厦门筼筜湖表层沉积物金属元素赋存形态及污染评价

用ICP-MS测定了厦门筼筜湖表层沉积物中15种金属元素的含量,分析了金属元素的分布特征,并用改进的BCR提取法分析其赋存形态.结果表明,Cd、Cu、Sr、Pb、Zn和U在不同湖区的含量表现为:外湖干渠内湖;Cr、Co、Ni、V、Fe、Li、Rb和Mn的含量表现为:内湖外湖干渠.Cu、Zn和Pb主要存在于可还原态;Cd元素主要存在于弱酸溶态和可还原态;Co、Ni、U、Fe和Mn元素主要存在于可还原态和残渣态;Li、V、Cr、Rb和Ba主要存在于残渣态.潜在生态风险评价结果表明,元素V、Cr、Co、Ni、Zn、Cu、Cd和Pb等处于轻微潜在生态风险水平.次生相与原生相分布比值法评价结果显示,Cu、Cd和Zn表现出重度污染;Pb表现出中度污染;Co、Mn、Sr和U表现出轻度污染;Ni、Fe、Cr、V、Li、Ba和Rb表现出无污染.筼筜湖表层沉积物已受轻微的金属元素污染,处于轻微生态风险水平.

Fractionation and Contamination Assessment of Metal Elements in the Surface Sediments of Yundang Lagoon in Xiamen

Total concentrations of 15 metal elements in the surface sediments of Yundang Lagoon in Xiamen were determined using ICP-MS. The fractions were extracted by a modified BCR method. The results indicated that in different areas of Yundang Lagoon, the order of the concentrations of Cd, Cu, Sr, Pb, Zn and U was:outer lagoon > ditch > inner lagoon, the order for Cr, Co, Ni, V, Fe, Li, Rb and Mn was:inner lake > outer lake > ditch. Cu, Zn and Pb were mainly in the reducible phase; Cd was mainly in the acid soluble-extractable and reducible phases; Co, Ni, U, Fe and Mn were mainly in the reducible and residual phases; Li, V, Cr, Rb and Ba were dominated by residual phase. The potential ecological risk of metal elements suggested that V, Cr, Co, Ni, Zn, Cu, Cd and Pb were at a low potential ecological risk level. The results of ratio of secondary phase to primary phase (RSP) assessment indicated that Cu, Cd and Zn showed high pollution level; Pb showed moderate pollution level; Co, Mn, Sr and U were in a low polluted condition; Ni, Fe, Cr, V, Li, Ba and Rb showed no pollution. In general, Yundang Lagoon was in a low potential ecological risk.