珠三角河网沉积物中氯代有机物垂直分布特征

Vertical distribution characteristics of polychlorinated organics in sediments from Pearl River Delta

用自制采样器在珠江三角洲典型河网珠江广州段、东莞运河和三水西南涌采集沉积物柱样,对其中的有机氯农药六六六(HCHs)、滴滴涕(DDTs)和氯苯类化合物(CBs)以GC/ECD外标法定量分析测定,以了解珠江三角洲河网沉积物中POPs的污染现状及污染史.结果表明,三水西南涌S1号柱样HCBs、DDTs和CBs的垂直含量范围分别为14.41~49.83 ng/g、32.71~190.65 ng/g和236.2~1551.7 ng/g;东莞运河的D2号柱样含量分别为0.97~5.03 ng/g、2.85~19.98 ng/g和53.5~310.9ng/g;珠江广州段的G3号柱样含量分别为ND^2.04 ng/g、1.96~7.42 ng/g和4.5~23.4 ng/g.所有沉积物柱样均呈现表层中的POPs含量大于深层的含量.从污染区域分布特征看,呈现S1>D2>G3.污染结构分析表明,S1号样中DDT的转化率低,揭示着有关降解微生物的活性低下;D2和G3号样近期均有新的污染源进入.

Vertical distribution characteristics of organochlorinated pesticides （HCHs and DDTs） and chloronbzenes in sediments of the Pearl River Delta, are quantified by GC/ECD with the outer standard material. The result show that： the concentrations ranges of HCHs, DDTs and CBs in the S1 core, collected from Xinan rivulet of Sanshui, are 14.41 -49.83 ng/g, 32.71 - 190.65 ng/g and 236.2 - 1551.7 ng/g, respectively; those for the D2 core, collected from canal of Dongguan, are 0.97 - 5.03 ng/g, 2.85 - 19.98 ng/g and 53.5 310.9 ng/g, respectively ; those for the G3 core, collected from the pearl river of Guangzhou, are ND - 2.04 ng/g, 1.96 - 7.42 ng/g and 4.5 - 23.4 ng/g, respectively. The concentrations of chlorinated organic compounds in surface sediments are higher as compared with subtract sediments. The concentration distribution of the organoehlorinated pesticides （HCHs and DDTs） and chloronbzenes from region showed ： Xinan rivulet from Sanshui 〉 canal of Dongguan 〉 the pearl fiver of Guangzhou.