热水洗辅助微生物修复高含油落地油泥

为解决油田落地油泥含油率高但不能直接进行生物无害化处置的问题，探索一种热水洗辅助微生物修复工艺。利用热水洗实验考察了清洗配方和水温对降低含油率的影响；从落地油泥中分离出石油烃降解菌，以用于含油残砂的微生物降解过程，同时探究填料和烃降解微生物对残砂中石油烃降解效果的影响。结果表明，鼠李糖脂清洗剂在总用量为0.5%、水洗时间30 min和50 ℃条件下，可将油泥含油率由107.1 mg·g⁻¹降至为39.3 mg·g⁻¹；水洗后残砂中的土著菌群数量出现了明显下降。分离获得了2株烃降解菌，并优选出具有增加油泥溶氧和保水的沼渣。将烃降解微生物和优选沼渣加入残砂后，石油烃生物降解效率得到显著提升，200 d后含油率降为4.62 mg·g⁻¹。在此过程中，微生物优先降解分子量小的饱和烃和芳香烃组分，对胶质和沥青质等组分降解程度偏低。该研究结果可为油田高含油落地油泥的环保处置提供参考。

Remediation of high oil content of oil sludge-contaminated soil by hot water washing and biodegradation

In order to solve the problem of high oil content of oil sludge in oilfields but not directly biologically harmless disposal, the pre-treatment of hot water washing and subsequent bioremediation were carried out. Environmental friendly cleaning agent and optimum working condition were screened. Oil degrading microorganisms were isolated from the soil and used to the bioremediation of the residual sands. The effect of bulking agent and the isolated microorganisms were evaluated. The results of oil displacement efficiency shown that the cleaning agent of rhamnolipid was capable of decreasing the oil content from 107.1 mg·g−1 to 39.3 mg·g−1. The suited condition were determined as follows: dosage of cleaning agent 0.5%, the reaction temperature 50 ℃, reaction time 30 min. After washing, the number of indigenous flora in the residual sands has decreased significantly. Two oil degrading microorganisms were isolated, and a better water holding and oxygen dissolving bulking agent of digestate was screened. The results of bioremediation indicated that adding the isolated two strain and bulking agent were in favor of improving the degradation rete, resulted in the oil content decreased to 4.62 mg·g−1 for 200 days. Oil property analysis showed that saturates and aromatics were preferentially degraded compared with the heavy component of resins and asphaltenes. The combined technology would provide technical support to the high oil content of oil sludge-contaminated soil.