洋山海洋倾倒区倾倒前后沉积物中酸可挥发性硫化物与重金属的比较分析

为了更清楚认识洋山海洋倾倒区海域沉积物的污染状况,测定了该海域倾倒前后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、ΣSEM及ΣSEM-AVS差值的平面分布进行了分析。结果表明,该倾倒区及周边海域倾倒前、中、后表层沉积物中AVS含量分别为0.55~2.62,0.83~1.65和0.51~1.23 μmol·g^-1,倾倒后AVS含量呈下降态势,倾倒区AVS含量高于周边海域;ΣSEM倾倒前、中、后平均含量分别为2.80,2.79和2.60 μmol·g^-1,倾倒后ΣSEM含量略呈下降态势,往倾倒区方向富集;从单个重金属对ΣSEM的贡献率来看,Zn＞Cr＞Cu＞Pb＞Cd,SEM_Zn基本在35％以上,SEM_Cr基本在20％以上,而SEM_Cd均在1％以下,ΣSEM分布形态主要受Zn和Cr的控制;ΣSEM-AVS差值均大于0,且在倾倒区其ΣSEM-AVS值低于周边海域,说明倾倒区海域沉积物中重金属对生物可能有一定毒性。

Comparing study on the acid volatile sulfide and heavy metals in sediments of marine dumping site during dumping activity on Yangshan

In order to better understand the pollution state of sediments in a dumping site, the acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) of surface sediments collected from the marine dumping site of Yangshan were determined, while distributions of AVS, ΣSEM, ΣSEM-AVS were also analyzed. The results show that the AVS in the surface sediments of the dumping site and nearby area are 0.55~2.62 μmol·g^-1(before dumping), 0.83~1.65 μmol·g^-1(dumping) and 0.51~1.23 μmol·g^-1(after dumping) respectively, the contents of AVS present a decline trend after dumping, and the AVS in sediments is higher than that in nearby area after dumping. The mean values of ΣSEM in nearby area are 2.80 μmol·g^-1(before dumping), 2.79 μmol·g^-1(dumping) and 2.60 μmol·g^-1 (after dumping) respectively the contents of ΣSEM also present a decline trend after dumping, and the contents of ΣSEM are enriched toward to dumping site. The order of the contribution of heavy metal to ΣSEM is Zn＞Cr＞Cu＞Pb＞Cd, with the contribution of zinc basically being>35%, chromium>20%, cadmium<1%. Therefore, the distribution is mainly controlled by zinc and chromium. The different values of ΣSEM-AVS are larger than zero and lower in the dumping site than that in nearby area, which indicates that the metals (SEM) in the surface sediments of the dumping site probably have some toxicity to the life.