CN-118405790-B - Device and method for rapidly inhibiting nitrite oxidizing bacteria to realize deep denitrification and dephosphorization of municipal sewage

Abstract

The invention relates to a device and a method for rapidly inhibiting nitrite oxidizing bacteria to realize deep denitrification and dephosphorization of urban sewage, belonging to the field of sewage biological treatment. The device comprises a reactor inlet unit, a water inlet unit, an aeration unit and a water outlet unit. According to the method, a short-cut nitrification/anaerobic ammonia oxidation system with low denitrification and dephosphorization efficiency due to proliferation of nitrite oxidizing bacteria is operated in an anaerobic-aerobic-anoxic mode, and the total nitrogen and phosphate content in the effluent is reduced by controlling aerobic time and anoxic time distribution to rapidly improve the nitrite accumulation rate in an aerobic section of the system. According to the invention, nitrite oxidizing bacteria are quickly inhibited by changing the operation mode, the nitrogen and phosphorus removal efficiency of a short-range nitrification/anaerobic ammonia oxidation system operated in an anaerobic-aerobic-anoxic mode is improved, the deep nitrogen and phosphorus removal and stable operation of urban sewage with low carbon nitrogen ratio are realized, the operation control is simple and convenient, no external energy source is needed, and the energy is saved and the consumption is reduced.

Inventors

• PENG YONGZHEN
• CUI YANRU
• WANG SHUYING
• ZHANG QIONG
• LI XIYAO

Assignees

• 北京工业大学

Dates

Publication Date

20260505

Application Date

20240508

Claims (1)

1. 1. A method for rapidly inhibiting nitrite oxidizing bacteria to realize deep denitrification and dephosphorization of municipal sewage comprises a reactor unit, a water inlet unit, an aeration unit and a water outlet unit; The reactor unit comprises an SBR reactor (1), a stirring device (2), a water inlet (5), an aeration port (8), a water outlet (10), an overflow port (11), a sludge discharge port (12) and a pH/DO detector (13), wherein the water inlet unit comprises a raw water tank (3) and a water inlet peristaltic pump (4), the aeration unit comprises an aeration pump (6), a flowmeter (7) and a microporous aeration disc (9), and the water outlet unit comprises a water outlet tank (14); In the operation process, urban sewage in a raw water tank (3) is pumped into an SBR reactor (1) through a water inlet (5) by a water inlet peristaltic pump (4), a stirring device (2) drives muddy water in the SBR reactor to be mixed for reaction, an aeration pump (6) is operated in an aerobic stage, gas enters a system through a flowmeter (7), an aeration port (8) and a micropore aeration disc (9) to be contacted with activated sludge, aeration is controlled by the flowmeter (7), after anaerobic, aerobic and anoxic reactions are completed, muddy water separation is realized through precipitation, effluent is discharged to a water outlet (10) to a water outlet tank (14), and sludge is discharged out of the system through a sludge discharge port (12) during sludge discharge; The method is characterized by comprising the following steps of: (1) The first stage is to operate the short-cut nitrification/anaerobic ammonia oxidation system which is threatened by nitrite oxidizing bacteria proliferation in an anaerobic-aerobic-anoxic mode; The first stage, the system operation includes five parts of water inlet, operation, precipitation, drainage and idle, and the operation includes anaerobic stirring, aerobic aeration and anoxic stirring; the anaerobic time of the system is 1.5h, wherein the anaerobic time of the system comprises 10min of water inflow, 10min of sedimentation time, 10min of drainage, 50% of drainage ratio, 1 st to 31 th days, 2.5h of system aeration time, 32 nd to 57 th days, 5h of system aeration time, 58 th to 65 th days, 97 th to 101 th days, 4h of system aeration time, 102 th to 114 th days, 3h of system aeration time, 1 st to 31 th days, 7.5h of system anoxic time, 10min of idle time, 23h of HRT (heat transfer rate) and two cycles of each day, 32 nd to 48 th days, 11h of system anoxic time, 6h of idle time, 10min of HRT (heat transfer rate) and 35h of each day, one cycle of each day, 49 th to 57 th days, 4h of system anoxic time, 70min of idle time, 21h of each day, two cycles of each day, 58 th to 65 th, 97 th to 101 th days, 5h of system anoxic time, 70min of system anoxic time, 21 th to 21 th, two cycles of HRT, and 114 h of system anoxic time, and two cycles of each day of system anoxic time are respectively, wherein the anoxic time is 10min, 23h of each day, and the anoxic time is 21 th to 114 h of each cycle; The system has an oxygen dissolving concentration of 1.5-2.0mg/L, an operating temperature of 25 ℃, a sludge concentration of 2000-3000mg/L, raw water of municipal sewage, an ammonia nitrogen concentration of 61.56-87.77mg/L, a phosphate concentration of 6.73-10.79mg/L, and a COD/TIN of 2.86-4.55; In order to control nitrite oxidizing bacteria, adopting measures of adjusting pH of anaerobic end, increasing aeration, discharging mud and anaerobic starvation, operating for 49 th to 56 th days, adjusting pH of anaerobic end to 8 with sodium hydroxide, discharging mud from the system for 104 th to 114 th days and for 25 th to 30 th days, and carrying out anaerobic starvation treatment on the sludge from 66 th to 96 th days without water inflow and aeration; (2) A second stage, which is a system running from 155 th day and above, wherein the first stage is a system running continuously in an anaerobic-aerobic-anoxic mode; The second stage, the system operation comprises five parts of water inlet, operation, precipitation, drainage and idle, wherein the operation mode is anaerobic-aerobic-anoxic, the operation time of each section of the anaerobic-aerobic-anoxic system is 1.5h,2h,1.5h and 4h, the anaerobic time comprises water inlet 10min, precipitation time is 10min, water drainage 10min, the drainage ratio is 50%, the idle time is 70min, HRT is 21h, the system is operated for two cycles every day, the aerobic end dissolved oxygen is 2-2.5mg/L, the operation temperature is 25 ℃, the sludge age is 25-30d, the sludge concentration is 2000-3000mg/L, the raw water is municipal sewage, the ammonia nitrogen concentration is 64.09-84.66mg/L, the phosphate concentration is 6.24-10.24mg/L, and the COD/TIN is 3.26-4.24.

Description

Device and method for rapidly inhibiting nitrite oxidizing bacteria to realize deep denitrification and dephosphorization of municipal sewage Technical Field The invention relates to a device and a method for rapidly inhibiting nitrite oxidizing bacteria to realize deep denitrification and dephosphorization of urban sewage, belonging to the field of sewage biological treatment. Background The nitrogen and phosphorus elements in the urban sewage are plant nutrient elements, and the water discharged into the natural water body can cause mass propagation of algae and the like, so that the dissolved oxygen in the water body is consumed in a large amount and the water body is eutrophicated, thereby bringing adverse effects on various aspects of human life and production and even directly endangering the physical and mental health of human beings. In urban sewage treatment plants, denitrification and dephosphorization are usually carried out in different reaction tanks, the denitrification is mostly carried out by adopting the traditional nitrification/denitrification biological denitrification technology, and the dephosphorization is mostly carried out by adopting the chemical dephosphorization or the technology of combining biological dephosphorization with chemical dephosphorization. However, the conventional nitrification and denitrification technology is limited by a limited carbon source of raw water, and is difficult to meet increasingly strict denitrification standards. In addition, the nitrification and denitrification process needs huge aeration energy consumption and carbon source consumption, so that the traditional sewage treatment becomes a high energy consumption process. Chemical agents are needed to be added for chemical dephosphorization, and extra treatment cost is increased. The discovery and research of anaerobic ammoxidation technology provides a new idea for biological denitrification of urban sewage. The short-cut nitrification/anaerobic ammonia oxidation technology is a biological denitrification technology which is widely studied, partial ammonia nitrogen in urban sewage can be oxidized into nitrite to provide substrate nitrite for anaerobic ammonia oxidation by short-cut nitrification/anaerobic ammonia oxidation, autotrophic denitrification is carried out by utilizing ammonia nitrogen and nitrite in the anoxic section, so that aeration energy consumption can be greatly saved, and an additional carbon source is not needed. By using the anaerobic-aerobic-anoxic operation mode, nitrogen removal mainly depends on the endogenous denitrification of the rear anoxic section, and the carbon source in raw water can be fully utilized, so that the energy is saved and the consumption is reduced. In addition, the anaerobic-aerobic-anoxic operation mode is beneficial to the enrichment of endogenous denitrification phosphorus accumulating bacteria and the realization of the simultaneous deep denitrification and dephosphorization of urban sewage. However, in actual operation, nitrite oxidizing bacteria in the aerobic section often proliferate in large amounts, which makes it difficult for the system to provide sufficient nitrite required by anammox bacteria. In addition, in a longer anoxic section, the denitrification phosphorus accumulating bacteria are affected by anaerobic phosphorus release, and stable phosphorus removal is difficult to realize. Based on the problems and challenges faced in the denitrification and dephosphorization process of urban sewage, the invention converts the anaerobic-aerobic-anoxic operation mode into anaerobic-aerobic-anoxic, and rapidly improves the accumulation rate of nitrite in the aerobic section and the denitrification and dephosphorization performance of the system of the short-range nitrification/anaerobic ammonia oxidation system with low denitrification and dephosphorization efficiency caused by the proliferation of nitrite oxidizing bacteria by controlling the aerobic time and anoxic time distribution, thereby realizing the deep denitrification and dephosphorization of the urban sewage with low carbon nitrogen ratio and stably operating. The invention has simple operation and control, does not need external energy sources, provides necessary theoretical basis and technical support for advanced treatment of urban sewage and energy conservation and consumption reduction, and has important research significance and application value. Disclosure of Invention The invention provides a device and a method for rapidly inhibiting nitrite oxidizing bacteria to realize deep denitrification and dephosphorization of urban sewage. The short-range nitrification/anaerobic ammonia oxidation system with low denitrification and dephosphorization efficiency due to the proliferation of nitrite oxidizing bacteria is operated in an anaerobic-aerobic-anoxic mode, and the aerobic period and anoxic time distribution are controlled to rapidly improve the nitrite accumulation rate of the s