CN101041533A - Denitrogenation dephosphorizing technique for integral sewage treatment - Google Patents

Abstract

The integrated sewage treatment nitrogen and phosphorus removal process is based on anaerobic, anoxic and aerobic pools, and the principle of biochemical reactions to remove organic matter and phosphorus and nitrogen removal, but its unique pool structure and equipment configuration make the lack of biochemical pools The oxygen zone and the aerobic zone can be relatively separated, and can skillfully solve the contradiction of backflow in the mixed liquid, thus forming a new sewage treatment process. The inner circle of the process reaction tank is circular, the middle circle is semicircular, and the outer circle is circular again, which divides a round pool into three areas (namely anaerobic area, anoxic area, and aerobic area). district). Then, through the agitator and aerator, the hydrodynamics and biochemical reactions are regulated by computer, so as to complete a series of purification procedures and make the purified water meet the discharge standard. Main purposes: domestic sewage treatment in small and medium-sized towns, sewage treatment in residential quarters, various industrial wastewater treatment, high-concentration organic wastewater treatment, reclaimed water reuse, etc.

Description

Nitrogen and phosphorus removal process for integrated sewage treatment

technical field

The invention relates to a sewage treatment process, in particular to an integrated sewage treatment process for nitrogen and phosphorus removal.

Background technique

Eutrophication is an increasingly serious global water environment problem. Eutrophication will affect the water quality of the water body, and will reduce the transparency of the water, making it difficult for sunlight to penetrate the water layer, thereby affecting the photosynthesis of plants in the water, and may cause a supersaturated state of dissolved oxygen. The supersaturation of dissolved oxygen and the lack of dissolved oxygen in water are harmful to aquatic animals and cause a large number of fish deaths. At the same time, due to the eutrophication of the water body, a large number of algae with blue-green algae and green algae as the dominant species grow on the surface of the water body, forming a layer of "green scum", which causes the organic matter accumulated at the bottom to decompose under anaerobic conditions. Aquatic animals emit a foul odor. The increase in the concentration of nutrients such as nitrogen and phosphorus is the cause of algal blooms, and phosphorus is the key factor. Excess nitrogen, phosphorus and other nutrients in water mainly come from untreated or incompletely treated industrial wastewater and domestic sewage, organic waste, livestock and poultry manure, and agricultural fertilizers.

Contents of the invention

The purpose of the present invention is to provide a kind of integrated sewage treatment denitrification and dephosphorization process, the process is based on anaerobic, anoxic and aerobic in one pool, adopts the principle of biochemical reaction to remove organic matter and phosphorus and denitrification, so that the biochemical pool The anoxic zone and the aerobic zone can be relatively separated, which solves the contradiction of reflux in the mixed liquid. In addition to completing the removal of biochemical oxygen demand (BOD), biological denitrification and phosphorus removal can also be realized.

The purpose of the present invention is achieved through the following technical solutions:

The nitrogen and phosphorus removal process of integrated sewage treatment, the process is: the waste water enters the anaerobic zone of the reaction tank directly after mechanical pretreatment, and then the waste water enters the anoxic zone and the aerobic zone, and the waste water is hydrolyzed and reacted in these zones. Nitrification, biochemical reaction of nitrification and biological oxidation, and finally the wastewater enters the secondary sedimentation tank for solid-liquid separation and then discharged.

In the above-mentioned integrated wastewater treatment process for nitrogen and phosphorus removal, the reaction tank is divided into three areas that are closely related to each other, each of which is equipped with an immersion agitator, and the agitator promotes the mixing and mass transfer of the mixed solution in the two areas, which can be changed The volume of nitrification zone and denitrification zone and the suitable hydraulic retention time of nitrification and denitrification reaction.

The nitrogen and phosphorus removal process of the integrated sewage treatment as mentioned above, the water intake is controlled by the regulating valve, the aeration tube is installed at the bottom of the aerobic zone for air distribution, and the air compressor is used for aeration, and the aeration volume is controlled by the air Flow meter control.

As mentioned above, the nitrogen and phosphorus removal process of the integrated sewage treatment, the operating parameters of the process are as follows:

Reactor effective volume: 60(L);

Water intake: 80~100(L/d);

Sludge load: 0.05～0.2[KgBOD ₅ /kgMLSS·d];

Volume load: 0.57～0.83[KgBOD ₅ /M ³ ·d]

Hydraulic retention time: 4～6(h);

Residence time distribution: anaerobic: anoxic: aerobic = 1:2:3.3;

Mixed liquid suspension concentration: 3960～7920(mg/L);

Mud age: 15~20d;

The maximum reflux ratio of the mixed liquid: 200%.

Or adjust the operating parameters according to the requirements of influent water quality, pollutant load and effluent water quality.

Advantage and effect of the present invention are:

1. The structure of the present invention is compact, and the anaerobic, aerobic, and anoxic zones are all in one structure, separated and formed, and connected to each other. Save land occupation area;

2. The present invention does not set up the pump required for internal circulation, and replaces it with a stirrer, the equipment is simple and feasible, and energy consumption is saved;

3. The present invention limits the harm of sludge bulking and can effectively utilize endogenous carbon for biological denitrification;

4. The present invention can carry out effective biological phosphorus removal, and can be combined with chemical strengthening measures to carry out synchronously, so that the total removal rate of phosphorus is greatly improved;

5. The invention has a high degree of automation, and can maintain stable and reliable operation of the system through the change of water intake and water quality, and through the regulation of the aeration and stirring system;

6. The present invention has less equipment and fewer structures (primary sedimentation tank is also free of construction), easy operation and management, low operating cost, good flexibility and good sludge stabilization.

Description of drawings

Fig. 1 is a system process schematic diagram of the present invention;

Fig. 2 is a structural schematic diagram of the reaction cell of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings.

As shown in the figure, the inner circle of the process reaction pool is circular, the middle circle is semicircular, and the outer circle is circular again, which divides a round pool into three areas, namely the anaerobic area 1. Oxygen zone 2 and aerobic zone 3 are controlled by computer through agitator 5 and aerator 6 to control their hydrodynamics and biochemical reactions, so as to complete a series of purification procedures and make the purified water meet the discharge standard. An aeration head 6 and an aeration pipe 7 are installed in the aerobic zone of the reaction tank; agitators are installed in the aerobic zone 3 , the anoxic zone 2 and the anaerobic zone 1 . A water outlet pipe 9 is provided between the anoxic zone 2 and the anaerobic zone 1 , a water inlet pipe 8 is installed in the anaerobic zone, and a water outlet pipe 10 and a mud discharge pipe 11 are installed in the mixing zone 4 .

The process of each reaction zone will be described separately below.

1. Anaerobic zone 1: In this zone, under anaerobic operating conditions, the molecules of complex organic matter are decomposed by anaerobic hydrolysis (acidification) and degraded into simple molecular components. The hydraulic retention time (HRT) of wastewater in this area is about 30-40min.

2. Anoxic zone 2: Under the condition of anoxic operation, this zone denitrifies the nitrate in the wastewater, converts it into gaseous nitrogen and releases it. The oxygen in the anoxic zone is maintained at a very low level. In this zone, the denitrifying bacteria use the oxygen in the nitrate as the electron acceptor and the organic carbon compound as the carbon source and electron in the environment with extremely low dissolved oxygen concentration. The donor provides energy and is oxidatively stabilized.

3. Aerobic zone (aeration zone) 3: The following reactions are mainly carried out in this zone: ① Biodegradation of organic matter; ② Nitrification of ammonia nitrogen. In this area, through the mixing action of the agitator, the anoxic area and the aerobic area communicate with each other (here, the pumping is not used for stirring and mixing), so that the anoxic area and the aerobic area generate internal circulation, and promote the two The nitrification and denitrification reaction process in the area, so as to achieve the purpose of biological denitrification. The removal rate of organic matter in the process system reaches over 90%, and the removal rate of nitrogen in the system reaches over 90%.

4. Mixing zone 4: By controlling aeration and stirring, the anaerobic-anoxic-aerobic state is cycled and switched. The mixed liquor in the aerobic zone 1 is mixed with the mixed liquor in the anoxic zone 2.

The whole system has a high degree of automation. The probe of the DO meter is set in the aerobic area to detect the dissolved oxygen (DO) online. The time and space of the predetermined DO level require the computer to control the opening and closing of the blower and the air supply. At the same time, the opening and closing of the agitator is also regulated according to the different time and space requirements of the pre-designed anoxic zone and aerobic zone and the requirements of the denitrification process, which not only promotes the mixing and mass transfer of the mixed liquid in the two zones, but also changes the nitrification process. The volume of the zone and the denitrification zone and the appropriate hydraulic retention time for the nitrification and denitrification reactions. According to the requirements of influent water quality, pollutant load and effluent water quality, the operation is regulated through pre-designed software.

The automatic control device continuously switches, runs or stops running through the aeration device and the agitator. Thereby ensuring that Zone 2 and Zone 3 are in aerobic state or anoxic state and reflux cycle in turn. There is no need to set up a circulating return pump, so it saves energy. Also, the agitator ensures a high circulation rate.

Claims (4)

1. the denitrification dephosphorization technique handled of integrated sewage water, it is characterized in that, this technological process is: waste water directly enters the anaerobic zone (1) of reaction tank after mechanical pretreatment, then waste water enters oxygen-starved area (2) and aerobic zone (3), waste water is hydrolyzed in these districts, the biochemical reaction of denitrification, nitrated and bio-oxidation, and last waste water is gone into second pond and carried out effluxing after the solid-liquid separation.

2. the denitrification dephosphorization technique that integrated sewage water according to claim 1 is handled, it is characterized in that, three districts that are divided into mutual tight association in the reaction tank, be equipped with immersion agitator (5), agitator promotes mixing, the mass transfer of two interval mixed solutions, can change the volume of nitrification zone and denitrification zone and the suitable hydraulic detention time of nitrification and denitrification reaction.

3. the denitrification dephosphorization technique that integrated sewage water according to claim 1 is handled is characterized in that flooding quantity is controlled by variable valve, and the aerobic zone inner bottom part is provided with aeration tube (7), carries out gas distribution, and air compressor machine carries out aeration, and aeration rate is controlled by air flowmeter.

4. the denitrification dephosphorization technique that integrated sewage water according to claim 1 is handled is characterized in that this technology operating parameter is as follows:

Reactor useful volume: 60 (L);

Flooding quantity: 80～100 (L/d);

Sludge loading: 0.05～0.2[KgBOD ₅/ kgMLSSd];

Volumetric loading: 0.57～0.83[KgBOD ₅/ M ³D]

Hydraulic detention time: 4～6 (h);

The residence time distributes: anaerobism: anoxic: aerobic=1: 2: 3.3;

Mixed solution concentration of suspension: 3960～7920 (mg/L);

Mud age: 15～20d;

The maximum reflux ratio of mixed solution: 200%.

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