化学氧化技术异位处理地下水非水相有机污染物中试研究

Ex-situ Chemical Oxidation Treatment for Non-aqueous Liquid Contaminated Groundwater: A Pilot Study

选取某农药厂旧厂区为试验场地,考察化学氧化技术异位处理地下水非水相有机污染物的运行效果。基于小试研究,确定高锰酸钾、高铁酸钾、芬顿试剂以及次氯酸钠4种氧化剂在中试试验中的适宜投加量。中试结果表明,当进水流量为1.0 m^3/h时,不同氧化剂对于常规水质指标及特征有机污染物的去除效果存在差异性。总体而言,四种氧化剂对于中长链石油烃类污染物(C10-C36)的去除率可达20%~70%,但对氯代烷烃类污染物的去除效果低于20%;高铁酸钾和次氯酸钠分别对于苯酚类和多环芳烃类污染物的去除效果较好(70%~100%);芬顿试剂对各类污染物均有显著氧化效果,其中对于短链石油烃(C6-C9,去除率20%~40%)、苯系物(去除率40%~90%)的去除效果高于其他三种氧化剂。研究不同氧化剂对于多组分有机污染地下水的处理效果,为将化学氧化技术应用于此类污染场地提供了理论和技术支持。

In this study,a former pesticide plant was selected to test the performance of the ex-situ chemical oxidation technology in eliminating non-aqueous organic contaminants from groundwater.Through laboratorybased experiment,the appropriate dosage of the four oxidants(i.e.,potassium permanganate,potassium ferrate,Fenton's reagent,and sodium hypochlorite) for the pilot-scale study were determined.The results(flow rate: 1.0 m^3/h) show distinct variations in removal efficiency of the different oxidants on conventional pollutants and target organic pollutants.In general,the removal efficiency of the four oxidants for medium-and longchain petroleum hydrocarbons(C10-C36) can reach 20% to 70%,while removal performance is poor( 20%) on chlorinated alkane pollutants.Potassium ferrate and sodium hypochlorite achieved better removal efficiency for phenolic compounds and PAHs(70%-100%);Fenton's reagent has significant oxidation effects on most pollutants,among which the removal efficiency on short-chain petroleum hydrocarbons(C6-C9,20%-40%),as well as benzene,toluene,ethylbenzene,o-and p-xylene(BTEX)(40%-90%) is higher than that of the other three oxidants.Our finding is useful to the application of chemical oxidation technology on similar contaminated sites.