Screening Of Denitrifying Bacteria And Denitrification Performance In Polar Microorganisms

One of the main difficulties and hot spots in sewage treatment is the discharge of nitrogen and phosphorus removal.The traditional sewage treatment method uses the medium temperature bacteria for biological treatment,but the northern part of China has a long winter time,the climate is cold,not suitable for the growth and reproduction of medium temperature bacteria,sewage treatment effect is poor.The use of low temperature microorganisms for sewage treatment can improve the effect of sewage treatment in the northern region.Therefore,it is of great significance to study the effect of low temperature microbial flora denitrification efficiency.In this experiment,81 strains of low temperature strains were isolated and purified by microbial isolation from low-temperature microorganisms in Arctic marine sediments.After gradual screening,strains WZD-1-35,WZD-3-52,WZD-4-17 and WZD-4-28 and WZD-4-29 have good denitrification ability.The strains of WZD-1-35,WZD-4-33,WZD-4-58 and WZD-4-29 have good denitrification ability.Since the strains WZD-1-35and WZD-4-29 both had the ability of nitrification and denitrification,the strains WZD-1-35 and WZD-4-29 were mixed and the denitrification performance was studied.The removal efficiency of NH₄⁺-N was 76.8%and the removal rate of NO₃^--N was the highest when the mixed flora was the best at 15?.And NH₄⁺-N and NO₃^--N were removed at different salinity conditions.When the salinity was 2%,the removal rate was the highest.When the initial pH was 8,the removal efficiency of NH₄⁺-N and NO₃^--N was good.