System and method for efficient phosphorus removal from high-phosphorus biodegradable wastewater

Abstract

The application provides a system and method for efficiently removing phosphorus from high-phosphorus biodegradable wastewater, and relates to the technical field of wastewater phosphorus removal. The system comprises a biological phosphorus removal tank, an anaerobic zone and an aerobic zone arranged in the biological phosphorus removal tank in sequence along the water flow direction, a sedimentation tank communicated with the aerobic zone, and an oxygenation device with an aeration part arranged in the sedimentation tank. The effluent of the biological phosphorus removal tank enters the sedimentation tank to realize mud-water separation, the oxygenation device arranged in the sedimentation tank can form an aerobic environment, thereby inhibiting the secondary phosphorus release of phosphorus accumulating organisms in the sedimentation tank and avoiding the increase of TP in the effluent of the sedimentation tank. The method applies the biological phosphorus removal method to the treatment of high-phosphorus biodegradable wastewater, greatly reduces the addition of chemical agents and the generation of chemical sludge, significantly reduces the treatment cost of high-phosphorus wastewater, is economical and efficient, and does not cause secondary pollution.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sewage phosphorus removal, and more particularly relates to a system and method for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater. BACKGROUND

[0002] Sewage phosphorus removal technology mainly includes biological phosphorus removal method and chemical phosphorus removal method; the biological phosphorus removal method mainly relies on the characteristics of phosphorus release of polyphosphorus bacteria under anaerobic conditions and excessive phosphorus absorption under aerobic conditions, and the phosphorus in the water body is removed through the discharge of activated sludge after aerobic phosphorus absorption; the biological phosphorus removal method is mainly used for the treatment of low-phosphorus-content sewage such as domestic sewage; the chemical phosphorus removal method forms insoluble phosphate precipitates by adding calcium salt, aluminum salt, iron salt and other chemical agents, and finally removes phosphorus from sewage through solid-liquid separation method; the chemical phosphorus removal method is simple in operation and stable in effect, but a large amount of chemical agents need to be added when the phosphorus content in the sewage is high, and a large amount of chemical sludge (up to 0.5% of the treated water volume) will be generated; the addition of chemical agents and the treatment and disposal of chemical sludge both bring a substantial increase in treatment cost; when the phosphorus concentration in the sewage is higher than 50 mg / L, there is a potential for phosphorus recovery, but due to many influencing factors of phosphorus recovery, the yield and purity of phosphorus recovery are difficult to guarantee; in addition, the current domestic phosphorus market price is low, and the income of phosphorus recovery products is difficult to cover the current cost of phosphorus recovery, so there are only a few domestic phosphorus recovery devices in operation.

[0003] If the biological phosphorus removal technology is applied to the treatment of high-phosphorus and easily biodegradable wastewater, the treatment cost can be significantly reduced; however, there are few reports on the engineering cases of biological phosphorus removal of high-phosphorus wastewater, and one of the major obstacles affecting its application is the problem of secondary phosphorus release, that is, the anaerobic phosphorus release of polyphosphorus bacteria during the sludge-water separation process in the sedimentation tank will cause the TP concentration in the effluent to rise again, and how to maintain a low TP concentration in the sedimentation tank is of great significance for the application of biological phosphorus removal technology to the treatment of high-phosphorus wastewater. SUMMARY

[0004] The present application aims to solve the problems in the prior art, and provides a system and method for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater, which solves the problem of secondary phosphorus release of polyphosphorus bacteria during the sludge-water separation process in the sedimentation tank when the biological phosphorus removal of high-phosphorus wastewater is carried out, and how to efficiently achieve the biological phosphorus removal of high-phosphorus wastewater to reduce the treatment cost of high-phosphorus wastewater.

[0005] In order to achieve the above-mentioned purpose, the present application provides a system for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater, which comprises:

[0006] a biological phosphorus removal tank, wherein the inside of the biological phosphorus removal tank is provided with an anaerobic zone and an aerobic zone in sequence along the water flow direction;

[0007] a sedimentation tank, wherein the sedimentation tank is in communication with the aerobic zone;

[0008] The oxygenation device is provided in the sedimentation tank to form an oxygenated sedimentation tank, and the oxygenated environment inhibits the release of phosphorus by polyphosphorus bacteria in the sedimentation tank, so as to control the TP concentration of the effluent of the sedimentation tank.

[0009] Preferably, the high-phosphorus biodegradable wastewater high-efficiency phosphorus removal system further comprises:

[0010] The adjusting tank is in communication with the anaerobic zone.

[0011] The pH adjusting liquid storage tank stores the pH adjusting liquid inside, and is in communication with the adjusting tank.

[0012] The organic carbon source storage tank stores the organic carbon source inside, and is in communication with the adjusting tank.

[0013] Preferably, the high-phosphorus biodegradable wastewater high-efficiency phosphorus removal system further comprises:

[0014] The sludge return pipe has two ends in communication with the sedimentation tank and the anaerobic zone, respectively.

[0015] The excess sludge discharge pipe has one end in communication with the sedimentation tank.

[0016] Preferably, the oxygenation device comprises:

[0017] A plurality of flat membranes are sequentially and spacedly arranged inside the sedimentation tank, the bottom corner and the top corner of the flat membrane are respectively provided with an air inlet hole and an air outlet hole, and the inside of the flat membrane is used for circulating air.

[0018] The air inlet pipe is in communication with the air inlet hole.

[0019] The air outlet pipe is in communication with the air outlet hole.

[0020] The air inlet pipe is in communication with the air inlet hole.

[0021] The pressure gauge and the air volume adjusting valve are both arranged on the air outlet pipe.

[0022] Preferably, one side of the sedimentation tank is provided with a water inlet end in communication with the aerobic zone, the high-phosphorus biodegradable wastewater high-efficiency phosphorus removal system further comprises a baffle, the baffle is arranged inside the sedimentation tank, the baffle is spacedly arranged with one side of the sedimentation tank, the bottom of the baffle and the bottom of the sedimentation tank are provided with a circulation passage, a plurality of flat membranes are arranged between the other side of the sedimentation tank and the baffle, and the flat membranes are arranged obliquely.

[0023] Preferably, the interior of the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone is provided with a dynamic adjustment zone, which can be dynamically switched between anaerobic state and aerobic state.

[0024] Preferably, the interior of the anaerobic zone and the dynamic adjustment zone is provided with a stirrer, and the interior of the aerobic zone and the dynamic adjustment zone is provided with aeration disc.

[0025] A method for efficient phosphorus removal of high-phosphorus biodegradable wastewater, using a system for efficient phosphorus removal of high-phosphorus biodegradable wastewater, the method comprising:

[0026] Inoculating activated sludge into the interior of the biological phosphorus removal tank and introducing wastewater to carry out biological phosphorus removal reaction;

[0027] Aerating the sedimentation tank to form an aerobic sedimentation tank to inhibit phosphorus release of polyphosphorus bacteria in the sedimentation tank.

[0028] Preferably, when the interior of the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone is provided with a dynamic adjustment zone, which can be dynamically switched between anaerobic state and aerobic state, the inoculating activated sludge into the interior of the biological phosphorus removal tank and introducing wastewater to carry out biological phosphorus removal reaction comprises:

[0029] The phosphorus release amount of the anaerobic zone is maintained at 1.5-2.5 times the influent TP concentration, when the phosphorus release amount of the anaerobic zone is greater than 2.5 times the influent TP concentration, the dynamic adjustment zone is switched to aerobic state, and the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone is reduced, when the phosphorus release amount of the anaerobic zone is less than 1.5 times the influent TP concentration, the dynamic adjustment zone is switched to anaerobic state, and the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone is increased;

[0030] Monitoring the TP concentration at the end of the aerobic zone, when the TP concentration at the end of the aerobic zone is higher than 2 mg / L, increasing the organic carbon source dosage of the adjustment tank or prolonging the hydraulic retention time to improve the TP removal rate.

[0031] Preferably, when the oxygenation device comprises a plurality of flat membranes, an air inlet pipe, an air outlet pipe, an aeration pump, a pressure gauge and a gas quantity regulating valve, the plurality of flat membranes are sequentially and spacedly arranged in the interior of the sedimentation tank, the bottom corner and the top corner of the flat membrane are respectively provided with an air inlet hole and an air outlet hole, the interior of the flat membrane is used for circulating air, the air inlet pipe is in communication with the air inlet hole, the air outlet pipe is in communication with the air outlet hole, the air inlet pipe is in communication with the aeration pump, and the pressure gauge and the gas quantity regulating valve are both arranged on the air outlet pipe, aerating the flat membrane to form an aerobic sedimentation tank to inhibit phosphorus release of polyphosphorus bacteria in the sedimentation tank comprises:

[0032] To avoid phosphorus release of phosphorus accumulating organisms under anaerobic condition in the sludge-water separation process, the air flow of the flat membrane in the sedimentation tank is regulated to maintain the pressure in the flat membrane below the bubble point, so that the dissolved oxygen above the flat membrane is maintained at 0.2-1.0 mg / L;

[0033] When it is observed that sludge is accumulated on the flat membrane and is not easy to slide off, or the dissolved oxygen above the flat membrane is obviously decreased under the same air flow and pressure in the flat membrane, the pressure in the flat membrane is increased to above the bubble point of the flat membrane, and the accumulated sludge on the flat membrane is cleaned by the impact of the overflowed air bubbles.

[0034] The present application provides a system and method for efficient phosphorus removal of high-phosphorus biodegradable wastewater, which has the beneficial effect that the conventional sedimentation tank is in an anaerobic state, and the phosphorus release of phosphorus accumulating organisms under anaerobic conditions will cause the increase of the effluent TP concentration, while the system is provided with an oxygenation device in the sedimentation tank, which can inhibit the secondary phosphorus release of phosphorus accumulating organisms in the sedimentation tank under aerobic conditions, avoiding the increase of the effluent TP concentration of the sedimentation tank; at the same time, the anaerobic processes such as denitrification and anaerobic digestion can also be inhibited, and there is no risk of sludge floating.

[0035] The method applies the biological phosphorus removal method to the treatment of high-phosphorus biodegradable wastewater by using the system, greatly reduces the addition of chemical agents and the generation of chemical sludge, significantly reduces the treatment cost of high-phosphorus wastewater, is economical and efficient, and has no secondary pollution.

[0036] The method uses the system to convert the phosphorus in the wastewater into the form of phosphate through the biological phosphorus removal process, and the anaerobic phosphorus release process can concentrate the TP in the incoming water after the discharge of the excess sludge, which is more helpful to realize phosphorus recovery, and whether the phosphorus in the excess sludge is recovered can be determined according to the TP concentration and water quantity of the incoming water according to the economy.

[0037] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the several views, and in which the exemplary embodiments of the present application are shown.

[0039] Figure 1 A flow chart of a method for efficient phosphorus removal of high-phosphorus biodegradable wastewater according to one embodiment of the present application is shown;

[0040] Figure 2 A structural schematic diagram of a system for efficient phosphorus removal of high-phosphorus biodegradable wastewater according to one embodiment of the present application is shown;

[0041] Figure 3The application provides a high-phosphorus and easily-biodegradable wastewater high-efficiency phosphorus removal system.

[0042] Mark number explanation:

[0043] 1 regulating tank; 1.1, pH adjusting liquid storage tank; 1.2, organic carbon source storage tank; 2, biological phosphorus removal tank; 2.1, anaerobic zone; 2.2, dynamic adjustment zone; 2.3, aerobic zone; 3, sedimentation tank; 3.1, flat membrane; 3.2, air inlet pipe; 3.3, air outlet pipe; 3.4, pressure gauge; 3.5, gas volume adjusting valve. DETAILED DESCRIPTION

[0044] The preferred embodiments of the application will be described in more detail below. Although the preferred embodiments of the application are described below, it should be understood that the application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the application is more thoroughly and completely conveyed to those skilled in the art, and the scope of the application is fully conveyed to those skilled in the art.

[0045] As Figure 2 shown, the application provides a high-phosphorus and easily-biodegradable wastewater high-efficiency phosphorus removal system, which comprises:

[0046] The biological phosphorus removal tank 2 is internally provided with the anaerobic zone 2.1 and the aerobic zone 2.3 in sequence along the water flow direction;

[0047] The sedimentation tank 3 is in communication with the aerobic zone 2.3;

[0048] The oxygenation device is provided in the sedimentation tank 3 to form an aerobic sedimentation tank, so that the phosphorus release of the phosphorus accumulating bacteria in the sedimentation tank 3 is inhibited under the aerobic environment, and the TP concentration of the effluent of the sedimentation tank 3 is controlled.

[0049] Specifically, to solve the problem that the phosphorus accumulating bacteria anaerobic phosphorus release in the sludge-water separation process of the sedimentation tank will cause the TP concentration of the effluent to increase again during the biological phosphorus removal of the high-phosphorus wastewater, the application provides a high-phosphorus and easily-biodegradable wastewater high-efficiency phosphorus removal system, the effluent of the biological phosphorus removal tank 2 enters the sedimentation tank 3 to realize sludge-water separation, the oxygenation device is arranged in the sedimentation tank 3 to form an aerobic sedimentation tank 3, the phosphorus release of the phosphorus accumulating bacteria in the sedimentation tank 3 is inhibited under the aerobic environment, the TP (total phosphorus) concentration of the effluent of the sedimentation tank 3 is prevented from increasing, and the anaerobic processes such as denitrification and anaerobic digestion are also inhibited, so that no gas is generated, and there is no risk of sludge floating.

[0050] Preferably, the high-phosphorus and easily-biodegradable wastewater high-efficiency phosphorus removal system further comprises:

[0051] The regulating tank 1 is in communication with the anaerobic zone 2.1;

[0052] a pH adjusting liquid reserve tank 1.1, the interior of the pH adjusting liquid reserve tank 1.1 storing a pH adjusting liquid, the pH adjusting liquid reserve tank 1.1 being in communication with the adjusting tank 1;

[0053] an organic carbon source reserve tank 1.2, the interior of the organic carbon source reserve tank 1.2 storing an organic carbon source, the organic carbon source reserve tank 1.2 being in communication with the adjusting tank 1.

[0054] Specifically, the interior of the pH adjusting liquid reserve tank 1.1 is provided with a stirrer, so as to realize preparation and storage of the pH adjusting liquid, and the pH adjusting liquid reserve tank 1.1 is in communication with the adjusting tank 1; the interior of the organic carbon source reserve tank 1.2 is provided with a stirrer, so as to realize preparation and storage of the organic carbon source, and the organic carbon source reserve tank 1.2 is in communication with the adjusting tank 1, the pH adjusting liquid reserve tank 1.1 can adjust the pH of the incoming water, and the organic carbon source reserve tank 1.2 can adjust the COD / TP of the incoming water.

[0055] Preferably, the system for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater further comprises:

[0056] a sludge backflow pipe, two ends of the sludge backflow pipe being in communication with the sedimentation tank 3 and the anaerobic zone 2.1 respectively;

[0057] a residual sludge discharge pipe, one end of the residual sludge discharge pipe being in communication with the sedimentation tank 3.

[0058] Specifically, part of the sludge deposited at the bottom of the sedimentation tank 3 is backflowed to the front end of the anaerobic zone 2.1 of the efficient biological phosphorus removal tank 2 through the sludge backflow pipe, and part of the sludge is discharged through the residual sludge discharge pipe to control the sludge age of the efficient biological phosphorus removal tank; when the water treatment amount is low, the benefits of phosphorus recovery cannot cover the cost, and the residual sludge is directly subjected to dewatering treatment, a small amount of ferrous chloride is added before dewatering to reduce the content of phosphate in the dewatering liquid and reduce the overflow of hydrogen sulfide odor; the dewatering liquid is backflowed to the adjusting tank 1.

[0059] As shown in Figure 3 Preferably, the oxygenation device comprises:

[0060] a plurality of flat sheet membranes 3.1, the plurality of flat sheet membranes 3.1 being sequentially and spacedly arranged in the interior of the sedimentation tank 3, the bottom corner and the top corner of the flat sheet membrane 3.1 being respectively provided with an air inlet hole and an air outlet hole, the interior of the flat sheet membrane 3.1 being used for flowing air;

[0061] an air inlet pipe 3.2, the air inlet pipe 3.2 being in communication with the air inlet hole

[0062] an air outlet pipe 3.3, the air outlet pipe 3.3 being in communication with the air outlet hole;

[0063] an air charging pump, the air inlet pipe 3.2 being in communication with the air charging pump;

[0064] A pressure gauge 3.4 and a gas volume regulating valve 3.5 are arranged on the gas outlet pipe 3.3.

[0065] Specifically, a plurality of flat sheet membranes 3.1 are arranged in parallel and at intervals along the water flow direction inside the sedimentation tank 3, the sedimentation tank 3 is a horizontal flow sedimentation tank, the flat sheet membranes 3.1 are provided with air, and under a certain pressure, bubbleless oxygenation can be achieved to provide dissolved oxygen for the sedimentation tank 3. A plurality of dissolved oxygen sensors are arranged above the flat sheet membranes 3.1 to monitor the dissolved oxygen level.

[0066] The bubbleless oxygenation mode can provide dissolved oxygen for the sedimentation tank without affecting the sludge settling effect, maintain an aerobic environment in the horizontal flow sedimentation tank, and inhibit the release of phosphorus by polyphosphorus bacteria in the sedimentation tank 3 to maintain a low TP concentration of the effluent of the sedimentation tank 3.

[0067] The flat sheet membranes 3.1 are arranged at an angle of not less than 60 degrees with the horizontal direction, which can act as a inclined plate to increase the sedimentation area and shorten the sedimentation time.

[0068] Preferably, one side of the sedimentation tank 3 is provided with a water inlet end communicating with the aerobic zone 2.3, and the high-phosphorus biodegradable wastewater efficient phosphorus removal system further comprises a baffle, the baffle is arranged in the sedimentation tank 3, the baffle is arranged at intervals with one side of the sedimentation tank 3, a flow passage is arranged at the bottom of the baffle and the bottom of the sedimentation tank 3, and a plurality of flat sheet membranes 3.1 are arranged between the other side of the sedimentation tank 3 and the baffle.

[0069] Preferably, a dynamic adjustment zone 2.2 is arranged inside the biological phosphorus removal tank and between the anaerobic zone 2.1 and the aerobic zone 2.3, and the dynamic adjustment zone 2.2 can be dynamically switched between an anaerobic state and an aerobic state.

[0070] Specifically, the anaerobic state and the aerobic state can be switched according to the operating conditions, and by switching the anaerobic state and the aerobic state, the ratio of the anaerobic residence time and the aerobic residence time of the efficient biological phosphorus removal tank 2 can be adjusted.

[0071] Preferably, a stirrer is arranged inside the anaerobic zone 2.1 and the dynamic adjustment zone 2.2, and an aeration disc is arranged inside the aerobic zone 2.3 and the dynamic adjustment zone 2.2.

[0072] Preferably, the sedimentation tank 3 is provided with an automatic sludge scraping device, and the sludge deposited at the bottom is returned to the front end of the anaerobic zone 2.1 of the efficient biological phosphorus removal tank 2 through a sludge return pipe.

[0073] Preferably, the on-line control system comprises a controller, a signal transmission system and a plurality of on-line sensors arranged in the system.

[0074] Specifically, the several online sensors are respectively pH sensor, dissolved oxygen sensor, sludge concentration sensor, COD sensor, ammonia nitrogen sensor, nitrate nitrogen sensor and TP sensor, precise regulation and control of key control parameters are realized through the online control system, the requirement for the on-site operation personnel is low, the processing effect guarantee degree can be improved while the operation cost is reduced.

[0075] As shown in Figure 1 A method for efficient phosphorus removal of high-phosphorus easily biodegradable wastewater, using a system for efficient phosphorus removal of high-phosphorus easily biodegradable wastewater, the method comprising:

[0076] Inoculating activated sludge into the interior of the biological phosphorus removal tank 2 and introducing wastewater to perform biological phosphorus removal reaction;

[0077] Aerating the sedimentation tank 3 to form an aerobic environment in the sedimentation tank 3 to inhibit phosphorus release of polyphosphorus bacteria in the sedimentation tank 3.

[0078] Preferably, when the dynamic adjustment zone 2.2 is provided in the interior of the biological phosphorus removal tank 2 and between the anaerobic zone 2.1 and the aerobic zone 2.3, and the dynamic adjustment zone 2.2 can be dynamically switched between the anaerobic state and the aerobic state, the regulation and control step of inoculating activated sludge into the interior of the biological phosphorus removal tank 2 and introducing wastewater to perform biological phosphorus removal reaction specifically comprises:

[0079] The hydraulic retention time of the anaerobic zone 2.1 is controlled to be 1-3 hours, the phosphorus release amount of the anaerobic zone 2.1 is maintained to be 1.5-2.5 times of the influent TP concentration, when the phosphorus release amount of the anaerobic zone 2.1 is greater than 2.5 times of the influent TP concentration, the agitator of the dynamic adjustment zone 2.2 is closed and the aeration disc of the dynamic adjustment zone 2.2 is opened to reduce the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone, when the phosphorus release amount of the anaerobic zone 2.1 is less than 1.5 times of the influent TP concentration, the aeration disc of the dynamic adjustment zone 2.2 is closed and the agitator of the dynamic adjustment zone 2.2 is opened to increase the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone;

[0080] The hydraulic retention time of the aerobic zone 2.3 is controlled to be 5-10 hours, the dissolved oxygen is 1-3 mg / L, and the TP concentration at the end of the aerobic zone 2.3 is monitored, when the TP concentration at the end of the aerobic zone 2.3 is higher than 2 mg / L, the TP removal rate is increased by increasing the organic carbon source addition of the adjustment tank 1 or prolonging the hydraulic retention time.

[0081] Preferably, when the oxygenation device comprises a plurality of flat sheet membranes 3.1, an air inlet pipe 3.2, an air outlet pipe 3.3, an air pump, a pressure gauge 3.4 and an air volume regulating valve 3.5, the plurality of flat sheet membranes 3.1 are sequentially and spacedly arranged inside the sedimentation tank 3, the bottom corner and the top corner of the flat sheet membrane 3.1 are respectively provided with an air inlet hole and an air outlet hole, the inside of the flat sheet membrane 3.1 is used for circulating air, the air inlet pipe 3.2 is communicated with the air inlet hole, the air outlet pipe 3.3 is communicated with the air outlet hole, the air inlet pipe 3.2 is communicated with the air pump, and the pressure gauge 3.4 and the air volume regulating valve 3.5 are both arranged on the air outlet pipe 3.3, air is filled into the flat sheet membrane, so that the sedimentation tank 3 forms an oxygen environment, and the release of phosphorus by the phosphorus accumulating organisms in the sedimentation tank 3 is inhibited.

[0082] In order to avoid the release of phosphorus by the phosphorus accumulating organisms under anaerobic conditions in the process of mud-water separation, the air volume of the flat sheet membrane 3.1 in the sedimentation tank 3 is regulated, the pressure inside the flat sheet membrane 3.1 is maintained below the bubble point, and the dissolved oxygen above the flat sheet membrane 3.1 is maintained at 0.2-1.0 mg / L.

[0083] When it is observed that the sludge accumulated on the flat sheet membrane 3.1 is not easy to slide off, or when the dissolved oxygen above the flat sheet membrane 3.1 obviously decreases under the same air volume and the pressure inside the flat sheet membrane 3.1, the pressure inside the flat sheet membrane 3.1 is increased to above the bubble point of the flat sheet membrane 3.1, and the accumulated sludge on the flat sheet membrane 3.1 is cleaned by the impact of the overflowing air bubbles.

[0084] The specific method steps are as follows:

[0085] S1: The pH and COD / TP of the wastewater in the adjusting tank 1 are monitored and adjusted, so that the pH of the wastewater is maintained at 7-8, and if the COD / TP of the wastewater is less than 13, the COD / TP of the wastewater is increased to 13-20 by adding an organic carbon source.

[0086] S2: The general activated sludge is inoculated into the high-efficiency biological phosphorus removal tank 2, preferably the activated sludge with good biological phosphorus removal effect, and the sludge concentration is 4000-8000 mg / L.

[0087] S3: The hydraulic retention time of the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2 is controlled at 1-3 hours, the release of phosphorus in the anaerobic zone 2.1 is maintained at 1.5-2.5 times the concentration of the influent TP, when the release of phosphorus in the anaerobic zone 2.1 is greater than 2.5 times the concentration of the influent TP, the agitator of the dynamic adjustment zone 2.2 is closed and the aeration disc of the dynamic adjustment zone 2.2 is opened, so as to reduce the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone in the high-efficiency biological phosphorus removal tank 2; when the release of phosphorus in the anaerobic zone 2.1 is less than 1.5 times the concentration of the influent TP, the aeration disc of the dynamic adjustment zone 2.2 is closed and the agitator of the dynamic adjustment zone 2.2 is opened, so as to increase the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone in the high-efficiency biological phosphorus removal tank 2.

[0088] S4: The hydraulic retention time of the aerobic zone 2.3 of the high-efficiency biological phosphorus removal tank 2 is controlled to be 5-10 hours, and the dissolved oxygen is controlled to be 1-3 mg / L; the TP concentration at the end of the aerobic zone 2.3 is monitored, and when the TP concentration at the end of the aerobic zone 2.3 is higher than 2 mg / L, the TP removal rate is increased by increasing the dosage of the organic carbon source in the adjusting tank 1 or prolonging the hydraulic retention time.

[0089] S5: In order to avoid the phosphorus release of the phosphorus accumulating bacteria under anaerobic conditions in the sludge-water separation process, the pressure in the flat membrane 3.1 is controlled to be below the bubble point by controlling the aeration amount of the flat membrane 3.1 in the sedimentation tank, so that the dissolved oxygen above the flat membrane 3.1 is maintained at 0.2-1.0 mg / L.

[0090] S6: Part of the sludge deposited at the bottom of the sedimentation tank is returned to the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank, and part is discharged as excess sludge; by controlling the amount of excess sludge, the sludge age of the system is maintained at 5-10 days.

[0091] In the present application, the method for realizing high-efficiency phosphorus removal of high-phosphorus biodegradable wastewater by using the system comprises the following steps: after the suspended solids and sand particles are removed from the high-phosphorus biodegradable wastewater by primary treatment, the wastewater is introduced into the adjusting tank 1 to adjust the pH and COD / TP of the wastewater to meet the requirements of biological phosphorus removal; the effluent from the adjusting tank 1 is introduced into the high-efficiency biological phosphorus removal tank 2, and in the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2, the organic matter is adsorbed and partially degraded, and the phosphorus accumulating bacteria complete the PHA storage and phosphorus release process; after the anaerobic phosphorus release, the organic matter is degraded and the phosphorus accumulating bacteria excessively absorb phosphorus in the aerobic zone; the effluent from the high-efficiency biological phosphorus removal tank 2 is introduced into the sedimentation tank to realize sludge-water separation, and the bubbleless oxygenation device is arranged in the sedimentation tank, and the aerobic environment can inhibit the secondary phosphorus release of the phosphorus accumulating bacteria in the sedimentation tank 3, so as to avoid the increase of the TP of the effluent from the sedimentation tank 3; by using the online control system, the real-time control of the key control parameters of the system is realized, and the treatment cost is reduced while the phosphorus removal efficiency is ensured.

[0092] Preferably, in step S1, the organic carbon source can be simple organic matter such as sodium acetate and sodium propionate, or easily biodegradable high-concentration organic wastewater such as food processing wastewater.

[0093] Preferably, in step S5, when it is observed that the sludge accumulated on the flat membrane 3.1 is not easy to slide off, or when the dissolved oxygen above the flat membrane 3.1 significantly decreases under the same aeration amount and membrane pressure, the membrane pressure is increased to be above the bubble point of the flat membrane 3.1, and the accumulated sludge on the flat membrane 3.1 is cleaned by the impact of the overflowing gas bubbles.

[0094] Preferably, when the activated sludge in the high-efficiency biological phosphorus removal tank 2 has poor settling effect and sludge bulking occurs, powdered activated carbon is added to the aerobic zone 2.3 of the high-efficiency biological phosphorus removal tank 2 to improve the sludge settling effect; meanwhile, the powdered activated carbon can act as "nuclei" to help the formation of granular sludge.

[0095] Preferably, when the ammonia nitrogen concentration in the wastewater is high, an inhibitor is added to the sludge return pipeline at regular intervals to inhibit the ammonia nitrogen oxidation process and avoid the inhibition of phosphorus release by phosphorus bacteria due to high nitrate nitrogen concentration in the sludge return liquid; the inhibitor can be selected from hydroxylamine; and the sludge age is shortened by increasing the discharge of excess sludge, so that the ammonia-oxidizing bacteria are washed out by taking advantage of the difference in doubling time between the heterotrophic bacteria and the ammonia-oxidizing bacteria (autotrophic bacteria).

[0096] Preferably, the excess sludge can be treated in two different ways according to the TP concentration and water quantity of the incoming water.

[0097] When the TP concentration of the incoming water is greater than 50 mg / L and the water quantity is large, the excess sludge is subjected to anaerobic digestion treatment, and the supernatant after anaerobic digestion is subjected to phosphorus recovery by adding magnesium salt in the form of ammonium magnesium phosphate.

[0098] When the TP concentration of the incoming water is less than 50 mg / L or the water quantity is small, the excess sludge is directly subjected to dewatering treatment after being discharged from the self-settling tank, a small amount of ferrous chloride is added before dewatering to reduce the content of phosphate in the dewatering liquid and reduce the emission of hydrogen sulfide odor, and the dewatering liquid is returned to the adjusting tank 1.

[0099] Embodiment

[0100] The specific test water is train toilet wastewater from a certain railway station, and the water quality is as follows: the COD concentration is 1600-2000 mg / L, the ammonia nitrogen concentration is 800-1100 mg / L, and the TP concentration is 80-100 mg / L; all the reaction devices are made of stainless steel, the effective volume of the high-efficiency biological phosphorus removal tank 2 is 2.0 m 3 , the effective volume of the anaerobic zone 2.1 is 0.4 m 3 , the effective volume of the dynamic adjustment zone 2.2 is 0.4 m 3 , the effective volume of the aerobic zone 2.3 is 1.2 m 3 , and the effective volume of the aerobic settling tank 3 is 0.7 m 3 .

[0101] The method for realizing efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater by using the system in this embodiment includes the following steps:

[0102] S1: The pH and COD / TP of the wastewater in the adjusting tank 1 are monitored and adjusted, so that the pH of the wastewater is maintained at 7-8 and the COD / TP of the wastewater is greater than 16, and the organic carbon source is sufficient and does not need to be supplemented.

[0103] S2: inoculate the activated sludge with good biological phosphorus removal effect into the high-efficiency biological phosphorus removal tank 2, and the sludge concentration is 5000-6000 mg / L.

[0104] S3: control the hydraulic retention time of the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2 to be 1.5 hours; maintain the phosphorus release amount of the anaerobic zone 2.1 to be 1.5-2.5 times of the TP concentration of the influent, when the phosphorus release amount of the anaerobic zone 2.1 is greater than 2.5 times of the TP concentration of the influent, turn off the stirrer of the dynamic adjustment zone 2.2 and turn on the aeration disc of the dynamic adjustment zone 2.2, and reduce the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone in the high-efficiency biological phosphorus removal tank 2; when the phosphorus release amount of the anaerobic zone 2.1 is lower than 1.5 times of the TP concentration of the influent, turn off the aeration disc of the dynamic adjustment zone 2.2 and turn on the stirrer of the dynamic adjustment zone 2.2, and increase the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone in the high-efficiency biological phosphorus removal tank.

[0105] S4: control the hydraulic retention time of the aerobic zone 2.3 of the high-efficiency biological phosphorus removal tank 2 to be 6 hours, and the dissolved oxygen to be 1-3 mg / L; monitor the TP concentration at the end of the aerobic zone 2.3, and when the TP concentration at the end of the aerobic zone 2.3 is higher than 2 mg / L, increase the TP removal rate by increasing the organic carbon source dosage of the adjusting tank 1 or prolonging the hydraulic retention time.

[0106] S5: in order to avoid the phosphorus release of the phosphorus accumulating bacteria under the anaerobic state in the sludge-water separation process, the pressure in the flat membrane 3.1 is maintained below the bubble point by controlling the aeration amount of the flat membrane 3.1 in the sedimentation tank 3, so that the dissolved oxygen above the flat membrane 3.1 is maintained at 0.2-1.0 mg / L.

[0107] Step S5 further comprises:

[0108] When it is observed that the sludge accumulated on the flat membrane 3.1 is not easy to slide off, or the dissolved oxygen above the flat membrane 3.1 is obviously decreased under the same aeration amount and membrane pressure, the membrane pressure is increased to be above the bubble point of the flat membrane 3.1, and the accumulated sludge on the flat membrane 3.1 is cleaned by the impact of the overflowing gas bubbles.

[0109] S6: part of the sludge deposited at the bottom of the sedimentation tank 3 is backflowed to the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2, and part of it is discharged as excess sludge, and the sludge age of the system is maintained at 6 days by controlling the amount of excess sludge discharge.

[0110] When the settling effect of the activated sludge in the high-efficiency biological phosphorus removal tank 2 becomes poor and sludge bulking phenomenon occurs, powdered activated carbon is added to the aerobic zone 2.3 of the high-efficiency biological phosphorus removal tank 2 to improve the sludge settling effect. At the same time, the powdered activated carbon can act as a "crystal nucleus" to help the formation of granular sludge.

[0111] Due to high ammonia nitrogen concentration of wastewater, an inhibitor hydroxylamine is added in sludge return pipeline every half month to inhibit ammonia nitrogen oxidation process, avoid high nitrate nitrogen concentration in sludge return liquid to inhibit phosphorus releasing bacteria to release phosphorus, and shorten sludge age to 5 days by increasing residual sludge discharge, and by the difference between doubling time of heterotrophic bacteria and ammonia oxidizing bacteria (autotrophic bacteria), the ammonia oxidizing bacteria are elutriated.

[0112] In the embodiment, due to small water quantity, phosphorus recovery is not economical, and the residual sludge is discharged from the self-sedimentation tank and directly subjected to dewatering treatment, and a small amount of ferrous chloride is added before dewatering to reduce the content of phosphate in the dewatering liquid and reduce the overflow of hydrogen sulfide odor. The dewatering liquid is returned to the adjusting tank 1.

[0113] The test results show that after stable operation, the COD concentration in the final effluent of the system is 40-80 mg / L, and TP < 1 mg / L, and the system and method for efficient phosphorus removal of high-phosphorus biodegradable wastewater provided in the application can be widely applied to the treatment of high-phosphorus biodegradable wastewater.

[0114] In summary, the method for efficient phosphorus removal of high-phosphorus biodegradable wastewater provided in the application utilizes the system, and the treatment process thereof is as follows: after high-phosphorus biodegradable wastewater is subjected to primary treatment to remove suspended solids and sand, the wastewater enters the adjusting tank 1 to adjust the pH and COD / TP of the incoming water to meet the requirements of biological phosphorus removal; the effluent of the adjusting tank 1 enters the high-efficiency biological phosphorus removal tank 2, organic matter is adsorbed and partially degraded in the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2, and the phosphorus accumulating bacteria complete the PHA storage and phosphorus release processes; after anaerobic phosphorus release, the degradation of organic matter and the excessive phosphorus absorption of the phosphorus accumulating bacteria are completed in the aerobic zone 2.3; the effluent of the high-efficiency biological phosphorus removal tank 2 enters the sedimentation tank 3 to realize mud-water separation, and the bubble-free oxygenation device is arranged in the sedimentation tank 3, and the aerobic environment can inhibit the secondary phosphorus release of the phosphorus accumulating bacteria in the sedimentation tank 3, thereby avoiding the increase of TP in the effluent of the sedimentation tank 3; part of the sludge deposited at the bottom of the aerobic sedimentation tank 3 is returned to the front end of the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2 through the sludge return pipeline, and part of the sludge is discharged through the residual sludge pipeline to control the sludge age of the high-efficiency biological phosphorus removal tank 2; according to the TP concentration and water quantity of the incoming water, the residual sludge has two treatment modes: when phosphorus recovery is valuable, the residual sludge is subjected to anaerobic digestion, and the phosphorus in the supernatant is recovered; when the income of phosphorus recovery cannot cover the cost, the residual sludge is directly subjected to dewatering treatment, a small amount of ferrous chloride is added before dewatering to reduce the content of phosphate in the dewatering liquid and reduce the overflow of hydrogen sulfide odor; and the dewatering liquid is returned to the adjusting tank 1.

[0115] The method utilizes the system to realize economic and efficient treatment of high-phosphorus biodegradable wastewater, and there is no secondary pollution caused by chemical sludge, when the water quantity is large, the supernatant can be subjected to phosphorus recovery after anaerobic digestion of the residual sludge, when the water quantity is small, phosphorus recovery is not economical, and the residual sludge is directly subjected to dewatering treatment.

[0116] Having described various embodiments of the application, it is to be understood that the above description is meant to be illustrative only, and that many modifications and variations of the embodiments are possible without departing from the scope and spirit of the described embodiments. Many modifications and variations of the described embodiments are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the described embodiments can be practiced otherwise than as specifically described.

Claims

1. A method for efficient phosphorus removal from high-phosphorus biodegradable wastewater, using a system for efficient phosphorus removal from high-phosphorus biodegradable wastewater, characterized by, The system comprises: a biological phosphorus removal tank, an anaerobic zone and an aerobic zone being sequentially arranged in the inside of the biological phosphorus removal tank along the water flow direction; a sedimentation tank, the sedimentation tank being in communication with the aerobic zone; an oxygenation device, an air charging part of the oxygenation device being arranged in the sedimentation tank, so that the sedimentation tank can form an aerobic sedimentation tank, and the release of phosphorus by polyphosphorus bacteria in the sedimentation tank is inhibited by the aerobic environment, so as to control the TP concentration of the effluent of the sedimentation tank; the oxygenation device comprises: a plurality of flat membranes, the plurality of flat membranes being sequentially and spacedly arranged in the inside of the sedimentation tank, the bottom corner and the top corner of the flat membrane being respectively provided with an air inlet hole and an air outlet hole, the inside of the flat membrane being used for circulating air, and the flat membrane is arranged in an inclined manner, and the included angle with the horizontal direction is not less than 60 degrees; an air inlet pipe, the air inlet pipe being in communication with the air inlet hole; an air outlet pipe, the air outlet pipe being in communication with the air outlet hole; an air charging pump, the air inlet pipe being in communication with the air charging pump; a pressure gauge and a gas volume adjusting valve, the pressure gauge and the gas volume adjusting valve being arranged on the air outlet pipe. The method comprises: inoculating activated sludge into the inside of the biological phosphorus removal tank and introducing wastewater, and performing biological phosphorus removal reaction; charging air into the sedimentation tank, so that the sedimentation tank forms an aerobic sedimentation tank, and the release of phosphorus by polyphosphorus bacteria in the sedimentation tank is inhibited; when the inside of the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone is provided with a dynamic adjustment zone, the dynamic adjustment zone can be dynamically switched between the anaerobic state and the aerobic state, and the inoculation of activated sludge into the inside of the biological phosphorus removal tank and the introduction of wastewater, and the biological phosphorus removal reaction comprise: maintaining the release amount of phosphorus in the anaerobic zone to be 1.5-2.5 times of the TP concentration of the influent, when the release amount of phosphorus in the anaerobic zone is greater than 2.5 times of the TP concentration of the influent, the dynamic adjustment zone is switched to the aerobic state, and the proportion of the hydraulic retention time of the anaerobic zone to the aerobic zone is reduced, when the release amount of phosphorus in the anaerobic zone is less than 1.5 times of the TP concentration of the influent, the dynamic adjustment zone is switched to the anaerobic state, and the proportion of the hydraulic retention time of the anaerobic zone to the aerobic zone is increased; monitoring the TP concentration at the end of the aerobic zone, when the TP concentration at the end of the aerobic zone is higher than 2 mg / L, the TP removal rate is increased by increasing the addition of organic carbon source in the adjusting tank or prolonging the hydraulic retention time.

2. The method for high-efficiency phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that, The system for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater further comprises: an adjusting tank, the adjusting tank being in communication with the anaerobic zone; a pH adjusting liquid storage tank, the inside of the pH adjusting liquid storage tank storing pH adjusting liquid, the pH adjusting liquid storage tank being in communication with the adjusting tank; an organic carbon source storage tank, the inside of the organic carbon source storage tank storing organic carbon source, the organic carbon source storage tank being in communication with the adjusting tank.

3. The method for high-efficiency phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that, The system for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater further comprises: a sludge backflow pipe, two ends of the sludge backflow pipe being in communication with the sedimentation tank and the anaerobic zone respectively; a residual sludge discharge pipe, one end of the residual sludge discharge pipe being in communication with the sedimentation tank.

4. The method for high-efficiency phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that, One side of the sedimentation tank is provided with a water inlet end communicated with the aerobic zone, the system for efficient phosphorus removal of high-phosphorus and easily biodegradable wastewater further comprises a baffle, the baffle is arranged in the sedimentation tank, the baffle is arranged at intervals with one side of the sedimentation tank, the bottom of the baffle and the bottom of the sedimentation tank are provided with a flow channel, a plurality of flat sheet membranes are arranged between the other side of the sedimentation tank and the baffle, and the flat sheet membranes are arranged obliquely.

5. The method for high-efficiency phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that, The inside of the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone is provided with a dynamic adjustment zone, which can be dynamically switched between anaerobic state and aerobic state.

6. The method for high-efficiency phosphorus removal from high-phosphorus biodegradable wastewater according to claim 5, characterized in that, The inside of the anaerobic zone and the dynamic adjustment zone is provided with a stirrer, and the inside of the aerobic zone and the dynamic adjustment zone is provided with an aeration disc.

7. The method for high-efficiency phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that, When the oxygenation device comprises a plurality of flat sheet membranes, an air inlet pipe, an air outlet pipe, an air charging pump, a pressure gauge and a gas volume regulating valve, the plurality of flat sheet membranes are arranged at intervals in the inside of the sedimentation tank, the bottom corner and the top corner of the flat sheet membrane are respectively provided with an air inlet hole and an air outlet hole, the inside of the flat sheet membrane is used for flowing air, the air inlet pipe is communicated with the air inlet hole, the air outlet pipe is communicated with the air outlet hole, the air inlet pipe is communicated with the air charging pump, and the pressure gauge and the gas volume regulating valve are arranged on the air outlet pipe, air is charged into the flat sheet membrane, the sedimentation tank forms an aerobic sedimentation tank, and the release of phosphorus by the phosphorus accumulating bacteria in the sedimentation tank is inhibited, which comprises: In order to avoid the release of phosphorus by the phosphorus accumulating bacteria in the anaerobic state during the sludge-water separation process, the air flow of the flat sheet membrane in the sedimentation tank is regulated, the pressure in the flat sheet membrane is maintained below the bubble point, and the dissolved oxygen above the flat sheet membrane is maintained at 0.2-1.0 mg / L; When it is observed that the sludge accumulated on the flat sheet membrane is not easy to slide off, or the dissolved oxygen above the flat sheet membrane is obviously decreased under the same air flow and pressure conditions in the flat sheet membrane, the pressure in the flat sheet membrane is increased to above the bubble point of the flat sheet membrane, the accumulated sludge on the flat sheet membrane is impacted by the overflow air bubbles, and the accumulated sludge on the flat sheet membrane is cleaned.

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