沉积物中多环芳烃和有机氯农药赋存状态

The distribution state of PAHs and organochlorine pesticides in sediments

对珠江广州河段高污染沉积物进行粒度分级,对不同粒径的样品重液分离,收集轻组分(有机质)和重组分(主要为无机矿物及无定型有机质).用显微镜对沉积物中不同粒径轻重组分的吸附剂进行鉴定,测定其中的多环芳烃(PAHs)和有机氯农药(OCPs).结果表明,沉积物样品中有机质占总重量9.1%,富集了81.5%的多环芳烃,77.2%的有机氯农药;无机矿物和无定型有机质占90.9%,富集了18.5%的多环芳烃,22.8%的有机氯农药;轻组分中的有机吸附剂对PAHs和OCPs的富集能力比重组分无机矿物和无定型有机质高1～2个数量级.

The highly polluted sediment in Guangzhou section of the Pearl River was graded on size; and samples of different particle diameter were separated with density to collect low density fraction (organic matter) and high-density fractions (mainly inorganic mineral and amorphous organic matter). The sorbents of these fraction were identified with microscope to determine polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). The organic matter in sediment sample occupied 90.9%, accumulating 18.5% PAHs and 22.8% OCPs. The capacity of accumulating PAHs and OCPs of organic sorbents of low density fraction was 1~2 orders of magnitude higher than that of high density fraction.