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为研究有机氯农药(OCPs)在重庆南山老龙洞地下河流域表土中的分布趋势、组成特征、来源及污染水平,采用气相色谱-微池电子捕获检测器(GC-μECD)分析了6个代表性表层土样中20种OCPs.结果表明,研究区表层土壤中20种OCPs均有不同程度检出,其中(除DDE、顺式氯丹、反式氯丹、狄氏剂)16种检出率高达100%,氯丹类和DDTs是主要污染物,不同采样点有机氯农药含量差异较大.OCPs总量变化范围在5.57~2 618.57 ng·g~(-1)之间,平均值为467.28 ng·g~(-1),与国内外其它区域相比,研究区表层土壤中HCHs和DDTs含量处于中上水平.有机氯农药总量和HCHs、DDTs、氯丹类农药总量分布具有相似的空间变化趋势,均为:上游>中游>下游,并且上游与中、下游的差距尤为显著.来源分析表明,HCHs主要来源于林丹的使用,DDTs既来源于历史农药残留,也来源于近期工业DDT的非法使用和三氯杀螨醇的输入,氯丹主要来自历史残留和大气沉降.结合中外土壤质量标准,新力村土壤属于有机氯农药严重污染土壤,下龙井湾、夏家咀和赵家院子土壤受到有机氯农药轻度污染,龙井旁和高中寺土壤属于无污染土壤.
In order to study the distribution trend, compositional characteristics, sources and pollution levels of organochlorine pesticides (OCPs) in the surface soil of Laolongdong underground river basin in Nanshan, Chongqing, GC-μECD was used to analyze six representative Twenty kinds of OCPs in the topsoil were detected.The results showed that 20 kinds of OCPs were detected in different degrees in the topsoil of the study area, of which 16 kinds (except DDE, cis-chlordane, trans-chlordane and dieldrin) The rates of up to 100%, chlordane and DDTs were the main pollutants, and the content of organochlorine pesticides differed greatly among different sampling sites.The total amount of total OCPs ranged from 5.57 to 2 618.57 ng · g -1, with an average of 467.28 ng · g -1, compared with other regions at home and abroad, the contents of HCHs and DDTs in the topsoil of the study area were in the upper-middle level.The total amount of organochlorine pesticides and the distribution of HCHs, DDTs and chlordane pesticides were Similar spatial variation trends are: upstream> middle reaches> downstream, and the difference between upstream and middle and lower reaches is especially significant. Source analysis shows that HCHs mainly comes from the use of lindane, DDTs originated both from historical pesticide residues and from recent Industrial DDT is used illegally and dicofol imports, mainly from chlordane History residue and atmospheric settlement.Under the standards of Chinese and foreign soil quality, the soil of Xinli village belongs to organochlorine pesticide seriously polluted soil, the soil of Xiaolongjingwan, Xiajiazui and Zhaojiayuan are slightly polluted by organochlorine pesticides, Polluted soil.