CN115947453A - Sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system and method - Google Patents

Abstract

The invention relates to a sulfur autotrophic and low-carbon heterotrophic short-range denitrification coupling anaerobic ammonia oxidation denitrification system and a method. Is suitable for the field of urban sewage biochemical treatment and is suitable for nitrogen and phosphorus removal of urban sewage. The technical scheme of the invention is a sulfur autotrophic and low-carbon heterotrophic short-range denitrification coupling anaerobic ammonia oxidation denitrification system, which is characterized in that: comprises a domestic sewage raw water tank, a multi-stage AO biological tank and a sedimentation tank which are sequentially communicated along the sewage flow direction; the anaerobic-anoxic-oxic (AO) biological pond is characterized in that all the stages of the multi-stage AO biological pond are sequentially communicated along the sewage flow direction, each stage is provided with an anoxic zone and an aerobic zone which are sequentially arranged along the sewage flow direction, a sulfur filter material and anaerobic ammonia oxidation filler are filled in the anoxic zone, and an aeration device is arranged in the aerobic zone; the domestic sewage raw water tank is respectively communicated with the anoxic zones through water conveying pipelines; the water outlet of the sedimentation tank is connected with a water outlet pipe, and a sludge outlet of the sedimentation tank is communicated with a first anoxic zone in the multistage AO biological tank along the flow direction of the sewage through a sludge return pipe.

Description

Sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system and method

technical field

The invention relates to a sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anaerobic ammonium oxidation denitrification system and method. It is suitable for the field of biochemical treatment of urban sewage, and is suitable for denitrification and phosphorus removal of urban sewage.

Background technique

The domestic sewage generated in daily activities contains a large amount of nitrogen and phosphorus elements. Excessive nitrogen and phosphorus pollutants will cause water pollution. The activated sludge method is usually used for sewage treatment. The traditional activated sludge method oxidizes the ammonia nitrogen in the raw water to nitrate nitrogen through nitrification and then removes it through heterotrophic denitrification. The denitrification process requires a large amount of carbon source, and due to the widespread use of septic tanks, resulting in low carbon nitrogen ratio domestic sewage characteristics, which cannot meet the needs of deep denitrification and dephosphorization. The emergence of anaerobic ammonium oxidation provides the possibility for the realization of autotrophic denitrification, which can simultaneously remove ammonia nitrogen and nitrite nitrogen under anaerobic conditions, without aeration and can save energy consumption of carbon sources. Among them, there are two ways to produce nitrite nitrogen: short-range nitrification and short-range denitrification. The former is difficult to sustain and stabilize, and the latter still needs a small amount of carbon source to realize short-range denitrification of nitrate nitrogen into nitrite nitrogen, that is, short-range denitrification. The coupled anammox process is still limited by carbon sources to a certain extent.

Contents of the invention

The technical problem to be solved by the present invention is to provide a sulfur autotrophic + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system and method for the above existing problems.

The technical solution adopted in the present invention is: a sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system, which is characterized in that it includes domestic sewage raw water tanks connected sequentially along the sewage flow direction, multi-stage AO biological pool and sedimentation tank;

The stages of the multi-stage AO biological pool are sequentially connected along the direction of sewage flow, and each stage has anoxic zones and aerobic zones arranged sequentially along the direction of sewage flow, wherein the anoxic zone is filled with sulfur filter materials and anaerobic Oxygen ammonium oxidation filler, with aeration device in the aerobic zone;

The domestic sewage raw water tank is respectively connected to each of the anoxic zones through a water delivery pipeline; the water outlet of the sedimentation tank is connected to an outlet pipe, and the mud outlet of the sedimentation tank is connected to the multi-stage AO biological water tank through a sludge return pipe. The first anoxic zone in the pond along the direction of sewage flow.

The filling ratio of the sulfur filter material and the anaerobic ammonium oxidation filler in the anoxic zone is 15%-25%.

Water inlet pumps are installed on the water delivery pipeline corresponding to each of the anoxic zones; sludge return pumps are connected to the sludge return pipe.

The anoxic zone is evenly divided into two compartments, and a stirring device is provided in each compartment.

A sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification method based on the system, characterized in that:

Send the domestic sewage raw water in the domestic sewage raw water tank into each anoxic zone of the multi-stage AO biological pool;

In the first anoxic zone along the sewage flow direction, anaerobic phosphorus release occurs by using part of the carbon source in the raw water of domestic sewage, and the nitrate nitrogen in the mud-water mixture returned from the sedimentation tank is absorbed by the sulfur filter material and anammox filler in the anoxic zone. Under the action of sulfur autotrophic short-range denitrification and carbon heterotrophic short-range denitrification to generate nitrite nitrogen, the long-term coexistence of ammonia nitrogen and nitrite nitrogen in the anoxic zone is conducive to the retention and enrichment of anammox bacteria, and the sulfur filter The material and the anammox filler as the carrier can provide nitrite nitrogen for the anammox bacteria through autotrophy and heterotrophy, and realize the synchronous removal of ammonia nitrogen and nitrite nitrogen under the condition of low carbon-to-nitrogen ratio influent;

In the aerobic zone, the aeration device is used to control sufficient dissolved oxygen to ensure that the remaining ammonia nitrogen in the anoxic zone is fully nitrified into nitrate nitrogen, and aerobic phosphorus uptake is completed;

The effluent from the aerobic zone is mixed with the raw water of domestic sewage in the latter anoxic zone, part of the raw water provides carbon source for anaerobic phosphorus release, and part of the nitrate nitrogen carried by the effluent from the aerobic zone undergoes sulfur autotrophic short-range denitrification and carbon heterotrophic short-range denitrification. After denitrification generates nitrite nitrogen and influent ammonia nitrogen is removed by anaerobic ammonium oxidation, the latter aerobic zone nitrifies the remaining ammonia nitrogen to nitrate nitrogen throughout the process.

Through sulfur autotrophic short-range denitrification and heterotrophic short-range denitrification under low organic matter concentration in the influent, nitrous is provided for anammox at the same time, and the ratio of autotrophic denitrification of anammox is synergistically increased.

The hydraulic retention time in each anoxic zone and aerobic zone is the same.

The total hydraulic retention time HRT of the multi-stage AO biological pool is 12-15h.

The dissolved oxygen concentration in the aerobic zone is controlled at 1.0-2.0 mg/L, and the sludge age is 15-25 days.

The beneficial effects of the present invention are: the present invention provides biological carriers for the anammox bacteria by adding sulfur filter material and anammox filler to the anoxic area, retains and enriches the anammox bacteria, and drives short-range nitrate nitrogen Denitrification into nitrite nitrogen, realizing sulfur autotrophy and carbon heterotrophic short-range denitrification coupling anammox denitrification in the anoxic zone, the carbon source in the raw water is used for anaerobic phosphorus release, and aerobic absorption in the aerobic zone Phosphorus, the final effluent contains only nitrate nitrogen, realizing deep nitrogen and phosphorus removal of domestic sewage with low carbon-to-nitrogen ratio.

The present invention realizes sulfur autotrophic short-range denitrification and carbon heterotrophic short-range denitrification process by adding sulfur filter material and anammox filler, saves the carbon source required for traditional nitrification and denitrification, and reduces processing cost; sulfur filter material and anammox The presence of oxidizing filler provides a good biological carrier for anammox bacteria, which is beneficial to the enrichment and retention of anammox bacteria; most of the carbon source in raw water is used for anaerobic phosphorus release, ensuring a stable phosphorus removal effect ; The reaction process of sulfur autotrophic short-range denitrification and anammox is an autotrophic reaction, which not only saves energy consumption but also reduces sludge production and reduces the burden of subsequent sludge treatment.

Description of drawings

Fig. 1 is the structural representation of embodiment.

1. Domestic sewage raw water tank; 2. Multi-stage AO biological pool; 3. Anoxic first zone; 3-1. First water inlet pump; 4. Aerobic first zone; 5. Anoxic second zone; Second water inlet pump; 6. Aerobic second zone; 7. Anoxic third zone; 7-1. Third water inlet pump; 8. Aerobic third zone; 9. Sedimentation tank; 9-1. Outlet pipe; 9-2. Sludge discharge pipe; 9-3, sludge return pump; 10, stirring device; 11, sulfur filter material and anammox filler; 12, air pump; 13, aeration head.

Detailed ways

As shown in Figure 1, this embodiment is a sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anaerobic ammonia oxidation denitrification system, including domestic sewage raw water tanks connected sequentially along the sewage flow direction, multi-stage AO biological ponds and sedimentation ponds.

In this implementation, the multi-stage AO biological pool includes anoxic zone 1, aerobic zone 1, anoxic zone 2, aerobic zone 2, anoxic zone 3, and aerobic zone 3, which are connected sequentially along the direction of sewage flow. The hydraulic retention time ratio of zone 1, aerobic zone 1, anoxic zone 2, aerobic zone 2, anoxic zone 3 and aerobic zone 3 is 1:1:1:1:1:1.

In this example, sulfur filter material and anaerobic ammonium oxidation filler are filled in anoxic zone 1, anoxic zone 2 and anoxic zone 3, with a filling ratio of 15%-25% and a particle size of 3-6mm; aerobic zone 1 Aeration devices are installed in the second aerobic area and the third aerobic area. The aeration device includes an aeration head arranged at the bottom of the aerobic area, and an air pump arranged outside the multi-stage AO biological pool and connected to the aeration head.

In this embodiment, the domestic sewage raw water tank is respectively connected to the hypoxia zone 1, hypoxia zone 2 and hypoxia zone 3 through the water delivery pipeline. The first water inlet pump, the second water inlet pump and the third water inlet pump.

In this embodiment, the effluent from the third aerobic area enters the sedimentation tank, part of the sludge at the bottom of the pool flows back to the anoxic area through the sludge return pipe and the sludge return pump, and part of it is discharged through the sludge discharge pipe. It is discharged from the outlet pipe at the outlet of the sedimentation tank.

In this example, the first anoxic area, the second anoxic area and the third anoxic area are divided into two grids, and each grid is equipped with a stirring device.

The operating method of the system in the present embodiment is as follows:

1) Process start:

Inoculate the return sludge of urban sewage treatment plant, sulfur filter material and anaerobic ammonium oxidation filler in the multi-stage AO biological pool, so that the sludge concentration in the three aerobic zones is maintained at 3000-5000mg/L; at the same time in the three anoxic zones Add sulfur filter material and anaerobic ammonium oxidation filler, the filling ratio is 15%-25%, the particle size is 3-6mm; the influent is urban domestic sewage, and the influent flow distribution ratio of the three anoxic zones is 4:3: 3. Influent COD: 70-250mg/L, NH ₄ ⁺ -N: 30-50mg/L, C/N is 2-5; total hydraulic retention time HRT is 12-15h, sludge reflux ratio is 80%-150 %; the dissolved oxygen concentration in aerobic zone 1, aerobic zone 2 and aerobic zone 3 is controlled at 1.0-2.0mg/L, and the sludge age is 15-25d, so as to ensure that all ammonia nitrogen is nitrated into nitrate nitrogen in the aerobic zone.

Regularly detect the changes of ammonia nitrogen, nitrite, nitrate nitrogen and total nitrogen in each reaction zone, the anoxic zone sulfur filter material and anammox filler and floc sludge ectopic activity small test, ammonia nitrogen and nitrate nitrogen in the presence or absence of carbon source In the anoxic test under the two conditions, there was an obvious synchronous decline, and the sulfur autotrophy + carbon heterotrophy short-range denitrification coupling anaerobic ammonium oxidation in the anoxic area was successfully started; when the ammonia nitrogen in the anoxic area decreased significantly, the decline exceeded 1.0-2.0mg/L and maintained for more than 10 days, the anammox bacteria in the system can be persistently enriched; at the same time, the presence of sulfur-autotrophic short-range denitrifying bacteria and anammox bacteria was detected by high-throughput and metagenomic techniques. Then the reactor starts up successfully.

2) Process operation after startup:

The influent is urban domestic sewage, the influent flow distribution ratio of the three anoxic zones is 4:3:3, the influent COD: 70-250mg/L, NH ₄ ⁺ -N: 30-50mg/L, C/N 2-5; the total hydraulic retention time HRT is 12-15h, the sludge reflux ratio is 80%-150%; L, the sludge age is 15-25 days, add sulfur filter material and anammox filler in the anoxic zone, the filling ratio is 15%-25%, and the particle size is 3-6mm; the sludge concentration in the aerobic zone three is maintained at 3000～5000mg/L.

Long-term measurement of ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, and phosphate content in the effluent, by adjusting the dissolved oxygen in the aerobic zone and HRT to ensure that the total inorganic nitrogen in the effluent only contains nitrate nitrogen and the content is less than 8mg/L, while the effluent does not contain Phosphate, to achieve deep nitrogen and phosphorus removal in the reactor.

The operating principle of the system in this embodiment is as follows:

The domestic sewage is pumped into the three anoxic zones of the multi-stage AO biological pool in a ratio of 4:3:3;

In the anoxic zone 1, anaerobic phosphorus release occurs by using part of the carbon source in 40% raw water, and the nitrate nitrogen in the mud-water mixture returned from the sedimentation tank, under the action of sulfur filter material and anammox filler, undergoes short-term sulfur autotrophy Denitrification and carbon heterotrophic short-term denitrification generate nitrite nitrogen. The long-term coexistence of ammonia nitrogen and nitrite nitrogen in the anoxic zone is conducive to the retention and enrichment of anammox bacteria. Using sulfur filter materials and anammox fillers as carriers can Provide nitrite nitrogen for anammox bacteria through autotrophy and heterotrophy, and realize simultaneous removal of ammonia nitrogen and nitrite nitrogen under the condition of low carbon-to-nitrogen ratio influent;

Control sufficient dissolved oxygen in the aerobic zone 1 to ensure that the remaining ammonia nitrogen in the anoxic zone is fully nitrified into nitrate nitrogen, and aerobic phosphorus uptake is completed;

The effluent from the aerobic zone 1 is mixed with 30% raw water in the anoxic zone 2. Part of the raw water provides carbon source for anaerobic phosphorus release, and part of the nitrate nitrogen carried by the effluent from the aerobic zone 1 undergoes sulfur autotrophic short-range denitrification and carbon heterotrophy. After the short-range denitrification generates nitrite nitrogen and the influent ammonia nitrogen is removed by anaerobic ammonium oxidation, the aerobic second zone nitrifies the remaining ammonia nitrogen into nitrate nitrogen throughout the process;

Similarly, the anoxic third zone continues to use part of the carbon source in the raw water to complete anaerobic phosphorus release, as well as sulfur autotrophic short-range denitrification and carbon heterotrophic short-range denitrification coupled with anaerobic ammonium oxidation, and the aerobic three-zone ammonia nitrogen full nitrification It is nitrate nitrogen and absorbs phosphorus aerobically, then discharges water, and finally realizes deep denitrification and phosphorus removal.

Claims (8)

1. A sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system, characterized in that: it includes domestic sewage raw water tanks, multi-stage AO biological pools and sedimentation tanks connected sequentially along the direction of sewage flow; The stages of the multi-stage AO biological pool are sequentially connected along the direction of sewage flow, and each stage has anoxic zones and aerobic zones arranged sequentially along the direction of sewage flow, wherein the anoxic zone is filled with sulfur filter materials and anaerobic Oxygen ammonium oxidation filler, with aeration device in the aerobic zone; The domestic sewage raw water tank is respectively connected to each of the anoxic zones through a water delivery pipeline; the water outlet of the sedimentation tank is connected to an outlet pipe, and the mud outlet of the sedimentation tank is connected to the multi-stage AO biological water tank through a sludge return pipe. The first anoxic zone in the pond along the direction of sewage flow. 2. The sulfur autotrophic denitrification + carbon heterotrophic denitrification coupling anammox denitrification system according to claim 1, characterized in that: the sulfur filter material and the anammox filler are in the anoxic zone The filling ratio is 15% to 25%. 3. The sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system according to claim 1, characterized in that: the water delivery pipeline is equipped with water inlet pumps corresponding to the anoxic zones ; The sludge return pipe is connected with a sludge return pump. 4. The sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification system according to claim 1, characterized in that: the anoxic zone is divided into two compartments, and each compartment is equipped with Stirring device. 5. A sulfur autotrophy + low-carbon heterotrophic short-range denitrification coupled anammox denitrification method based on the system described in any one of claims 1 to 4, characterized in that: Send the domestic sewage raw water in the domestic sewage raw water tank into each anoxic zone of the multi-stage AO biological pool; In the first anoxic zone along the sewage flow direction, anaerobic phosphorus release occurs by using part of the carbon source in the raw water of domestic sewage, and the nitrate nitrogen in the mud-water mixture returned from the sedimentation tank is absorbed by the sulfur filter material and anammox filler in the anoxic zone. Under the action of sulfur autotrophic short-range denitrification and carbon heterotrophic short-range denitrification to generate nitrite nitrogen, the long-term coexistence of ammonia nitrogen and nitrite nitrogen in the anoxic zone is conducive to the retention and enrichment of anammox bacteria, and the sulfur filter The material and the anammox filler as the carrier can provide nitrite nitrogen for the anammox bacteria through autotrophy and heterotrophy, and realize the synchronous removal of ammonia nitrogen and nitrite nitrogen under the condition of low carbon-to-nitrogen ratio influent; In the aerobic zone, the aeration device is used to control sufficient dissolved oxygen to ensure that the remaining ammonia nitrogen in the anoxic zone is fully nitrified into nitrate nitrogen, and aerobic phosphorus uptake is completed; The effluent from the aerobic zone is mixed with the raw water of domestic sewage in the latter anoxic zone, part of the raw water provides carbon source for anaerobic phosphorus release, and part of the nitrate nitrogen carried by the effluent from the aerobic zone undergoes sulfur autotrophic short-range denitrification and carbon heterotrophic short-range denitrification. After denitrification generates nitrite nitrogen and influent ammonia nitrogen is removed by anaerobic ammonium oxidation, the latter aerobic zone nitrifies the remaining ammonia nitrogen to nitrate nitrogen throughout the process. 6. The method according to claim 5, characterized in that: the hydraulic retention time in each anoxic zone and aerobic zone is the same. 7. The method according to claim 5 or 6, characterized in that: the total hydraulic retention time HRT of the multi-stage AO biological pool is 12-15h. 8. The method according to claim 5, characterized in that: the dissolved oxygen concentration in the aerobic zone is controlled at 1.0-2.0mg/L, and the sludge age is 15-25d.

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