Study On The Denitrification And Phenol Removal Efficiency Of Phenolic Resistant Bacteria

With the rapid development of chemical industry,the total amount of phenolic wastewater discharge increases by thousands of ton every year.Phenol is a common aromatic compound,which was widely used in pharmaceutical and pesticide industries.At present,the treatment of phenolic wastewater mainly adopts biological method.But the phenolic organic compounds are not easy to be biodegraded,due to their molecular structure characteristics.When it inevitably entered the environment with the discharge of treated water and residual sludge,will pose a potential threat to the ecological environment and human health.At the mean time,biological methods are mainly used for the treatment of nitrogen wastewater.Aerobic denitrification,as a new method for nitrogen removal,has the advantages that traditional methods do not have.Therefore,the development of an economic and effective use of organic phenolic substances for aerobic denitrification of wastewater treatment methods,the toxic phenolic substances into non-toxic and non-polluting compounds,to achieve the safe discharge of wastewater,to alleviate the current situation of China's water shortage,the protection of the water environment and ecological security is of great significance.In this paper phenol,o-cresol and p-chlorophenol was used as the target organic pollutants?7 strains was cultured with good removal effect on phenols.Compared with its bacterial turbidity,bacterial count,bacterial activity,phenols removal rate and nitrate removal rate,there were 3 strains selected for further experiments.These strains were identificated by 16 Sr DNA The different removal rates of phenol and nitrate at different primary phenol concentration,pH value,temperature,amount of bacteria and mixing speed were studied,by which the optimal conditions of target strain were got.The No.14 strain was found to be the best strain in degrading phenol with denitrification,which was Acinetobacter sp.using 16 Sr DNA indification and marked as Acinetobacter sp.A2 in this paper.The optimum growth conditions of Acinetobacter sp.A2 were as following: phenol initial concentration around 500 mg/L,pH value 6 to 7,temperature 30?,10% bacteria amount and mixing speed 140 rpm.The degradation kinetics equation and aerobic denitrification equation of the A2 were establised under different restricted environment conditions.Finally,the influence of phenol on degradation of o-cresol,p-chlorophenol,denitrification of nitrate were investigated.The result of this paper will play an important role in degradation of phenols wastewater,providing theoretical and practical basis for the further research of biological nitrogen removal.