Preliminary Study on Degradation of Nnitrobenzene by Strain M

[Objective]The study aimed to provide the theoretical basis for biological degradation of nitrobenzene in the wastewater through the research on growing conditions,degradation effects on nitrobenzene,tolerance and biological toxicity of metabolites for the strain M.[Method]The strain M,which could use nitrobenzene as a sole carbon source,was screened from the nitrobenzene-contaminated soil and the degradation concn.of nitrobenzene was determined by Zinc reduction-hydrochloric acid naphthalene ethylenediamine spectrophotometric method so as to study the effects of different pH,temperature,inoculated volume and nitrobenzene concn.on the degradation rate of nitrobenzene.[Result]Under the optimum condition with temperature of 30 ℃,pH of 7 and inoculated volume of M 10%(v/v),the nitrobenzene within 500 mg/L was completely degraded by the strain M within 12 h and the nitrobenzene at 600-700 mg/L was completely degraded within 24 h.The highest tolerance concn.of nitrobenzene to nitrobenzene was 900 mg/L.After the nitrobenzene at 300 mg/L was degraded by strain M,the biological toxicity of its metabolite was decreased gradually till nontoxic within 12 h.[Conclusion]The strains M had a very fast degradation effects on the nitrobenzene wastewater and could make the dynamics fit for the degradation,which could provided the basis for the practical wastewater treatment.