渗滤液中有机物在不同氧化还原带中的降解机理与效率研究

Degradation Mechanism and Efficiency of Organic Pollutants of Landfill Leachate in Different Redox Zones

通过土柱模拟实验研究了垃圾渗滤液中的有机污染物在地下环境中的降解机理和效率.结果表明,铁还原带对有机污染物的降解起重要作用,平均降解效率达86.24%,其次是氧还原带、硝酸盐还原带、硫酸盐还原带和产甲烷带,分别平均达到75.93%、79.81%、74.02%和65.09%;厌氧还原环境可能对苯并噻唑、安替吡啉、茚等物质的降解起重要作用;萘、环己酮、部分环烷烃等不易被微生物降解;不同污染物在不同氧化还原带中的最大降解效率也不同,如1,1,1-三氯乙烷和邻二甲苯在硫酸盐还原带中的降解效率最高,分别为80%和71.43%;三氯乙烯和MTBE则在硝酸盐还原带中的降解效率最高,分别为81.25%和92.58%;而苯在硫酸盐还原带和铁还原带中均被全部降解.

A soil column filled with sandy soil was constructed to investigate degradation mechanism and efficiency of organic landfill leachate pollutants in subsurface environment.Experimental results indicated that iron reduction zone may be play an important role on degradation of organics,and its efficiency was up to 86.24% averagely,reduction zone for nitrate,sulfate and methanogenic followed,and that was 75.93%,79.81%,74.02% and 65.09% averaged,respectively.Anaerobic reducing environment could have played an important role on degradation of benzoxazole,antipyrine,indene,etc.naphthalene,cyclohexanone and part of cyclo-alkyl hydrocarbon,etc.Which were difficult to biodegrade.Maximum degradation efficiency of pollutants was different in different redox zones.For instance,in sulfate reduction zone,the highest degradation efficiency of 1,1,1-trichloroethane and 1,2-dimethylbenzene was 80% and 71.43%,respectively.The highest degradation efficiencies of TCE and MTBE were in nitrate reduction zone,and reached 81.25% a nd 92.58%.respectively;Benzene was degraded completely in sulfate reduction zone and iron reduction zone.