生物可渗透性反应墙修复石油烃污染地下水的效果及微生物多样性研究

摘要

采用可渗透性反应墙(PRB)协同微生物作用对石油烃污染地下水进行室内模拟修复.研究结果表明,生物PRB对石油烃污染地下水具有较好的处理效果.反应器运行200 d后,生物PRB前端介质总石油烃(TPH)含量高,15个取样点的TPH质量浓度为0.74～5.42 mg/L,后端介质TPH含量较低且分布较均匀,10个取样点中TPH均低于0.29 mg/L,生物PRB出水中未检出TPH.采用聚合酶链式反应(PCR)-变性梯度凝胶电泳(DGGE)技术对生物PRB内的微生物群落结构进行分析,结果显示,生物PRB中微生物群落结构的相似性随着横向距离的增大而降低,其中B2与B5取样点微生物相似度最高,达83.1％.在生物PRB前端TPH浓度高的部位,微生物群落较为稳定,多样性较低,而后端TPH浓度低的部位,微生物群落不稳定,多样性较高.%The permeable reactive barrier (PRB) combined with microbial action was designed for the bio-remediation of groundwater contaminated by petroleum hydrocarbons. The results indicated that the bio-PRB presented perfect performance for petroleum hydrocarbons removal. After 200 days of bioremediation,the total petroleum hydrocarbons (TPH) was higher in the fore-end of the reactor with the concentration ranged from 0. 74-5. 42 mg/L in the fore-end 15 sampling points, while it distributed averagely in the back-end of reactor with the TPH concentration of sampling points all lower than 0. 29 mg/L. There was no TPH detected in the effluent of the reactor after remediation. The PCR-DGGE technology was used to analyze the microbial community structure of bio-PRB, atlas of DGGE showed that the similarity of microbial community decreased along the length of bio-PRB,and the highest similarity of 83. 1% was found between B2 and B5. The microbial diversity was lower in fore-end of bio-PRB,microbial community was more stable in this area. Conversely,the microbial community was less stable and more diversiform in t back-end of reactor.