Configuration method of denitrification process unit for upgrading and reconstruction of sewage treatment plants in industrial agglomeration areas

Abstract

A method for configuring a denitrification process unit for an industrial agglomeration wastewater treatment plant upgrading and reconstruction project includes the following steps: ① Calculation of the denitrification rate required for the upgrading and reconstruction project: the calculation formula is (designed inlet TN concentration-outlet TN control concentration) / designed inlet TN concentration*100%; ② Combined with the current biological treatment system process design (designed hydraulic retention time and suspended filler addition) and aerobic pool capacity utilization analysis, the feasibility of using part of the existing biological pool capacity to transform the anoxic zone is evaluated; ③ According to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + ‑N‑NO3 ‑ ‑N‑NO2 ‑ ‑N, that is, the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent can be calculated and analyzed. The present invention can reduce the risk of excessive TN in effluent, reduce the ineffective loss of carbon sources, and reduce project investment.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to a method for configuring a denitrification process unit for an upgrading and transformation project of a sewage treatment plant in an industrial agglomeration area. Background Art

[0002] In recent years, with the promulgation and implementation of local sewage discharge standards in Beijing, Tianjin, Hefei, Taihu Lake area of ​​Jiangsu Province and other places, sewage treatment plants in industrial agglomeration areas are generally faced with the need to upgrade from the national Class A standard (GB18918-2002) to more stringent local emission standards. The effluent TN limit is usually increased from 15mg / L to 10mg / L. In order to ensure that the effluent TN stably meets the standard, the configuration of the denitrification process unit is an important part of the design of the upgrading and transformation project of sewage treatment plants in industrial agglomeration areas. However, the current status survey of a large number of typical sewage treatment plants in industrial agglomeration areas in my country shows that there are many problems in the actual denitrification process unit configuration, which are mainly manifested in: ① The denitrification process unit is over-configured, and the post-anoxic zone and denitrification filter are set up at the same time, resulting in excessive project investment; ② The current biological treatment system is insufficiently evaluated, and the denitrification filter is more inclined to be used to enhance denitrification. At the same time, the full process control design of the dissolved oxygen concentration of the denitrification filter inlet and the setting of the carbon source precise dosing control system are not emphasized, resulting in a large ineffective loss of carbon source in the denitrification filter unit (8-9 mg / LCOD) and a high risk of exceeding the standard of effluent COD and BOD5; ③ The influence of the soluble non-ammonifiable organic nitrogen in the current secondary effluent on the configuration of the denitrification process unit of the upgrading and transformation project is ignored, resulting in a high risk of exceeding the standard of effluent TN in actual production operation; ④ No deoxygenation zone is set between the post-anoxic zone and the aerobic zone, resulting in ineffective loss of carbon source in the anoxic zone and the post-anoxic zone. ⑤ The designed hydraulic retention time of the anoxic zone is too short, resulting in the inability to fully utilize the influent carbon source or the carbon source in the sludge.

[0003] Based on this, it is urgent to propose a scientific and reasonable denitrification process unit configuration method for the upgrading and transformation project of sewage treatment plants in industrial agglomeration areas, so as to solve the problems of high risk of effluent TN exceeding the standard, ineffective loss of carbon source, high project investment, etc. caused by the unscientific and unreasonable configuration method of denitrification process units in the upgrading and transformation project of sewage treatment plants in existing industrial agglomeration areas. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the existing denitrification process unit configuration method for the upgrading and transformation project of the sewage treatment plant in the industrial agglomeration area, and to provide a denitrification process unit configuration method for the upgrading and transformation project of the sewage treatment plant in the industrial agglomeration area. The method is based on the denitrification rate calculation required by the upgrading and transformation project, the feasibility assessment of the anoxic zone after the transformation of part of the pool capacity of the existing biological pool, and the analysis of the concentration of soluble non-ammonifiable organic nitrogen in the existing secondary effluent. It can reduce the risk of exceeding the TN of the effluent, reduce the ineffective loss of carbon sources, and reduce project investment.

[0005] As conceived above, the technical solution of the present invention is: a method for configuring a denitrification process unit for an industrial agglomeration area sewage treatment plant upgrading and transformation project, comprising the following steps:

[0006] ① Calculation of denitrification rate required for upgrading and renovation project: based on the designed inlet TN concentration and outlet TN control concentration of upgrading and renovation project, the calculation formula is (designed inlet TN concentration - outlet TN control concentration) / designed inlet TN concentration * 100%;

[0007] ② Feasibility assessment of using part of the existing biological pool capacity to transform the anoxic zone: Combined with the current biological treatment system process design (designed hydraulic retention time and suspended filler addition) and aerobic pool capacity utilization analysis, the feasibility of using part of the existing biological pool capacity to transform the anoxic zone is assessed;

[0008] ③ Analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent: According to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + -N-NO3 - -N-NO2 - -N, which means the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent can be calculated and analyzed.

[0009] Furthermore, in step ①, the TN emission limit of the effluent from the upgrading and reconstruction project is raised from 15 mg / L of the national Class A standard to 10 mg / L of the local standard.

[0010] Furthermore, when the required denitrification rate of the upgrading and transformation project calculated in step ① is greater than 75% and it is feasible to transform the anoxic zone using part of the existing biological pond capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + post-anoxic zone".

[0011] Furthermore, when the upgrading and transformation project calculated in step ① requires a denitrification rate of >75% and it is not feasible to transform the anoxic zone using part of the existing biological pool capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + denitrification filter".

[0012] Furthermore, when the required denitrification rate of the upgrading and transformation project calculated in step ① is ≤75% and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is ≤2.5 mg / L, the denitrification process unit of the upgrading and transformation project is determined to be configured as an anoxic zone.

[0013] Furthermore, when the upgrading and transformation project calculated in step ① requires a denitrification rate of ≤75%, and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is >2.5 mg / L, and it is feasible to transform the anoxic zone using part of the existing biological pool capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + post-anoxic zone".

[0014] Furthermore, when the upgrading and transformation project calculated in step ① requires a denitrification rate of ≤75%, and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is >2.5 mg / L, and it is assessed in step ② that it is not feasible to transform the anoxic zone using part of the existing biological pool capacity, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + denitrification filter".

[0015] Furthermore, the anoxic zone is designed with a hydraulic retention time of ≥4h to utilize the carbon source in the influent or the carbon source in the sludge.

[0016] Furthermore, the designed hydraulic retention time of the post-anoxic zone is 1 to 2 hours, and an oxygen-eliminating zone with a designed hydraulic retention time of 1 to 1.5 hours is arranged before it to control the ineffective loss of carbon sources in the anoxic zone and the post-anoxic zone.

[0017] Furthermore, the dissolved oxygen concentration of the influent of the denitrification filter is lower than 0.5 mg / L, and the designed hydraulic retention time can be reduced by 5 to 10 minutes.

[0018] Furthermore, a mixed liquid reflux pump is provided at the end of the deoxidation zone.

[0019] Furthermore, the denitrification filter is provided with a precise carbon source dosing control system to reduce the risk of effluent COD exceeding the standard.

[0020] The present invention has the following advantages and positive effects:

[0021] 1. The present invention is based on the calculation of the denitrification rate required for the upgrading and transformation project, the feasibility assessment of the anoxic zone after the transformation using part of the existing biological pool capacity, and the analysis of the concentration of soluble non-ammonifiable organic nitrogen in the existing secondary effluent. The proposed denitrification process unit configuration method for the upgrading and transformation project of sewage treatment plants in industrial agglomeration areas is scientific and reasonable, and can systematically solve the problems of high risk of effluent exceeding the standard, ineffective loss of carbon source, high project investment, etc. caused by the existing denitrification process unit configuration method for upgrading and transformation projects. It has the advantages of simple operation, reduced risk of effluent exceeding the standard, basic control of carbon source loss, saving of carbon source addition cost, and significant economic, social and environmental benefits.

[0022] 2. The present invention proposes to adopt a denitrification process unit configuration of "anoxic zone + post-anoxic zone" when it is feasible to utilize part of the existing biological pool capacity to transform the anoxic zone, so that biological denitrification can be completed in the biological treatment system, which can avoid the ineffective loss of carbon source caused by high concentration of dissolved oxygen in the denitrification filter influent and the high risk of excessive effluent COD caused by excessive addition of carbon source.

[0023] 3. The analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent is used as a key consideration for the configuration of denitrification process units in the upgrading and transformation project of sewage treatment plants in industrial agglomeration areas, so that the configuration of denitrification process units with a required denitrification rate not exceeding 75% can be scientific and reasonable, which can solve the problem of excessive TN in the effluent of sewage treatment plants in industrial agglomeration areas caused by non-ammonifiable organic nitrogen.

[0024] 4. By setting up an oxygen-depleting zone before the post-anoxic zone, the problem of ineffective loss of carbon sources in the anoxic zone and the post-anoxic zone caused by dissolved oxygen at the end of the aerobic zone can be solved.

[0025] 5. By taking measures to control the dissolved oxygen concentration of the denitrification filter inlet water throughout the entire process, the problem of ineffective loss of added carbon source caused by high DO concentration in the denitrification filter inlet water can be solved, and the designed hydraulic retention time of the denitrification filter can be reduced by 5 to 10 minutes compared with the traditional denitrification filter design hydraulic retention time, thereby saving land and reducing project investment.

[0026] 6. The present invention is highly targeted, practical and operable, and can provide new ideas for the refined design and operation of denitrification process units in high-emission standard upgrading and transformation projects of industrial agglomeration areas and urban sewage treatment plants in my country. It is of great significance to the stable compliance with standards and energy conservation and consumption reduction of high-emission standard sewage treatment plants in industrial agglomeration areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the denitrification process unit configuration method for the industrial agglomeration area sewage treatment plant upgrading and transformation project of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0029] like Figure 1 As shown: The present invention provides a denitrification process unit configuration method for an industrial agglomeration area sewage treatment plant upgrading and transformation project, which includes the following 4 steps:

[0030] ① Calculation of denitrification rate required for upgrading and renovation project: The calculation of required denitrification rate is based on the designed influent TN concentration and effluent TN control concentration of upgrading and renovation project. The calculation formula is (designed influent TN concentration - effluent TN control concentration) / designed influent TN concentration * 100%;

[0031] ② Feasibility assessment of using part of the existing biological pool capacity to transform the anoxic zone: Combined with the current biological treatment system process design (designed hydraulic retention time and suspended filler addition) and aerobic pool capacity utilization analysis, the feasibility of using part of the existing biological pool capacity to transform the anoxic zone is assessed;

[0032] ③ Analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent: Usually, the soluble organic nitrogen in the secondary effluent can be considered as soluble non-ammonifiable organic nitrogen. Through multiple tests of the concentration of different nitrogen components in the current secondary effluent, according to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + -N-NO3 - -N-NO2 - -N, which means the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent can be calculated and analyzed;

[0033] ④ Comprehensive determination of the configuration of denitrification process units for upgrading and transformation projects. Based on the calculation of denitrification rate required by upgrading and transformation projects, feasibility assessment of anoxic zones after transformation using existing biological pools, and analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent, the configuration of denitrification process units for upgrading and transformation projects of sewage treatment plants in industrial agglomeration areas is comprehensively determined according to specific circumstances.

[0034] Furthermore, in step ①, the TN emission limit of the effluent from the upgrading and reconstruction project is raised from 15 mg / L of the national Class A standard to 10 mg / L of the local standard.

[0035] Furthermore, when the required denitrification rate of the upgrading and transformation project calculated in step ① is greater than 75% and it is feasible to transform the anoxic zone using part of the existing biological pond capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + post-anoxic zone".

[0036] Furthermore, when the upgrading and transformation project calculated in step ① requires a denitrification rate of >75% and it is not feasible to transform the anoxic zone using part of the existing biological pool capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + denitrification filter".

[0037] Furthermore, when the required denitrification rate of the upgrading and transformation project calculated in step ① is ≤75% and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is ≤2.5 mg / L, the denitrification process unit of the upgrading and transformation project is determined to be configured as an anoxic zone.

[0038] Furthermore, when the upgrading and transformation project calculated in step ① requires a denitrification rate of ≤75%, and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is >2.5 mg / L, and it is feasible to transform the anoxic zone using part of the existing biological pool capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + post-anoxic zone".

[0039] Furthermore, when the upgrading and transformation project calculated in step ① requires a denitrification rate of ≤75%, and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is >2.5 mg / L, and it is assessed in step ② that it is not feasible to transform the anoxic zone using part of the existing biological pool capacity, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + denitrification filter".

[0040] Furthermore, the hydraulic retention time of the anoxic zone is designed to be ≥4h to fully utilize the carbon source in the influent or the carbon source in the sludge.

[0041] Furthermore, the designed hydraulic retention time of the post-anoxic zone is 1 to 2 hours, and an oxygen-eliminating zone with a designed hydraulic retention time of 1 to 1.5 hours is arranged before it to control the ineffective loss of carbon sources in the anoxic zone and the post-anoxic zone.

[0042] Furthermore, the denitrification filter adopts the whole process influent dissolved oxygen control measures from the end of the aerobic zone to the water inlet of the denitrification filter, so that the dissolved oxygen concentration of the denitrification filter influent is lower than 0.5 mg / L, the designed hydraulic retention time can be reduced by 5 to 10 minutes, and a carbon source precise dosing control system is set to reduce the risk of excessive COD in the effluent. The whole process influent dissolved oxygen concentration control measures of the denitrification filter include aeration volume control in the end of the aerobic zone, oxygenation control of the waterfall in the secondary sedimentation tank, flooding of the inlet and outlet of the pump room, covering of the local waterfall area to isolate the air, and the use of a constant water level denitrification filter.

[0043] Furthermore, a mixed liquid internal reflux pump is provided at the end of the deoxidation zone, and its specific designed hydraulic retention time is determined according to the designed internal reflux ratio.

[0044] Example 1: A method for configuring a denitrification process unit for an industrial agglomeration area sewage treatment plant upgrading and transformation project includes the following four steps:

[0045] ① The upgrading and renovation project requires calculation of denitrification rate. The design scale of a sewage treatment plant in an industrial cluster area is 50,000 tons / day. It originally implemented the national Class B standard and the design process was A 2 / O (suspended filler) + carbon adsorption clarification tank + flotation, the design hydraulic retention time of anaerobic zone, anoxic zone and aerobic zone is 1h, 3h and 4h respectively, and the filling rate of suspended filler in aerobic zone is 50%. Due to the promulgation and implementation of Tianjin local standard (DB12 / 599-2015) in October 2015, the plant needs to implement Tianjin A standard upgrading and transformation project, in which the effluent TN emission limit is increased from 20mg / L of the current Class B standard to 10mg / L of Tianjin A standard. Combined with the actual situation of the plant, the design influent TN concentration of the upgrading and transformation project is 30mg / L, and the effluent TN control concentration is 8mg / L. According to the calculation formula of denitrification rate required by the upgrading and transformation project (design influent TN concentration-effluent TN control concentration) / design influent TN concentration*100%, the calculation requirement denitrification rate is (30-8) / 30*100%=73.3%.

[0046] ② Feasibility assessment of using part of the existing biological pool to transform the anoxic zone. In combination with the actual situation of the plant, considering that the hydraulic retention time of the existing aerobic zone is only 4h, and the filling rate of suspended fillers in the existing aerobic zone is as high as 50%, the assessment believes that it is not feasible for the plant to use part of the existing biological pool to transform the anoxic zone.

[0047] ③ Analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent. The test of nitrogen components in the current secondary effluent of the plant shows that the soluble TN and NH4 + -N、NO3 - -N and NO2 - -N concentrations are 12.5mg / L, 3.2mg / L, 5.7mg / L and 0.1mg / L respectively. According to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + -N-NO3 - -N-NO2 - -N, the calculation and analysis showed that the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent was 12.5-3.2-5.7-0.1=3.5 mg / L.

[0048] ④ Comprehensive determination of the denitrification process unit configuration for the upgrading and renovation project. Based on the calculation results of the denitrification rate required in step ①, the feasibility assessment results of the anoxic zone after the transformation of the existing biological pool in step ②, and the analysis results of the concentration of non-ammonifiable organic nitrogen in the existing secondary effluent in step ③, combined with the configuration of denitrification process units under different situations, it is comprehensively determined that the denitrification process unit configuration of the plant's upgrading and renovation project is "anoxic zone + denitrification filter", in which the denitrification filter is designed with a hydraulic retention time of 10 minutes, and measures are taken to control the dissolved oxygen in the denitrification filter inlet throughout the process.

[0049] Example 2: A method for configuring a denitrification process unit for an industrial agglomeration area sewage treatment plant upgrading and transformation project includes the following four steps:

[0050] ① The upgrading and renovation project requires calculation of denitrification rate. The design scale of a sewage treatment plant in an industrial cluster area is 150,000 tons / day. It originally implemented the national Class A standard and the design process is improved A 2 / O+V filter, the design hydraulic retention time of pre-anoxic zone, anaerobic zone, anoxic zone and aerobic zone are 1h, 1.5h, 7h and 13h respectively. Due to the promulgation and implementation of Tianjin local standard (DB12 / 599-2015) in October 2015, the plant needs to implement Tianjin A standard upgrading and transformation project, in which the effluent TN discharge limit is increased from 15mg / L of the current Class A standard to 10mg / L of Tianjin A standard. Combined with the actual situation of the plant, the design influent TN concentration of the upgrading and transformation project is 50mg / L, and the effluent TN control concentration is 8mg / L. According to the denitrification rate calculation formula required by the upgrading and transformation project (design influent TN concentration-effluent TN control concentration) / design influent TN concentration*100%, the required denitrification rate is (50-8) / 50*100%=84%.

[0051] ② Feasibility assessment of using part of the existing biological pool to transform the anoxic zone. Combined with the actual situation of the plant, considering the current biological pool effluent NH4 + -N is lower than 1mg / L and the designed hydraulic retention time of the aerobic zone is relatively long (13h). The analysis of the utilization rate of the aerobic zone capacity under the most unfavorable conditions shows that the pool capacity of the existing aerobic zone with a designed hydraulic retention time of about 2.5h is actually not utilized. Combined with the designed hydraulic retention time of the post-anoxic zone and the anoxic zone, it is assessed that it is feasible for the plant to utilize part of the pool capacity of the existing biological pool to transform the post-anoxic zone.

[0052] ③ Analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent. The test of nitrogen components in the current secondary effluent of the plant shows that the soluble TN and NH4 + -N、NO3 - -N and NO2 - -N concentrations are 12.5mg / L, 3.2mg / L, 5.7mg / L and 0.1mg / L respectively. According to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + -N-NO3 - -N-NO2 - -N=11-0.9-9.6-0=0.5mg / L. The calculated analysis shows that the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent is 0.5mg / L.

[0053] ④ Comprehensive determination of the denitrification process unit configuration for the upgrading and renovation project. Based on the calculation results of the denitrification rate required in step ①, the feasibility assessment results of the anoxic zone after the renovation of the existing biological pool in step ②, and the analysis results of the concentration of non-ammonifiable organic nitrogen in the existing secondary effluent in step ③, combined with the configuration of denitrification process units under different situations, it is comprehensively determined that the denitrification process unit configuration of the plant's upgrading and renovation project is "anoxic zone + post-anoxic zone", and an anoxic zone is set before the post-anoxic zone. The designed hydraulic retention times of the post-anoxic zone and the anoxic zone are 1h and 1.5h, respectively.

[0054] Example 3: A method for configuring a denitrification process unit for an industrial agglomeration area sewage treatment plant upgrading and transformation project includes the following 4 steps:

[0055] ① The upgrading and renovation project requires calculation of denitrification rate. The design scale of a sewage treatment plant in an industrial cluster area is 25,000 tons / day. It originally implemented the national Class A standard and the design process is improved A 2 / O+active sand filter, the design hydraulic retention time of pre-anoxic zone, anaerobic zone, anoxic zone and aerobic zone are 0.5h, 1h, 5h and 10h respectively. Due to the promulgation and implementation of Tianjin local standard (DB12 / 599-2015) in October 2015, the plant needs to implement Tianjin A standard upgrading and transformation project, in which the effluent TN emission limit is increased from 15mg / L of the current Class A standard to 10mg / L of Tianjin A standard. Combined with the actual situation of the plant, the design influent TN concentration of the upgrading and transformation project is 32mg / L, and the effluent TN control concentration is 8mg / L. According to the denitrification rate calculation formula required by the upgrading and transformation project (design influent TN concentration-effluent TN control concentration) / design influent TN concentration*100%, the calculation requires denitrification rate is (32-8) / 32*100%=75%.

[0056] ② Feasibility assessment of using part of the existing biological pool to transform the anoxic zone. In combination with the actual situation of the plant, considering that the hydraulic retention time of the existing aerobic zone is relatively long and no suspended filler is added, the enhanced nitrification measures of adding suspended fillers to part of the aerobic zone can be taken to free up part of the aerobic zone capacity for the setting of the post-anoxic zone and the oxygen elimination zone. The assessment believes that it is feasible for the plant to use part of the existing biological pool capacity to transform the anoxic zone.

[0057] ③ Analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent. The test of nitrogen components in the current secondary effluent of the plant shows that the soluble TN and NH4 + -N、NO3 - -N and NO2 - -N concentrations are 12.5mg / L, 3.2mg / L, 5.7mg / L and 0.1mg / L respectively. According to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + -N-NO3 - -N-NO2- -N, the calculation and analysis showed that the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent was 11-2.2-5.5-0.15=3.15 mg / L.

[0058] ④ Comprehensive determination of the configuration of the denitrification process unit for the upgrading and renovation project. Based on the calculation results of the denitrification rate required in step ①, the feasibility assessment results of the anoxic zone after the transformation of the existing biological pool in step ②, and the analysis results of the concentration of non-ammonifiable organic nitrogen in the existing secondary effluent in step ③, combined with the configuration of the denitrification process unit under different circumstances, it is comprehensively determined that the configuration of the denitrification process unit for the upgrading and renovation project of the plant is "anoxic zone + post-anoxic zone", and an anoxic zone is set before the post-anoxic zone. The designed hydraulic retention times of the post-anoxic zone and the anoxic zone are 1h and 1h, respectively.

[0059] The various implementation cases and methods introduced in the present invention are original to the present invention. After understanding the specific implementation methods and corresponding variations, relevant field personnel derive a series of similar methods based on the present invention, which are all within the protection scope of the present invention; any substitution, improvement, and modification made within the principles and concepts of the present invention should fall within the protection scope of the present invention.

Claims

1. A method for configuring a denitrification process unit for a sewage treatment plant upgrading and transformation project in an industrial agglomeration area, characterized by: The steps include: ① Calculation of denitrification rate required for upgrading and renovation project: Based on the designed inlet TN concentration and effluent TN control concentration of upgrading and renovation project, the calculation formula is (designed inlet TN concentration - effluent TN control concentration) / designed inlet TN concentration * 100%; ② Feasibility assessment of using part of the existing biological pool capacity to transform the anoxic zone: Based on the hydraulic retention time of the current biological treatment system process design and the addition of suspended fillers, and the analysis of the utilization rate of the aerobic pool capacity, the feasibility of using part of the existing biological pool capacity to transform the anoxic zone is assessed; ③ Analysis of the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent: According to the formula, soluble non-ammonifiable organic nitrogen = soluble TN-NH4 + -N-NO3 - -N-NO2 - -N, which means the concentration of soluble non-ammonifiable organic nitrogen in the secondary effluent can be calculated and analyzed; If the required denitrification rate of the upgrading and transformation project calculated in step ① is greater than 75% and it is feasible to transform the anoxic zone after using part of the existing biological pool capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + post-anoxic zone"; The required nitrogen removal rate of the upgrading and reconstruction project calculated in step ① is greater than 75%, and in the case where it is not feasible to use part of the existing biological pool capacity to transform the anoxic zone as assessed in step ②, the configuration of the denitrification process unit of the upgrading and reconstruction project is determined to be "anoxic zone + denitrification filter"; When the required denitrification rate of the upgrading and transformation project calculated in step ① is ≤75% and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is ≤2.5mg / L, the denitrification process unit of the upgrading and transformation project is determined to be configured as anoxic zone; Under the circumstance that the required denitrification rate of the upgrading and transformation project calculated in step ① is ≤75% and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent analyzed in step ③ is >2.5mg / L and it is feasible to transform the anoxic zone after using part of the existing biological pool capacity as assessed in step ②, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + post-anoxic zone"; In the case where the denitrification rate required for the upgrading and transformation project calculated in step ① is ≤75%, and the concentration of soluble non-ammonifiable organic nitrogen in the current secondary effluent obtained by analysis in step ③ is >2.5 mg / L, and it is assessed in step ② that it is not feasible to transform the anoxic zone using part of the capacity of the existing biological pool, the denitrification process unit configuration of the upgrading and transformation project is determined to be "anoxic zone + denitrification filter".

2. The method for configuring denitrification process units for upgrading and renovating industrial agglomeration wastewater treatment plants according to claim 1, characterized in that: In step ①, the TN emission limit of the effluent from the upgrading and reconstruction project is raised from 15 mg / L of the national Class A standard to 10 mg / L of the local standard.

3. The method for configuring denitrification process units for upgrading and renovating industrial agglomeration wastewater treatment plants according to claim 1, characterized in that: The designed hydraulic retention time of the anoxic zone is ≥4h to utilize the carbon source of the influent or the carbon source in the sludge.

4. The method for configuring denitrification process units for upgrading and renovating industrial agglomeration wastewater treatment plants according to claim 1, characterized in that: The designed hydraulic retention time of the post-anoxic zone is 1 to 2 hours, and an oxygen-eliminating zone with a designed hydraulic retention time of 1 to 1.5 hours is arranged before it to control the ineffective loss of carbon sources in the anoxic zone and the post-anoxic zone.

5. The method for configuring denitrification process units for upgrading and renovating industrial agglomeration wastewater treatment plants according to claim 1, characterized in that: The dissolved oxygen concentration of the influent of the denitrification filter is lower than 0.5 mg / L, and the designed hydraulic retention time is 5 to 10 minutes shorter than that of the conventional denitrification tank.

6. The method for configuring denitrification process units for upgrading and renovating industrial agglomeration wastewater treatment plants according to claim 1, characterized in that: The denitrification filter is provided with a carbon source precise dosing control system to reduce the risk of effluent COD exceeding the standard.

7. The method for configuring denitrification process units for upgrading and renovating industrial agglomeration wastewater treatment plants according to claim 4, characterized in that: A mixed liquid internal reflux pump is arranged at the end of the deoxidation zone.

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