原位生物修复过程中石油烃降解特征研究

Study on Degradation Characteristics of Petroleum Hydrocarbons During In-situ Bioremediation

江汉油田经过多年的石油开采,产生了大量受到污染的废弃油井场地。项目组选取一处典型的石油污染场地,开展了微生物—植物联合修复研究。通过松土、施用高效降解菌、种植油葵,表层土壤石油烃总量从1 216～8 501 mg/kg下降到10～160 mg/kg,降解率为92. 6%～99. 7%;深层土壤石油烃总量从126～1 330 mg/kg下降到10～260 mg/kg,降解率为42. 1%～98. 9%。研究发现,高效降解菌—油葵联合修复法能够有效降解石油烃,且土壤表层的石油烃降解效果要优于土壤深层;在生物修复过程中,短链正构烷烃会被优先降解,长链正构烷烃逐渐占优势且呈奇数碳分布特征;多环芳烃在修复前2～6环均有检出,修复后仅检出2～3环为主的低分子量多环芳烃。

After years of oil exploitation,Jianghan oilfield has produced a large number of contaminated abandoned oil well sites.The project team selected a typical oil-contaminated site and conducted a microbes-plant joint remediation study.By loosening the soil,applying highly efficient degrading bacteria and planting oil sunflower,the total amount of petroleum hydrocarbons in the topsoil decreased from 1 216~8 501 mg/kg to 10~160 mg/kg,and the degradation rate was 92.6%~99.7%.The total amount of petroleum hydrocarbons in the deep soil decreased from 126~1 330 mg/kg to 10~260 mg/kg,and the degradation rate was 42.1%to 98.9%.The study found that the efficient degrading bacteria-oil sunflowers combined remediation method can effectively degrade petroleum hydrocarbons,and the degradation effect of petroleum hydrocarbon in the surface layer soil was better than that on deep soil layer.During the process of bioremediation,short-chain n-alkanes were preferentially degraded,and long-chain n-alkanes were gradually dominant and showed odd carbon distribution characteristics.The polycyclic aromatic hydrocarbons of 2~6 rings were all detected before the remediation,and low-molecular-weight polycyclic aromatic hydrocarbons that composed of 2~3 rings were mainly detected after remediation