that is smoothly connected to an inlet (3) or an inlet (4) near the bottom of the bioreactor, the influent distribution system distributing the influent containing the biodegradable substrate evenly across the bottom of the bioreactor.

[0195] A bioreactor and / or biomass separator may include one or more gas-liquid separators located at the upper end of the bioreactor or separator. The one or more gas-liquid separators are preferably located at the upper end of the separator. Preferably, no gas-liquid separator is provided in the bioreactor.

[0196] Preferably, neither the bioreactor nor the biomass separator uses a gas-liquid separator to achieve gas-liquid separation; that is, biogas is separated by allowing it to escape from the top of the bioreactor and the top of the biomass separator.

[0197] The gas-liquid separator is preferably selected from inclined plate settlers, cyclone separators and combinations thereof.

[0198] Preferably, the upper ends of the bioreactor and the biomass separator are connected by a conduit that fluidly connects the gas inlet (15) at the upper end of the bioreactor to the gas inlet (16) at the upper end of the biomass separator. The gas inlet (15) is located above the outlet (5) for the treated fluid, and the gas inlet (16) is located above the inlet (6) for the treated fluid. This arrangement provides the advantage that both the bioreactor and the biomass separator operate at the same headspace pressure, and a single outlet for further processing of biogas is sufficient.

[0199] In another preferred embodiment, the biomass separator includes a conditioning chamber (18) located below one or more inclined plate biomass separators. This conditioning chamber includes an inlet (3) for an aqueous liquid containing a biodegradable substrate and an outlet (4) for a flow containing a biomass-rich fluid phase. A flow containing a biomass-rich fluid phase is generated within this conditioning chamber by mixing the aqueous liquid with the biomass-rich fluid phase.

[0200] In an alternative embodiment, the device includes a mixing unit (19) comprising an inlet (3) for an aqueous liquid containing a biodegradable substrate, an inlet (20) for a biomass-rich fluid phase fluidly connected to an outlet (9) of a biomass separator, and an outlet (21) fluidly connected to an inlet (4) of a bioreactor. Attached Figure Description

[0201] Figure 1 An apparatus for microbial treatment, which can be used to operate the method according to the invention, is schematically depicted.

[0202] Figure 2 An alternative apparatus for microbial treatment is schematically depicted, which can be used to operate the method according to the invention.

[0203] Figure 3 Another alternative device for microbial treatment is schematically depicted, which can be used to operate the method according to the invention.

[0204] Figure 4 The horizontal cross-section of the upper part of the biomass separator is schematically depicted.

[0205] Description of the Implementation Examples

[0206] Figure 1 An apparatus for use in the method according to the invention is schematically depicted. The apparatus includes a bioreactor (1) and a biomass separator (2).

[0207] An aqueous liquid containing biodegradable substrate is introduced into the lower part (3) of the bioreactor via an influent distribution system (22). The incoming fluid flows upward through the bioreactor and through a granular biomass bed (23), where at least a portion of the biodegradable substrate is converted into biogas by anaerobic microorganisms (“biomass”). The biogas rises naturally to the top of the bioreactor. Most of the biogas is separated from the fluid at the surface (10) of the bioreactor liquid and collected in the top space (12) of the reactor. The biogas is guided out of the bioreactor from the top space via a biogas collection pipe (13), which may alternatively be connected to the top space of a biomass separator. The treated liquid (with a low concentration of biodegradable substrate) flows from the top of the bioreactor through one or more outlets (5) to one or more inlets (6) at the top of the biomass separator.

[0208] At the top of the biomass separator, further / final degassing occurs at the liquid surface (11). Biogas in the top space of the biomass separator can flow to the top space of the bioreactor via the biogas outlet (16) and biogas inlet (15) and exit the bioreactor via the biogas collection pipe. The degassed fluid then flows downward through the biomass separator. At least at the bottom of the biomass separator, one or more inclined plate settlers (7) are provided. The fluid flows from bottom to top and is fed into the inlet of the inclined plate settler. In the case of multiple inclined plate settlers, these biomass separators are vertically stacked and the fluid flows are fed at different heights. To ensure efficient separation in the inclined plate settlers, a uniform fluid flow distribution is required on the multiple inclined plate settlers, and the flow through the inclined plate settlers must not be too turbulent. The first can be achieved by designing a pipe (8) for collecting the fluid from the biomass, such that the total flow rate is uniformly distributed on the multiple inclined plate settlers. The second measure can be achieved by taking into account the minimum space between the biomass separator shell and the inclined plate settler, allowing for high flow velocities without inducing significant turbulence near the inlet of the separator. The merging flow of low-biomass fluid leaving the biomass separator is controlled by valve (17) to maintain a stable water level in both the biomass separator and the bioreactor. The biomass-rich fluid flow further downwards toward the bottom of the biomass separator, as does the recirculated flow that does not pass through the inclined plate settler.

[0209] At the bottom of the biomass separator, a combination of the recirculated flow and the biomass-rich fluid flow is drawn as a biomass-rich fluid phase through the outlet (9) of the biomass separator and introduced into the bioreactor through the inlet (4). This can be accomplished using a mechanical pump or by generating a gas lift to drive the fluid from the biomass separator to the bioreactor. Alternatively, the combined recirculated flow and biomass-rich fluid flow can be introduced into the bioreactor along with an aqueous liquid containing biodegradable substrate through the inlet (3).

[0210] The fluid level in the biomass separator is similar to that in a bioreactor, where the fluid level is higher during normal operation to allow gravity flow from the bioreactor to the biomass separator. The volume of the biomass separator is efficiently utilized by vertically expanding the settling area of ​​the inclined plate settling tank. This can be achieved, for example, by stacking multiple inclined plate settling tanks vertically on top of each other, or by vertically expanding the capacity of a single settling tank, as described, for example, in CN 2880214 Y. By vertically expanding the settling area, the fluid handling capacity per square meter of the biomass separator can be easily increased to 20 m³. 3 / m 2 / h or more, depending on how far the settling zone extends vertically. Considering that one or more inclined plate settling tanks are placed inside the biomass separator housing, and that free space is required around the inclined plate settling tank to allow fluid flow, the biomass separator will have a larger footprint than the inclined plate settling tank.

[0211] In embodiments of the invention, the upper portion of the biomass separator serves as a highly efficient degassing device. The upper portion of the biomass separator can also provide additional volume that enables high recirculation flow rates without generating excessive turbulence near the inlets of one or more inclined plate settlers located in the lower portion of the biomass separator. The aforementioned objectives of the upper portion of the biomass separator can be further optimized by introducing an off-center fluid flow into the top of the biomass separator, thereby generating a tangential flow pattern.

[0212] A high water level in the biomass separator is advantageous for the separation efficiency of one or more inclined plate settlers. To ensure that one or more inclined plate settlers benefit from separation under increased hydrostatic pressure, it is ideal to place the top of one or more inclined plate settlers at least 5 meters below the water level in the biomass separator.

[0213] Maintenance of the biomass separator can be easily performed, for example, by closing the inlet (3) for the aqueous liquid containing the biodegradable substrate, returning the remaining biomass to the bioreactor, and then stopping the recirculation flow. Next, the biomass separator is separated from the bioreactor by closing the interconnecting fluid connections (4 and 9, 5 and 6) and gas connections (15 and 16). It is not necessary to wait until residual biogas production ceases in the bioreactor, as this biogas can continue to be collected from the top space (12) of the bioreactor (13). Maintenance / inspection / cleaning of the biomass separator can then be performed while the anaerobic biomass remains inside the bioreactor.

[0214] Figure 2 An alternative device for use in the method according to the invention is schematically depicted.

[0215] In this embodiment of the invention, the lower end of the biomass separator acts as a so-called conditioning tank. An aqueous liquid containing biodegradable substrate is introduced into a conditioning chamber (18), located at the lower end of the biomass separator (2). The aqueous liquid containing biodegradable substrate, a biomass-rich fluid stream, and a recirculation stream are mixed in this conditioning chamber, and the mixed stream exits the biomass separator via an outlet (9) and enters the inlet (4) of the bioreactor. If necessary, further conditioning of the mixed stream can be accomplished by adding, for example, chemicals for adjusting pH or chemicals used as a nutrient supply for the biomass in the bioreactor.

[0216] Figure 3 Another alternative device for use in the method according to the invention is illustrated schematically.

[0217] In this embodiment, a biomass-rich fluid phase and an aqueous liquid containing biodegradable substrate are mixed together before being introduced into the bioreactor via an influent distribution system. The aqueous liquid containing biodegradable substrate is introduced into the mixing unit (19) via inlet (3). Simultaneously, the biomass-rich fluid phase is transferred from the outlet (9) of the biomass separator to the inlet (20) of the mixing unit. If desired, chemicals (e.g., chemicals for pH adjustment) or nutrients may also be introduced into the mixing unit. The mixed stream is then transferred from the outlet (21) of the mixing unit to the inlet (4) of the bioreactor.

[0218] Figure 4 The upper horizontal cross-section of the biomass separator (2) is schematically depicted. The treated fluid enters the biomass separator through an inlet (6) which introduces the treated fluid at an angle α relative to the inner wall of the separator, thereby generating a downward spiral flow.

[0219] List of reference numerals

[0220] 1. Bioreactor

[0221] 2 Biomass separator

[0222] 3. Inlet for aqueous liquids containing biodegradable substrates

[0223] 4. Inlet for a flow containing a biomass-rich fluid phase

[0224] 5. Outlet for the treated fluid

[0225] 6. Inlet for containing the flow of treated liquid

[0226] 7 Inclined Plate Settling Device

[0227] 8. For the outlet of the liquid phase with reduced biomass content

[0228] 9. Outlet for a flow containing a biomass-rich fluid phase

[0229] 10. Liquid level of fluid in a bioreactor

[0230] 11. Liquid level of fluid in the biomass separator

[0231] 12. Top space of the bioreactor

[0232] 13. Top space of the biomass separator

[0233] 15 Gas connection port

[0234] 16 Gas connection ports

[0235] 17 Control valve

[0236] 18. Adjustment Room

[0237] 19 Hybrid Units

[0238] 20 Inlet for biomass-rich fluid phase

[0239] 21. Outlet for a flow containing a biomass-rich fluid phase

[0240] 22. Inflow Distribution System

[0241] 23 Pellet Biomass Beds

Claims

1. A method for microbial treatment of an aqueous liquid containing a biodegradable substrate in an apparatus comprising (i) a bioreactor (1) containing biomass sludge and (ii) a biomass separator (2) separate from the bioreactor and comprising two or more inclined plate settling tanks (7) stacked one on top of the other, the method comprising: • Introduce the aqueous liquid containing the biodegradable substrate into the bioreactor; • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator through an inlet (6) for a flow containing the treated liquid; • The treated fluid is separated into a liquid phase with reduced biomass content and a biomass-rich fluid phase in two or more inclined plate settling tanks located below the inlet for containing the flow of treated liquid. • Remove the liquid phase with reduced biomass content from the two or more inclined plate settlers; as well as • At least a portion of the biomass-rich fluid phase is transferred from the lower part of the biomass separator to the bioreactor; The biomass separator has a capacity of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the biomass separator onto the horizontal surface; and The two or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows: - PSA = - PSAR = PSA / A psa i The tilting plate element i is represented by m 2 The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and in ; Alternatively, the method may include: • Introduce the aqueous liquid containing the biodegradable substrate into the bioreactor; • The treated biomass-containing fluid is transferred from the top of the bioreactor to the top of the biomass separator through an inlet (6) for a flow containing the treated liquid; • The treated fluid is separated into a liquid phase with reduced biomass content and a biomass-rich fluid phase in two or more inclined plate settling tanks located below the inlet for containing the flow of treated liquid. • Remove the liquid phase with reduced biomass content from the two or more inclined plate settlers; • A mixture comprising an aqueous liquid containing a biodegradable substrate and at least a portion of a biomass-rich fluid phase generated by the two or more inclined plate setters is introduced into the bioreactor, wherein the mixture (i) Generated by introducing the aqueous liquid containing the biodegradable substrate into the lower part of the biomass separator and mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase, or (ii) The mixture is produced by introducing at least a portion of the aqueous liquid containing the biodegradable substrate and the biomass-rich fluid phase into a mixing unit, mixing the aqueous liquid with at least a portion of the biomass-rich fluid phase, and transferring the mixture of the aqueous liquid and at least a portion of the fluid phase to the bioreactor. The biomass separator has a capacity of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the biomass separator onto the horizontal surface; and The two or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows: - - PSAR = PSA / A psa i The tilting plate element i is represented by m 2 The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and in .

2. The method according to claim 1, wherein, Operate the biomass separator so as to achieve a flow rate of at least 20 m 3 / h / m 2 The flow rate produces the liquid phase with reduced biomass content, which is calculated by dividing the flow rate of the liquid phase with reduced biomass content by the floor area of ​​the biomass separator.

3. The method according to claim 1 or 2, wherein, The volume of the bioreactor is at least 5 times that of the biomass separator.

4. The method according to claim 1 or 2, wherein, The height of the fluid column in the bioreactor differs from the height of the fluid column in the biomass separator by no more than 5%.

5. The method according to claim 1 or 2, wherein, This biomass separator has a capacity of over 1 m -1 Height: Percentage of land area.

6. The method according to claim 1 or 2, wherein, The inclined plate elements of the two or more inclined plate settlers are composed of rectangular plates, and wherein, psa i The calculation is as follows: in I i The length of inclined plate I, expressed in meters; W i The width of the inclined plate I, expressed in meters; This indicates the inclination of the inclined plate i.

7. The method according to claim 1 or 2, wherein, The inclined plate elements of the two or more inclined plate settlers consist of open-top cones stacked on top of each other.

8. The method according to claim 1 or 2, wherein, The inclined plate elements in the two or more inclined plate settlers include: • At least two concentric shells that include an outermost shell and an innermost shell and define at least one concentric cavity; • One or more spiral channels formed in the at least one concentric cavity; • A fluid inlet for receiving fluid, located at the bottom of the one or more helical channels; • A solids outlet for discharging solids contained in the fluid, located at the bottom of the separation device; and • A liquid outlet for discharging the liquid contained in the fluid, located at the top of the one or more spiral channels.

9. The method according to claim 1 or 2, wherein, The aqueous liquid containing the biodegradable substrate is introduced into the lower part of the bioreactor.

10. The method according to claim 1 or 2, wherein, The biomass separator includes a conditioning chamber located below the two or more inclined plate settlers, wherein an aqueous liquid containing a biodegradable substrate is introduced into the conditioning chamber, in which the aqueous liquid is mixed with the biomass-rich fluid phase, and then the mixture of the aqueous liquid and the fluid phase is transferred to the lower part of the bioreactor.

11. The method according to claim 1 or 2, wherein, A portion of the biomass-rich fluid phase obtained from the separation unit is returned to the bioreactor, while the other portion is discarded.

12. The method according to claim 1 or 2, wherein, Both the bioreactor and the biomass separator include a top space filled with biogas, wherein the top space of the bioreactor and the top space of the biomass separator are connected by a gas conduit, and wherein the method includes removing biogas from the top space of the bioreactor or from the top space of the biomass separator.

13. The method according to claim 1 or 2, wherein, Tangential downward flow was achieved in the upper part of the biomass separator.

14. The method according to claim 1 or 2, wherein, The bioreactor and the biomass separator operate under anaerobic conditions.

15. An apparatus for microbial treatment of an aqueous liquid containing a biodegradable substrate, wherein, The device includes • Bioreactor (1), which includes: - Inlet (4) for a flow containing a biomass-rich fluid phase; and - An outlet (5) for the treated liquid, located at the top of the bioreactor; • A biomass separator (2) separate from the bioreactor, the biomass separator comprising: - An inlet (6) located at the top of the biomass separator for containing a flow of treated liquid, the inlet for treated liquid being fluidly connected to the outlet (5) for treated liquid of the bioreactor. - Two or more inclined plate settlers (7) stacked on top of each other below the inlet (6) for containing the flow of treated liquid, each inclined plate settler having an outlet (8) for the liquid phase with reduced biomass content. - An outlet (9) for biomass-rich fluid located at the lower part of the biomass separator below the two or more inclined plate settlers, the outlet (9) for biomass-rich fluid being fluidly connected to the inlet (4) of the bioreactor for a flow containing a biomass-rich fluid phase or the inlet (20) of the mixing unit (19), the mixing unit including an outlet (21) fluidly connected to the inlet (4) of the bioreactor for a flow containing a biomass-rich fluid phase. The bioreactor, the lower part of the biomass separator, or the mixing unit includes an inlet (3) for an aqueous liquid containing a biodegradable substrate; and the biomass separator has a diameter of 0.5 to 30 m. 2 The footprint A is equal to the horizontal surface area covered by the vertical projection of the biomass separator onto the horizontal surface; and The two or more inclined plate settlers comprise a total of n inclined plate elements, which together provide the total projected surface area (PSA) and total projected surface area ratio (PSAR) calculated as follows: - - PSAR = PSA / A psa i The tilting plate element i is represented by m 2 The total projected surface area is calculated, and the total projected surface area is equal to the horizontal component of the surface area of ​​the inclined plate element; and in .

Images