Sewage treatment process integrating activated sludge process and membrane process

Abstract

The invention relates to the technical field of electronic component detection devices, sewage is drained, preliminary grid filtration is performed on the sewage, large-particle impurities are removed, then sand setting treatment is performed, and inorganic particles such as sand in the sewage are separated; according to the backflow starting device and the impurity monitoring module, when it is detected that large impurities in sewage are not separated to a certain numerical value, backflow equipment is started, and filtering is conducted again; the filtered sewage enters a jet aeration biological membrane reaction tank, so that an aerobic reaction, a nitration reaction and a denitrification reaction of the sewage are completed; according to the sewage treatment process integrating the activated sludge process and the membrane process, various pollutants such as organic pollutants, nitrogen and phosphorus in sewage can be effectively removed through the synergistic effect of various microbial florae in the activated sludge process and efficient filtration of the membrane separation device, the effluent quality is stable and excellent, and the sewage treatment efficiency is improved. All indexes can reach or exceed relevant national emission standards or reuse standards.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to a sewage treatment process integrating an activated sludge method and a membrane method. Background Art

[0002] Wastewater treatment is of vital importance for protecting the environment and achieving sustainable use of water resources. The traditional activated sludge method is widely used in wastewater treatment, but it has problems such as sludge bulking, poor sludge settling performance, unstable effluent quality and large footprint. Membrane wastewater treatment technologies, such as ultrafiltration and microfiltration, have the advantages of high separation efficiency and good effluent quality, but when used alone, they have the disadvantages of severe membrane pollution and high operating costs.

[0003] Therefore, the sewage treatment process that combines the activated sludge method with the membrane method has become a hot topic of current research, aiming to combine the advantages of the two, overcome their respective shortcomings, and improve the efficiency and effect of sewage treatment. Technical personnel in this field have provided a sewage treatment process that integrates the activated sludge method and the membrane method to solve the problems raised in the above background technology. Summary of the invention

[0004] In order to solve the problems raised in the above background technology, the present application provides a sewage treatment process integrating activated sludge method and membrane method.

[0005] The present application provides a sewage treatment process integrating activated sludge method and membrane method, which adopts the following technical scheme:

[0006] A sewage treatment process integrating activated sludge method and membrane method, including the following steps:

[0007] S1. Drain the sewage, filter it through a preliminary screen to remove large particles, and then perform sand settling treatment to separate sand and other inorganic particles in the sewage;

[0008] S2, reflux start-up equipment and impurity monitoring module, when it is detected that the larger impurities in the sewage have not been separated to a certain value, the reflux equipment is started and filtering is performed again;

[0009] S3, the filtered sewage enters the jet aeration biofilm reaction tank, thereby completing the aerobic reaction, nitrification reaction and denitrification reaction of the sewage;

[0010] S4, introducing the mixed liquid in the jet aeration biofilm reaction tank into a membrane separation device, wherein the membrane separation device uses an ultrafiltration membrane or a microfiltration membrane, and the membrane material is polyvinylidene fluoride or polyether sulfone;

[0011] S5. Sludge return and disposal.

[0012] Preferably, the grid can remove large suspended solids with a particle size greater than 5 mm, and when the sewage is initially filtered, the sewage stays in the preliminary filtration tank for 2-6 hours.

[0013] Preferably, the impurity monitoring module comprises the following steps:

[0014] S21. After the sewage is filtered, the sewage impurity detection module set by the impurity monitoring module detects the value of large suspended matter per cubic meter of water;

[0015] The numerical detection formula for large suspended solids is:

[0016] D=S÷Y≥1.5

[0017] Among them, S represents the volume of sewage per minute, and Y represents the larger particles detected in the sewage per minute. When D≥1.5, it means that the sewage needs to be returned to the preliminary filtration tank for re-filtration. When D<1.5, the sewage enters the next treatment step;

[0018] S22, the reflux equipment includes re-extracting the sewage into the preliminary sewage pool for re-filtration.

[0019] Preferably, the filtered sewage enters the jet aeration biofilm reaction tank, comprising the following steps:

[0020] S31, introducing the pretreated sewage into the jet aeration biofilm reaction tank, and injecting activated sludge containing a variety of microbial flora into the jet aeration biofilm reaction tank;

[0021] S32, the sewage and the activated sludge are fully mixed and contacted by aeration, and the microorganisms in the activated sludge decompose the organic pollutants in the sewage under aerobic conditions, and the temperature, pH value, dissolved oxygen concentration and sludge retention time in the reaction tank are controlled within a specific range, wherein the temperature range is 20° C.-30° C., the pH value range is 7-8, the dissolved oxygen concentration range is 1000 mg / L-2000 mg / L, and the sludge retention time is 1 day-2 days;

[0022] S33. Decomposing organic pollutants in sewage through the metabolism of microorganisms; wherein the activated sludge contains a variety of microbial flora such as aerobic heterotrophic bacteria, nitrifying bacteria, denitrifying bacteria, and polyphosphate bacteria, and the proportions of each flora in the activated sludge are: aerobic heterotrophic bacteria 40%-60%, nitrifying bacteria 10%-20%, denitrifying bacteria 15%-25%, and polyphosphate bacteria 5%-15%.

[0023] Preferably, the activated sludge biological treatment step further comprises:

[0024] S34, an operation of adding nutrients to the activated sludge reaction tank, wherein the nutrients include a carbon source, a nitrogen source and a phosphorus source, wherein the carbon source is measured in biochemical oxygen demand, the nitrogen source is measured in ammonia nitrogen, the phosphorus source is measured in phosphate, and the ratio of oxygen source, nitrogen source in ammonia nitrogen, and phosphorus source in phosphate is 100:5:1.

[0025] Preferably, the mixed liquid is introduced into the membrane separation device, comprising the following steps:

[0026] S41, introducing the mixed liquid in the jet aeration biofilm reaction tank into a membrane separation device, wherein the membrane separation device uses an ultrafiltration membrane or a microfiltration membrane, and the membrane material is polyvinylidene fluoride or polyether sulfone;

[0027] S42, the membrane pore size of the membrane assembly is 0.05-0.4μm, the operating pressure is controlled at 0.05-0.3MPa, and the membrane flux is 10-30L / (m 2 h);

[0028] S43. During the membrane separation process, the membrane surface is flushed by intermittent aeration. The aeration interval is 5-15 minutes and the aeration time is 30-60 seconds to slow down membrane pollution. During the flushing, there is a short-range nitrification reaction. The reaction equation is: NH4++NO2-→N2↑+H2O;

[0029] S44. The biofilm can fall off automatically and has a fixed renewal cycle. With the action of water flow, the aged biofilm will fall off naturally, and at the same time, new microorganisms will attach and grow on the filler to form a new biofilm. This cyclic renewal process ensures the activity of the biofilm and the sewage treatment effect.

[0030] Preferably, the monitoring module comprises the following steps:

[0031] S51, returning 50%-90% of the concentrated sludge mixed liquor produced by the membrane separation device to the jet aeration biofilm reaction tank, so that the sludge concentration in the reaction tank is maintained at 4000-8000 mg / L;

[0032] S52. The remaining concentrated sludge mixture is dehydrated by mechanical dehydration, such as by using a plate and frame filter press, a belt filter press or a centrifugal dehydrator. After dehydration, the moisture content of the sludge is reduced to below 80%. The dehydrated sludge is subsequently disposed of by landfill, incineration or composting.

[0033] In summary, the present application includes the following beneficial technical effects: through the synergistic effect of various microbial flora in the activated sludge method and the efficient filtration of the membrane separation device, various pollutants such as organic pollutants, nitrogen, phosphorus, etc. in sewage can be effectively removed, the effluent quality is stable and excellent, and various indicators can meet or exceed the relevant national emission standards or reuse standards. For example, the removal rate of chemical oxygen demand can reach more than 90%, the removal rate of ammonia nitrogen can reach more than 85%, and the removal rate of total phosphorus can reach more than 95%;

[0034] Compared with the traditional activated sludge sewage treatment process, the present invention integrates the activated sludge process with the membrane process, reduces the floor space of the treatment unit, saves land resources, and is particularly suitable for the construction of sewage treatment facilities in areas with limited land resources such as urban centers;

[0035] Due to the interception effect of the membrane separation device, some microorganisms are retained in the reaction tank, which prolongs the residence time of the sludge in the system, improves the decomposition and mineralization degree of the sludge, thereby reducing the sludge output, the cost of sludge treatment and disposal, and the environmental pressure;

[0036] The use of specific membrane materials, operating parameters, and intermittent aeration to flush the membrane surface have effectively slowed down the rate of membrane pollution, extended the membrane cleaning cycle and service life, reduced membrane replacement costs and operating and maintenance costs, and improved the economy and stability of the entire sewage treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is an overall process flow chart of a sewage treatment process integrating activated sludge method and membrane method in an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0039] like Figure 1 As shown, a sewage treatment process integrating activated sludge method and membrane method includes the following steps:

[0040] S1. Drain the sewage, filter it through a preliminary screen to remove large particles, and then perform sand settling treatment to separate sand and other inorganic particles in the sewage;

[0041] S2, reflux start-up equipment and impurity monitoring module, when it is detected that the larger impurities in the sewage have not been separated to a certain value, the reflux equipment is started and filtering is performed again;

[0042] S3, the filtered sewage enters the jet aeration biofilm reaction tank, thereby completing the aerobic reaction, nitrification reaction and denitrification reaction of the sewage;

[0043] S4, introducing the mixed liquid of the jet aeration biofilm reaction tank into a membrane separation device, wherein the membrane separation device uses an ultrafiltration membrane or a microfiltration membrane, and the membrane material is polyvinylidene fluoride or polyether sulfone;

[0044] S5. Sludge return and disposal.

[0045] In this embodiment, the grid can remove large suspended solids with a particle size greater than 5 mm, and when the sewage is initially filtered, the sewage stays in the initial filtration tank for 2-6 hours.

[0046] It needs to be explained that the early large-particle filtration of sewage can improve the filtration efficiency for the subsequent sewage active adsorption and membrane adsorption, while improving the efficiency of sewage treatment and conducting multi-stage effective filtration treatment on sewage.

[0047] In this embodiment, the impurity monitoring module includes the following steps:

[0048] S21. After the sewage is filtered, the sewage impurity detection module set by the impurity monitoring module detects the value of large suspended matter per cubic meter of water;

[0049] Among them, the numerical detection formula for large particle suspended matter is:

[0050] D=S÷Y≥1.5

[0051] Among them, S represents the volume of sewage per minute, and Y represents the larger particles detected in the sewage per minute. When D≥1.5, it means that the sewage needs to be returned to the preliminary filtration tank for re-filtration. When D<1.5, the sewage enters the next treatment step;

[0052] S22, backflow equipment, including re-pumping the sewage into the preliminary sewage tank for re-filtration.

[0053] It needs to be explained that if the pH value of sewage does not meet the standard, it may cause damage to the biofilm or the environment in the later stage. Therefore, the monitoring module is set up to have a better effect on sewage treatment.

[0054] In this embodiment, the filtered sewage enters the jet aeration biofilm reaction tank, including the following steps:

[0055] S31, introducing the pretreated sewage into the jet aeration biofilm reaction tank, and injecting activated sludge containing a variety of microbial flora into the jet aeration biofilm reaction tank;

[0056] S32. The sewage and activated sludge are fully mixed and contacted by aeration. Under aerobic conditions, the microorganisms in the activated sludge decompose the organic pollutants in the sewage. At the same time, the temperature, pH value, dissolved oxygen concentration and sludge retention time in the reaction tank are controlled within a specific range, the temperature range is 20°C-30°C, the pH range is 7-8, the dissolved oxygen concentration range is 1000mg / L-2000mg / L, and the sludge retention time is 1 day-2 days;

[0057] S33. Decompose organic pollutants in sewage through the metabolism of microorganisms; wherein, the activated sludge contains a variety of microbial flora such as aerobic heterotrophic bacteria, nitrifying bacteria, denitrifying bacteria, and polyphosphate bacteria, and the proportions of each flora in the activated sludge are: aerobic heterotrophic bacteria 40%-60%, nitrifying bacteria 10%-20%, denitrifying bacteria 15%-25%, and polyphosphate bacteria 5%-15%.

[0058] In this embodiment, the activated sludge biological treatment step further includes:

[0059] S34. The operation of adding nutrients to the activated sludge reaction tank, the nutrients include a carbon source, a nitrogen source and a phosphorus source, wherein the carbon source is measured in biochemical oxygen demand, the nitrogen source is measured in ammonia nitrogen, the phosphorus source is measured in phosphate, and the ratio of oxygen source, nitrogen source in ammonia nitrogen, and phosphorus source in phosphate is 100:5:1.

[0060] In this embodiment, the mixed liquid is introduced into the membrane separation device, comprising the following steps:

[0061] S41, introducing the mixed liquid in the jet aeration biofilm reaction tank into a membrane separation device, wherein the membrane separation device uses an ultrafiltration membrane or a microfiltration membrane, and the membrane material is polyvinylidene fluoride or polyether sulfone;

[0062] S42, the membrane pore size of the membrane assembly is 0.05-0.4μm, the operating pressure is controlled at 0.05-0.3MPa, and the membrane flux is 10-30L / (m 2 h);

[0063] S43. During the membrane separation process, the membrane surface is flushed by intermittent aeration. The aeration interval is 5-15 minutes and the aeration time is 30-60 seconds to slow down membrane pollution. During the flushing, there is a short-range nitrification reaction. The reaction equation is: NH4++NO2-→N2↑+H2O;

[0064] S44. The biofilm can fall off automatically and has a fixed renewal cycle. With the action of water flow, the aged biofilm will fall off naturally, and at the same time, new microorganisms will attach and grow on the filler to form a new biofilm. This cyclic renewal process ensures the activity of the biofilm and the sewage treatment effect.

[0065] In this embodiment, the monitoring module includes the following steps:

[0066] S51, returning 50%-90% of the concentrated sludge mixed liquor produced by the membrane separation device to the jet aeration biofilm reaction tank, so that the sludge concentration in the reaction tank is maintained at 4000-8000 mg / L;

[0067] S52. The remaining concentrated sludge mixture is dehydrated by mechanical dehydration, such as by using a plate and frame filter press, a belt filter press or a centrifugal dehydrator. After dehydration, the moisture content of the sludge is reduced to below 80%. The dehydrated sludge is subsequently disposed of by landfill, incineration or composting.

[0068] It needs to be explained that the biofilm can be divided into the anaerobic layer, aerobic layer, attached water layer and moving water layer from the filter material to the outside. As the organisms mature, the thickness of the biofilm continues to increase, and the deep inside where oxygen cannot penetrate will turn into an anaerobic state, forming an anaerobic film. As the anaerobic reaction proceeds, the anaerobic metabolites continue to increase, causing the balance between the anaerobic film and the aerobic film to be destroyed. The gaseous substances produced by anaerobic reaction continue to escape, weakening the biofilm's ability to adhere to the filler, causing the aging biofilm to fall off continuously.

[0069] The implementation principle of a sewage treatment process integrating an activated sludge method and a membrane method in an embodiment of the present application is as follows: first, the sewage is drained, the sewage is subjected to preliminary grid filtration to remove large particle impurities, and then a sand settling treatment is performed to separate inorganic particles such as sand particles in the sewage. Then, the pretreated sewage is introduced into a jet aeration biofilm reaction tank, and activated sludge containing a variety of microbial flora is injected into the jet aeration biofilm reaction tank. The sewage and the activated sludge are fully mixed and contacted through aeration. Under aerobic conditions, the microorganisms in the activated sludge decompose the organic pollutants in the sewage. At the same time, the temperature, pH value, dissolved oxygen concentration and sludge retention time in the reaction tank are controlled within a specific range. Finally, the mixed liquid of the jet aeration biofilm reaction tank is introduced into a membrane separation device. During the membrane separation process, the membrane surface is flushed by intermittent aeration. The aeration interval is 5-15 minutes and the aeration time is 30-60 seconds to reduce membrane pollution.

[0070] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0071] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0072] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sewage treatment process integrating activated sludge process and membrane process, characterized in that: The sewage treatment method integrating the activated sludge method and the membrane method comprises the following steps: S1. Drain the sewage, filter it through a preliminary screen to remove large particles, and then perform sand settling treatment to separate sand and other inorganic particles in the sewage; S2, reflux start-up equipment and impurity monitoring module, when it is detected that the larger impurities in the sewage have not been separated to a certain value, the reflux equipment is started and filtering is performed again; S3, the filtered sewage enters the jet aeration biofilm reaction tank, thereby completing the aerobic reaction, nitrification reaction and denitrification reaction of the sewage; S4, introducing the mixed liquid in the jet aeration biofilm reaction tank into a membrane separation device, wherein the membrane separation device uses an ultrafiltration membrane or a microfiltration membrane, and the membrane material is polyvinylidene fluoride or polyether sulfone; S5. Sludge return and disposal.

2. The sewage treatment process integrating activated sludge process and membrane process according to claim 1, characterized in that: The grid can remove large suspended solids with a particle size greater than 5 mm, and when the sewage is initially filtered, the sewage stays in the initial filtration tank for 2-6 hours.

3. The sewage treatment process integrating activated sludge process and membrane process according to claim 1, characterized in that: The impurity monitoring module includes the following steps: S21. After the sewage is filtered, the sewage impurity detection module set by the impurity monitoring module detects the value of large suspended matter per cubic meter of water; The numerical detection formula for large suspended solids is: D=S÷Y≥1.5 Among them, S represents the volume of sewage per minute, and Y represents the larger particles detected in the sewage per minute. When D≥1.5, it means that the sewage needs to be returned to the preliminary filtration tank for re-filtration. When D<1.5, the sewage enters the next treatment step; S22, the reflux equipment includes re-extracting the sewage into the preliminary sewage pool for re-filtration.

4. The sewage treatment process integrating activated sludge process and membrane process according to claim 1, characterized in that: The filtered sewage enters the jet aeration biofilm reaction tank and comprises the following steps: S31, introducing the pretreated sewage into the jet aeration biofilm reaction tank, and injecting activated sludge containing a variety of microbial flora into the jet aeration biofilm reaction tank; S32, the sewage and the activated sludge are fully mixed and contacted by aeration, and the microorganisms in the activated sludge decompose the organic pollutants in the sewage under aerobic conditions, and the temperature, pH value, dissolved oxygen concentration and sludge retention time in the reaction tank are controlled within a specific range, wherein the temperature range is 20° C.-30° C., the pH value range is 7-8, the dissolved oxygen concentration range is 1000 mg / L-2000 mg / L, and the sludge retention time is 1 day-2 days; S33. Decomposing organic pollutants in sewage through the metabolism of microorganisms; wherein the activated sludge contains a variety of microbial flora such as aerobic heterotrophic bacteria, nitrifying bacteria, denitrifying bacteria, and polyphosphate bacteria, and the proportions of each flora in the activated sludge are: aerobic heterotrophic bacteria 40%-60%, nitrifying bacteria 10%-20%, denitrifying bacteria 15%-25%, and polyphosphate bacteria 5%-15%.

5. The sewage treatment process integrating activated sludge process and membrane process according to claim 4, characterized in that: The activated sludge biological treatment step also includes: S34, an operation of adding nutrients to the activated sludge reaction tank, wherein the nutrients include a carbon source, a nitrogen source and a phosphorus source, wherein the carbon source is measured in biochemical oxygen demand, the nitrogen source is measured in ammonia nitrogen, the phosphorus source is measured in phosphate, and the ratio of oxygen source, nitrogen source in ammonia nitrogen, and phosphorus source in phosphate is 100:5:

1.

6. The sewage treatment process integrating activated sludge process and membrane process according to claim 1, characterized in that: The mixed liquid is introduced into the membrane separation device, comprising the following steps: S41, introducing the mixed liquid in the jet aeration biofilm reaction tank into a membrane separation device, wherein the membrane separation device uses an ultrafiltration membrane or a microfiltration membrane, and the membrane material is polyvinylidene fluoride or polyether sulfone; S42, the membrane pore size of the membrane assembly is 0.05-0.4μm, the operating pressure is controlled at 0.05-0.3MPa, and the membrane flux is 10-30L / (m 2 h); S43. During the membrane separation process, the membrane surface is flushed by intermittent aeration. The aeration interval is 5-15 minutes and the aeration time is 30-60 seconds to slow down membrane pollution. During the flushing, there is a short-range nitrification reaction. The reaction equation is: NH4++NO2-→N2↑+H2O; S44. The biofilm can fall off automatically and has a fixed renewal cycle. With the action of water flow, the aged biofilm will fall off naturally, and at the same time, new microorganisms will attach and grow on the filler to form a new biofilm. This cyclic renewal process ensures the activity of the biofilm and the sewage treatment effect.

7. The sewage treatment process integrating activated sludge process and membrane process according to claim 1, characterized in that: The monitoring module comprises the following steps: S51, returning 50%-90% of the concentrated sludge mixed liquor produced by the membrane separation device to the jet aeration biofilm reaction tank, so that the sludge concentration in the reaction tank is maintained at 4000-8000 mg / L; S52. The remaining concentrated sludge mixture is dehydrated by mechanical dehydration, such as by using a plate and frame filter press, a belt filter press or a centrifugal dehydrator. After dehydration, the moisture content of the sludge is reduced to below 80%. The dehydrated sludge is subsequently disposed of by landfill, incineration or composting.

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