Study On Isolation And Characteristic Of Denitrifying Phosphate Accumulating Bacteria

The biological denitrifying phosphorus removing simultaneously has being a difficult problem in the wastewater treatment domain.As denitrifying phosphate accumulating bacteria(DPB)been detected and its biological mechanism been researched,DPB had been confirmed as a efficient microorganism on denitrifying and phosphorus removal,the trait of DPB is using nitrate as a electron receiver and absorbing phosphorus under anoxic condition.This paper explored a new method to separate,purify,screen and identify DPB,research physiological and ecological characteristics of DPB,and provide theoretic elements on applying.Double-sludge SBR process was adopted to acclimate and cultivate denitrifying phosphorus-removal bacteria in this experiment,and the process was operated under conditions of anaerobic aerobic and anoxic subsequently within one cycle.After sixty-cycle operation,the system could keep the removal efficiency of ammonia above 90%stability,while total phosphorus above 85%as well as COD,Combining with the biological removal mechanism of DPB to phosphorus,the experiment investigated the vary trend of COD,NH₃-N,NO₃^-N,TP under the alternating conditions,which indicate the mechanism of DPB.Three DPBs were separated from the activated sludge by especial culture medium and denitrifying nitrates to gas and inspection of metachromatic.They are number 1,3,5。Its physiological and biochemical testing results indicate their generation time were longer;The denitrifying and phosphorus removing velocity of number 3 reach to 3.7mg/h,1.76mg/h during the first 24h,and denitrifying and phosphorus removing rate is 84.6%,76.8%;lower temperature is more efficiency than high temperature,the best temperature is between 25℃and 30℃;pH effects denitrifying and phosphorus removing rate are remarkable,the best pH is between 7 and 8.