Water Treatment Research About Microbial Safety And Autotrophic Denitrification Technology Research

Water pollution may cause the water quality of security problems,especially biological safety is one of the important aspects. Therefore some waterworks have adopted the depth of water treatment technology,including activated carbon filter process and ozone-biological carbon process. The removal efficiency of microorganism is evaluated by the biomass of water. Pathogenic bacterias are judged by the appraisal of the microbial communitystructure.One waterworks use the activated carbon of two years carbon age and the efficiency is 40%-60% about adsorpting HPC. The other waterworks is 12%-50%.The adsorption efficiency of the new carbon will increase to 55%-80%.Molecular cloning research suggests thatα-Proteobacteria bacteria have the dominant position in waterworks. 13 cloning bacterias have a directly genetical relationship with pure culture,four of them are pathogenic bacterias. They were Hyphomicrobium sp. Ellin112 and SLG5B–19;and it include Polaromonas sp.BAC41 and BAC163.Comamonas trstosteroni distributed widely in nature.It is pathogens,which can cause infection of respiratory. Afipia bacteria is pathogens for human. golden coliseptic meningosepticum can cause neonatal meningitis.Nitrate nitrogen were chosen as the aim pollutants to investigate the removal ability of nitrogen.This experiments focus on the mechanism of autotrophic denitrificans and study the relationship between time and the nitrate in the sludge.The removal of Nitrate nitrogen follows the pseudo-frist order kinetics with the half life t1/2 of 1.15h and 1.89h and the rate constant are 0.6024h-1 and 0.3663h-1.Autotrophic denitrifier was screened from facultative sludge that it can oxidize elemental sulfur, degradate nitrate through bio-denitrification.The removal of denitrification by autotrophic denitrifier conforms to first order reaction kinetics equation with a half-life of 1.42 hours and rate constant of 0.488 h-1 .The optimum reaction conditions were obtained as follows: a neutral pH of 7, 30℃and concentration of sodium bicarbonate greater than or equal to 2.5g/L.