Screening of Microbe and Its Characteristics for Benzene Compounds Degradation

To select efficient strains which was used to degrade benzene compounds,the study selected activated sludge as a bacteria source in Shanghai Jinshan chemical industry zone sewage treatment plant,toluene,ethylbenzene and xylene as substrates separately. Under aerobic conditions,the micro-strains were isolated that can live upon above-mentioned compounds as the sole growth carbon and energy source.The micro-strains are preliminary identified as Pseudomonas sp.,Bacillus sp.,Rhodococcus sp.,etc.Aerobic biodegradation study showed that the degradation efficiency of toluene can reach 95%-98%,which of ethylbenzene can reach 80% -88%and which of p-xylene can reach 70%-80%.The optimal growth conditions for hybrid bacteria are 30℃,reaction time 48 h, inoculation 10%,shaking rotate 180 r/min,pH 7-9 for toluene,ethylbenzene degradation and pH 4 or 10 for xylene degradation,respectively.