颗粒活性炭固定化菌修复石油污染地下水

Remediation of Petroleum Contaminated Groundwater by Immobilized Bacteria on Granular Activated Carbon

从东营某炼油厂油污土中筛得可高效降解石油的Pseudomonas aeruginosa HL菌和Salmonella sp.L4,二者复配后并以颗粒活性炭为载体制备固定化菌剂。采用室内批量实验研究固定化菌对不同环境条件地下水中石油的修复效能以及作用机理。结果表明,该固定化菌去除石油的最优条件为固定化菌投加量1.0 g/L、油质量浓度1000 mg/L、pH值为7。活性炭对微生物的固定化时间为36 h时,固定化菌量为1.18×10^(11)cell/g。在温度15℃且最优条件下固定化菌对地下水中原油和柴油的去除率分别为85.02%和74.53%;固定化菌对原油中正构烷烃和多环芳烃的去除率比游离菌分别提高18.86和35.84百分点。固定化菌通过快速吸附地下水中的石油,增加微生物和石油之间的接触,从而增加石油的微生物降解和低温地下水中的油,特别是多环芳烃组分的去除率。因此,活性炭固定化菌具有清洁又高效的优势,可用于低温条件石油污染地下水的修复。

Pseudomonas aeruginosa HL and Salmonella sp.L4,which can efficiently degrade oil,were screened from the petroleum-contaminated soil of a refinery in Dongying,and further mixed to prepare the immobilized bacteria using granular activated carbon as the carrier.The remediation efficiency and action mechanism of oil in groundwater by immobilized bacteria under different environmental conditions were investigated through indoor batch experiments.The results show that the optimal conditions for the removal of oil by the immobilized bacteria are as follows:the dosage of immobilized bacteria of 1.0 g/L,the mass concentration of oil of 1000 mg/L,and the pH value of 7.The number of immobilized bacteria is 1.18×10^(11) cell/g when the immobilization time of microorganisms on activated carbon is 36 h.The removal rates of crude oil and diesel oil in underground water by immobilized bacteria at the temperature of 15℃under optimal conditions are 85.02%and 74.53%,respectively;the removal rate of n-alkanes and polycyclic aromatic hydrocarbons(PAHs)in crude oil by immobilized bacteria is 18.86 percent point and 35.84 percent point higher than that by free bacteria,respectively.Immobilized bacteria can increase the contact between microorganisms and oil through rapidly adsorbing the oil in the groundwater,thus increasing the biodegradation and the removal rate of oil,especially PAHs in low temperature groundwater.Therefore,it is a promising clean and efficient treatment method to apply immobilized bacteria on activated carbon for the remediation of oil in low-temperature groundwater.