Study On Development And Application Of Solid Fertilizer Based On Oil-degrading Bacteria

With the continuous development of China’s oil industry, the oil-contaminated soil areexpanded and result in serious damage to the oilfield and the ecological environment.Microbial remediation technology is an efficient method, it does not have secondarypollution and has been widely used in oil-contaminated soil remediation. Because the liquidoil-degrading bacteria have some problems in the storage, transport and active preservation,therefore immobilizing the oil-degrading bacteria on solid medium to get efficient, easypreservation the solid fertilizer is an effective method for bioremediation of oil-contaminatedsoil. The main purpose of this study is to develop the solid fertilizer with the high number ofviable bacteria and good degradation effect,in order to providing theoretical foundation for thebioremediation of saline alkali soil contaminated by petroleum with the petroleum degradingsolid fertilizer.The soil sample was collected from oil-contaminated soil in the Tianjin Dagang, whichwas respectively enriched and acclimated with low salt LB, high salt medium LB to obtain2kinds of oil-degrading bacteria, the oil-degrading ability, microbial community structure,growth curve were analyzed and providing the basis for follow-up experiments. The solidfertilizer is based on oil-degrading bacteria using wheat bran and sawdust as the solid medium,the solid fertilizer with high number of viable bacteria and good degradation effect on oil isdeveloped by the study of the effects of different temperature, inoculation quantity, incubationtime on it, After the optimal temperature, inoculation quantity, incubation time weredetermined, the low salt and salt tolerance solid fertilizer were made of2kinds of bacteria.The fertilizer is stored under the condition of4℃and the changes of the fertilizer in thepreservation process were studied. The fertilizer is used for the remediation of petroleumcontaminated soil with different salt to study its remediation effects. The quality guaranteeperiod is determined by the study of the characteristics in the preservation process and theremediation effects on petroleum contaminated soil.Through the experimental study, we candraw the following conclusions:The sample is respectively domesticated with low salt、high salt culture medium forfour cycles. Then2kinds of petroleum degrading bacterial flora are required, after10days theoil degradation rate is respectively36.35%,31.75%.Through the study of the effects of different inoculation quantity on properties of solidfertilizer at different temperature (room temperature、37℃), determine the The cultivationconditions of solid fertilizer is determined:37℃、15%inoculation quantity、maintaining the60%moisture content、cultivation of3days..The low salt solid fertilizer is prepared with low salt petroleum degradingbacterial flora, then the fertilizer is stored in4℃.The changes of the properties of solid fertilizer in the preservation process show that the total microbe amount of the solid fertilizerdecreased, pH firstly increased and then decreased.The high salt solid fertilizer is prepared with high salt petroleum degradingbacterial flora and stored in4℃.The changes of the properties of solid fertilizer show that thetotal microbe amount of the solid fertilizer decreased, pH increased firstly and then decreasedin the preservation process.The remediation of low salt fertilizer on oil contaminated soil shows that the fertilizer isrespectively applied to low salt (2.0g/kg), high salt (6.1g/kg) petroleum contaminated soil, theoil degradation rate of was respectively52.91%、34.74%after the remediation of60days, thefertilizer is suitable for the low saline alkali soil. The fertilizers in different preservation timeare applied to soil, with the increase of storage time, the oil degradation rate decreased.Through the study of the properties of the solid fertilizer and oil degradation effect in thepreservation process, the quality guarantee period is determined for35days at4℃.The remediation of low salt fertilizer on oil contaminated soil shows that the fertilizer isrespectively applied to low salt (2.0g/kg), high salt (6.1g/kg) petroleum contaminated soil, theoil degradation rate of was respectively31.45%、45.96%after the remediation of60days, thefertilizer is suitable for the low saline alkali soil. The fertilizers in different preservation timeare applied to soil, with the increase of storage time, the oil degradation rate decreased.Through the study of the properties of the solid fertilizer and oil degradation effect in thepreservation process, the quality guarantee period is determined for35days at4℃.