Do you know about sewage treatment bacteria?
Among the many sewage treatment methods, biological treatment has become the most important sewage treatment process because of its simple process, remarkable effect, low cost, natural environmental protection, and less secondary harm. Among them, biofilm method, activated sludge method and other methods all use the decomposition ability of organisms to achieve the purpose of purifying water quality. The types of pollution sources in modern industrialized sewage are quite complex. In order to achieve the purpose of degrading pollutants in sewage, microbial bacteria with special degradation ability for sewage are selected after a series of domestication and cultivation to obtain salt-resistant, impact-resistant and stable sewage. It can effectively remove ammonia nitrogen, BOD, COD, SS, nitrate, sulfate, chroma, odor, toxic substances, compound pollutants, etc. The sewage can effectively degrade various pollutants in the water through the front-end pretreatment, and then through the biochemical anaerobic and aerobic stages.
Sewage treatment bacteria are mainly divided into the following categories according to their functions:
1. Nitrifying bacteria: It is a kind of aerobic bacteria, including nitrous bacteria and nitrate bacteria. Living in aerobic water or sand layers plays an important role in the nitrogen cycle water purification process. Extensive in all corners of nature, air, rivers, sea, soil, there are thousands of nitrifying bacteria found in biology.
2. Denitrifying bacteria: Denitrifying bacteria are bacteria that can cause denitrification. Most of them are heterotrophic and facultative anaerobic bacteria, such as denitrifying bacillus, Stella spp. Under the condition of xenon, they use the oxygen in nitric acid to oxidize organic substances to obtain the energy required for their own life activities. Denitrifying bacteria are widely distributed in soil, manure and sewage. It is possible to convert nitrate nitrogen to nitrogen gas instead of ammonia nitrogen. Mainly used in sewage treatment, such as landscape water treatment, urban river treatment, aquaculture treatment, etc.
3. Nitrification and denitrification compound strains: compound strains with dual functions of nitrification and denitrification, in the case of increasingly complex sewage treatment environment, it is more and more difficult to use nitrifying or denitrifying strains alone to achieve the balance of strains. The ratio of nitrification and denitrification is also difficult to accurately grasp, resulting in waste or shortage of a large number of bacteria, and it is difficult to achieve the ideal sewage treatment effect. The compound strains can self-expand and reproduce according to the water quality to achieve the balance of strains, making sewage treatment simpler and more efficient.
4. COD degrading bacteria: COD degrading bacteria are mainly used in sewage biochemical pools to degrade COD indicators. It mainly degrades COD in wastewater, improves water quality color, increases sludge floc particles, adjusts sludge floc structure, and inhibits the growth of algae. When the concentration of organic matter in the sewage biochemical tank is too high or the volume of the biochemical tank is small, the inflow of high-load sewage will easily impact the microorganisms in the biochemical tank. For the high-concentration COD index of the sewage after pretreatment, in the process of culturing bacteria in the biochemical tank, some COD-degrading bacteria can be appropriately added, which can effectively remove COD and better stabilize the biochemical system.
The advantages of sewage treatment bacteria
1. Short cultivation cycle: the biological contact oxidation method can quickly form the film, and the amount of sludge is very small; the activated sludge method uses the sludge as the attachment point, and then adds solid powder bacteria, which can greatly shorten the cycle. .
2. Wide range of treatment: solid powder microbial strains can effectively remove BOD, COD, SS, ammonia nitrogen, total nitrogen and other indicators in wastewater
3. Strong stability: The strain is very important for the new stable operation in the later stage.
4. Strong adaptability: solid powder bacteria have strong adaptability to water quality load.
5. Significant deodorization effect: strong ability to eliminate NH3, P, H2S and organic acids.
6. Simple operation: the bacteria and sludge are dissolved and added to the biochemical tank for aeration culture in a ratio of 10:1.
7. Strong reproductive ability: The bacterial species reproduce from the first generation to the second generation, and the cycle of the third generation is very short, and the recovery ability to the impact of high-load water quality is relatively strong.
8. Inhibit viruses, germs and parasites. Inhibit algae reproduction, purify water and chroma.
9. Can remove low-concentration heavy metal pollution, such as zinc, manganese, iron, chromium...etc.
10. Easy to cultivate, fast reproduction, sewage treatment bacteria have strong adaptability and evolution ability to the environment. For new pollutants, they can spontaneously or induce new enzymes to degrade or transform new compounds.
Mechanism of Action
1. Aerobic microbial sewage treatment bacteria use dissolved oxygen (DO) in water to decompose organic pollutants into water and carbon dioxide, or convert them into nutrients for sewage treatment microorganisms, and use these nutrients for reproduction, while degrading pollutants. , To achieve the purpose of decontamination and deodorization, this treatment method is called aerobic treatment, and the most widely used is the activated sludge method.
2. Anaerobic sewage treatment Microorganisms reduce nitrate (using the oxygen in nitrate) in the absence of dissolved oxygen, carry out a denitrification reaction, and generate nitrogen gas. This method is widely used in wastewater treatment. Acid-producing bacteria (universal Anaerobic Microorganisms) are often used in the early acidification reaction in absolute anaerobic microbial wastewater treatment processes.
3. Anaerobic biological treatment is to use acid-generating bacteria for acidification reaction to decompose sugars or proteins in sewage into monosaccharides, amino acids or lower fatty acids (organic acids). Then, the monosaccharides, amino acids or organic acids in the sewage are decomposed into acetic acid by acetic acid-producing bacteria (absolute Anaerobic Microorganisms). Finally, methanotrophs (absolute anaerobic microorganisms) decompose acetic acid to form methane
4. Most sewage treatment microorganisms feed on pollutants, such as carbohydrates, proteins and fats, which can be decomposed by various sewage treatment microorganisms and become nutrients for their own growth and reproduction. The use of photosynthetic bacteria and Bacillus can convert the malodorous gas hydrogen sulfide into the sulfur element required for its own growth to achieve the purpose of deodorization.
5. The polysaccharide-like viscous substances possessed by microbial sewage treatment strains themselves can adsorb pollutants in the environment. This characteristic is often used for the adsorption of heavy metal ions.
