采集广东省南澳岛白沙湾海水养殖区不同养殖类型的表层和柱状沉积物,分析了沉积物中酸挥发性硫化物( acid volatile sulfides, AVS)和同步提取重金属( simultaneously extracted metals, SEM ) Cd、Pb、 Cr、 Ni、 Cu以及Zn的含量.结果发现,白沙湾表层沉积物(干质量)中AVS和∑SEM质量摩尔浓度分别介于0.04-37.62和1.54-3.82μmol/g,平均值分别为6.36和2.45μmol/g.鱼类养殖区表层沉积物中AVS、∑SEM以及AVS与∑SEM比值均最高.柱状沉积物(干质量)中AVS和∑SEM干质量摩尔浓度范围为0.04-16.27和1.72-21.14μmol/g,平均值分别为2.26和4.71μmol/g.鱼类养殖区的AVS质量摩尔浓度及贝类养殖区的∑SEM 从底层到表层均迅速增加.鱼类养殖区、贝类养殖区和龙须菜栽培区AVS与∑SEM比值均大于1,表明该养殖海域因重金属与硫化物结合导致水生生物受重金属危害较轻.
Surface and core sediments were collected from Baisha Bay, Nan’ao Island, one of Guangdong Province’s largest mariculture bases in Southern China. Acid-volatile sulfide ( AVS ) and simultaneously extracted metals ( SEM) including Cd, Pb, Cr, Ni, Cu and Zn were analyzed to evaluate sediment quality. In surface sediments, the contents ( dry weight) of AVS and∑SEM were from 0. 04 to 37. 62 μmol/g and from 1. 54 to 3. 82 μmol/g, with average levels of 6. 36 and 2. 45 μmol/g, respectively. The highest contents of AVS,∑SEM and molar ratios of AVS to∑SEM were in fish culture zones. In core sediments, the concentrations ( dry weight) of AVS and∑SEM varied in the range of 0. 04-16. 27 μmol/g and 1. 72-21. 14 μmol/g, with average levels of 2. 26 μmol/g and 4. 71 μmol/g, respectively. The AVS content dramatically increased from bottom to surface sediments in fish culture zone, suggesting that AVS might play a major role in binding heavy metals. On the contrary, the∑SEM content rapidly decreased from bottom to surface sediments in shellfish culture zone. In the surface sediments, the ration of AVS/∑SEM is larger than 1 in the fish cage, shellfish and seaweed zones, indicating that those heavy metals lightly damaged aquatic organisms.