System and method for efficiently removing phosphorus from high-phosphorus biodegradable wastewater

Abstract

The invention provides a system and a method for efficiently removing phosphorus from high-phosphorus easily-biodegradable wastewater, and relates to the technical field of sewage phosphorus removal, the system comprises a biological phosphorus removal tank, the inner part of the biological phosphorus removal tank is sequentially provided with an anaerobic zone and an aerobic zone along the water flow direction; the sedimentation tank is communicated with the aerobic zone; an aeration part of the aeration device is arranged in the sedimentation tank. The effluent of the biological phosphorus removal tank of the system enters the sedimentation tank to realize mud-water separation, and the oxygenation device arranged in the sedimentation tank can form an aerobic environment, so that secondary phosphorus release of phosphorus-accumulating bacteria in the sedimentation tank is inhibited, and the TP (Total Phosphorus) rise of the effluent of the sedimentation tank is avoided. According to the method, a biological phosphorus removal method is applied to treatment of the high-phosphorus easily-biodegradable wastewater, addition of chemical agents and generation of chemical sludge are greatly reduced, the treatment cost of the high-phosphorus wastewater is remarkably reduced, and the method is economical, efficient and free of secondary pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater phosphorus removal, and more specifically, relates to a system and method for efficient phosphorus removal from high-phosphorus biodegradable wastewater. Background Art

[0002] Sewage phosphorus removal technologies mainly include biological phosphorus removal and chemical phosphorus removal. Biological phosphorus removal mainly relies on the characteristics of polyphosphate bacteria releasing phosphorus under anaerobic conditions and absorbing excessive phosphorus under aerobic conditions. The removal of phosphorus in water bodies is achieved by discharging activated sludge after aerobic phosphorus absorption. Biological phosphorus removal is mainly used for the treatment of low-phosphorus sewage such as domestic sewage. Chemical phosphorus removal forms insoluble phosphate precipitates by adding chemical agents such as calcium salts, aluminum salts, and iron salts, and finally removes phosphorus from sewage by solid-liquid separation. The chemical phosphorus removal method is simple to operate and has stable effects, but when sewage When the phosphorus content is high, a large amount of chemical agents need to be added, and a large amount of chemical sludge will be produced (up to 0.5% of the volume of treated water). The addition of chemical agents and the treatment and disposal of chemical sludge will greatly increase the treatment cost; when the phosphorus concentration in sewage is higher than 50 mg / L, there is potential for phosphorus recovery, but due to the many factors affecting 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 from phosphorus recovery products is difficult to cover the current cost of phosphorus recovery. There are only a handful of phosphorus recovery devices put into operation in China.

[0003] If biological phosphorus removal technology is applied to the treatment of high-phosphorus, biodegradable wastewater, its treatment cost can be significantly reduced. However, there are currently few reports on engineering cases of biological phosphorus removal from high-phosphorus wastewater. One of the major obstacles affecting its application is the problem of secondary phosphorus release, that is, the anaerobic phosphorus release of polyphosphate bacteria during the mud-water separation process in the sedimentation tank will cause the TP concentration of the effluent to increase again. How to maintain a low TP concentration in the sedimentation tank is of great significance for the application of biological phosphorus removal technology in the treatment of high-phosphorus wastewater. Summary of the invention

[0004] The purpose of the present invention is to provide a system and method for efficient phosphorus removal from high-phosphorus biodegradable wastewater in view of the deficiencies in the existing technology, so as to solve the problems raised in the above background technology that during the biological phosphorus removal from high-phosphorus wastewater, the anaerobic phosphorus release of polyphosphate bacteria during the mud-water separation in the sedimentation tank will cause the TP concentration of the effluent to increase again, and how to efficiently achieve biological phosphorus removal from high-phosphorus wastewater to reduce the cost of high-phosphorus wastewater treatment.

[0005] In order to achieve the above object, the present invention provides a system for efficiently removing phosphorus from high-phosphorus biodegradable wastewater, the system comprising:

[0006] A biological phosphorus removal tank, wherein an anaerobic zone and an aerobic zone are sequentially arranged inside the biological phosphorus removal tank along the water flow direction;

[0007] A sedimentation tank, the sedimentation tank is connected to the aerobic zone;

[0008] An oxygenating device, wherein the aeration portion of the oxygenating device is arranged in the sedimentation tank so that the sedimentation tank can form an aerobic sedimentation tank, and the aerobic environment is used to inhibit polyphosphate bacteria from releasing phosphorus in the sedimentation tank, so as to control the TP concentration of the effluent from the sedimentation tank.

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

[0010] A regulating tank, the regulating tank is connected to the anaerobic zone;

[0011] A pH regulating liquid storage tank, wherein the pH regulating liquid is stored in the pH regulating liquid storage tank, and the pH regulating liquid storage tank is connected to the regulating tank;

[0012] An organic carbon source storage tank, wherein the organic carbon source is stored in the organic carbon source storage tank, and the organic carbon source storage tank is connected to the regulating tank.

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

[0014] A sludge return pipe, the two ends of which are respectively connected to the sedimentation tank and the anaerobic zone;

[0015] A residual sludge discharge pipe, one end of which is connected to the sedimentation tank.

[0016] Preferably, the oxygenation device comprises:

[0017] A plurality of flat membranes, wherein the plurality of flat membranes are sequentially arranged at intervals inside the sedimentation tank, wherein the bottom corners and the top corners of the flat membranes are respectively provided with air inlet holes and air outlet holes, and the interior of the flat membranes is used for circulating air;

[0018] An air intake pipe connected to the air intake hole

[0019] An air outlet pipe, the air outlet pipe is connected to the air outlet hole;

[0020] An air pump, the air inlet pipe being in communication with the air pump;

[0021] A pressure gauge and an air volume regulating valve, wherein the pressure gauge and the air volume regulating valve are both arranged on the air outlet pipe.

[0022] Preferably, a water inlet end connected to the aerobic zone is provided on one side of the sedimentation tank, and the system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes a baffle, which is arranged in the sedimentation tank, and the baffle is spaced apart from one side of the sedimentation tank, and a flow channel is provided between the bottom of the baffle and the bottom of the sedimentation tank, and 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, a dynamic adjustment zone is provided inside the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone, and the dynamic adjustment zone can dynamically switch between the anaerobic state and the aerobic state.

[0024] Preferably, a stirrer is provided inside the anaerobic zone and the dynamic adjustment zone, and an aeration disk is provided inside the aerobic zone and the dynamic adjustment zone.

[0025] A method for efficiently removing phosphorus from high-phosphorus biodegradable wastewater, using a system for efficiently removing phosphorus from high-phosphorus biodegradable wastewater, the method comprising:

[0026] Inoculate activated sludge into the biological phosphorus removal tank and introduce wastewater to carry out biological phosphorus removal reaction;

[0027] Aerate the sedimentation tank to form an aerobic sedimentation tank, thereby inhibiting the release of phosphorus by polyphosphate bacteria in the sedimentation tank.

[0028] Preferably, when a dynamic adjustment zone is provided inside the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone, and the dynamic adjustment zone can dynamically switch between the anaerobic state and the aerobic state, the step of inoculating activated sludge into the biological phosphorus removal tank and introducing wastewater to perform biological phosphorus removal reaction comprises:

[0029] Maintain the phosphorus release in the anaerobic zone at 1.5 to 2.5 times the influent TP concentration. When the phosphorus release in the anaerobic zone is greater than 2.5 times the influent TP concentration, dynamically adjust the zone to switch to an aerobic state to reduce the ratio of hydraulic retention time between the anaerobic zone and the aerobic zone. When the phosphorus release in the anaerobic zone is less than 1.5 times the influent TP concentration, dynamically adjust the zone to switch to an anaerobic state to increase the ratio of hydraulic retention time between the anaerobic zone and the aerobic zone.

[0030] Monitor 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, increase the TP removal rate by increasing the dosage of organic carbon source in the regulating tank or extending the hydraulic retention time.

[0031] Preferably, when the oxygenation device includes a plurality of flat membranes, an air inlet pipe, an air outlet pipe, an air pump, a pressure gauge and an air volume regulating valve, the plurality of flat membranes are sequentially arranged in intervals inside the sedimentation tank, the bottom corners and the top corners of the flat membranes are provided with air inlets and air outlets, respectively, the interior of the flat membranes is used for circulating air, the air inlet pipe is connected to the air inlet, the air outlet pipe is connected to the air outlet, the air inlet pipe is connected to the air pump, the pressure gauge and the air volume regulating valve are both arranged on the air outlet pipe, and air is inflated into the flat membranes to form an aerobic sedimentation tank, and inhibiting polyphosphate bacteria from releasing phosphorus in the sedimentation tank includes:

[0032] In order to avoid the release of phosphorus by polyphosphate bacteria under anaerobic conditions during the mud-water separation process, the pressure inside the flat membrane is maintained below the bubble point by regulating the ventilation volume of the flat membrane in the sedimentation tank, 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 accumulates on the flat membrane and is not easy to slide off, or when the dissolved oxygen above the flat membrane decreases significantly under the same ventilation volume and pressure inside the flat membrane, the pressure inside the membrane is increased to above the bubble point of the flat membrane, and the overflowing bubbles form an impact on the sludge accumulated on the flat membrane, thereby clearing the sludge accumulated on the flat membrane.

[0034] The present invention provides a system and method for efficient phosphorus removal from high-phosphorus biodegradable wastewater, and the beneficial effects are as follows: a conventional sedimentation tank is in an anaerobic state, and phosphorus release by polyphosphate bacteria in the anaerobic state will lead to an increase in TP concentration in effluent, while an oxygenating device is arranged in the sedimentation tank of the system, which can inhibit the secondary phosphorus release of polyphosphate bacteria in the sedimentation tank under aerobic conditions, thereby avoiding an increase in TP concentration in effluent from the sedimentation tank; at the same time, anaerobic processes such as denitrification and anaerobic digestion can also be inhibited, and no gas will be generated, so there is no risk of sludge floating.

[0035] This method utilizes the system to apply biological phosphorus removal to the treatment of high-phosphorus biodegradable wastewater, greatly reducing the addition of chemical agents and the generation of chemical sludge, significantly reducing the treatment cost of high-phosphorus wastewater, being economical and efficient, and having no secondary pollution.

[0036] The method utilizes the system to convert phosphorus in wastewater into phosphate form through biological phosphorus removal process. The anaerobic phosphorus release process after the residual sludge is discharged can achieve the concentration of TP in the incoming water, which is more conducive to phosphorus recovery. Whether to recover phosphorus in the residual sludge can be determined according to the economic feasibility based on the TP concentration and water volume of the incoming water.

[0037] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

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

[0040] Figure 2 A schematic diagram of the structure of a system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to an embodiment of the present invention is shown;

[0041] Figure 3A schematic structural diagram of an oxygenation device of a system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to an embodiment of the present invention is shown.

[0042] Description of reference numerals:

[0043] 1. Regulating tank; 1.1. pH regulating 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. Inlet pipe; 3.3. Outlet pipe; 3.4. Pressure gauge; 3.5 Gas volume regulating valve. DETAILED DESCRIPTION

[0044] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0045] like Figure 2 As shown, the present invention provides a system for efficient phosphorus removal from high-phosphorus biodegradable wastewater, the system comprising:

[0046] A biological phosphorus removal tank 2, wherein an anaerobic zone 2.1 and an aerobic zone 2.3 are sequentially arranged inside the biological phosphorus removal tank 2 along the water flow direction;

[0047] Sedimentation tank 3, which is connected to aerobic zone 2.3;

[0048] The oxygenating device, the aeration part of the oxygenating device is arranged in the sedimentation tank 3, so that the sedimentation tank 3 can form an aerobic sedimentation tank, and the polyphosphate bacteria are inhibited from releasing phosphorus in the sedimentation tank 3 through the aerobic environment, so as to control the TP concentration of the effluent of the sedimentation tank 3.

[0049] Specifically, in order to solve the problem that during the biological phosphorus removal of high-phosphorus wastewater, anaerobic phosphorus release by polyphosphate bacteria during the mud-water separation process in the sedimentation tank will cause the TP concentration of the effluent to increase again, the present invention provides a system for efficient phosphorus removal of high-phosphorus and biodegradable wastewater. The effluent of the biological phosphorus removal tank 2 in the system enters the sedimentation tank 3 to achieve mud-water separation. An oxygenating device is arranged in the sedimentation tank 3 to form an aerobic sedimentation tank 3. Under aerobic environmental conditions, the secondary phosphorus release of polyphosphate bacteria in the sedimentation tank 3 can be inhibited, thereby avoiding the increase of TP (total phosphorus) in the effluent of the sedimentation tank 3. At the same time, anaerobic processes such as denitrification and anaerobic digestion can also be inhibited, and no gas will be generated. Therefore, there is no risk of sludge floating.

[0050] Preferably, the system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes:

[0051] Regulating tank 1, regulating tank 1 is connected with anaerobic zone 2.1;

[0052] A pH regulating liquid storage tank 1.1, wherein the pH regulating liquid is stored in the pH regulating liquid storage tank 1.1, and the pH regulating liquid storage tank 1.1 is connected to the regulating tank 1;

[0053] The organic carbon source storage pool 1.2 stores an organic carbon source inside the organic carbon source storage pool 1.2, and the organic carbon source storage pool 1.2 is connected to the regulating pool 1.

[0054] Specifically, a stirrer is provided inside the pH adjusting liquid storage tank 1.1, which can realize the preparation and storage of the pH adjusting liquid, and the pH adjusting liquid storage tank 1.1 is connected to the adjusting tank 1; a stirrer is provided inside the organic carbon source storage tank 1.2, which can realize the preparation and storage of the organic carbon source, and the organic carbon source storage tank 1.2 is connected to the adjusting tank 1, the pH adjusting liquid storage tank 1.1 can adjust the pH of the incoming water, and the organic carbon source storage tank 1.2 can adjust the COD / TP of the incoming water.

[0055] Preferably, the system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes:

[0056] A sludge return pipe, the two ends of which are connected to the sedimentation tank 3 and the anaerobic zone 2.1 respectively;

[0057] A residual sludge discharge pipe, one end of which is connected to the sedimentation tank 3.

[0058] Specifically, part of the sludge deposited at the bottom of the 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 pipe, and part of the sludge is discharged through the residual sludge discharge pipe to control the sludge age of the high-efficiency biological phosphorus removal tank; when the treated water volume is low and the income from phosphorus recovery cannot cover the cost, the residual sludge is directly dehydrated, and a small amount of ferrous chloride is added before dehydration to reduce the phosphate content in the dehydrated liquid and reduce the overflow of hydrogen sulfide odor; the dehydrated liquid is returned to the regulating tank 1.

[0059] like Figure 3 As shown, preferably, the oxygenation device comprises:

[0060] A plurality of flat membranes 3.1 are arranged in sequence in the sedimentation tank 3 at intervals, and air inlets and air outlets are respectively arranged at the bottom corners and top corners of the flat membranes 3.1, and the interior of the flat membranes 3.1 is used for circulating air;

[0061] Inlet pipe 3.2, the air intake pipe 3.2 is connected to the air intake hole

[0062] An air outlet pipe 3.3, the air outlet pipe 3.3 is connected to the air outlet hole;

[0063] An air pump, the air inlet pipe 3.2 is connected to the air pump;

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

[0065] Specifically, a plurality of flat 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 membranes 3.1 are ventilated with air and can achieve bubble-free oxygenation under a certain pressure to provide dissolved oxygen for the sedimentation tank 3. A plurality of dissolved oxygen sensors are arranged above the flat membranes 3.1 to monitor the dissolved oxygen level.

[0066] The bubble-free oxygenation method can provide dissolved oxygen to 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 polyphosphate bacteria in sedimentation tank 3 through the aerobic environment to maintain a low TP concentration in the effluent of sedimentation tank 3.

[0067] The flat membrane 3.1 is arranged obliquely, with an angle of not less than 60 degrees with the horizontal direction, and can act as an inclined plate to increase the sedimentation area and shorten the sedimentation time.

[0068] Preferably, a water inlet end connected to the aerobic zone 2.3 is provided on one side of the sedimentation tank 3. The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes a baffle, which is arranged in the sedimentation tank 3. The baffle is spaced apart from one side of the sedimentation tank 3. A flow channel is provided between the bottom of the baffle and the bottom of the sedimentation tank 3. A plurality of flat 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 provided 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 dynamically switch between the anaerobic state and the aerobic state.

[0070] Specifically, the anaerobic state and the aerobic state can be switched according to the operating conditions. By switching between the anaerobic state and the aerobic state, the ratio of the anaerobic retention time and the aerobic retention time of the high-efficiency biological phosphorus removal tank 2 can be adjusted.

[0071] Preferably, agitators are provided inside the anaerobic zone 2.1 and the dynamic adjustment zone 2.2, and aeration disks are provided 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 high-efficiency biological phosphorus removal tank 2 through the sludge return pipe.

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

[0074] Specifically, several online sensors are pH sensor, dissolved oxygen sensor, sludge concentration sensor, COD sensor, ammonia nitrogen sensor, nitric nitrogen sensor, and TP sensor. Through the online control system, precise regulation of key control parameters can be achieved. The requirements for on-site operating personnel are low, which can improve the guarantee of treatment effects while reducing operating costs.

[0075] like Figure 1 As shown, a method for efficiently removing phosphorus from high-phosphorus biodegradable wastewater is provided, using a system for efficiently removing phosphorus from high-phosphorus biodegradable wastewater, the method comprising:

[0076] Inoculate activated sludge into the biological phosphorus removal tank 2 and introduce wastewater to carry out biological phosphorus removal reaction;

[0077] Aeration is added to the sedimentation tank 3 to form an aerobic environment in the sedimentation tank 3, thereby inhibiting the polyphosphate bacteria from releasing phosphorus in the sedimentation tank 3.

[0078] Preferably, when a dynamic adjustment zone 2.2 is provided inside 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 dynamically switch between the anaerobic state and the aerobic state, activated sludge is inoculated into the biological phosphorus removal tank 2 and wastewater is introduced, the regulation steps for the biological phosphorus removal reaction specifically include:

[0079] Control the hydraulic retention time of the anaerobic zone 2.1 to 1 to 3 hours, maintain the phosphorus release of the anaerobic zone 2.1 to be 1.5 to 2.5 times the influent TP concentration. When the phosphorus release of the anaerobic zone 2.1 is greater than 2.5 times the influent TP concentration, close the agitator of the dynamic adjustment zone 2.2 and open the aeration disk of the dynamic adjustment zone 2.2 to reduce the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone. When the phosphorus release of the anaerobic zone 2.1 is lower than 1.5 times the influent TP concentration, close the aeration disk of the dynamic adjustment zone 2.2 and open the agitator of the dynamic adjustment zone 2.2 to increase the ratio of the hydraulic retention time of the anaerobic zone to the aerobic zone.

[0080] Control the hydraulic retention time of aerobic zone 2.3 at 5 to 10 hours and the dissolved oxygen at 1 to 3 mg / L, monitor the TP concentration at the end of aerobic zone 2.3, and when the TP concentration at the end of aerobic zone 2.3 is higher than 2 mg / L, increase the TP removal rate by increasing the dosage of organic carbon source in regulating tank 1 or extending the hydraulic retention time.

[0081] Preferably, when the oxygenation device includes a plurality of flat 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 membranes 3.1 are sequentially arranged in intervals inside the sedimentation tank 3, the bottom corners and the top corners of the flat membranes 3.1 are provided with air inlets and air outlets, respectively, the interior of the flat membranes 3.1 is used for circulating air, the air inlet pipe 3.2 is connected to the air inlet, the air outlet pipe 3.3 is connected to the air outlet, the air inlet pipe 3.2 is connected to the air pump, the pressure gauge 3.4 and the air volume regulating valve 3.5 are both arranged on the air outlet pipe 3.3, the flat membranes are inflated to form an aerobic environment in the sedimentation tank 3, and inhibiting polyphosphate bacteria from releasing phosphorus in the sedimentation tank 3 includes:

[0082] In order to avoid the release of phosphorus by polyphosphate bacteria under anaerobic conditions during the mud-water separation process, the pressure inside the flat membrane 3.1 is maintained below the bubble point by regulating the ventilation volume 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;

[0083] When it is observed that sludge is accumulated on the flat membrane 3.1 and is not easy to slide off, or when the dissolved oxygen above the flat membrane 3.1 is significantly reduced under the same ventilation volume and pressure inside the flat membrane 3.1, the pressure inside the flat membrane 3.1 is increased to above the bubble point of the flat membrane 3.1, and the overflowing bubbles form an impact on the sludge accumulated on the flat membrane 3.1, thereby cleaning the sludge accumulated on the flat membrane 3.1.

[0084] The specific steps are as follows:

[0085] S1: Monitor the pH and COD / TP of the wastewater in the regulating tank 1 and adjust them to maintain the pH of the wastewater at 7-8. 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: ordinary activated sludge is inoculated into the high-efficiency biological phosphorus removal pool 2. Preferably, activated sludge with good biological phosphorus removal effect is inoculated, and the sludge concentration is 4000-8000 mg / L.

[0087] S3: Control the hydraulic retention time of the anaerobic zone 2.1 of the high-efficiency biological phosphorus removal tank 2 to be 1 to 3 hours, maintain the phosphorus release of the anaerobic zone 2.1 to be 1.5 to 2.5 times the influent TP concentration; when the phosphorus release of the anaerobic zone 2.1 is greater than 2.5 times the influent TP concentration, close the agitator of the dynamic adjustment zone 2.2 and open the aeration disk of the dynamic adjustment zone 2.2 to reduce the ratio of the hydraulic retention time of the anaerobic area to the aerobic area in the high-efficiency biological phosphorus removal tank 2; when the phosphorus release of the anaerobic zone 2.1 is lower than 1.5 times the influent TP concentration, close the aeration disk of the dynamic adjustment zone 2.2 and open the agitator of the dynamic adjustment zone 2.2 to increase the ratio of the hydraulic retention time of the anaerobic area to the aerobic area in the high-efficiency biological phosphorus removal tank 2.

[0088] S4: Control the hydraulic retention time of aerobic zone 2.3 of high-efficiency biological phosphorus removal pool 2 at 5 to 10 hours and the dissolved oxygen at 1 to 3 mg / L; monitor the TP concentration at the end of aerobic zone 2.3. When the TP concentration at the end of aerobic zone 2.3 is higher than 2 mg / L, increase the TP removal rate by increasing the dosage of organic carbon source in regulating pool 1 or extending the hydraulic retention time.

[0089] S5: In order to avoid the release of phosphorus by polyphosphate bacteria under anaerobic conditions during the mud-water separation process, the ventilation volume of the flat membrane 3.1 in the sedimentation tank is regulated to maintain the pressure inside the flat membrane 3.1 below the bubble point, 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 of it is discharged as residual sludge. By controlling the discharge amount of residual sludge, the sludge age of the system is maintained at 5-10 days.

[0091] In the present application, the method for realizing efficient phosphorus removal of high-phosphorus biodegradable wastewater by using the system includes: after the high-phosphorus biodegradable wastewater is subjected to primary treatment to remove suspended solids and sand particles, it enters the regulating tank 1, and the pH and COD / TP of the incoming water are adjusted to meet the requirements of biological phosphorus removal; the effluent from the regulating tank 1 enters the efficient biological phosphorus removal tank 2, and the organic matter is adsorbed and partially degraded in the anaerobic zone 2.1 of the efficient biological phosphorus removal tank 2, and the polyphosphate bacteria complete the PHA storage and phosphorus release process; after the anaerobic phosphorus release, the degradation of organic matter and the excessive phosphorus absorption of the polyphosphate bacteria are completed in the aerobic zone; the effluent from the efficient biological phosphorus removal tank 2 enters the sedimentation tank to realize mud-water separation, and a bubble-free oxygenation device is arranged in the sedimentation tank, and the aerobic environment can inhibit the polyphosphate bacteria from releasing phosphorus for the second time in the sedimentation tank 3, so as to avoid the increase of the TP of the effluent from the sedimentation tank 3; the real-time regulation of the key control parameters of the system is realized through the online control system, so as to reduce the treatment cost while ensuring the phosphorus removal efficiency.

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

[0093] Preferably, in step S5, when it is observed that sludge is accumulated on the flat membrane 3.1 and is not easy to slide off, or when the dissolved oxygen above the flat membrane 3.1 decreases significantly under the same ventilation volume and membrane pressure conditions, the membrane pressure is increased to above the bubble point of the flat membrane 3.1, and the overflowing bubbles form an impact on the sludge accumulated on the flat membrane 3.1, thereby cleaning the sludge accumulated on the flat membrane 3.1.

[0094] Preferably, when the activated sludge settling effect in the high-efficiency biological phosphorus removal tank 2 deteriorates and sludge swelling 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 serve as a "crystal nucleus" to help the formation of granular sludge.

[0095] Preferably, when the ammonia nitrogen concentration in the wastewater is high, an inhibitor is regularly added to the sludge return line to inhibit the ammonia nitrogen oxidation process, thereby avoiding the high nitric nitrogen concentration in the sludge return liquid inhibiting the release of phosphorus by polyphosphate bacteria. The inhibitor can be hydroxylamine; and the sludge age is shortened by increasing the discharge of residual sludge, and the ammonia oxidizing bacteria are screened out through the difference in doubling time between heterotrophic bacteria and ammonia oxidizing bacteria (autotrophic bacteria).

[0096] Preferably, the excess sludge can be treated in two different ways depending on the TP concentration and water volume of the incoming water.

[0097] When the TP concentration of the incoming water is greater than 50 mg / L and the water volume is large, the remaining sludge is subjected to anaerobic digestion treatment, and after anaerobic digestion, phosphorus is recovered from the supernatant, and magnesium salt is added to recover phosphorus in the form of magnesium ammonium phosphate.

[0098] When the TP concentration of the incoming water is lower than 50 mg / L or the water volume is small, the remaining sludge is directly dehydrated after being discharged from the sedimentation tank. A small amount of ferrous chloride is added before dehydration to reduce the phosphate content in the dehydrated liquid and reduce the overflow of hydrogen sulfide odor. The dehydrated liquid is returned to the regulating tank 1.

[0099] Example

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

[0101] The method for realizing efficient phosphorus removal from high-phosphorus biodegradable wastewater using the system in this embodiment comprises the following steps:

[0102] S1: Monitor the pH and COD / TP of the wastewater in the regulating tank 1 and adjust them to maintain the pH of the wastewater at 7-8, the COD / TP of the wastewater greater than 16, and the organic carbon source is sufficient and does not need to be supplemented.

[0103] S2: Activated sludge with good biological phosphorus removal effect is inoculated into the high-efficiency biological phosphorus removal pool 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 at 1.5 hours; maintain the phosphorus release of the anaerobic zone 2.1 to be 1.5 to 2.5 times the influent TP concentration. When the phosphorus release of the anaerobic zone 2.1 is greater than 2.5 times the influent TP concentration, close the agitator of the dynamic adjustment zone 2.2 and open the aeration disk of the dynamic adjustment zone 2.2 to reduce the ratio of the hydraulic retention time of the anaerobic area to the aerobic area in the high-efficiency biological phosphorus removal tank 2; when the phosphorus release of the anaerobic zone 2.1 is lower than 1.5 times the influent TP concentration, close the aeration disk of the dynamic adjustment zone 2.2 and open the agitator of the dynamic adjustment zone 2.2 to increase the ratio of the hydraulic retention time of the anaerobic area to the aerobic area in the high-efficiency biological phosphorus removal tank.

[0105] S4: Control the hydraulic retention time of aerobic zone 2.3 of high-efficiency biological phosphorus removal pool 2 at 6 hours and the dissolved oxygen at 1-3 mg / L; monitor the TP concentration at the end of aerobic zone 2.3. When the TP concentration at the end of aerobic zone 2.3 is higher than 2 mg / L, increase the TP removal rate by increasing the dosage of organic carbon source in regulating pool 1 or extending the hydraulic retention time.

[0106] S5: To prevent phosphorus release by polyphosphate bacteria under anaerobic conditions during mud-water separation, the ventilation volume of the flat membrane 3.1 in the sedimentation tank 3 is regulated to maintain the pressure inside the flat membrane 3.1 below the bubble point, so that the dissolved oxygen above the flat membrane 3.1 is maintained at 0.2-1.0 mg / L.

[0107] Step S5 also includes:

[0108] When it is observed that sludge is accumulated on the flat membrane 3.1 and is not easy to slide off, or when the dissolved oxygen above the flat membrane 3.1 decreases significantly under the same ventilation volume and membrane pressure conditions, the membrane pressure is increased to above the bubble point of the flat membrane 3.1, and the overflowing bubbles form an impact on the sludge accumulated on the flat membrane 3.1, thereby cleaning the sludge accumulated on the flat membrane 3.1.

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

[0110] When the activated sludge settling effect in the high-efficiency biological phosphorus removal tank 2 deteriorates 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. At the same time, the powdered activated carbon can serve as a "crystal nucleus" to help the formation of granular sludge.

[0111] Due to the high ammonia nitrogen concentration in the wastewater, the inhibitor hydroxylamine is added to the sludge return pipeline once every half a month to inhibit the ammonia nitrogen oxidation process and avoid the high nitric nitrogen concentration in the sludge return liquid inhibiting the release of phosphorus from polyphosphate bacteria. The sludge age is shortened to 5 days by increasing the discharge of residual sludge, and the ammonia oxidizing bacteria are washed out by the difference in doubling time between heterotrophic bacteria and ammonia oxidizing bacteria (autotrophic bacteria);

[0112] In this embodiment, due to the small amount of water, phosphorus recovery is not economical, and the excess sludge is directly dehydrated after being discharged from the sedimentation tank. A small amount of ferrous chloride is added before dehydration to reduce the phosphate content in the dehydrated liquid and reduce the overflow of hydrogen sulfide odor. The dehydrated liquid is returned to the regulating 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 is less than 1 mg / L. The system and method for efficient phosphorus removal from high-phosphorus biodegradable wastewater proposed in this application can be widely used in the treatment of high-phosphorus biodegradable wastewater.

[0114] In summary, when the method for efficient phosphorus removal from high-phosphorus biodegradable wastewater provided by the present invention utilizes the system, its treatment process is as follows: after the high-phosphorus biodegradable wastewater is subjected to primary treatment to remove suspended matter and sand particles, it enters the regulating tank 1, and the pH and COD / TP of the incoming water are adjusted to meet the requirements of biological phosphorus removal; the effluent from the regulating tank 1 enters the efficient biological phosphorus removal tank 2, and the organic matter is adsorbed and partially degraded in the anaerobic zone 2.1 of the efficient biological phosphorus removal tank 2, and the polyphosphate bacteria complete the PHA storage and phosphorus release process; after the anaerobic phosphorus release, the organic matter is degraded and the polyphosphate bacteria absorb excessive phosphorus in the aerobic zone 2.3; the effluent from the efficient biological phosphorus removal tank 2 enters the sedimentation tank 3 to achieve mud-water separation, and the sedimentation tank 3 is provided with a bubble-free oxygenation device, and the aerobic The environment can inhibit the secondary release of phosphorus by polyphosphate bacteria in sedimentation tank 3 to avoid the increase of TP in the effluent of sedimentation tank 3; part of the sludge deposited at the bottom of aerobic sedimentation tank 3 is returned to the front end of anaerobic zone 2.1 of high-efficiency biological phosphorus removal tank 2 through the sludge return pipe, and part of the sludge is discharged through the residual sludge pipeline to control the sludge age of high-efficiency biological phosphorus removal tank 2; according to the TP concentration and water volume of the incoming water, there are two ways to treat the residual sludge. When phosphorus recovery is valuable, the phosphorus in the supernatant is recovered after the residual sludge is anaerobically digested; when the phosphorus recovery income cannot cover the cost, the residual sludge is directly dehydrated, and a small amount of ferrous chloride is added before dehydration to reduce the phosphate content in the dehydrated liquid and reduce the overflow of hydrogen sulfide odor; the dehydrated liquid is returned to the regulating tank 1.

[0115] The method utilizes the system to achieve economical and efficient treatment of high-phosphorus biodegradable wastewater without secondary pollution caused by chemical sludge. When the water volume is large, the supernatant can be used to recover phosphorus after anaerobic digestion of the remaining sludge. When the water volume is small, phosphorus recovery is not economical and the remaining sludge is directly dehydrated.

[0116] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A system for efficient phosphorus removal from high-phosphorus biodegradable wastewater, characterized in that: The system includes: A biological phosphorus removal tank, wherein an anaerobic zone and an aerobic zone are sequentially arranged inside the biological phosphorus removal tank along the water flow direction; A sedimentation tank, the sedimentation tank is connected to the aerobic zone; An oxygenating device, wherein the aeration portion of the oxygenating device is arranged in the sedimentation tank so that the sedimentation tank can form an aerobic sedimentation tank, and the aerobic environment is used to inhibit polyphosphate bacteria from releasing phosphorus in the sedimentation tank, so as to control the TP concentration of the effluent from the sedimentation tank.

2. A system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that: The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes: A regulating tank, the regulating tank is connected to the anaerobic zone; A pH regulating liquid storage tank, wherein the pH regulating liquid is stored in the pH regulating liquid storage tank, and the pH regulating liquid storage tank is connected to the regulating tank; An organic carbon source storage tank, wherein the organic carbon source is stored in the organic carbon source storage tank, and the organic carbon source storage tank is connected to the regulating tank.

3. The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that: The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes: A sludge return pipe, the two ends of which are respectively connected to the sedimentation tank and the anaerobic zone; A residual sludge discharge pipe, one end of which is connected to the sedimentation tank.

4. The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that: The oxygenation device comprises: A plurality of flat membranes, wherein the plurality of flat membranes are sequentially arranged at intervals inside the sedimentation tank, wherein the bottom corners and the top corners of the flat membranes are respectively provided with air inlet holes and air outlet holes, and the interior of the flat membranes is used for circulating air; An air intake pipe connected to the air intake hole An air outlet pipe, the air outlet pipe is connected to the air outlet hole; An air pump, the air inlet pipe being in communication with the air pump; A pressure gauge and an air volume regulating valve, wherein the pressure gauge and the air volume regulating valve are both arranged on the air outlet pipe.

5. A system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 4, characterized in that: A water inlet end connected to the aerobic zone is provided on one side of the sedimentation tank. The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater also includes a baffle, which is arranged in the sedimentation tank. The baffle is spaced apart from one side of the sedimentation tank. A flow channel is provided between the bottom of the baffle and the bottom of the sedimentation tank. 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.

6. The system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 1, characterized in that: A dynamic adjustment zone is provided inside the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone. The dynamic adjustment zone can dynamically switch between the anaerobic state and the aerobic state.

7. A system for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 6, characterized in that: Agitators are provided inside the anaerobic zone and the dynamic adjustment zone, and aeration plates are provided inside the aerobic zone and the dynamic adjustment zone.

8. A method for efficient phosphorus removal from high-phosphorus, easily biodegradable wastewater, using the system for efficient phosphorus removal from high-phosphorus, easily biodegradable wastewater according to claims 1-7, the method comprising: Inoculate activated sludge into the biological phosphorus removal tank and introduce wastewater to carry out biological phosphorus removal reaction; Aerate the sedimentation tank to form an aerobic sedimentation tank, thereby inhibiting the release of phosphorus by polyphosphate bacteria in the sedimentation tank.

9. The method for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 8, characterized in that: When a dynamic adjustment zone is provided inside the biological phosphorus removal tank and between the anaerobic zone and the aerobic zone, and the dynamic adjustment zone can dynamically switch between the anaerobic state and the aerobic state, the biological phosphorus removal reaction is carried out by inoculating activated sludge into the biological phosphorus removal tank and introducing wastewater, and comprising: Maintain the phosphorus release in the anaerobic zone at 1.5 to 2.5 times the influent TP concentration. When the phosphorus release in the anaerobic zone is greater than 2.5 times the influent TP concentration, the zone is dynamically adjusted to switch to an aerobic state, reducing the ratio of the hydraulic retention time between the anaerobic zone and the aerobic zone. When the phosphorus release in the anaerobic zone is lower than 1.5 times the influent TP concentration, the zone is dynamically adjusted to switch to an anaerobic state, increasing the ratio of the hydraulic retention time between the anaerobic zone and the aerobic zone. Monitor 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, increase the TP removal rate by increasing the dosage of organic carbon source in the regulating tank or extending the hydraulic retention time.

10. The method for efficient phosphorus removal from high-phosphorus biodegradable wastewater according to claim 9, characterized in that: When the oxygenation device includes a plurality of flat membranes, an air inlet pipe, an air outlet pipe, an air pump, a pressure gauge and an air volume regulating valve, the plurality of flat membranes are sequentially arranged in intervals inside the sedimentation tank, the bottom corners and the top corners of the flat membranes are provided with air inlets and air outlets respectively, the interior of the flat membranes is used for circulating air, the air inlet pipe is connected with the air inlet, the air outlet pipe is connected with the air outlet, the air inlet pipe is connected with the air pump, the pressure gauge and the air volume regulating valve are both arranged on the air outlet pipe, and air is inflated into the flat membranes to form an aerobic sedimentation tank, and inhibiting polyphosphate bacteria from releasing phosphorus in the sedimentation tank includes: In order to avoid the release of phosphorus by polyphosphate bacteria under anaerobic conditions during the mud-water separation process, the pressure inside the flat membrane is maintained below the bubble point by regulating the ventilation volume of the flat membrane in the sedimentation tank, so that the dissolved oxygen above the flat membrane is maintained at 0.2-1.0 mg / L. When it is observed that sludge accumulates on the flat membrane and is not easy to slide off, or when the dissolved oxygen above the flat membrane decreases significantly under the same ventilation volume and pressure inside the flat membrane, the pressure inside the membrane is increased to above the bubble point of the flat membrane, and the overflowing bubbles form an impact on the sludge accumulated on the flat membrane, thereby clearing the sludge accumulated on the flat membrane.

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