苍南海洋倾倒区沉积物中酸可挥发性硫化物与重金属的研究

Study on acid volatile sulfide and trace metals in sediments of marine dump site of Cangnan

为了更清楚认识倾倒区海域沉积物的污染状况,测定了苍南海洋倾倒区海域表层沉积物中酸可挥发性硫化物(AVS)、酸可提取重金属(SEM)的含量,并对AVS、SEM、及SEM-AVS的平面分布进行分析。结果表明,该倾倒区表层沉积物中AVS含量为0.19-1.88μmol.g-1,倾倒区附近海域AVS含量高于周边海域;SEM平均含量为2.4μmol.g-1,SEM含量往倾倒区方向有增加趋势。从单个重金属对SEM的贡献率来看,Zn>Cr>Cu>Pb>Cd,SEMZn基本在50%以上,而SEMCd均在1%以下,其分布形态主要受Zn的控制。SEM-AVS差值均大于0,且在倾倒区及附近海域其SEM-AVS值高于沿岸各站,说明倾倒区海域沉积物中重金属对生物可能有一定毒性,具有潜在重金属生态风险。

In order to reveal the pollution state of sediment in dump site, we determined the acid volatile sulfides （AVS） and simultaneously extracted metals （SEM） of surface sediment collected from the marine dump site of Cangnan, and the AVS, SEM, SEM-AVS and their distributions were also analyzed. The result showed that the AVS in the surface sediment of dump site was between 0.19-1.88 μmol.g-1, and the AVS in sediment near dump site was higher than the circumjacent areas. The mean value of SEM was 2.4 μmol-g-l, and the contents of SEM were increased toward to dump site. At the mention of the contribution to ESEM from single heavy metal, the order was Zn〉Cr〉Cu〉Pb〉Cd, and the contribution of zinc basically was higher up to 50%, while the cadmium was less than 1%; therefore, the distribution was mainly controlled by zinc. The rations were larger than zero of SEM-AVS; furthermore, SEM-AVS in the dump site and nearby area was hiher than the seacoast stations. The metals （SEM） in the surface sediment of dump site posed toxicity to the organisms, thus, there could be potential heavy metals ecological risk in the dump site.