General process of sewage treatment

The sewage treatment process is detailed as follows.

1, nitrogen removal by anoxic-aerobic activated sludge process

This method mainly combines anoxic denitrification tank and aerobic nitrification tank, and realizes the two reactions in the same tank through reasonable separation and aeration control, which has the advantages of small floor space and low construction cost.

2.t-type oxidation ditch system technology

T-shaped oxidation ditch, also known as three-ditch oxidation ditch, has the advantages of no secondary sedimentation tank, small floor space and low construction cost compared with traditional oxidation ditch.

3. Traditional activated sludge denitrification process

The traditional activated sludge denitrification process adopts aerobic-aerobic-anoxic treatment, and each tank is equipped with a secondary sedimentation tank to return sludge. Its working principle is that BOD is removed in the aerobic tank first, then nitrated in the nitrification tank, and the nitrated liquid enters the denitrification tank for final denitrification. Although this process has a good denitrification effect, it has some disadvantages, such as large floor space, extra carbon source and high operating cost, so it is not commonly used at present.

4. Two-stage biological denitrification process

The difference between this process and traditional denitrification activated sludge process is that aerobic BOD removal and aerobic nitrification are combined in the same tank, which has the advantages of saving land and low construction cost. Aerobic nitrification process can utilize raw water organic matter and save carbon source.

5. Batianfu Nitrogen and Phosphorus Removal Process

The principle of the process is as follows: sewage enters the first anaerobic reactor to remove nitrogen and release phosphorus, and then the nitration solution comes to the first aerobic reactor through internal circulation, which has three functions: one is to remove BOD, the other is to nitrate, but the degree of nitration is not high because the BOD concentration is still high, and the third is to absorb phosphorus by phosphorus accumulating bacteria. Similarly, because the unit belongs to anoxic environment, the phosphorus absorption effect will not be very good. After the first anaerobic aerobic treatment, the mixed liquid comes to the second anaerobic tank, where it also undergoes denitrification and phosphorus release, mainly denitrification, and then flows through the second aerobic tank, where it mainly undergoes phosphorus absorption and nitrification to further remove COD.

The advantages of this process are: the effect of nitrogen and phosphorus removal is good, basically the nitrogen removal efficiency is 90%~95%, and the phosphorus removal rate is 97%. However, the disadvantages of this process are also obvious, that is, the process is complex, there are many units, the operation is complex and the cost is high.

6, biological filter sewage treatment system

Bio-filtration technology is a process of collecting sewage into an aerobic fixed-bed reactor and performing aerobic treatment on the sewage through various purification processes such as comprehensive filtration, adsorption and degradation of biological flora. This technology has the advantages of effectively removing SS, COD and ammonia nitrogen. And the subsequent sedimentation tank can be omitted, but its disadvantage is that the treatment scale is relatively small.

7, partial dissolved air flotation process

The working principle of dissolved air flotation is that the air sent by the air compressor into the air tank is brought into the dissolved air tank through the jet device, and is forced to dissolve in water under the pressure of 0.35Mpa to form dissolved air water, which is sent into the air flotation tank. In the case of sudden release, the air dissolved in water is precipitated to form a large number of microbubbles, which fully contact with the flocculated suspended matter in the pumped sewage after dosing, and are absorbed in the flocculated suspended matter in the process of slowly rising, so that its density is reduced and it floats to the water surface, thus achieving the purpose of removing ss and CODcr.

8. Reflux pressurized dissolved air flotation process

The principle of this process is the same as that of partial dissolved air flotation process, but the difference is that the dissolved air comes from the treated water, so this process has better adaptability to the concentration of suspended solids in raw water, and can treat wastewater with high suspended solids, such as slaughterhouse wastewater containing a lot of pig hair.

9. Total dissolved air flotation process

The principle of this process is the same as that of the partial dissolved air flotation process, but the difference is that the partial dissolved air flotation only pressurizes part of the inlet water to dissolve air, while the total dissolved air flotation processes all the raw water. It is also not suitable for wastewater with high concentration of suspended solids, such as hair wastewater.

10, two-phase biological fluidized bed process

Two-phase (liquid-solid two-phase) biological fluidized bed refers to the structural treatment process in which wastewater flows through the sand bed from bottom to top to make the carrier layer in a flowing state, thereby increasing the contact area between biofilm and wastewater in unit time and providing sufficient oxygen, and using the boiling state of fillers to strengthen the biological treatment process of wastewater. The process has high efficiency, less land occupation and less investment, and can be used for advanced treatment of sewage such as nitrification and denitrification, secondary treatment of sewage and treatment of other phenol-containing industrial wastewater and pharmaceutical wastewater.

1 1, three-phase biological fluidized bed process

The difference between this process and two-phase fluidized bed process is that aeration is also completed in fluidized bed reactor, and gas, liquid and solid contact in this reaction zone. Compared with the two-phase fluidized bed process, it saves more land and investment.

12, biological turntable treatment process

Biological rotary table process is a biological sewage treatment technology using biofilm method. Bacteria, fungi, protozoa and other microorganisms grow and reproduce on the turntable packing carrier, forming biofilm. After the primary treatment in the sedimentation tank, the sewage contacts with the biofilm, and the microorganisms on the biofilm absorb the organic pollutants in the sewage as nutrients, so that the sewage can be purified, which can be used alone or in the secondary sedimentation tank. At present, it can be divided into hydraulic and pneumatic types.

13, biological turntable secondary treatment process

The two-stage treatment process of biological turntable is the process of two-stage series connection of biological turntable, and the principle is the same.

14, biosorption method

The characteristic of this process is that the two processes (adsorption and metabolic degradation) of organic matter degradation by activated sludge are carried out in their respective reactors (adsorption tank and regeneration tank). This method can fully increase the concentration of activated sludge and reduce the ratio of organic nutrients to microorganisms. It is a method to treat sewage by physical action (adsorption) of activated sludge. Pay attention to the difference between this method and AB method, and don't confuse it.

15, sludge high temperature dry distillation cracking process

Sludge high-temperature carbonization and cracking process is a sludge reduction method, which can obviously reduce the volume of excess sludge and realize the "trinity" treatment of reduction, harmlessness and stability, but it also has the disadvantages of high treatment cost and difficulty in resource disposal.

16, sludge composting process

Sludge composting process is a good means of sludge resource utilization, and its products are mostly good soil improvers. When compost is used in farmland, it can increase organic matter, improve soil structure, reduce the amount of chemical fertilizer and reduce the potential erosion of soil.