Development Of Mixed Microbial Agent For Degradation Of Petroleum Hydrocarbons And Indoor Simulated Remediation Of Petroleum Contaminated Groundwater

Petroleum is an important energy source,in the process of production,processing,transportation and use,because of leakage and non-discharge,it will be accompanied by the spillover and infiltration of petroleum hydrocarbon mixtures,resulting in serious pollution of the environment by petroleum,which makes it urgent to remedy petroleum hydrocarbon pollution.As an efficient,safe,low-cost,non-secondary pollution,economic and effective oil pollution remediation technology,microbial remediation technology has been paid more and more attention by domestic and foreign scholars in the past few years.Because microbial strains are susceptible to external factors in the actual polluted environment and are not easy to preserve,the degradation of microbial strains can not be brought into full play.The preparation technology of microbial solid microbial agent refers to the carrier carrying the target strain,which can effectively eliminate the influence of external environmental factors and shield the inhibition of indigenous bacteria,and ultimately improve the degradation rate of petroleum pollutants,so it has great potential for application.In this paper,three strains of petroleum hydrocarbon degrading bacteria were screened from petroleum contaminated soil in Song yuan Oilfield,then identified and compounded them.The optimized mixed strains were fermented on specific carriers to prepare mixed microbial solid microbial agents.The preparation conditions of mixed microbial solid microbial agents were studied from five aspects:(1)pH,(2)drying temperature,(3)carrier ratio,(4)feed-water ratio,(5)inoculation quantity.Find the best preparation conditions of petroleum hydrocarbon degrading bacteria agent,then prepare petroleum hydrocarbon degrading bacteria agent according to the optimal conditions,and finally use the bacteria agent in the follow-up indoor simulation to repair Petroleum Contaminated groundwater.1?The strains identified were Stenotrophomonas acidaminiphila strain,Pseudomonas pseudoalcaligenes strain and Rhodococcus sp.2?Three strains have synergistic effect on petroleum hydrocarbon degradation.When the ratio of three strains(YH:TM:K1)is 1:0.5:1.5,the degradation effect of petroleum hydrocarbon is the best.The degradation rate of petroleum hydrocarbons reached 94.3% after 6 days of shaking culture at 130 r/min and 30 C with the initial concentration of petroleum hydrocarbons of 2000 mg/L and the addition of mixed strains.The kinetic curve of petroleum hydrocarbon degradation was well fitted with zero-order kinetic equation.3?The solid microbial agent prepared with carrier(rice husk: sawdust: diatomite)ratio of 80%:10%:10%,pH=8,drying temperature of 35 C,material-water ratio of 1:2 and carrier inoculation amount of 80% had the best effect on petroleum hydrocarbon degradation.The degradation rate of total petroleum hydrocarbons reached 98.8% after 6 days of shaking culture at 130 r/min and 30 C with the initial concentration of petroleum hydrocarbons of 2000 mg/L and the addition of microbial agents.4?The results of simulated remediation of groundwater contaminated by petroleum hydrocarbons with mixed bacteria showed that the concentration of petroleum hydrocarbons changed from 34.6 mg/L to 3.3 mg/L after 30 days of operation,and the remediation effect of petroleum hydrocarbons was remarkable.