条子河中多环芳烃和有机氯农药的时空分布及来源解析

以辽河支流条子河中的多环芳烃(PAHs)和有机氯农药(OCPs)为目标物,分别于春汛期、丰水期、平水期和枯水期采集水样及表层沉积物样品,分析样品中PAHs和OCPs的赋存状态及污染物在该区域的分布和来源.结果表明:条子河水中总PAHs的质量浓度为658.1~3 096.6ng/L,均值(算术平均值,下同)为1 522.1ng/L;沉积物中总PAHs的质量比为775.7~2 835.4ng/g,均值为1 374.0ng/g;条子河水中总α,β,γ-HCHs(六六六)的质量浓度为5.36~16.57ng/L,均值为10.93ng/L;滴滴涕(DDTs)未检出;沉积物中总HCHs的质量比为2.87~5.56ng/g,均值为4.34ng/g;条子河水和沉积物中PAHs的含量均为自上游至下游递减,且枯水期平水期春汛期丰水期;条子河水中HCHs的质量浓度自上游至下游递增,且丰水期春汛期平水期枯水期,沉积物中HCHs的质量比自上游至下游递减,且枯水期平水期春汛期丰水期;条子河中的PAHs主要来源于煤炭燃烧和交通燃烧,HCHs主要来源于农药林丹的使用.

Temporospatial Distribution and Source Identification of PolycyclicAromatic Hydrocarbons and Organochlorine Pesticides in Tiaozi River

Water and surface sediment samples were collected from the Tiaozi River, a branch of Liaohe River, in spring, summer, autumn and winter to determine the contents of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). On this basis, the distribution and sources of the two organic pollutants were investigated. Results indicate that the total PAHs levels in the water samples were 658.1—3 096.6 ng/L (arithmetic mean: 1 522.1 ng/L) and those in the sediments were 775.7—2 835.4 ng/g (1 374.0 ng/g). α,β,γ Hexachlorocyclohexanes (HCHs) were detected in all the samples and the total HCHs were 5.36—16.57 ng/L (10.93 ng/L) in the water samples and 2.87—5.56 ng/g (4.34 ng/g) in the sediments. Dichlorodiphenyl trichloroethanes (DDTs) in all the samples were below the detection limit. Temporospatial distributions of PAHs in the river water and sediments were similar: the PAHs levels decreased in the order of winter>autumn>spring>summer and decreased from the upstream to the downstream. In contrast, temporospatial distributions of HCHs in the river water and sediments were opposite: HCHs levels in the water decreased in the order of summer>spring>autumn>winter and reduced from the downstream to the upstream; HCHs levels in the sediments decreased in the order: winter>autumn>spring>summer and decreased from the upstream to the downstream. The results for source identification of PAHs and HCHs reveal that PAHs in the river were mainly from the combustion of coal and transportation, and HCHs were from the past use of lindane.