污灌渠中有机氯农药对沿渠土壤的影响

Influence of Organochlorine Pesticides in Wastewater on the Soil Along the Channel

为了研究污水灌渠侧渗对土壤的影响,采用气相色谱-电子捕获检测器(GC-ECD)方法对太原市小店污灌区9个剖面土和2个灌溉污水样进行有机氯化合物(OCPs)分析.结果表明退水渠中有机氯农药主要由六六六(HCHs)组成,滴滴涕(DDTs)及其它有机氯农药含量较低或未检出,在8个离渠较近剖面的地表土中ΣOCPs和HCHs含量一定程度上符合随垂直于渠的直线距离增加而逐步降低的趋势,表明污水渠侧渗对土壤存在着一定影响.8个剖面土壤中的HCHs含量随着深度的增加而降低,在水平方向上,同一深度土壤中的HCHs含量也沿远离渠的直线方向逐步递减.研究区土壤中HCHs含量与TOC之间存在较为显著的正相关性,而与pH之间不存在相关性.

Nine profile soil samples and two sewage water samples were collected from Xiaodian sewage irrigation area in Taiyuan city,concentrations of organochlorine pesticides（OCPs） were determined by the gas chromatography coupled with electron capture detector（GC-ECD） to analyze the influence of the leakage of sewage water.The result shows that OCPs in sewage water were mainly composed of HCHs.Concentrations of DDTs and other organochlorine pesticides were very low or out of the detection limit.Concentrations of ΣOCPs and HCHs in eight profiles near irrigation channels to some extend decreased with the increasing of the linear distance off the channel,which shows influences of the leakage of sewage water on the soil nearby.Concentrations of HCHs clearly decreased with the increasing of soil depth in most profile soils.For the horizontal direction,concentrations of HCHs also decreased with the increasing of the linear distance off the channel.The correlation between HCHs and TOC was positive,but no correlation between pH and HCHs was found.