Enhanced nitrogen and phosphorus removal device and process for enhancing utilization of internal carbon source by compounding lateral flow mud film

Abstract

The invention discloses an enhanced nitrogen and phosphorus removal device for enhancing utilization of an internal carbon source by side flow mud film composite, which comprises an SBR (sequencing batch reactor), the bottom of the SBR is connected with the top of a bypass flow anaerobic tank through a peristaltic pump III, the bottom of the bypass flow anaerobic tank is connected with the top of the SBR through a peristaltic pump II, the top and the bottom of the SBR are respectively connected with a peristaltic pump I and a peristaltic pump IV, and the peristaltic pump I and the peristaltic pump IV are connected with a water pump II. The SBR reactor, the bypass flow anaerobic tank, the peristaltic pump I, the peristaltic pump II, the peristaltic pump III and the peristaltic pump IV are all connected with the controller. The invention also discloses an enhanced nitrogen and phosphorus removal process for enhancing the utilization of the internal carbon source by compounding the lateral flow mud film. The device and the process disclosed by the invention solve the problem of poor acid production capacity of a bypass flow reactor under a low-temperature condition in the existing process.

Description

Technical Field

[0001] The present invention belongs to the technical field of biological sewage treatment methods, and specifically relates to an enhanced denitrification and phosphorus removal device with a lateral flow mud film composite to enhance internal carbon source utilization, and also relates to an enhanced denitrification and phosphorus removal process with a lateral flow mud film composite to enhance internal carbon source utilization. Background Art

[0002] The rapid development of human society has brought about the discharge of a large amount of agricultural, industrial and domestic sewage, making water eutrophication an increasingly serious problem of water resource pollution. Among them, the discharge of nitrogen and phosphorus nutrients is the main cause of eutrophication of receiving water bodies.

[0003] Chemical and biological methods are the most common methods of phosphorus removal. Chemical phosphorus removal (CPR) is a method of adding chemical agents such as iron salts and aluminum salts to react with PO4 in sewage. 3- -P forms insoluble chemical precipitates and is then removed; Biological Phosphorus Removal (BPR) utilizes the characteristics of anaerobic phosphorus release and aerobic excess phosphorus absorption by polyphosphate bacteria to remove phosphorus from wastewater by discharging phosphorus-containing residual sludge at the end of aerobic period. In the actual operation of the process, it is usually necessary to ensure sufficient carbon source (mainly volatile fatty acids (VFAs)) to achieve good phosphorus removal effect.

[0004] However, many sewage treatment plants have the problem of insufficient carbon source in the influent. Improving the phosphorus removal effect by adding commercial carbon sources and chemical phosphorus removal agents will result in high operating costs and a long carbon footprint. Although the S2EBPR process can supplement some additional carbon sources to the mainstream reactor through the side-stream anaerobic fermentation tank, the fermentation acid production capacity of the side-stream anaerobic tank under low temperature conditions and the nitrogen and phosphorus removal performance of the mainstream reactor still need to be further optimized. Summary of the invention

[0005] The first object of the present invention is to provide a side-stream mud membrane composite enhanced internal carbon source utilization enhanced denitrification and phosphorus removal device to solve the problem of poor acid production capacity of the side-stream reactor under low temperature conditions in the existing process.

[0006] The second object of the present invention is to provide a process for enhancing nitrogen removal and phosphorus removal by using a side stream mud membrane composite to enhance internal carbon source utilization.

[0007] The first technical solution adopted by the present invention is: a side-stream mud film composite enhanced internal carbon source utilization enhanced denitrification and phosphorus removal device, including an SBR reactor, the bottom of the SBR reactor is connected to the top of the side-stream anaerobic tank through a peristaltic pump III, the bottom of the side-stream anaerobic tank is connected to the top of the SBR reactor through a peristaltic pump II, the top and bottom of the SBR reactor are respectively connected to a peristaltic pump I and a peristaltic pump IV, which serve as an inlet pump and an outlet pump respectively, and the SBR reactor, the side-stream anaerobic tank, the peristaltic pump I, the peristaltic pump II, the peristaltic pump III and the peristaltic pump IV are all connected to a controller.

[0008] The first technical solution adopted by the present invention is also characterized in that: Furthermore, in the side-stream mud film composite enhanced internal carbon source utilization enhanced denitrification and phosphorus removal device, an agitator is arranged inside the SBR reactor.

[0009] Furthermore, a stirrer is provided inside the side-flow anaerobic tank.

[0010] The second technical solution adopted by the present invention is: a side-stream mud film composite enhanced internal carbon source utilization enhanced nitrogen removal and phosphorus removal process, using the above-mentioned side-stream staged water inlet enhanced acid production enhanced biological phosphorus removal device, specifically implemented according to the following steps: Step 1: Pump the raw sewage into the SBR reactor in sections through peristaltic pump I and keep it at 15°C-30°C for 6 hours; Step 2, the supernatant after precipitation in step 1 is directly discharged out of the system through the peristaltic pump IV, and part of the remaining sludge is discharged out of the system through the sludge outlet at the bottom of the SBR reactor; the other part of the sludge is stirred and then used as return sludge to enter the top of the side stream anaerobic tank from the bottom opening of the SBR reactor through the peristaltic pump III; The return sludge from step 3 and step 2 is subjected to anaerobic fermentation and polyphosphate bacteria screening in a side-stream anaerobic tank, and then returned to the SBR reactor via peristaltic pump II; Step 4, introducing raw sewage into the SBR reactor, and repeating steps 2 and 3 to perform biological phosphorus removal on the raw sewage.

[0011] The second technical solution adopted by the present invention is also characterized in that: Furthermore, the sludge retention time in the system is 17 days.

[0012] Furthermore, the SBR reactor adopts a staged water inlet multi-stage A / O operation mode.

[0013] Furthermore, the SBR reactor is divided into a first anaerobic section and a second anaerobic section. The first anaerobic section has 1 / 2 of the total water inflow, the anaerobic time is 60 min, and the aerobic time is 90 min. The second anaerobic section has 1 / 2 of the total water inflow, the anaerobic time is 60 min, and the aerobic time is 90 min. The sedimentation time is 30 min, the drainage time is 25 min, and the water is fed into the sidestream anaerobic tank in a stirring state for 5 min.

[0014] Furthermore, in step 2, the sludge bypass ratio entering the bypass anaerobic tank is 20%.

[0015] Furthermore, the hydraulic retention time of the return sludge in step 3 in the side-stream anaerobic tank is 96 h, the dissolved oxygen concentration is 0.01-0.1 mg / L, and the sludge concentration is 5800 mg / L.

[0016] Furthermore, a biofilm carrier, specifically an anaerobic biocarrier AMC, is added into the side-stream anaerobic tank, with a filling ratio of 25%.

[0017] The beneficial effects of the present invention are: The SBR reactor of the present invention adopts a staged water inlet multi-stage A / O operation mode, and fully utilizes the carbon source to improve the denitrification efficiency.

[0018] The deep anaerobic conditions of the side-stream anaerobic tank of the present invention create favorable conditions for the polyphosphate bacteria to gain an advantage in the competition with the polysaccharide-accumulating bacteria, thereby enhancing the phosphorus removal performance of the process.

[0019] The biofilm carrier added to the sidestream anaerobic tank of the present invention increases the biomass per unit volume, enriches the fermentation-capable microorganisms, and increases the VFAs yield. Organic matter such as VFAs enters the mainstream reactor to supplement the carbon source required by the denitrifying bacteria and polyphosphate bacteria in the mainstream reactor, thereby improving the denitrification and phosphorus removal performance and system stability of the overall process.

[0020] The process structure of the invention is simple and flexible, and can be easily combined with and transformed into an existing SBR process.

[0021] The side-stream anaerobic tank of the present invention anaerobic ferments part of the excess sludge, which has a certain sludge reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the enhanced biological phosphorus removal device with side-flow staged water inlet and enhanced acid production according to the present invention; Figure 2 Schematic diagram of TP removal effect in Examples 1-6 of the present invention; Figure 3 Schematic diagram of COD removal effect in Examples 1-6 of the present invention; Figure 4 Schematic diagram of TN removal effect in Examples 1-6 of the present invention.

[0023] In the figure: 1. SBR reactor, 2. controller, 3. side-stream anaerobic tank, 4-1. peristaltic pump I, 4-2. peristaltic pump II, 4-3. peristaltic pump III, 4-4. peristaltic pump IV. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0025] The present invention provides a device for strengthening nitrogen removal and phosphorus removal by combining side-flow mud membrane to enhance internal carbon source utilization, such as Figure 1 As shown, it includes an SBR reactor 1, the bottom of the SBR reactor 1 is connected to the top of the side-stream anaerobic tank 3 through a peristaltic pump III 4-3, the bottom of the side-stream anaerobic tank 3 is connected to the top of the SBR reactor 1 through a peristaltic pump II 4-2, the top and bottom of the SBR reactor 1 are respectively connected to a peristaltic pump I 4-1 and a peristaltic pump IV 4-4, which serve as an inlet pump and an outlet pump, respectively, and the SBR reactor 1, the side-stream anaerobic tank 3, the peristaltic pump I 4-1, the peristaltic pump II 4-2, the peristaltic pump III 4-3, the peristaltic pump IV 4-4 and are all connected to a controller 2.

[0026] Agitators are provided inside the SBR reactor 1 and the side-stream anaerobic tank 3 .

[0027] The functions of each part are as follows: SBR Reactor 1: SBR reactor 1 adopts multi-stage water inlet and multi-level A / O operation mode. The specific operation is that the first stage anaerobic water inlet is 1 / 2 of the total amount, the anaerobic time is 60 minutes, and the first stage aerobic time is 90 minutes; the second stage anaerobic water inlet is 1 / 2 of the total amount, the anaerobic time is 60 minutes, and the second stage aerobic time is 90 minutes; the sedimentation time is 30 minutes, the drainage time is 25 minutes, and the water is added to the side flow anaerobic tank 3 in a stirring state for 5 minutes.

[0028] The first anaerobic stage mainly removes the residual nitrate in the influent and the reactor at the end of the previous operation cycle through denitrification. The chemical oxygen demand (COD) in the influent and the bypass fermentation liquid provides sufficient nutrients for denitrification, and at the same time, it is used for the synthesis of polyphosphate bacteria to absorb excess PO4 from the water in the aerobic stage. 3- -P's carbon energy storage substance PHA provides a carbon source; In the first aerobic stage, the aeration device is turned on to provide the dissolved oxygen required by aerobic microorganisms and the conditions for full contact with activated sludge, degrading organic pollutants and further utilizing and consuming COD; the influent, bypass fermentation liquid and the remaining ammonia nitrogen in the reactor at the end of the previous operation cycle are oxidized to nitrate through nitrification; polyphosphate bacteria absorb PO4 3- -P is stored in the cells as polyphosphate, thus forming phosphorus-rich activated sludge.

[0029] The second anaerobic stage mainly removes nitrates produced by the influent and the first aerobic stage through denitrification. The chemical oxygen demand (COD) in the influent provides nutrients for denitrification and also synthesizes PO4 for the second aerobic stage to absorb excess PO4 from the water. 3--P's carbon energy storage substance PHA provides a carbon source, and in the early stage of the second anaerobic stage, due to the presence of a large amount of NO3 - -N acts as an electron acceptor to keep the reactor in an anoxic state, so denitrifying phosphorus-accumulating bacteria can absorb phosphorus synchronously; In the second aerobic stage, the aeration device is turned on again to provide the dissolved oxygen required by aerobic microorganisms and the conditions for full contact of activated sludge, degrading organic pollutants and further utilizing and consuming COD; Through nitrification, the influent and the remaining ammonia nitrogen in the reactor at the end of the previous operation cycle are oxidized to nitrate; polyphosphate bacteria absorb PO4 in the sewage 3- -P is stored in the cells as polyphosphate, thus forming phosphorus-rich activated sludge; After the reaction is completed, the mud and water are separated by sedimentation to make the effluent clear. Some of the remaining concentrated phosphorus-containing sludge is discharged from the system to achieve biological phosphorus removal. After the drainage is completed, the stirring device is started to flow a certain amount of mixed sludge into the side-stream anaerobic tank for anaerobic fermentation to release phosphorus.

[0030] Sidestream anaerobic tank 3: The dissolved oxygen in this reaction zone is generally zero. The influx of aerobic nitrification liquid may cause a short-term increase in dissolved oxygen but will not affect the overall anaerobic environment. In the deep anaerobic environment, sludge hydrolysis and fermentation produce additional VFAs. Polyphosphate bacteria absorb VFAs and other available carbon sources and assimilate them into intracellular carbon energy storage substances PHA, which store the necessary carbon sources and energy for subsequent aerobic excess phosphorus absorption. In the anaerobic environment, polyphosphate bacteria provide the necessary capacity for life metabolism through the hydrolysis and glycolysis of intracellular polyphosphates. The phosphates produced by hydrolysis will diffuse outside the cells to increase the phosphorus concentration.

[0031] The present invention also provides a process for enhanced biological phosphorus removal with side-flow staged water inflow and enhanced acid production, which is as follows: Step 1: Raw sewage enters SBR reactor 1, with COD of 300 mg / L, total nitrogen (TN) of 30 mg / L, total phosphorus (TP) of 9 mg / L, water temperature of 19°C, hydraulic retention time (HRT) of 6h, dissolved oxygen concentration of aerobic section of 2.0-4.5 mg / L, and sludge concentration of 2700 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal. The sludge retention time (SRT) is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the bypass anaerobic tank 3, and the bypass ratio is 20%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic section of the SBR reactor 1. The HRT of the side-stream anaerobic tank is 96 h, the dissolved oxygen concentration is 0.01-0.1 mg / L, and the sludge concentration is 5800 mg / L; The mixed sludge tank of influent and bypass anaerobic tank 3 provides carbon source for denitrifying bacteria and polyphosphate bacteria in the first anaerobic stage, removes nitrate from influent and residual nitrate from the previous operation cycle to achieve denitrification, and at the same time synthesizes PO4 for polyphosphate bacteria to absorb excess PO4 from water in the aerobic stage 3 -P carbon energy storage material polyhydroxy fatty acid ester (PHA) provides carbon source; the first aerobic stage relies on heterotrophic microorganisms to further decompose organic matter, polyphosphate bacteria consume internal carbon source to absorb excessive phosphorus from the water, and at the same time, ammonia nitrogen is converted into nitrate nitrogen under the action of nitrifying bacteria; the second anaerobic stage uses the influent to provide carbon source for denitrifying bacteria and polyphosphate bacteria, removes nitrates produced in the first aerobic stage, and polyphosphate bacteria synthesize carbon energy storage material PHA. In the early stage of the second anaerobic stage, due to the presence of a large amount of NO3 - -N acts as an electron acceptor to keep the reactor in an anoxic state, so denitrifying phosphorus-accumulating bacteria can simultaneously absorb phosphorus; the second aerobic stage converts the remaining ammonia nitrogen from the previous operation stage into NO3 through nitrification. - -N, while the polyphosphate bacteria consume the internal carbon source to absorb excessive phosphorus from the water to form phosphorus-containing sludge. Through sedimentation and sludge discharge, phosphorus is discharged from the system to achieve the purpose of phosphorus removal; after part of the sludge flows to the side stream anaerobic tank 3, the sludge is hydrolyzed and fermented to produce acid under deep anaerobic conditions, and the polyphosphate bacteria are screened and domesticated before returning to the first anaerobic section of the mainstream. After measuring and analyzing the effluent water quality, it can be concluded that the COD removal rate reaches 89.88±3.81%, and 92.86% of the effluent COD can meet the discharge standard of Class A or above (COD concentration <50 mg / L); PO4 absorption 3- -P removal rate reached 90.94±4.53%, with strong phosphorus removal performance; NH4 + -N removal rate reached 97.26±2.76%, and 71.43% of the effluent NH4 + -N is lower than 1.0mg / L, meeting the surface water Class III standard, with 50.0% NH4 in the outflow + -N is lower than 0.5 mg / L, reaching the surface water Class II standard; TN removal rate reaches 74.51±4.25%, and 92.86% of the effluent TN is lower than 10 mg / L.

[0032] The composition of the present invention is further described below by way of examples and drawings.

[0033] Example 1 Step 1: Raw sewage enters SBR reactor 1, with COD of 300 mg / L, TN of 30 mg / L, TP of 9 mg / L, water temperature of 19°C, HRT of 6h, dissolved oxygen concentration in aerobic zone greater than 2.0 mg / L, and sludge concentration of 2700 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal, where the SRT is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the side-flow anaerobic tank 3, and the side-flow ratio is 20%. Biofilm carriers are added inside the side-flow anaerobic tank 3, specifically anaerobic biological carrier AMC, and the filling ratio is 25%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic section of the SBR reactor 1. The HRT of the side-stream anaerobic tank is 96h, the dissolved oxygen concentration is less than 0.1mg / L, and the sludge concentration is 5800mg / L; The final effluent indicators are: COD=18.9mg / L, TN=6.4mg / L, TP=0.4mg / L. All indicators meet the Level A emission standards specified in the "Pollutant Emission Index Standard for Urban Wastewater Treatment Plants (GB18918-2002)".

[0034] Example 2 Step 1: Raw sewage enters SBR reactor 1, with COD of 290 mg / L, TN of 27 mg / L, TP of 8 mg / L, water temperature of 30°C, hydraulic retention time (HRT) of 6 h, dissolved oxygen concentration in aerobic zone greater than 2.0 mg / L, and sludge concentration of 2600 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal, where the SRT is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the side-flow anaerobic tank 3, and the side-flow ratio is 20%. Biofilm carriers are added inside the side-flow anaerobic tank 3, specifically anaerobic biological carrier AMC, and the filling ratio is 25%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic section of the SBR reactor 1. The HRT of the side-stream anaerobic tank is 96h, the dissolved oxygen concentration is less than 0.1mg / L, and the sludge concentration is 5700mg / L; The final effluent indicators are: COD=19.5mg / L, TN=6.8mg / L, TP=0.5mg / L. All indicators meet the Level A emission standards specified in the "Pollutant Emission Index Standard for Urban Wastewater Treatment Plants (GB18918-2002)".

[0035] Example 3 Step 1: Raw sewage enters SBR reactor 1, with COD of 310 mg / L, TN of 33 mg / L, TP of 10 mg / L, water temperature of 15°C, hydraulic retention time (HRT) of 6 h, dissolved oxygen concentration in aerobic zone greater than 2.0 mg / L, and sludge concentration of 2800 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal, where the SRT is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the side-flow anaerobic tank 3, and the side-flow ratio is 20%. Biofilm carriers are added inside the side-flow anaerobic tank 3, specifically anaerobic biological carrier AMC, and the filling ratio is 25%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic section of the SBR reactor 1. The HRT of the side-stream anaerobic tank is 96h, the dissolved oxygen concentration is less than 0.1mg / L, and the sludge concentration is 5900mg / L; The final effluent indicators are: COD=18.4mg / L, TN=6.2mg / L, TP=0.4mg / L. All indicators meet the Level A emission standards specified in the "Pollutant Emission Index Standard for Urban Wastewater Treatment Plants (GB18918-2002)".

[0036] Example 4 Step 1: Raw sewage enters SBR reactor 1, with COD of 275 mg / L, TN of 27 mg / L, TP of 7.8 mg / L, water temperature of 19°C, hydraulic retention time (HRT) of 6 h, dissolved oxygen concentration in aerobic zone greater than 2.0 mg / L, and sludge concentration of 2900 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal, where the SRT is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the side-flow anaerobic tank 3, and the side-flow ratio is 20%. Biofilm carriers are added inside the side-flow anaerobic tank 3, specifically anaerobic biological carrier AMC, and the filling ratio is 25%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic stage of the SBR reactor (1). The HRT of the side-stream anaerobic tank is 96h, the dissolved oxygen concentration is less than 0.1mg / L, and the sludge concentration is 5700mg / L. The final effluent indicators are: COD=20.4mg / L, TN=6.5mg / L, TP=0.4mg / L. All indicators meet the Level A emission standards specified in the "Pollutant Emission Index Standard for Urban Wastewater Treatment Plants (GB18918-2002)".

[0037] Example 5 Step 1: Raw sewage enters SBR reactor 1, with COD of 330 mg / L, TN of 35 mg / L, TP of 11.2 mg / L, water temperature of 19°C, hydraulic retention time (HRT) of 6 h, dissolved oxygen concentration in aerobic zone greater than 2.0 mg / L, and sludge concentration of 2850 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal, where the SRT is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the side-flow anaerobic tank 3, and the side-flow ratio is 20%. Biofilm carriers are added inside the side-flow anaerobic tank 3, specifically anaerobic biological carrier AMC, and the filling ratio is 25%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic section of the SBR reactor 1. The HRT of the side-stream anaerobic tank is 96h, the dissolved oxygen concentration is less than 0.1mg / L, and the sludge concentration is 5600mg / L; The final effluent indicators are: COD=18.7mg / L, TN=6.1mg / L, TP=0.4mg / L. All indicators meet the Level A emission standards specified in the "Pollutant Emission Index Standard for Urban Wastewater Treatment Plants (GB18918-2002)".

[0038] Example 6 Step 1: Raw sewage enters SBR reactor 1, with COD of 250 mg / L, TN of 35 mg / L, TP of 12 mg / L, water temperature of 19°C, hydraulic retention time (HRT) of 6 h, dissolved oxygen concentration in aerobic zone greater than 2.0 mg / L, and sludge concentration of 2700 mg / L; Step 2: After the reaction of SBR reactor 1 is completed and the sedimentation is completed for 30 minutes, the discharge is divided into sewage and sludge. The supernatant is directly discharged from the system, and part of the remaining sludge is discharged from the system through the bottom sludge outlet of SBR reactor 1 to achieve biological phosphorus removal, where the SRT is 17 days; the other part of the sludge is stirred and then flows from the bottom opening of SBR reactor 1 through peristaltic pump III 4.3 into the top of the side-flow anaerobic tank 3, and the side-flow ratio is 20%. Biofilm carriers are added inside the side-flow anaerobic tank 3, specifically anaerobic biological carrier AMC, and the filling ratio is 25%; Step 3: The return sludge is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank 3, and then returned to the first anaerobic section of the SBR reactor 1. The HRT of the side-stream anaerobic tank is 96h, the dissolved oxygen concentration is less than 0.1mg / L, and the sludge concentration is 5900mg / L; The final effluent indicators are: COD=33.7mg / L, TN=8.7mg / L, TP=0.4mg / L. All indicators meet the Level A emission standards specified in the "Pollutant Emission Index Standard for Urban Wastewater Treatment Plants (GB18918-2002)".

[0039] The TP removal effects of Examples 1-6 are as follows: Figure 2 As shown, COD removal effect is as follows Figure 3 As shown, the TN removal effect is as follows Figure 4 As shown in the figure, it can be seen that the TP removal rate of the present invention for sewage is above 90%, the TN removal rate is above 70%, and the effluent COD is above 80%.

Claims

1. A side stream mud membrane composite enhanced internal carbon source utilization enhanced nitrogen and phosphorus removal device, characterized in that: The invention comprises an SBR reactor (1), wherein the bottom of the SBR reactor (1) is connected to the top of a side-flow anaerobic tank (3) via a peristaltic pump III (4-3), and the bottom of the side-flow anaerobic tank (3) is connected to the top of the SBR reactor (1) via a peristaltic pump II (4-2). The top and bottom of the SBR reactor (1) are respectively connected to a peristaltic pump I (4-1) and a peristaltic pump IV (4-4), which serve as an inlet pump and an outlet pump, respectively. The SBR reactor (1), the side-flow anaerobic tank (3), the peristaltic pump I (4-1), the peristaltic pump II (4-2), the peristaltic pump III (4-3) and the peristaltic pump IV (4-4) are all connected to a controller (2).

2. The device for enhancing nitrogen removal and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 1 is characterized in that: The SBR reactor (1) is provided with a stirrer inside.

3. The device for enhancing nitrogen removal and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 1 is characterized in that: A stirrer is arranged inside the side-flow anaerobic tank (3).

4. The enhanced nitrogen and phosphorus removal process of the side stream mud membrane composite enhanced internal carbon source utilization is characterized by: The enhanced biological phosphorus removal device with side-stream staged water inflow and enhanced acid production as described in any one of claims 1 to 3 is implemented in the following steps: Step 1: Pump the raw sewage into the SBR reactor in sections through peristaltic pump I and keep it at 15°C-30°C for 6 hours; Step 2: the supernatant after precipitation in step 1 is directly discharged out of the system through the peristaltic pump IV (4-4), and part of the remaining sludge is discharged out of the system through the sludge outlet at the bottom of the SBR reactor (1); the other part of the sludge is stirred and then discharged as return sludge from the bottom opening of the SBR reactor (1) through the peristaltic pump III (4-3) into the top of the side stream anaerobic tank (3); Step 3: The return sludge from step 2 is subjected to anaerobic fermentation and polyphosphate bacteria screening in the side-stream anaerobic tank (3), and then returned to the SBR reactor (1) via the peristaltic pump II (4-2); Step 4, introducing raw sewage into the SBR reactor (1), and repeating steps 2 and 3 to perform biological phosphorus removal on the raw sewage.

5. The process for enhancing nitrogen removal and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 4 is characterized in that: The sludge retention time in the system is 17 days.

6. The process for enhanced nitrogen and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 4 is characterized in that: The SBR reactor (1) adopts a staged water inlet multi-stage A / O operation mode.

7. The device for enhancing nitrogen removal and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 6 is characterized in that: The SBR reactor (1) is divided into a first anaerobic section and a second anaerobic section. The first anaerobic section is fed with 1 / 2 of the total amount of water, the anaerobic time is 60 minutes, and the aerobic time is 90 minutes. The second anaerobic section is fed with 1 / 2 of the total amount of water, the anaerobic time is 60 minutes, and the aerobic time is 90 minutes. The sedimentation time is 30 minutes, the drainage time is 25 minutes, and the water is fed into the side stream anaerobic tank (3) in a stirring state for 5 minutes.

8. The process for enhancing nitrogen and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 4 is characterized in that: In step 2, the sludge bypass ratio entering the bypass anaerobic tank (3) is 20%.

9. The process for enhancing nitrogen removal and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 4, characterized in that: The hydraulic retention time of the return sludge in the side-stream anaerobic tank (3) in step 3 is 96 hours, the dissolved oxygen concentration is 0.01-0.1 mg / L, and the sludge concentration is 5800 mg / L.

10. The process for enhancing nitrogen removal and phosphorus removal by composite enhanced internal carbon source utilization of side stream mud membrane according to claim 4, characterized in that: A biofilm carrier, specifically an anaerobic biocarrier AMC, is added to the side-stream anaerobic tank (3), with a filling ratio of 25%.

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