空气曝气技术修复石油类污染地下水的影响因素

目的]研究空气曝气（AS）技术修复石油类污染地下水的影响因素.方法]选择二甲苯和萘作为典型的石油烃污染物,砾砂、粗砂和中砂作为模拟含水层介质,通过土柱模拟试验研究了不同影响因素下（如曝气量、介质渗透性、曝气方式）空气曝气技术对石油类污染地下水的修复效果.结果]曝气量和介质渗透性对AS的修复效果有较大影响,污染物的去除效率随着曝气量的增加而增大,但曝气量超过300 ml/min,污染物的去除率不再随曝气量的增加而增加;介质渗透性越强,污染物的去除率越高.对于渗透系数较小的中砂,间歇曝气较连续曝气效果好;对于砾砂和粗砂,2种曝气方式效果相仿.AS在去除污染物的过程中存在明显的拖尾现象.污染物萘不适合采用AS技术去除.结论]该研究可为AS技术应用提供数据支持.

Influence Factors of Remediation of Petroleum Contaminated Groundwater by Air Sparging

Objective] The research aimed to study influence factors of remediation of petroleum contaminated groundwater by air sparging （AS）.Method] Selecting xylene and naphthalene as typical petroleum hydrocarbon pollutants,gravel sand,coarse sand and medium sand as the simulated aquifer media,remediation effects of AS on petroleum contaminated groundwater under different impact factors （such as aeration rate,medium permeability and air injection mode） were studied by soil column experiment.Result] Aeration rate and medium permeability had larger impacts on remediation effect of AS.Removal rate of pollutant increased with aeration rate increase but changed little when the aeration rate exceeded 300 ml/min.The bigger the hydraulic conductivity was,the higher the removal rate of pollutant was.Under the same operation condition,intermittent air injection had advantages over continuous air injection for pollutant remediation in sand medium with low hydraulic conductivity,while the effects of two kinds of air injection modes were similar for coarse sand and gravel sand.It was apparent that there was tailing phenomenon when AS remediation performed.Naphthalene was not suitable using AS for remediation.Conclusion] The research could provide data support for AS application.