CN102757161B - Low-carbon double-effect nitrogen removing sewage treatment system and process - Google Patents

Abstract

Low-carbon double-effect denitrification sewage treatment system and process, the system includes a coarse grid lifting pump station for sequentially pretreating sewage, a regulation-regeneration-adsorption pool, and a fine grid; it is characterized in that it also includes the first low-temperature catalytic oxidation Equipment, static oxidation and active mud film layer tank, sludge storage tank, hydrolytic acidification tank and A/O tank, secondary sedimentation tank, second low-temperature catalytic oxidation device, static oxidation and thickener, UF filtration system, RO treatment system . The system is to enrich the carbon source in the wastewater through relatively high concentration technology in the stage of denitrification, which meets the basic conditions of denitrification, that is, high concentration of carbon source, high nitrate and nitrite; The carbon source in the mud is released as a supplementary carbon source; the third is that the substances that are toxic to organisms are rich in a large amount of carbon sources, and the carbon source is supplemented by breaking the chain of toxic substances and small molecules. It mainly solves the problem of low-carbon and high-nitrogen wastewater treatment.

Description

Low-carbon double-effect denitrification sewage treatment system and process

technical field

The invention relates to a sewage treatment system and process, in particular to a treatment system and process for ensuring that the ammonia nitrogen and total nitrogen in the waste water meet the standard while meeting the COD standard after the low-carbon high-nitrogen waste water is treated.

Background technique

At present, water treatment technology at home and abroad is developing rapidly, but with the acceleration of industrial processes, the water quality of wastewater discharge has also undergone certain changes. Process ideas lead to the ineffective consumption of carbon in wastewater) increasing. The use of a large amount of chemical fertilizers and the contradictory characteristics of nitrification, denitrification and dephosphorization processes lead to the fact that the COD of wastewater treatment often has reached the national standard, but the concentration of ammonia nitrogen and total nitrogen is still exceeding the standard. It is also the main cause of eutrophication in water bodies. Therefore, it is necessary to develop a process that can interface with the existing water quality characteristics, meet the COD standard, and ensure that the total nitrogen in the ammonia section in the wastewater reaches the standard.

However, there are several contradictions in the existing water treatment process:

The current basic water treatment process is A2O process (A2O method is also called AAO method, which is the abbreviation of the first letter of English Anaerobic-Anoxic-Oxic (anaerobic-anoxic-aerobic method), which is a commonly used sewage treatment process . It can be used for secondary sewage treatment or tertiary sewage treatment, as well as reclaimed water reuse, with good nitrogen and phosphorus removal effects), all sewage treatment processes are considered as different wastewater characteristics, and are developed as variants of this process. For example, the SBR process (short for Sequencing Batch Reactor: also known as sequencing batch activated sludge process or intermittent activated sludge process) that completes wastewater treatment in a single pool, oxidation ditch and different ditch types that strengthen backflow control, in order to ensure biomass development The biofilm method based on this process. And the membrane technology process to ensure water effluent.

Its notable feature is the contradiction between denitrification and dephosphorization. For low-carbon and high-nitrogen wastewater, carbon sources need to be supplemented to increase operating costs. For wastewater containing carbon sources but with high biological toxicity, the carbon cannot be effectively utilized. Using iron-carbon internal electrolysis increases iron consumption and cannot solve the clogging problem. Using Fenton oxidation increases the dosage and adjusts pH to increase operating costs and increase sludge production. The electro-oxidation process results in a large amount of ineffective energy consumption in wastewater. At present, with the rapid development of China's industry, there is a large amount of low-carbon and high-ammonia-nitrogen wastewater in wastewater. The current national standards only restrict ammonia nitrogen, but less restrictions on total nitrogen. Therefore, future water pollution standards will definitely impose strict requirements on total nitrogen. It is particularly important to fully realize the relationship among ammonia nitrogen, Kjeldahl nitrogen, inorganic nitrogen and total nitrogen.

Contents of the invention

In order to overcome the above-mentioned shortcomings in the prior art, the object of the present invention is to provide a low-carbon double-effect denitrification sewage treatment system and process.

This technology is the shortest double-effect treatment process for wastewater with high ammonia nitrogen, total nitrogen and TKN. And focus on considering the characteristics of this type of wastewater. Generally, the concentration of carbon sources is low. Usually, the carbon sources are not used by organisms or are toxic to organisms, and the situation of insufficient denitrification carbon sources is proposed.

Its technical scheme is based on the following ideas:

The characteristic of low-carbon wastewater is that the carbon source is low or cannot be used biologically. First, the carbon source in the wastewater is enriched by relatively high-concentration technology in the denitrification stage to meet the basic conditions for denitrification, that is, high-concentration carbon. source, high nitrate and nitrite. The second part is that the carbon source in the sludge produced by wastewater is released as a supplementary carbon source, and the third is that the substances that are toxic to organisms are rich in a large amount of carbon sources, and the carbon is realized by breaking the chain and small molecules of toxic substances. source supplement.

Secondly: solve the rapid nitrification of organic nitrogen TKN and ammonia nitrogen in the incoming water as the premise, and immediately enter the high-active sludge age layer for high-carbon denitrification after nitrification.

Use the conventional process to complete post-installation A/O, secondary nitrification and denitrification, and then connect an external ultrafiltration system to realize reuse or discharge.

In order to achieve the above purpose and based on the above idea:

The low-carbon double-effect denitrification sewage treatment system provided by the present invention includes a coarse grid lifting pump station, a regulation-regeneration-adsorption pool, and a fine grid for sequentially pretreating sewage; it also includes:

The first low-temperature catalytic oxidation device is provided with a sewage input end and a sewage output end, and the sewage input end communicates with the sewage output end of the fine grid through a sewage pipeline;

The static oxidation and active mud film layer pool is provided with a sewage input end, a process starting bacteria input end, a sewage output end, and a residual sludge output end; the sewage input end is connected to the first low-temperature catalytic oxidation device through a sewage pipeline. The sewage output end is connected; the process start strain input end is connected with the process start strain generation device through the dosing pipeline;

The sludge storage tank is provided with an excess sludge input end and an excess sludge output end, and the excess sludge input end communicates with the excess sludge output end of the static oxidation and active mud film layer tank through the excess sludge pipeline; The excess sludge output end is connected to the sludge dewatering device through the excess sludge pipeline;

The hydrolytic acidification pool and the A/O pool are provided with a sewage input end, an air input end, a return sludge input end, and a sewage output end; the sewage input end is connected to the sewage of the static oxidation and active mud film layer pool through the sewage pipeline The output end is connected; the air input end is connected with a blower device through an air pipeline;

The secondary sedimentation tank is provided with a sewage input end, a return sludge output end, and a sewage output end. The sewage input end is connected to the sewage output end of the hydrolysis acidification tank and the A/O pool through a sewage pipeline, and the return sludge output end Connect the return sludge input end of the adjustment-regeneration-adsorption tank, the return sludge input end of the hydrolysis acidification tank and the A/O tank through the return sludge pipeline and the return sludge pump;

The second low-temperature catalytic oxidation device is provided with a sewage input end and a sewage output end; the sewage input end communicates with the sewage output end of the secondary sedimentation tank through a sewage pipeline;

The static oxidation and thickening machine is provided with a sewage input end, a sewage output end, and a return sludge output end. The sewage input end communicates with the sewage output end of the second low-temperature catalytic oxidation device through a sewage pipeline, and the return sludge output end Connect with the return sludge input end of the adjustment-regeneration-adsorption tank through the return sludge pipeline;

The sewage output end of the static oxidation and thickener is connected to the intermediate pool, UF filtration system, RO water inlet pool, and RO treatment system in sequence through the sewage pipeline;

The RO treatment system is provided with a reusable water output end and a sewage output end, the reusable water output end is connected to the reuse water pool through the reuse water pipeline; the sewage output end is connected to the sewage input end of the thick water pool through the sewage pipeline, and the thick water pool The sewage output end is connected to the sewage input end of the first low-temperature catalytic oxidation device through a sewage pipeline.

The low-carbon double-effect denitrification sewage treatment process provided by the present invention comprises:

a) Pretreatment of sewage by using coarse grids to lift pump stations, adjustment-regeneration-adsorption pools, and fine grids;

b) In the first low-temperature catalytic oxidation device, wet catalytic technology is used to generate a large number of hydroxyl radicals to complete the nitrification of ammoniacal nitrogen and partial nitrification of organic nitrogen in wastewater; Biologically utilized carbon sources, using hydroxyl radicals to act on organic matter in sewage to generate small molecules of carbon sources that can be directly utilized by organisms, to achieve non-toxic treatment of wastewater and release of carbon sources;

c) In the static oxidation and active mud film layer tank, the sewage is enriched by carbon source through the active mud film layer, and achieves first-level denitrification under the condition of high sludge age;

d) In the hydrolytic acidification pool and A/O pool, the secondary nitrification and denitrification denitrification are carried out after hydrolysis and A/O treatment, so as to realize the two-effect denitrification under low carbon conditions;

e) Sewage treated by the hydrolytic acidification tank and A/O tank enters the secondary sedimentation tank, and 100% of the sludge in the secondary sedimentation tank flows back to the adjustment-regeneration-adsorption tank, hydrolysis acidification tank and A/O tank; enters the adjustment-regeneration - The return sludge in the adsorption tank is then oxidized by hydroxyl in the first low-temperature catalytic oxidation device to release the contents of the cell wall to realize the reuse of carbon sources;

f) The sewage output from the secondary sedimentation tank passes through the second low-temperature catalytic oxidation device, and further uses the hydroxyl group to oxidize the organic matter in the wastewater to release the carbon source;

g) After static oxidation and thickener, further hydroxyl oxidation is carried out, and the degradation of COD and the separation of suspended solids are realized through the selective active mud film layer; and the continuously regenerated selective active mud film layer is realized;

h) After the sewage is treated by the UF filtration system and the RO treatment system, the recyclable water enters the reuse pool, and the non-recyclable water flows back into the first low-temperature catalytic oxidation device for retreatment in the next cycle .

In the above process, preferably: in the step b), in the first low-temperature catalytic oxidation device, the ratio of the hydroxyl radical concentration to the ammonia nitrogen concentration is 1:2-1:6.

In step c), in the static oxidation and active mud film layer tank, the hydroxyl concentration is consumed to 0 mg/L, and the sludge age is controlled at 35-50 days.

Preferably: the secondary sedimentation surface load of the secondary sedimentation tank is 0.8-2.5 cubic meters per square meter per hour.

The beneficial effects of the present invention are: the present invention is mainly used to solve the problem of low-carbon high-nitrogen wastewater treatment, the technology:

1. The low-temperature wet catalytic oxidation technology completes the release and nitrification of carbon sources, generates a large number of hydroxyl radicals through wet catalysis, and completes the nitrification of ammoniacal nitrogen and partial nitrification of organic nitrogen to achieve non-toxic wastewater and release of carbon sources.

2. Realize high sludge age layer structure through sludge return control, complete carbon source enrichment and achieve first-level denitrification under active high sludge age conditions. Followed by AO and ultrafiltration to achieve industrialized and stable low-carbon double-effect denitrification.

3. It is the shortest double-effect treatment process for wastewater with high ammonia nitrogen, total nitrogen, and TKN, and the shortest two-effect nitrification and denitrification process. The process flow is: wastewater-conventional pretreatment-low temperature wet catalysis-highly active sludge layer-A/O-ultrafiltration reuse.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

Fig. 1 is a structural schematic diagram of an embodiment of a low-carbon double-effect denitrification sewage treatment system of the present invention.

In the figure: 1 coarse grid lifting pump room, 2 adjustment-regeneration-adsorption pool, 3 fine grid, 4 the first low-temperature catalytic oxidation device, 5 process start-up strain generation device, 6 static oxidation and active mud film layer tank , 7 sludge storage tank, 8 sludge dehydration device, 9 hydrolytic acidification tank and A/O tank, 10 secondary sedimentation tank, 11 return sludge pump, 12 second low-temperature catalytic oxidation device, 13 static oxidation and thickener, 14 Intermediate tank, 15UF filtration system, 16RO water inlet tank, 17RO treatment system, 18 excess sludge pipeline, 19 return sludge pipeline, 20 sewage pipeline, 21 air pipeline, 22 dosing pipeline, 23 return water tank, 24 concentrated water tank, 25 Blowing device, 26 return water pipelines.

Detailed ways

The low-carbon double-effect denitrification sewage treatment system shown in Figure 1 includes a coarse grid lifting pump station 1, a regulating-regeneration-adsorption pool 2, a fine grid 3, and the first low-temperature catalytic oxidation device for sequentially pretreating sewage 4. Process start-up strain generation device 5. Static oxidation and active mud film layer tank 6. Sludge storage tank 7. Sludge dehydration device 8. Hydrolytic acidification tank and A/O tank 9. Secondary sedimentation tank 10. Return sewage Sludge pump 11, second low-temperature catalytic oxidation device 12, static oxidation and thickener 13, UF filter system 15, RO treatment system 17.

Coarse grid lifting pumping station 1, adjustment-regeneration-adsorption pool 2, fine grid 3 pre-treat the sewage first.

Its first low-temperature catalytic oxidation device 4 is provided with a sewage input end and a sewage output end, and the sewage input end communicates with the sewage output end of the fine grid 3 through the sewage pipeline 20 .

Static oxidation and active mud film layer pool 6 is provided with a sewage input end, a process starting bacteria input end, a sewage output end, and a residual sludge output end; the sewage input end is connected to the first low-temperature catalytic oxidation through a sewage pipeline 20 The sewage output end of the device 4 is connected; the process start strain input end is connected with the process start strain generation device 5 through the dosing pipeline 22 .

The sludge storage tank 7 is provided with an excess sludge input end and an excess sludge output end, and the excess sludge input end passes through the excess sludge pipeline 18 and the excess sludge output of the static oxidation and active mud film layer tank 6 The end is connected; the excess sludge output end is connected to the sludge dewatering device 8 through the excess sludge pipeline 18.

The hydrolytic acidification pool and the A/O pool 9 are provided with a sewage input end, an air input end, a return sludge input end, and a sewage output end; the sewage input end is connected to the static oxidation and active mud film layer pool through the sewage pipeline 20 6 is communicated with the sewage output end; the air input end is communicated with a blast device 25 through an air pipeline 21 .

The secondary settling tank 10 is provided with a sewage input port, a return sludge output port, and a sewage output port. The sludge output end is connected to the return sludge input end of the adjustment-regeneration-adsorption tank 2, the return sludge input end of the hydrolytic acidification tank and the A/O pool 9 through the return sludge pipeline 19 and the return sludge pump 11.

The second low-temperature catalytic oxidation device 12 is provided with a sewage input end and a sewage output end; the sewage input end communicates with the sewage output end of the secondary sedimentation tank 10 through a sewage pipeline 20 .

The static oxidation and thickening machine 13 is provided with a sewage input end, a sewage output end, and a return sludge output end. The sewage input end is connected with the sewage output end of the second low-temperature catalytic oxidation device 12 through the sewage pipeline 20. The sludge output end communicates with the return sludge input end of the adjustment-regeneration-adsorption tank 2 through the return sludge pipeline 19 .

The sewage output end of the static oxidation and thickener 13 is sequentially connected to an intermediate pool 14 , a UF filter system 15 , an RO water inlet pool 16 , and an RO treatment system 17 through a sewage pipeline 20 .

The RO treatment system 17 is provided with a reusable water output end and a sewage output end, the reusable water output end is connected to the reuse water pool 23 through the reuse water pipeline 26; the sewage output end is connected to the sewage input of the concentrated water pool 24 through the sewage pipeline 20 The sewage output end of the thick water tank 24 is connected to the sewage input end of the first low-temperature catalytic oxidation device 4 through the sewage pipeline 20 .

The low-carbon double-effect denitrification sewage treatment process provided by the present invention comprises:

a) Pretreatment of sewage by using the coarse grid to lift the pump station 1, the adjustment-regeneration-adsorption tank 2, and the fine grid 3;

b) In the first low-temperature catalytic oxidation device 4, wet catalytic technology is used to generate a large number of hydroxyl radicals to complete the nitrification of ammoniacal nitrogen and partial nitrification of organic nitrogen in wastewater; The carbon source that is not used by biology can generate small molecule carbon source that can be directly used by biology through the action of hydroxyl on the organic matter in sewage, so as to realize the non-toxic treatment of wastewater and the release of carbon source;

In this step, the ratio of the concentration of hydroxyl radicals to the concentration of ammonia nitrogen is 1:2 to 1:6. Under this condition, the non-selective effect of hydroxyl radicals on organic matter is used to generate small molecules that can be directly used by organisms. carbon source;

c) In the static oxidation and active mud film layer tank 6, the sewage is enriched by carbon source through the active mud film layer, and realizes the first-level denitrification under the condition of high sludge age;

Preferably, in step c), in the static oxidation and active mud film layer pool 6, the hydroxyl concentration is consumed to 0 mg/L, and the sludge age is controlled at 35-50 days;

d) In the hydrolytic acidification pool and A/O pool 9, secondary nitrification and denitrification denitrification are carried out after hydrolysis and A/O treatment to achieve two-effect denitrification under low-carbon conditions;

e) Sewage treated by the hydrolytic acidification tank and A/O tank 9 enters the secondary sedimentation tank 10, and 100% of the sludge in the secondary sedimentation tank 10 returns to the adjustment-regeneration-adsorption tank 2, hydrolytic acidification tank and A/O tank 9. Enter the return sludge in the adjustment-regeneration-adsorption tank 2 and then oxidize the hydroxyl in the first low-temperature catalytic oxidation device 4 to release the content of the cell wall to realize the reuse of carbon sources;

Preferably, in the step e), the secondary sedimentation surface load of the secondary sedimentation tank 10 is 0.8-2.5 cubic meters per square meter per hour.

f) The sewage output from the secondary sedimentation tank 10 passes through the second low-temperature catalytic oxidation device 12 to further utilize the hydroxyl group to oxidize the organic matter in the waste water to release the carbon source;

g) After static oxidation and thickener 13, further hydroxyl oxidation is carried out, and the degradation of COD and the separation of suspended solids are realized through the selective active mud film layer; and the continuously regenerated selective active mud film layer is realized;

h), after the sewage is treated by the UF filtration system 15 and the RO treatment system 17, the recyclable water enters the reuse pool 23, and the non-recyclable water flows back into the first low-temperature catalytic oxidation device 4 for the next step Cycle reprocessing.

Above-mentioned system and process method have realized its inventive conception:

The characteristic of low-carbon wastewater is that the carbon source is low or cannot be used biologically. First, the carbon source in the wastewater is enriched by relatively high-concentration technology in the denitrification stage to meet the basic conditions for denitrification, that is, high-concentration carbon. source, high nitrate and nitrite; the second part is that the carbon source in the sludge produced by wastewater is released as a supplementary carbon source; Chain breakage and small molecules realize carbon source supplementation.

Secondly: solve the rapid nitrification of organic nitrogen TKN and ammonia nitrogen in the incoming water as the premise, and immediately enter the high-active sludge age layer for high-carbon denitrification after nitrification.

Use the conventional process to complete post-installation A/O, secondary nitrification and denitrification, and then connect an external ultrafiltration system to realize reuse or discharge.

Claims (4)

1. low-carbon (LC) economic benefits and social benefits denitrogenation Sewage treatment systems is characterized in that: comprise that successively sewage being carried out pretreated coarse rack promotes pumping plant, adjusting-regeneration-adsorption tank, fine fack; Also comprise:

The first low-temperature catalytic oxidation device is provided with sewage input terminus, sewage output terminal, and this sewage input terminus is communicated with the sewage output terminal of described fine fack by sewer pipeline;

Leave standstill oxidation and active mud rete pond, be provided with sewage input terminus, technology startup bacterial classification input terminus, sewage output terminal, excess sludge output terminal; This sewage input terminus is communicated with by the sewage output terminal of sewer pipeline with the described first low-temperature catalytic oxidation device; Technology starts the bacterial classification input terminus and is communicated with technology startup bacterial classification generation device by the dosing pipeline;

Mud storage pond is provided with excess sludge input terminus, excess sludge output terminal, and this excess sludge input terminus leaves standstill oxidation and is communicated with the excess sludge output terminal in active mud rete pond with described by the excess sludge pipeline; This excess sludge output terminal is communicated with sludge dehydration device by the excess sludge pipeline;

Hydrolysis acidification pool and A/O pond are provided with sewage input terminus, air input terminus, returned sluge input terminus, sewage output terminal; This sewage input terminus leaves standstill oxidation and is communicated with the sewage output terminal in active mud rete pond with described by sewer pipeline; This air input terminus is communicated with air-blast device by air line;

Second pond, be provided with sewage input terminus, returned sluge output terminal, sewage output terminal, this sewage input terminus is connected by the sewage output terminal of sewer pipeline with described hydrolysis acidification pool and A/O pond, and this returned sluge output terminal is communicated with the returned sluge input terminus in returned sluge input terminus, hydrolysis acidification pool and the A/O pond of adjusting-regeneration-adsorption tank through return sludge line, return sludge pump;

The second low-temperature catalytic oxidation device is provided with sewage input terminus, sewage output terminal; This sewage input terminus is communicated with the sewage output terminal of second pond by sewer pipeline;

Static oxidation and thickener, be provided with sewage input terminus, sewage output terminal, returned sluge output terminal, this sewage input terminus is communicated with by the sewage output terminal of sewer pipeline with the described second low-temperature catalytic oxidation device, and this returned sluge output terminal is communicated with the returned sluge input terminus of adjusting-regeneration-adsorption tank by return sludge line;

The sewage output terminal of static oxidation and thickener is connected with intermediate pool, UF filtering system, RO pump sump, RO treatment system in turn backward by sewer pipeline;

But described RO treatment system is provided with reuse water output terminal, sewage output terminal, but should be communicated with reuse pool by the reuse water pipeline by the reuse water output terminal; This sewage output terminal is communicated with the sewage input terminus in dense pond by sewer pipeline, and the sewage output terminal in dense pond is communicated to the sewage input terminus of the described first low-temperature catalytic oxidation device by sewer pipeline.

2. low-carbon (LC) economic benefits and social benefits denitrification sewage treatment process is characterized in that, its step comprises:

A), the pre-treatment that utilizes coarse rack lifting pumping plant, adjusting-regeneration-adsorption tank, fine fack that sewage is carried out;

B), in the first low-temperature catalytic oxidation device, utilize the wet catalysis technology to produce the great amount of hydroxy group free radical, the part of finishing the nitrated and organonitrogen of ammonia-state nitrogen in the waste water is nitrated; And at show as in the material poisonous in the waste water TOC not by the carbon source of biological utilisation, utilize hydroxyl radical free radical that the organism effect in the sewage is generated the micromolecular carbon source that can directly be utilized by biology, realize that waste water does not have to poison to handle and carbon source discharges;

C), in leaving standstill oxidation and active mud rete pond, sewage carries out the carbon source enrichment through active mud rete, and realizes the one-level denitrification under high sludge age condition;

D), in hydrolysis acidification pool and A/O pond, handle through hydrolysis, A/O and to carry out second nitrification and denitrification denitrogenation, realize under the low-carbon (LC) condition that two imitate denitrogenations;

E), hydrolysis acidification pool and the A/O pond sewage after handling enters second pond, the mud 100% in the second pond is back to adjusting-regeneration-adsorption tank, hydrolysis acidification pool and A/O pond; Enter in adjusting-regeneration-adsorption tank returned sluge and again in the first low-temperature catalytic oxidation device hydroxyl oxidize cell walls content is discharged, realize the carbon source recycling;

F), by the sewage of second pond output again through the second low-temperature catalytic oxidation device, further utilize hydroxyl that oxidation operation effect in the waste water is realized that carbon source discharges;

G), again through static oxidation and thickener, carry out further hydroxyl oxidize and realize the degraded of COD and separating of suspended substance by selective active mud rete; And realized the selective active mud rete of the renewal of cyclic regeneration;

H), after the processing of UF filtering system, RO treatment system, the water of recyclable utilization enters reuse pool to sewage again, the water that can not recycle flow in the first low-temperature catalytic oxidation device again, carries out the processing again of next circulation.

3. low-carbon (LC) economic benefits and social benefits denitrification sewage treatment process according to claim 2 is characterized in that, in the described step b), in the first low-temperature catalytic oxidation device, the ratio of the corresponding ammonia nitrogen concentration of hydroxy free radical concentration is 1:2～1:6.

4. according to claim 2 or 3 described low-carbon (LC) economic benefits and social benefits denitrification sewage treatment process, it is characterized in that in step c), in leaving standstill oxidation and active mud rete pond, hydroxyl concentration is consumed to 0 mg/litre, sludge age is controlled on 35th～50.

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