What are the degradation effects of microorganisms in the purification of industrial wastewater
The material composition, temperature and pH value contained in industrial wastewater and waste are quite different. Some toxic substances can be degraded by microorganisms, while others are not easily degraded.
There are hundreds of microorganisms that can degrade hydrocarbons in nature, most of which are bacteria, yeasts and fungi. The degradation is completed by the enzymes and enzyme systems they produce. Compared with unsaturated compounds and aliphatic hydrocarbons, it is easier to be degraded and assimilated by more types of microorganisms than aromatic hydrocarbons. The degradation of linear hydrocarbons is that the terminal methyl group is first oxidized to form alcohols, aldehydes and then fatty acids, which are formed from fatty acids to acetic acid, and finally oxidized to form acetic acid. CO2 and H2O. The degradation of monocyclic aromatic hydrocarbons and their derivatives by microorganisms is somewhat similar to that of linear hydrocarbons. There are many types of microorganisms that can degrade benzene and phenol, including many genera in bacteria, actinomycetes, etc.
Cyanide (nitrile) is a highly toxic substance. It has been found that there are about 50 species of microorganisms with different degrees of cyanogen degradation ability, including Fusarium solanacearum, Pseudomonas, Nocardia and other genera. They can produce a cyanide Hydrolase, which converts carbon and nitrogen in cyanide into CO2 and NH3; Fusarium can also use cyanide as the carbon and nitrogen source required for synthesizing cells to purify and detoxify sewage. It has long been reported that the use of coral Xenoca Bacteria degrades acrylonitrile in acrylic fiber wastewater with fast speed and good effect, and 1g of bacteria can degrade 250mg of acrylonitrile in 25min.
Certain pollutants are carcinogenic to the human body, such as polycyclic aromatic hydrocarbons, which are a class of carcinogenic substances. Many bacteria can degrade a variety of polycyclic aromatic hydrocarbons, such as Alcaligenes, Corynebacterium, Nocardia, and Pseudomonas. Some species can degrade anthracene and phenanthrene. Many bacteria in activated sludge have a slower degradation effect on polycyclic aromatic hydrocarbons. Nitro compounds also have carcinogenic effects on humans. Enterobacter, Klebsiella and Pseudomonas are used in my country. The bacteria of the same genus can degrade the sewage in the process of making trinitrotoluene explosives, and the effect is very good.
The waste of many products such as plastics and synthetic fibers, detergents and surfactants in domestic sewage, etc., are difficult to be degraded and removed by microorganisms in ordinary activated sludge. Some people have cultivated a fake single with two enzymes in the body. Bacteria O-3, which can use polyvinyl alcohol as a carbon source and degrade it. When this bacteria is put into activated sludge, the efficiency of purifying polyvinyl alcohol-containing sewage can be greatly improved.
People have been able to synthesize organic compounds for a long time, but there is no enzyme system that decomposes these artificially synthesized compounds in the microorganisms in nature. After exploration, some special functional microorganisms with enzymes that can degrade artificially synthesized substances have been selected and bred after domestication and induction. For example, some pesticides such as 2,4-D and DDT can be degraded by microorganisms to eliminate pollution.
