161 results about "Polyphosphate-accumulating organisms" patented technology

The invention discloses a device and a method for nitrogen and phosphorus removal for low CN ratio urban sewage through nitrosation and anaerobic ammonia oxidation coupling denitrifying phosphorus removal intensification, and belongs to the field of biological sewage treatment. The device comprises an urban sewage raw water tank, a denitrifying phosphorus removal reactor, an adjusting water tank, a sedimentation tank, and an integrated partial nitrification and anaerobic ammonia oxidation reactor; when the urban sewage enters the denitrifying phosphorus removal reactor, phosphorus-accumulating bacteria utilizes organic carbon source in the urban sewage for anaerobic phosphorus release, sedimentation and water drainage are performed, the amount of output water is adjusted by the adjusting water tank, then the output water enters the integrated partial nitrification and anaerobic ammonia oxidation reactor, contained NH4<+>-N is converted into N2 to be effectively removed through partial nitrification and anaerobic ammonia oxidation, contained PO4 <3-> and a small amount of NO3<->-N produced in the anaerobic ammonia oxidation flow back with the output water to the denitrifying phosphorus removal reactor for denitrifying phosphorus removal, and then micro-aeration is carried out for a period of time. The method reduces oxygen consumption and energy consumption, improves the nitrogen and phosphorus removal rate, and avoids the problem of insufficient carbon source.

The invention provides a method for achieving partial short-cut nitrification-Anammox/denitrification of sewage by using sludge fermentation materials, and belongs to the field of treatment of sewagesludge. A device used by the method comprises a raw water tank, an SBR reactor, a sludge fermentation material storage tank and a residual sludge fermentation tank. The method comprises mixing residual sludge fermentation materials with domestic sewage for treating, and achieving the short-cut nitrification by using the sludge fermentation materials, wherein the inhibition of the sludge fermentation materials on nitrite oxidizing bacteria is far greater than the inhibition of the sludge fermentation materials on ammonia oxidizing bacteria. The method is specifically characterized in that in ananaerobic phase, polyphosphate accumulating bacteria are used for releasing phosphorus by using the sludge fermentation materials and carbon sources in raw water, and storing the inner carbon sources, in an aerobic phase, the partial short-cut nitrification is achieved through real-time control on DO and pH, in an anoxic phase, anaerobic ammonia oxidizing bacteria are used for converting ammonianitrogen and nitrite nitrogen into nitrogen and nitric nitrogen, and heterotrophic bacteria are used for reducing residual nitrite nitrogen and the generated nitric nitrogen into nitrogen by using theinner carbon sources. Through the method, the aeration intensity is reduced; meanwhile, the deep denitrification of the domestic sewage with a low C/N ratio and the reduction of exogenous sludge areachieved.

The invention discloses a whole process low-oxygen aeration SBMBBR (sequencing batch moving bed biofilm reactor) synchronous denitrification and dephosphorization method and belongs to the technical field of sewage treatment. The method achieves synchronous denitrification and dephosphorization by adding suspension filling into the traditional SBR (sequencing batch reactor) to form an SBMBBR, controlling an organic load, a nitrogen and phosphorus load and a DO (dissolved oxygen) value in the reactor, performing staged culture and acclimation on an inoculum, and performing synchronous nitrification-denitrification and denitrification-dephosphorization on enriched denitrification polyphosphate accumulating bacteria and aerobic polyphosphate accumulating bacteria and by other approaches. The method achieves the synchronous denitrification and dephosphorization for low C/N (carbon/nitrogen) ratio sewage in the same reactor under a whole process low-oxygen aeration condition, has the advantages of a simple technology, simple operational control, a high sludge load, small floor area, low energy consumption, no need of an additional carbon source, stable denitrification and dephosphorization effects and the like. The method has very practical significance in simplifying the traditional denitrification and dephosphorization sewage treatment technology, improving the denitrification and dephosphorization effects and reducing the floor area and energy consumption, and is a sewage treatment technology with good application prospects.

The invention discloses a quick starting method of an SBR (Sequencing Batch Reactor) for synchronously denitrifying and removing phosphor, and belongs to the field of sewage treatment. The quick starting method using a batch-injection chronological sequencing batch reactor comprises the following steps: (1), operating the SBR system under an anaerobic/aerobiotic alternation condition, and domesticating and enriching phosphorus-accumulating bacteria, so that the phosphorus-accumulating bacteria intake phosphor under the aerobiotic condition and release phosphor under the anaerobic condition; removing phosphate in water by removing mud; (2), changing an operating way of the system, and enriching denitrifying phosphate-accumulating organisms; increasing an anoxic zone and shortening the aeration time, so that the denitrifying phosphate-accumulating organisms utilize an intracellular carbon source and use nitrate/nitrite as an electron acceptor to intake phosphor; (3), adding a compound fungicide into the reaction, so that biological enhancement is repeatedly coupled with anaerobic/aerobiotic/anoxic/aerobiotic starting method, DPB (Denitrifying Phosphorus-removal Bacteria) are effectively proliferated, glycogen accumulating organisms are restrained, the starting time of the reactor is shortened, and the water outlet effect is improved. The starting way disclosed by the invention operates about 50 days in total, can be used for saving about 30 days and saving the aeration time by about 30% in comparison with an anaerobic/ aerobiotic/ anoxic starting method.

The invention belongs to the technical field of biological sewage treatment, in particular relates to a method for quickly enriching phosphorus accumulating organisms (PAOs) in activated sludge. In the invention, a SBR (sequencing batch reactor) is used for successively inoculating aerobic phosphorus accumulating activated sludge of an aeration tank in an AAO (anaerobic-anoxic-aerobic) process and denitrifying phosphorus accumulating sludge of a pre-anoxic tank in a pre-concentration oxidation ditch process, denitrifying phosphorus accumulating organisms (DNPAOs) can fully utilize aerobically generated nitrate nitrogen for carrying out denitrifying phosphorus uptake, and simultaneously, the degradation of the nitrate nitrogen is favorable for anaerobic phosphorus release of aerobic PAOs. Compared with the traditional direct continuous culture method, the method provided by the invention can effectively shorten the enrichment time of the PAOs, thereby realizing the efficient and stable operation of an enhanced biological phosphorus removal (EBPR) system.

The invention relates to an AOA (Angles-Of-Arrival) continuous flow biological nitrogen and phosphorus removal process for sewage treatment, relating to a sewage treatment process and solving the problems of low efficiency, great operation energy consumption and great carbon source dosage of synchronous nitrogen and phosphorus removal existing in traditional sewage treatment. The process comprises the following steps that: (1) the yielding water of a primary sedimentation tank respectively enters an anaerobic tank and an aerobic tank and the mud of a secondary sedimentation tank is refluxed to the initial end of the anaerobic tank to form a muddy water mixture; and (2) the muddy water mixture enters the aerobic tank from the anaerobic tank in a flow-pushing mode, then enters an anoxic tank and finally enters the secondary sedimentation tank to precipitate and drain. The process provided by the invention comprises the series connection of anaerobism, aerobism and anaerobism, original intake shunted in two parts enters the anaerobic tank and the aerobic tank so that polyphosphate accumulating organisms accumulate a great amount of intracellular polymers by utilizing carbon source in the original intake, the exogenous denitrification and denitrification phosphorus removal of inner carbon sources can be realized in the subsequent anoxic tank, and the synchronous nitrogen and phosphorus removal efficiency is improved. The process does not adopt a digestive juice reflux unit, has lower operation energy consumption than a traditional process and saves the carbon source dosage.

The invention relates to a sequencing batch reaction device and method for carrying out dephosphorization and partial nitrification on low-carbon urban sewage in a single-sludge system and belongs to the fields of urban sewage treatment and resource regeneration. The device comprises a sequencing batch reactor, a stirring mill and an aerator. The device comprises the following steps: controlling the sludge age, selectively discharging sewage, maintaining the low dissolved oxygen, carrying out time-controlled semi-nitrosation, preserving phosphorus-accumulating bacteria, inhibiting nitrite-oxidizing bacteria, enriching ammonia oxidizing bacteria, rapidly starting a microorganism system led by the phosphorus-accumulating bacteria and the ammonia oxidizing bacteria, and optimizing a microenvironment in which the phosphorus-accumulating bacteria and the ammonia oxidizing bacteria coexist, so as to enable the contents of water and phosphorus to reach a first-stage standard A, wherein the specific value of nitrite nitrogen to ammonia nitrogen is about 1:1; after carrying out precipitation and water discharging, creatively carrying out anaerobic stirring on the precipitated sewage, and restoring the residual nitrite nitrogen into nitrogen by virtue of endogenous denitrification. According to the device and the method, the problem that the phosphorus-accumulating bacteria and the ammonia oxidizing bacteria cannot harmoniously coexist in a single sewage system is solved, and a novel thought is provided for dephosphorization and autotrophic nitrogen removal processes.

The invention discloses a segmented drainage type short-cut nitrification parallelly-connected anaerobic ammonia oxidation denitrifying phosphorous removal coupled endogenous denitrification device and a method thereof. Municipal sewage firstly enters a short-cut nitrification phosphorous removal reactor, denitrifying glycogen accumulating bacteria ingest the organic matter and store it as PHAs, and phosphorus-accumulating bacteria store internal carbon source and simultaneously release phosphorous; then, phosphorus is absorbed and ammonia nitrogen is converted to nitrite nitrogen under the hypoxia aeration mode, and nitrosated sewage undergoes first water draining and enters an intermediate water tank; and after anaerobic stirring and denitrification, secondary water draining is carried out. A part of raw water enters an anaerobic ammonia oxidation denitrifying phosphorus removal coupled endogenous denitrification reactor, denitrifying glycogen accumulating bacteria store PHAs, and denitrifying phosphorus accumulating bacteria store an internal carbon source and release phosphorous. After the stage, nitrite nitrogen-containing sewage in the intermediate water tank enters the anaerobic ammonia oxidation denitrifying phosphorus removal coupled endogenous denitrification reactor to realize deep nitrogen and phosphorus removal. By the method, municipal sewage deep nitrogen and phosphorus removal with low C/N ratio can be stably realized.

The invention discloses a medicament for repairing polluted soil and a preparation method thereof. The medicament is prepared from the following components in parts by weight: 5 to 100 parts of microorganism bacterium agent and 1 to 200 parts of chemical agent, wherein the microorganism bacterium agent is prepared from indigenous microorganism culture, nitrifying bacterium culture, denitrifying bacterium culture, phosphorus accumulating bacterium culture, saccharomycetes culture and lactic acid bacterium culture; the weight ratio of the indigenous microorganism culture to the nitrifying bacterium culture to the denitrifying bacterium culture to the phosphorus accumulating bacterium culture to the saccharomycetes culture to the lactic acid bacterium culture is (5 to 10) to (10 to 15) to (10to 15) to (5 to 10) to (10 to 15) to (5 to 10); the chemical agent is prepared from a heavy metal passivating agent and a curing agent; the weight ratio of the heavy metal passivating agent to the curing agent ranges from (1 to 30) to (3 to 170). According to the medicament disclosed by the invention, polluted soil is treated through adopting a physical-chemical-biological combined treatment technology; the medicament has a good repairing effect on the polluted soil.

The invention discloses a device and a method for realizing deep denitrification of municipal sewage by coupling integrated short-cut nitrification and anaerobic ammonia oxidation with endogenous short-cut denitrification. The device comprises a municipal sewage raw water tank, a short-cut nitrification anaerobic ammonia oxidation coupling endogenous short-cut denitrification reactor and a water outlet tank. The method comprises the following steps: municipal sewage firstly enters a short-cut nitrification anaerobic ammonia oxidation coupling endogenous short-cut denitrification reactor, phosphorus-accumulating bacteria and denitrifying glycogen-accumulating bacteria release phosphorus while storing an internal carbon source, and the denitrifying glycogen-accumulating bacteria take in organic matters and convert the organic matters into PHAs to be stored in vivo; then low-oxygen aeration is carried out to convert part of ammonia nitrogen into nitrite nitrogen; anaerobic ammonia oxidation is performed on the residual ammonia nitrogen and the generated nitrite nitrogen to realize denitrification; and the generated nitrate nitrogen is used as an electron acceptor of denitrifying glycan-accumulating bacteria to perform endogenous short-cut denitrification, and the generated nitrite nitrogen can be continuously utilized for anaerobic ammonia oxidation. The method can stably realizelow C/N municipal sewage deep denitrification.

The invention discloses a continuous biological nitrogen and phosphorus removal recovery system. The system comprises an A/O system and a plurality of bio-membrane reactors arranged behind the A/O system in parallel, an aeration device is arranged in each bio-membrane reactor, and each bio-membrane reactor is rich in phosphorus-accumulating bacteria; the plurality of bio-membrane reactors are allcommunicated with the A/O system, and valves for controlling on-off are arranged on passages; and a phosphorus recovery tank is arranged behind the bio-membrane reactors and is communicated with the plurality of bio-membrane reactors. The invention also provides a continuous biological nitrogen and phosphorus removal recovery technology. The continuous biological nitrogen and phosphorus removal recovery technology has a good nitrogen removal effect, and synchronously achieves removal of phosphorus and enrichment of a phosphate solution.

A tubular membrane and rear anoxic endogenous denitrification combined nitrogen and phosphorous deep removal device belongs to the technical field of biological sewage treatment. According to the tubular membrane and rear anoxic endogenous denitrification combined nitrogen and phosphorous deep removal device, domestic sewage enters into the anaerobic section of an AOA (anaerobic/aerobic/anoxic) reactor via a raw sewage tank, glycogen accumulating organisms and polyphosphate accumulating organisms in the anaerobic section can fully absorb and convert external carbon sources in raw sewage into an internal carbon source (PHA, polyhydroxyalkanoates) which is stored in cells, and meanwhile, the polyphosphate accumulating organisms perform anaerobic phosphorous release; then mixed solution is pushed into an aerobic section of nitrification, and polyphosphate accumulating organisms in active silt perform aerobic phosphorous absorption to complete phosphorous absorption; then the mixed solution is pushed into the anoxic section, the glycogen accumulating organisms and the polyphosphate accumulating organisms perform endogenous denitrification on nitrate nitrogen; lastly, the mixed solutionis pushed into a tubular membrane system for slit-water separation, filtered water serves as final effluent for discharging, slit is returned to the anaerobic section and the anoxic section of the AOA reactor. According to the tubular membrane and rear anoxic endogenous denitrification combined nitrogen and phosphorous deep removal device, the anoxic section is arranged at the rear to make full use of the internal carbon source for denitrification nitrogen removal; the tubular membrane system solves the problem of large silt reflux amount, different silt-water separation and the like.

The invention discloses a germ water purifying agent. The germ purifying agent is characterized by comprising 5-12 parts of denitrifying bacteria, 5-12 parts of denitrifying bacteria, 5-12 parts of bacillus, 5-12 parts of photosynthetic bacteria, 8-12 parts of phosphorus-accumulating bacteria, 5-10 of saccharomycetes, and 2-8 parts of actinomycetes based on counting weight parts, and each gram medium of a single bacterium contains 2.5-3.2 hundreds of millions of bacteria. The germ water purifying agent has the advantages of being high-effciency, free of pollution, low in sewage treatment cost, little in investment, low in operation cost, strong in adaptability, low in mud output, and capable of possessing good economic and social benefit.

The invention belongs to the technical field of sewage treatment, and particularly relates to a method for removing nitrate nitrogen and total phosphorus in printing and dyeing wastewater by denitrifying poly-phosphorus accumulating organisms (B8). The denitrifying poly-phosphorus accumulating organisms (B8) are preserved in the CGMCC (China general microbiological culture collection center) with the preservation number of CGMCC NO.9168. The denitrifying poly-phosphorus accumulating organisms are proved to be pseudomonas putida sp. 10% of a bacterium solution prepared by bacteria in percentage by mass is fed into printing and dyeing wastewater and treated by an anaerobic-aerobiotic process or an anaerobic-anoxic process for 9-25 hours at the temperature of 26-30 DEG C respectively, and nitrate nitrogen and total phosphorus in the printing and dyeing wastewater can be effectively removed.

The invention discloses a device and method for enhancing nitrogen and phosphorus removal by combining multistage AO short-cut denitrification coupling Anammox with sludge hydrolytic acidification, and belongs to the technical field of activated sludge process sewage treatment. The system comprises a water tank, a water pump, a biochemical reaction area, a hydrolytic acidification tank and the like, raw water is injected into the reaction area in a segmented manner by a multi-stage AO segmented water inlet pipeline, so that the efficient utilization of organic matters in the raw water is ensured; biological membrane carriers are added into an anaerobic zone and an anoxic zone to enrich anaerobic ammonia oxidizing bacteria, nitrite nitrogen is generated through short-cut denitrification to provide a substrate for the anaerobic ammonia oxidizing bacteria, and nitrogen autotrophic removal is achieved; nitrification and phosphorus-accumulating bacteria aerobic phosphorus absorption are carried out in an aerobic zone; and part of residual sludge in a secondary sedimentation tank enters the hydrolytic acidification tank to convert macromolecular organic matters into micromolecular organic matters, a hydrolytic acidification mixture and the residual sludge in the secondary sedimentation tank synchronously flow back to the anaerobic zone, and the micromolecular organic matters serving as a high-quality carbon source can promote short-cut denitrification. The system provides a new method for efficient and energy-saving treatment of urban sewage.

The present invention provides a biological process for reducing the levels of nitrogen and phosphorous in wastewater, wherein said wastewater comprises at least 100mg/L total nitrogen wherein said process comprises feeding said wastewater into a reaction vessel in at least two steps, wherein said reaction vessel comprises an active biomass comprising nitrifying and denitrifying organisms and polyphosphate accumulating organisms (PAOs), wherein at least the first feed step is followed by a non-aerated period of sufficient duration to result in sufficiently low concentrations of NOx species in the wastewater to allow for accumulation of polyhydroxyalkanoates in the PAOs, and at least the first non-aerated period is followed by an aerated period of sufficient duration to allow for ammonium oxidation by the nitrifying organisms and assimilation by the PAOs of at least a portion of the phosphorous in the wastewater.

The invention relates to Novosphingobium and application thereof in wastewater phosphorus removal. The bacterial strain is Novosphingobium sp. SJB007 and preserved in the general microbiological center of the China Committee for Culture Collection of Microorganisms, and the preservation number is CGMCC No.21177. The invention further discloses an application of the Novosphingobium sp. SJB007 in removal of phosphorus in sewage. The application comprises the following steps that (1), strain culture is carried out, specifically, a preservation strain, namely Novosphingobium sp. SJB007, is inoculated into a seed culture medium, culturing is carried out for 24 hours under the conditions of 30 DEG C and 160rpm, centrifuging is carried out to obtain thalli, and the thalli are washed with sterile water to prepare a bacterial suspension with OD600 of 0.50-0.60; and (2), fermenting is carried out to remove phosphorus, specifically, the bacterial suspension prepared in the step (1) is inoculated into phosphorus-containing sewage according to the proportion of 2%, and fermenting is carried out under the conditions that the pH is 4-8 and the temperature is 15-35 DEG C to remove phosphorus. According to the efficient phosphorus-accumulating strain Novosphingobium sp. SJB007, when the concentration of phosphorus in sewage is 10-30mg/L under a proper condition, the removal rate exceeds 97%, and a relatively high removal rate is achieved.

The invention provides a detection method for diagnosing the structure of Poly-P Accumulating Organisms (PAO) in a sewage disposal system. The method comprises two operational phases of an NO2<-> suppressant check test and a phosphorus uptake determination test, wherein in the first phase, the highest NO2<-> concentration which sludge can bear is determined by examination of the influence of different NO2<-> initial concentrations on denitrifying phosphorus uptake of the tested sludge; and in the second phase, the sludge is subjected to aerobic or anoxic phosphorus uptake reaction under the condition of three different electron acceptors of O2, NO3<-> and NO2<-> respectively, and the phosphorus uptake MO, the phosphorus uptake MON and the phosphorus uptake MONn are obtained. Moreover, the quantitative proportion of various PAOs such as aerobic PAO (a-PAO), denitrifying PAO (d-PAO), facultative PAO (f-PAO), obligative aerobic PAO (oa-PAO) and obligative anoxic PAO (od-PAO) in the sludge is mastered according to the computing formula and the application scope of the sludge on the basis, so that the detection method is favorable for diagnosing and improving the operating efficiency of a phosphorus removal system in time.

A device and a method for enhancing biological phosphorus removal based on synergistic effect of double phosphorus-accumulating bacteria belong to the technical field of biological sewage treatment. The device comprises a water inlet tank, a biological phosphorus removal reactor, a peristaltic pump, a sludge storage tank and an air pump. According to the method, residual sludge is taken as a matrix and enters the biological phosphorus removal reactor together with wastewater, and in an anaerobic stage, a phosphorus-accumulating bacterium Tetrasphaera with fermentation capability generates volatile fatty acid (VFA) by using residual sludge as a matrix and supplies the volatile fatty acid (VFA) to the traditional phosphorus-accumulating bacteria Candidatus Accumulibacter for utilization, stores an internal carbon source and releases phosphate; and in an aerobic stage, phosphate in sewage can be excessively absorbed by the phosphorus-accumulating bacteria Tetrasphaera and Candidatus Accumulibacter together, so that the synergistic phosphorus removal is realized. By utilizing the synergistic effect of the phosphorus-accumulating bacteria Tetrasphaera and Candidatus Accumulibacter, thedependence on inlet water VFA can be reduced, meanwhile, phosphorus is absorbed by the phosphorus-accumulating Tetrasphaera and Candidatus Accumulibacter at the same time in an aerobic stage, biological phosphorus removal can be effectively enhanced, and a brand-new process solution is provided for treatment of sewage lack of carbon sources in many regions.

The invention discloses a device and a method for a side-flow enhanced biological phosphorus removal process developed based on a carbon source in excess sludge, and belongs to the field of biologicalsewage treatment. According to the method, a part of returned sludge in a secondary sedimentation tank enters a side-flow fermentation zone, activated sludge is used as a matrix of phosphorus-accumulating bacteria Tetrosphaera with fermentation capability, phosphate is released, an internal carbon source is absorbed and stored, and volatile fatty acid VFA is produced by fermentation and is used by other heterotrophic bacteria. The other part of the returned sludge, the effluent of the side-flow fermentation zone and municipal sewage inflow enter an anoxic zone of a main-flow reaction zone together, denitrification nitrogen and phosphorus removal are achieved by utilizing an internal carbon source absorbed and stored in the fermentation zone and volatile fatty acid VFA generated in the fermentation zone, and the effluent of the anoxic zone flows into an aerobic zone for aerobic phosphorus absorption and nitrification. According to the invention, a side-flow continuous flow process is utilized, a front anaerobic zone is omitted, the addition of a carbon source is greatly saved, and the dependence on inlet water VFA is reduced.

The invention discloses a denitrification nitrogen and phosphorus removal sewage treatment system and method, and the system comprises an MABR device, an air compressor, a water inlet barrel, a circulating pump with a circulating regulating valve. An MABR reactor based on coupling denitrification nitrogen and phosphorus removal continuously supplies air is to microorganisms growing on the surface of the membrane through the hollow fiber membrane by virtue of an air compressor, and aerobic, anoxic and anaerobic microenvironments are formed, so that phosphorus-accumulating bacteria, denitrifying phosphorus-removing bacteria, denitrifying bacteria and the like can synergistically remove nitrogen and phosphorus, and a sewage treatment system for denitrifying nitrogen and phosphorus removal is simple to operate, low in sludge yield high in sewage treatment efficiency. and small in occupied area, nitrogen and phosphorus removal microorganisms are coupled in the MABR single-stage reactor by establishing a unique biological membrane growth environment, and a traditional biological nitrogen and phosphorus removal process is simplified.

The invention discloses an A/O coupled sulfur autotrophic denitrification enhanced low carbon-nitrogen ratio sewage denitrification and dephosphorization device, and a method, and belongs to the fieldof biological sewage treatment. The method comprises steps: raw water, a reflux solution of a sulfur autotrophic denitrification filter tank and reflux sludge of a secondary sedimentation tank are introduced into an anaerobic tank of an A/O process together, easily degradable organic matters are absorbed by phosphorus-accumulating bacteria in the anaerobic tank to synthesize PHAs, the PHAs are stored in the body, and phosphate is released; and the easily degradable organic matters are used by sulfur reducing bacteria to reduce sulfate into polysulfide, the polysulfide is transferred into sulfur oxidizing bacteria, and meanwhile, a phosphorus release effect is realized by sulfur oxidizing bacteria; mixed liquid of the anaerobic tank is introduced into an aerobic zone of the A/O process, the concentration of dissolved oxygen is controlled, ammonia nitrogen is completely converted into nitrate, and meanwhile, phosphorus-accumulating bacteria and sulfur-oxidizing bacteria are adopted to absorb a large amount of phosphorus; a supernatant of a secondary sedimentation tank is introduced into a sulfur autotrophic denitrification filter tank, and deep denitrification is carried out throughthe sulfur autotrophic denitrification effect. According to the method, the requirement of the A/O process on the carbon-nitrogen ratio of inlet water is reduced, and synchronous nitrogen and phosphorus removal of low-carbon-nitrogen-ratio sewage can be realized.