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采用欧洲标准局连续提取法(Sequential extraction procedure of European Community Bureau of Reference)测定了汕头南澳白沙湾4种不同类型养殖区(鱼类、贝类、龙须菜和贝藻混养区)表层和柱状沉积物中4种重金属(Pb、Ni、Cu和Zn)不同形态的含量,初步评估了4种重金属的生物可利用性。结果表明,白沙湾表层沉积物中Pb和Zn主要以可还原态存在,而Ni和Cu均以残渣态存在。鱼类养殖区表层沉积物中4种重金属的生物可利用性较其他养殖区要高。4个养殖区柱状沉积物中4种重金属的生物可利用态总体上均随深度增加而减少;其中鱼类养殖区减小幅度较其余三种养殖区要大。形态风险准则评价表明,Zn对白沙湾水环境危害最重,已达到中等程度危害;Ni和Cu在各养殖区均为低危害;Pb在鱼类养殖区无危害,而在其余三个养殖区为低危害。
The surface and columnar shapes of four different types of aquaculture areas (fish, shellfish, asparagus, and cabbage algae) were determined using the Sequential extraction procedure of the European Community Bureau of Reference The contents of four kinds of heavy metals (Pb, Ni, Cu and Zn) in sediments were evaluated. The bioavailability of four heavy metals was evaluated preliminarily. The results show that Pb and Zn in Baishawan surface sediments mainly exist in the reducible state, while both Ni and Cu exist in the residual state. The bioavailability of four heavy metals in the surface sediment of fish culture areas was higher than that of other aquaculture areas. The bioavailabilities of four heavy metals in the columnar sediments of the four aquaculture areas all decreased as the depth increased. Among them, the decrease of fish culture areas was larger than that of the other three aquaculture areas. The evaluation of morphological risk criteria showed that Zn was the most harmful to the water environment of the Beibu Gulf and had reached a moderate degree of harm. Ni and Cu were all low-risk in all aquaculture areas; Pb was not harmful in the fish-farming areas, while in the remaining three aquaculture areas Low risk.