麦秸强化微生物降解石油烃及场地试验

在油-盐混合污染耕地的耕作层中施加麦秸以强化水浸洗盐和促进微生物对石油烃的降解.通过实验考察了麦秸添加量对降解石油烃所用的阴沟肠杆菌(Enterobacter cloacae)和刺孢小克银汉霉菌(Cunninghamella echinulata)的生长及其对于石油烃降解行为的影响.结果发现，在土壤中添加5%(质量分数)麦秸可使土壤中的细菌和真菌生物量提高至对照样品的25和3倍；19 d时总石油烃降解率从29.2% 提高到48.0%，其中饱和烃、芳烃的降解率分别从31.5%和39.1%提高到55.7%和55.9%.在中原油田污染耕地现场试验结果表明，石油烃降解菌添加25 d后，添加麦秸的修复土壤中的细菌和真菌生物量为对照土壤的158和9倍；45 d后试验地块中的总石油烃质量分数降至0.3%以下，石油烃降解率最高达到75%.上述结果显示出添加麦秸与真菌-细菌协同修复方法相结合在治理油-盐混合污染耕地中具有很好的应用前景.

Process Fundamentals and Field Demonstration of Wheat Straw Enhanced Biodegradation of Petroleum

A new bioaugmentation method utilizing wheat straw to enhance salt leaching and the subsequent petroleum biodegradation by consortia of bacteria and fungi was proposed. The present study aimed at the effects of wheat straw on the growth and the degradation behavior of E. cloacae and Cun. echinulata, the two species of the consortia. In the laboratory experiments, it was shown that the addition of 5% (mass fraction) straw led to an increase of biomass by 25- and 3-fold to the bacteria and fungi, respectively. The biodegradation ratio of total petroleum hydrocarbon (TPH) was elevated from 29.2% to 48.0% after 468 h treatment. The biodegradation ratio of alkane and aromatic hydrocarbons in petroleum were increased from 31.5% and 39.1%, to 55.7% and 55.9%, respectively. The field demonstration was carried in an area of 6 400 m², in which the bacteria and fungi were inoculated after salt leaching in the presence of wheat straw. The addition of wheat straw in the contaminated soil led to an increase by 158- and 9-fold to the bacteria and fungi, as compared to their counterpart in the control land without wheat straw, at 25 days after the inoculation. The content of TPH was down to below 0.3% while the maximum biodegradation ratio of TPH reached 75% after 45 days treatment. These results demonstrated the effectiveness and high potential of the wheat straw enhanced bioaugmentation of petroleum-salt contaminated soil.