黄河中下游表层沉积物中有机氯农药含量及分布

利用GC-ECD检测了黄河中下游干支流23个表层沉积物中的有机氯农药,主要检测出HCHs、DDTs、六氯苯、氯丹等,总含量范围为0.35～22.92 ng/g,其中HCHs和DDTs的含量较高,分别为0.09～12.88 ns/g和0.05～5.03 ng/g.干流中有机氯农药的含量从中游到中下游呈逐渐升高趋势,主要支流中的含量为:新蟒河＞金堤河＞汜水＞伊洛河＞沁河.干流中HCHs含量较海河、珠江、长江和黄浦江明显偏高;DDTs含量与除海河外的其它河流基本相同,但两者均低于国外河流.沿河流区域工业废水和主要支流的汇入、农药的广泛施用所引起的长期残留与风化土壤是黄河有机氯农药污染的主要来源.

Distribution of Organochlorine Pesticides in Surface Sediments from the Middle and Lower Reaches of the Yellow River

Organochlorine pesticides (OCPs) in twenty-three sediment samples from the middle and lower reaches of the Yellow River were analyzed by GC/ECD. The OCPs detected were comprised mainly of HCHs, DDTs, hexachlorobenzene, chlordane, etc. The range of total OCPs concentration was 0.35~22.92ng/g. The concentrations of HCHs and DDTs were much higher than other compounds and varied from 0.05~5.03ng/g and 0.09~12.88ng/g, respectively. Contamination level of OCPs in sediment increased from middle to lower reaches along the Yellow River. The distribution of total OCPs in main tributaries follows the sequence: Xinmang River > Jindi River >Si River> Yiluo River >Qin River. The Yellow River has a much higher concentration of HCHs than Hai River, the Pearl River, the Yangtze River and Huangpu River, and almost the same concentration of DDTs as other rivers except Hai River. The contamination of OCPs in the sediments from the middle and lower reaches of the Yellow River derived mainly from industrial contamination in riverbasim, the inflow of the main tributaries and the residues of organochlorine pesticides widely used for a long term and the aged and weathered agricultural soils.