Research And Development The Microbial Preparation For Nitrogen Removal

Most traditional effluent disposal establishments only be able to removal organic pollutants and solid suspend but have not the function of nitrogen removal. As to the problems, a kind of convenient and efficient microbial preparation for nitrogen removal was developed in this paper. As it was directly cast into the aeration tank, the effluent disposal establishments is capable of the function of nitrogen removal.The microbial preparation for nitrogen removal was equipped by making the high density culture liquid of nitrous bacteria and denitrifying bacteria centrifugal, mixing condensate bacteria in appropriate proportion and immobilizing the mixture with polyvinyl alcohol (PVA). In this thesis, the condition of culturing the nitrous bacteria and denitrifying bacteria of high density was determined, the method of immobilization by PVA was established, the environment for realizing nitrogen removal at high speed was studied, and the result of using the microbial preparation for nitrogen removal to treat waste water was detectedOn the silicate plate, pure nitrobacteria were obtained. Strain Y1 was identified to be Nitrisospira sp. Strain Y2 was Nitrosococcua sp. By extending the two bacteria for 6 weeks and selecting further, strain mixed of high amide oxidation rate produced. The results showed that under the optimum condition: NaHCO3 1g/L, (NH4) 2SO4 2g/L, pH 8.5, DO>2.4mg/L, trace element solution 1 ml, the concentration of nitrobacteria was up to 1.4×109MPN /mlThree high denitrification bacteria were isolated from sludge enrichment culture. The mixture of the three strains in same share is the type of highest nitrogen removal rate. The results showed that the high affection removal nitrogen bacteria screened out by sodium acetate was more easily than using carbinol, ethanol, Kalium natriumtartaric acid as carbon and energy sources. And nitrate wasn't produced in the course of nitrogen removal. The optimum condition for high-density cultures of denitrification bacteria was inoculation 10%, C/N 2.5, pH 7.0 to 8.0 and temperature 30℃.The immobilized microbes pellets were made from nitrosobacteria and denitrifying bacteria using polyvinyl alcohol(PVA)cross linked with boric acid ,PVA is embed carrier and powdered activated carbon is inorganic carrier. The source of nitrosobacteria and denitrifying bacteria come from activated sludge system. The results showed that while the COD between 500 and 1000mg/L,pH8.0 to 8.5 ,temperature 30℃ and DO 2 to 6mg/L,the removal efficiency -reached 90%.In biological fluidized bed reactor, Sequencing Batch Reactors system treating practical life wastewater was carried out. While the immobilized microbe's pellets package percentage was 10%, influent NH4-N concentration was 40 mg/L, reaction time was 8h, the NH4-N removal efficiency reach 90%, the TN removal efficiency could reach 80%; the COD removal efficiency could reach 40% as well.