Research The Bacterial Flora Changes In The Process Of Saline Waste Water Biological Treatment

With the rapid development of economy, the pollution caused by the saline waste water discharge to the environment increasingly highlight, the industrial organic waste water include salt material and refractory organic matter so that it has a great harm to the environment. Domestic and foreign research scholars still think biological method is the main method in the treatment of saline waste water, but the biological activity of microorganisms will affected by the high concentration of salts in the waste water, so it can’t reach the expected treatment effect. Use the biological method to deal with waste water simulated by salt crystal violet dye in this paper, Domesticated the activated sludge by gradually increase the system salinity to research the change of the microbial flora in the treatment process, and then screen the functional microbes of effective treatment in the saline waste water, lay a foundation biological method in the treatment of saline waste water. The main research content and experimental results are as follows:(1)Research the activated sludge microbial composition change and degradation performance at the salt tolerance domestication stage. With the system salinity gradually increase, Superiority strains is gram-positive bacterium, fungi and actinomycetes. With the system salinity gradually increase, the change tendency of the activated sludge removal efficiency is decline before returning in the waste water. When activated sludge adapt to the high salt environment, Microbes can remove 80% CODCr and 75% NH3-N.(2)In order to better mark and separate the salt-tolerant microorganism, this paper studies the preparation of MNPs. Using chemical coprecipitation preparation of magnetic nano ferroferric oxide The molar ratio of Fe2+:Fe3+:NH3·H2O=1:1:10, the Fe2+ and Fe3+ solution concentration is 0.5 moles per liter, the NH3·H2O concentration is 0.25 moles per liter, the temperature control at 25 degrees, the stirring speed is 1000 revolutions per minute, the preparation of MNPs particle size is about 20 nanometer, above all, it is the best reaction conditions of the experiment.(3)Analyse the microbial flora structure of activated sludge at the different domestication stage and find out the functional microbes. Extract the DNA from the microorganism in the activated sludge at three stages, it contains the salt tolerance domestication stage, crystal violet domestication stage and add the MNPs stage, sequence the extractive DNA by 16 S rDNA, with the system salinity gradually increase, the diversity of microorganisms gradually reduce by analyse the number change of the OUT; MNPs selected Acidocella, Winogradskyella and Rhodanobacter as the functional microbes, but decreased the variety and diversity of microbes in activated sludge.