CN117700046A - Novel sewage treatment system and process based on immobilized microorganisms - Google Patents

Abstract

The invention discloses a new sewage treatment system and process based on immobilized microorganisms, which includes a pretreatment unit, an anaerobic tank, an anoxic tank, a high-density sedimentation tank, a third-level aerobic tank unit, and an autotrophic tank connected in sequence by pipelines. The denitrification tank, ozone oxidation tank and clear water tank, the anaerobic tank, anoxic tank, the third-level aerobic tank unit and the autotrophic denitrification tank are all equipped with suspended fillers. The suspended fillers are equipped with microbial solidification carriers. The clear water tank It is connected to the third-level aerobic tank unit and the autotrophic denitrification tank through the backwash pipe network. The present invention adopts the above structure, and the microorganism immobilized carrier prevents the microorganisms from following the flow of sewage and reduces the microbial loss rate. The treated effluent water quality indicators fully meet or exceed the surface water Class IV water standard, the mud production is extremely low, and the overall Efficient recovery of phosphorus.

Description

A new sewage treatment system and process based on immobilized microorganisms

Technical field

The present invention relates to the technical field of sewage treatment, and in particular to a new sewage treatment system and process based on immobilized microorganisms.

Background technique

Biological treatment of wastewater refers to a treatment method that uses the metabolism of microorganisms to degrade and transform pollutants in wastewater, thereby purifying wastewater. Biological treatment of wastewater mainly includes three sections: (1) aerobic treatment; (2) anaerobic treatment; (3) nitrogen and phosphorus removal of sewage. Among these three sections, aerobic treatment and anaerobic treatment are mainly responsible for the treatment of organic matter in sewage, and the sewage denitrification and phosphorus removal process is mainly responsible for the treatment of nitrogen and phosphorus in sewage.

For a long time, the anaerobic biological treatment process of organic wastewater has been dominated by the anaerobic activated sludge method. Biological denitrification of wastewater means that nitrogen-containing organic matter in sewage is oxidized and decomposed by heterotrophic microorganisms and converted into ammonia nitrogen (ammonification process), which is then converted into NO ₃ ^- (nitrification process) by autotrophic nitrifying bacteria, and finally again It is reduced and converted into N ₂ by denitrifying bacteria (denitrification process), thereby achieving the purpose of nitrogen removal. Biological phosphorus removal from wastewater refers to the principle of biological phosphorus removal. In the biological phosphorus removal process, the sludge is placed under anaerobic repressive conditions so that the phosphorus accumulated in the phosphorus-accumulating bacteria can be fully discharged; A large amount of phosphorus is accumulated in the bacteria, and then the activated sludge containing this phosphorus-accumulating bacteria is allowed to settle in the secondary sedimentation tank.

There are many types of biological treatment processes for wastewater. It is common to choose one of these processes, or use a combination of some processes. Taking the most commonly used activated sludge method as an example, both anoxic and aerobic tanks are mainly composed of heterotrophic microorganisms and treat sewage in the form of bacterial jelly. This system needs to supplement organic carbon sources, but the utilization rate of carbon sources is low. Low, most of them are consumed by miscellaneous bacteria; the division of labor within the bacterial flora is unclear, there is competition among various bacteria, and the pollutant removal effect is difficult to balance. To effectively remove nitrogen, it is often necessary to supplement carbon sources, which ultimately leads to the deviation of effluent COD. high. Moreover, heterotrophic bacteria have limited ability to remove total nitrogen. When the total nitrogen drops below 10.0 mg/L, the effect is poor.

Therefore, according to the characteristics of each microorganism, combined with the improvement of various processes, giving full play to the characteristics and advantages of microorganisms in each component, it has very obvious potential in the sewage treatment process.

Contents of the invention

The purpose of the present invention is to provide a new sewage treatment system and process based on immobilized microorganisms, which overcomes the problems of low treatment efficiency, poor impact load resistance, high mud production, and large floor space in the existing process.

In order to achieve the above objectives, the present invention provides a new sewage treatment system based on immobilized microorganisms, including a pretreatment unit, an anaerobic tank, an anoxic tank, a high-density sedimentation tank, and a three-stage aerobic tank unit sequentially connected by pipelines. , autotrophic denitrification tank, ozone oxidation tank and clear water tank. The anaerobic tank, anoxic tank, third-level aerobic tank unit and autotrophic denitrification tank are all equipped with suspended fillers, and the suspended fillers are equipped with microbial solid carriers. , the clear water tank is connected to the third-level aerobic tank unit and the autotrophic denitrification tank through the backwash pipe network.

Preferably, the pretreatment unit includes a two-stage grille and a conditioning tank;

The two-level grille is a coarse grille and a fine grille set in sequence.

Preferably, the three-level aerobic pool unit is an aerobic pool one, an aerobic pool two and an aerobic pool three that are connected in sequence. The aerobic pool three is connected to the clean water pool and the anaerobic pool through the backwash pipe network.

Preferably, the levels of the high-density sedimentation tank, the third-stage aerobic tank unit, the autotrophic denitrification tank, the ozone oxidation tank and the clear water tank are all higher than the level of the pretreatment unit, the anaerobic tank and the anoxic tank.

The above-mentioned sewage treatment process of a new sewage treatment system based on immobilized microorganisms includes the following steps:

S1. Discharge the sewage to be treated into the pretreatment unit, and pass through the coarse grille and the fine grille in sequence to remove larger suspended solids and floating objects in the sewage. The sewage intercepted by the pretreatment unit is discharged into the regulating tank to adjust the water quality;

S2. Pump the sewage in the regulating tank in S1 into the anaerobic tank through a water pump. The microorganisms on the suspended fillers evenly arranged in the anaerobic tank decompose macromolecular organic matter into small molecular organic matter;

Specifically, fats are hydrolyzed into fatty acids, polysaccharides are hydrolyzed into monosaccharides, proteins are hydrolyzed into amino acids, long-chain alkanes are broken, and cyclic alkanes and benzene are ring-opened.

S3. Pump the sewage in the anaerobic tank in S2 into the anoxic tank. The microorganisms on the suspended fillers evenly arranged in the anoxic tank remove total nitrogen and most of the COD, and the third-level aerobic tank unit returns to the anoxic tank. The nitrification solution supplements electron acceptors to degrade COD;

S4. Pump the sewage from the anoxic tank in S3 into the high-density sedimentation tank, and add flocculant to the high-density sedimentation tank to remove most of the suspended matter, remaining phosphorus and part of the insoluble COD;

S5. Pass the sewage in the high-density sedimentation tank in S4 through aerobic tank one, aerobic tank two and aerobic tank three in sequence. The microorganisms on the suspended fillers evenly arranged in aerobic tank one and aerobic tank two will convert ammonia nitrogen in sequence. For nitrite and nitrate, aeration and oxygenation and zeolite filtration are carried out in the aerobic tank three;

S6. Pump the sewage in the third-stage aerobic tank unit in S5 into the autotrophic denitrification tank. The microorganisms on the evenly arranged suspended fillers in the autotrophic denitrification tank convert nitrate nitrogen and nitrite nitrogen into nitrogen and release them. sewage water bodies;

S7. Pump the sewage in the autotrophic denitrification tank in S6 into the ozone oxidation tank, and ozone oxidize the sewage to remove the remaining refractory COD;

S8. Disinfection equipment disinfects the effluent discharged from the ozone oxidation pool in S6, removes pathogenic microorganisms in the water body, and then pumps it into the clean water pool for discharge to meet standards.

Preferably, in S2, the microorganisms on the suspended filler evenly arranged in the anaerobic tank are hydrolytic fermentation bacteria, hydrogen-producing acetogenic bacteria and methanogenic bacteria.

Preferably, in S3, the microorganisms on the suspended fillers evenly arranged in the anoxic tank are heterotrophic denitrifying bacteria.

Preferably, in S5, the microorganisms on the evenly arranged suspension fillers in the aerobic pool one are autotrophic nitrite bacteria, the microorganisms on the evenly arranged suspension fillers in the aerobic pool two are nitrate bacteria, and the evenly arranged microorganisms on the aerobic pool three are nitrite bacteria. The microorganisms on the hanging filler are autotrophic nitrite bacteria and nitrate bacteria.

Preferably, in S6, the microorganisms on the suspended fillers evenly arranged in the autotrophic denitrification tank are autotrophic denitrifying bacteria.

Therefore, the present invention adopts the above structure and steps, and its beneficial effects are:

1. The present invention replaces the skeleton function of filamentous bacteria in activated sludge with a microbial solidified carrier to solve the problem of easy loss of traditional microbial agents when sprayed. It has strong impact resistance, blocks suspended solids in the water environment, and is resistant to toxic substances when encountered. Harmful substances can effectively protect microbial flora;

2. The sewage treated by the sewage treatment process of the present invention has no peculiar smell, no additional organic carbon source is needed, and the amount of activated sludge produced is less than 10% of that of the conventional sewage treatment process;

3. The sewage treatment process provided by the present invention has high total nitrogen removal efficiency, the design load of autotrophic denitrification and denitrification can reach 1.0-1.5kg/m ³ ·d, it occupies a small area, and the effluent quality indicators fully meet or are better than those on the surface The water meets Class IV water standards and can effectively recover total phosphorus.

The technical solution of the present invention will be further described in detail below through the accompanying drawings and examples.

Description of the drawings

Figure 1 is a flow chart of a new sewage treatment process based on immobilized microorganisms of the present invention.

Detailed ways

The technical solution of the present invention will be further described below through the drawings and examples.

The present invention can be explained in more detail through the following examples. The purpose of disclosing the present invention is to protect all changes and improvements within the scope of the present invention. The present invention is not limited to the following examples.

Example 1

A new sewage treatment system based on immobilized microorganisms, including a pretreatment unit, anaerobic tank, anoxic tank, high-density sedimentation tank, three-stage aerobic tank unit, autotrophic denitrification tank, and ozone oxidation connected in sequence by pipelines The pond and clear pool, anaerobic pool, anoxic pool, third-level aerobic pool unit and autotrophic denitrification pool are all equipped with suspended fillers. The suspended fillers are equipped with microbial solidified carriers. The clear pool is connected with the backwash pipe network through the backwash pipe network. The third-level aerobic tank unit is connected to the autotrophic denitrification tank.

The pretreatment unit includes a two-stage grille and a regulating tank. The two-stage grille is a coarse grille and a fine grille set in sequence. The pretreatment unit intercepts larger suspended solids and floating objects in the sewage, and the intercepted sewage enters the regulating tank. The regulating tank regulates the water quality of the sewage, regulating water quantity and balancing water quality.

The filler on the hanging filler is a solid carrier for microorganisms. The porous solid microorganism carrier is loaded with microorganisms, which solves the problem of easy loss of traditional microbial agents when sprayed. This makes the microorganisms in each sewage treatment tank single and do not participate in the entire treatment with the sewage. process. At the same time, the porous microbial solidification carrier blocks and throttles the activated sludge in the sewage, reducing the amount of activated sludge produced in the sewage treatment process. Microorganisms fixed on microbial solid carriers do not produce bacterial micelle when treating sewage. Microbial solid carriers replace the skeleton of filamentous bacteria in activated sludge. The sewage treatment process does not require external carbon sources, reduces oxygen demand, and does not produce activity. sludge.

The three-level aerobic pool unit is an aerobic pool one, an aerobic pool two and an aerobic pool three that are connected in sequence. The aerobic pool three is connected to the clean pool and anaerobic pool through the backwash pipe network. The nitrification liquid at the two ends of the aerobic pool in the third-level aerobic pool unit returns to the anoxic pool, providing electron acceptors to the anoxic pool to enhance the effect of COD degradation.

The levels of the high-density sedimentation tank, three-stage aerobic tank unit, autotrophic denitrification tank, ozone oxidation tank and clear water tank are all higher than those of the pretreatment unit, anaerobic tank and anoxic tank.

Example 2

A sewage treatment process based on a new type of sewage treatment system based on immobilized microorganisms, including the following steps, as shown in Figure 1,

S1. Discharge the sewage to be treated into the pretreatment unit, and pass through the coarse grille and the fine grille in sequence to remove larger suspended solids and floating objects in the sewage. The sewage intercepted by the pretreatment unit is discharged into the regulating tank to adjust the water quality.

S2. Pump the sewage in the regulating tank in S1 into the anaerobic tank through a water pump. The microorganisms on the suspended fillers evenly arranged in the anaerobic tank decompose macromolecular organic matter into small molecular organic matter;

In S2, the microorganisms on the suspended filler evenly arranged in the anaerobic tank are hydrolytic fermentation bacteria, hydrogen-producing acetogenic bacteria and methanogenic bacteria. The three types of anaerobic bacteria hydrolyze, acidify and methanate macromolecular organic matter in sewage water, hydrolyze fats into fatty acids, hydrolyze polysaccharides into monosaccharides, hydrolyze proteins into amino acids, break long-chain alkanes, and cyclic alkanes and Benzene undergoes ring opening, etc. Convert macromolecules into small molecules to remove macromolecular organic matter in the sewage water body, generate easily degradable volatile fatty acids, and improve the biodegradability of the sewage to facilitate subsequent treatment. The generated methane and other gases are directly released into the sewage water body.

S3. Pump the sewage in the anaerobic tank in S2 into the anoxic tank. The microorganisms on the suspended fillers evenly arranged in the anoxic tank remove total nitrogen and most of the COD, and the third-level aerobic tank unit returns to the anoxic tank. The nitrification solution supplements electron acceptors to degrade COD.

In S3, the microorganisms on the suspended filler evenly arranged in the anoxic tank are heterotrophic denitrifying bacteria. The heterotrophic denitrifying bacteria use nitrate ammonia as the electron acceptor and organic matter as the electron donor to grow and metabolize. During the metabolic process, total removal of total Nitrogen and most COD.

S4. Pump the sewage in the anoxic tank in S3 into the high-density sedimentation tank, and add flocculant to the high-density sedimentation tank. The flocculants are PAC and PAM. The flocculant is used to treat the activated sludge remaining in the sewage entering the high-density sedimentation tank to remove most of the suspended matter, remaining phosphorus and part of the insoluble COD.

S5. Pass the sewage in the medium-high density sedimentation tank of S4 through the aerobic tank one, aerobic tank two and aerobic tank three in sequence. Microorganisms convert ammonia nitrogen into nitrite and nitrate in sequence. The aerobic tank three adopts the form of delayed aeration. The aerobic tank three is aerated and oxygenated. The evenly arranged hanging filler is used to filter and convert all the ammonia nitrogen in the sewage. for nitrate. After the aerobic pool three has been running for a period of time, the water in the clear pool will backwash it, and the backwashed water will return to the anaerobic pool for reprocessing.

In S5, the microorganisms on the evenly placed suspended filler in the aerobic pool 1 are autotrophic nitrite bacteria, which convert ammonia nitrogen into nitrite. The microorganisms on the evenly arranged suspended filler in the second aerobic tank are nitrate bacteria, which convert nitrite into nitrate. The microorganisms on the evenly arranged suspended filler in the aerobic pool three are autotrophic nitrite bacteria and nitrate bacteria, which convert all the ammonia nitrogen and nitrite remaining in the sewage into nitrate. Suspension fillers are installed in aerobic pool one, aerobic pool two and aerobic pool three, which are not easy to block. At the same time, the high specific surface area of the microbial solid carrier can adhere to a large number of autotrophic nitrite bacteria and nitrate bacteria. Aerobic pool one and aerobic pool two return 1% of the sewage to the anoxic pool. The nitrate nitrogen in the returned sewage reacts with the hydrogen sulfide in the anaerobic pool, which can eliminate the odor generated by the sewage treatment process.

The third-level aerobic pool unit only oxidizes and reduces nitrogen, and the anoxic and anaerobic pools oxidize carbon to the greatest extent; before the sewage enters the third-level aerobic pool unit, all necessary nutrients for the proliferation of heterotrophic microorganisms are removed ( organic carbon source and phosphate) to achieve inhibition of the proliferation of heterotrophic microorganisms. After being treated in steps S1-S4, the organic carbon content in the sewage entering the third-level aerobic pool unit is very small, and autotrophic nitrite bacteria and nitrate bacteria do not need to rely on external organic carbon for growth and metabolism. Since this sewage water body is not conducive to the growth of heterotrophic microorganisms, no activated sludge is produced in this step.

S6. Pump the sewage in the third-stage aerobic tank unit in S5 into the autotrophic denitrification tank. The microorganisms on the evenly arranged suspended filler in the autotrophic denitrification tank convert nitrite nitrogen and nitrate nitrogen into nitrogen and release it. Sewage water bodies. After the autotrophic denitrification tank has been running for a period of time, it is backwashed with water from the clean tank, and the backwashed water is returned to the anaerobic tank for reprocessing.

In S6, the microorganisms on the evenly placed suspended fillers in the autotrophic denitrification tank are autotrophic denitrifying bacteria. Autotrophic denitrifying bacteria do not need to rely on external organic carbon for growth and metabolism, so this step does not produce activated sludge.

S7. Pump the sewage in the autotrophic denitrification tank in S6 into the ozone oxidation tank, and ozone oxidize the sewage to remove the remaining refractory COD.

S8. Disinfection equipment disinfects the effluent discharged from the ozone oxidation pool in S6, removes pathogenic microorganisms in the water body, and then pumps it into the clean water pool for discharge to meet standards.

Test example 1

The sewage treatment system and process provided by the present invention are used for sewage treatment in Taizhou Wool Farm, Mianchi Sewage Treatment Plant, Tangqi Sewage Treatment Plant and agricultural sewage treatment. The sewage composition is shown in Table 1. Comparison of data before and after sewage treatment of various pollutants, as shown in Table 2, it can be seen that the sewage treatment system and sewage treatment method provided by the present invention have high total nitrogen removal efficiency, and the effluent water quality indicators fully meet or are better than surface water Class IV water Standard, and can achieve effective recovery of total phosphorus, with excellent sewage treatment effect.

Table 1. List of pollutant components in various types of sewage

Table 2. Data comparison table before and after various types of sewage treatment

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: The technical solution of the present invention may be modified or equivalently substituted, but these modifications or equivalent substitutions cannot cause the modified technical solution to depart from the spirit and scope of the technical solution of the present invention.

Claims (9)

1. Novel sewage treatment system based on immobilized microorganism, its characterized in that: the device comprises a pretreatment unit, an anaerobic tank, an anoxic tank, a high-density sedimentation tank, a three-stage aerobic tank unit, an autotrophic denitrification tank, an ozone oxidation tank and a clean water tank which are sequentially communicated through pipelines, wherein hanging fillers are arranged in the anaerobic tank, the anoxic tank, the three-stage aerobic tank unit and the autotrophic denitrification tank, microbial solid carriers are arranged on the hanging fillers, and the clean water tank is communicated with the three-stage aerobic tank unit and the autotrophic denitrification tank through a back flushing pipe network.

2. The novel immobilized microorganism-based wastewater treatment system of claim 1, wherein: the pretreatment unit comprises a two-stage grating and an adjusting tank;

the two-stage grating is a coarse grating and a fine grating which are sequentially arranged.

3. The novel immobilized microorganism-based wastewater treatment system of claim 2, wherein: the three-stage aerobic tank unit is an aerobic tank I, an aerobic tank II and an aerobic tank III which are sequentially communicated, and the aerobic tank three is communicated with the clean water tank and the anaerobic tank through a back flushing pipe network.

4. A novel immobilized microorganism-based wastewater treatment system according to claim 3, wherein: the high-density sedimentation tank, the three-stage aerobic tank unit, the autotrophic denitrification tank, the ozone oxidation tank and the clean water tank are all higher than the pretreatment unit, the anaerobic tank and the anoxic tank.

5. The wastewater treatment process of the novel wastewater treatment system based on immobilized microorganisms according to any one of claims 4, wherein: comprises the steps of,

s1, discharging sewage to be treated into a pretreatment unit, sequentially passing through a coarse grating and a fine grating, removing larger suspended matters and floaters in the sewage, and discharging the sewage trapped by the pretreatment unit into an adjusting tank to adjust water quality;

s2, pumping sewage in the regulating tank in the S1 into an anaerobic tank through a water pump, and decomposing macromolecular organic matters into micromolecular organic matters by microorganisms on hanging fillers uniformly arranged in the anaerobic tank;

s3, pumping sewage in the anaerobic tank in the S2 into an anoxic tank, removing total nitrogen and most COD by microorganisms on suspended fillers uniformly arranged in the anoxic tank, and refluxing nitrifying liquid in the anoxic tank by a three-stage aerobic tank unit to supplement an electron acceptor for degrading COD;

s4, pumping the sewage in the anoxic tank in the S3 into a high-density sedimentation tank, and adding a flocculating agent into the high-density sedimentation tank to remove most suspended substances, residual phosphorus and partial insoluble COD;

s5, sequentially passing the sewage in the high-density sedimentation tank in the S4 through a first aerobic tank, a second aerobic tank and a third aerobic tank, sequentially converting ammonia nitrogen into nitrite and nitrate by microorganisms on suspension fillers uniformly arranged in the first aerobic tank and the second aerobic tank, carrying out aeration oxygenation in the third aerobic tank, filtering by using the suspension fillers uniformly arranged, and completely converting the ammonia nitrogen in the sewage into nitrate;

s6, pumping the sewage in the three-stage aerobic tank unit in the S5 into an autotrophic denitrification tank, and converting nitrate nitrogen and nitrite nitrogen into nitrogen by microorganisms on suspended fillers uniformly arranged in the autotrophic denitrification tank to release sewage water;

s7, pumping the sewage in the autotrophic denitrification tank in the S6 into an ozone oxidation tank, and removing residual nondegradable COD (chemical oxygen demand) from the ozone oxidation sewage;

and S8, sterilizing the effluent discharged from the ozone oxidation pond in the step 6 by using sterilizing equipment, removing pathogenic microorganisms in the water body, and pumping the water into a clean water pond to achieve the standard for discharge.

6. The wastewater treatment process of the novel wastewater treatment system based on immobilized microorganisms according to claim 5, wherein: in S2, microorganisms on hanging fillers uniformly arranged in the anaerobic tank are hydrolytic zymobacteria, hydrogen-producing acetogenic bacteria and methanogenic bacteria.

7. The wastewater treatment process of the novel wastewater treatment system based on immobilized microorganisms according to claim 5, wherein: and S3, the microorganisms on the hanging filler uniformly arranged in the anoxic tank are heterotrophic denitrifying bacteria.

8. The wastewater treatment process of the novel wastewater treatment system based on immobilized microorganisms according to claim 5, wherein: in S5, the microorganisms on the hanging fillers uniformly arranged in the first aerobic tank are autotrophic nitrite bacteria, the microorganisms on the hanging fillers uniformly arranged in the second aerobic tank are nitrate bacteria, and the microorganisms on the hanging fillers uniformly arranged in the third aerobic tank are autotrophic nitrite bacteria and nitrate bacteria.

9. The wastewater treatment process of the novel wastewater treatment system based on immobilized microorganisms according to claim 5, wherein: in S6, microorganisms on hanging fillers uniformly arranged in the autotrophic denitrification tank are autotrophic denitrification bacteria.