生物曝气技术对石油类污染地下水的修复效果及去除机制

针对东北某石油污染场地水文地质条件进行模拟,按照试验场地地层现状进行实验室缩放,研究微生物在含水层介质为砾砂、粗砂和中砂中的迁移速度以及含水层介质吸附的微生物量。选取苯和二甲苯作为目标石油污染物,研究生物曝气技术对被污染地下水的修复效果及其去除污染物的机制。实验结果表明:微生物在介质中的迁移速度从大到小为砾砂、粗砂、中砂;介质吸附微生物量的顺序从大到小为中砂、粗砂、砾砂;生物曝气4个月后,苯和二甲苯去除率分别为86.4%和81.7%,BS对中砂层中的苯和二甲苯去除效果好于砾砂层和粗砂层,苯的去除效果好于二甲苯。由挥发机制去除的污染物为46.24%,生物降解去除的污染物为36.98%,BS技术可以有效去除地下水中石油类污染物。

Removal Effect and Mechanisms of Biosparging Remediation on Petroleum Contaminated Groundwater

Biosparging is one of the most effective technologies to remove petroleum contamination in groundwater.Based on the hydro-geological conditions of petroleum contaminated sites in Northeast of China,the lab scale experiments were setup.Benzene and xylene were selected as target petroleum pollutants.The transport velocity and adsorption of bacteria in the aquifer(gravel sand,coarse sand and medium sand) were investigated.The removal efficiency and removal mechanism of benzene and xylene were studied by using biosparging technique in heterogeneous soil.The sequence of transport velocity from high to low is gravel sand,coarse sand,medium sand.The sequence of adsorption of bacteria in the aquifer from high to low is medium sand,gravel sand,coarse sand.After 4 months biosparging running,the removal efficiencies of benzene and xylene were reached up to 86.4% and 81.7%.The percentage of removal contamination is 46.24% by volatilization and 36.98% by biodegradation.The technology of biosparging can effectively remove the petroleum contamination in groundwater.