大宝山矿区水体中重金属的行为研究

广东大宝山矿区矿山废水的排放使周边生态环境遭受了严重的破坏。水体中重金属Cu、Zn、Cd和Pb的溶解态浓度分别达到13.82、50.83、0.103和2.91 mg.L-1。Cu、Zn、Cd和Pb的溶解态和悬浮态含量沿河流主干道断面呈相似的空间分布规律,上游都是沿水流方向降低,下游因吸附于悬浮物中的重金属重新释放略有增加。悬浮物中重金属元素的化学形态提取和扫描电镜能谱分析(SEM/EDAX)表明:4种重金属元素都以残渣态为主要存在形态,其次为可还原态,个别断面的Cd可还原态甚至超过了残渣态的含量,说明该水体这4种元素对环境都有一定的潜在威胁性。

DISTRIBUTION OF HEAVY METALS IN WATER AROUND THE DAOBAOSHAN MINE

The eco-environment was seriously damaged by heavy metals in Hengshi River near Dabaoshan mine, Guangdong province. The dissolved and particulate of Cu, Zn, Cd, Pb have the similar spatial distribution which decreased gradually along the river except in lower reaches. Dissolved metals were dominant and with maximum concentrations in the low pH region, the concentrations of Cu, Zn, Cd and Pb as high as 13.82, 50.83, 0. 103 and 2.91 mg . L^-1 , respectively. Some important behavior differences do exist in dissolved phase. Pb decreased sharply with the pH rising, however, Cd appears to be much slower. Studies on suspended particles with chemical speciation analysis and SEM/EDX indicate that the residual speciation was the major species for those four metals in suspend solids. And the reducible speciation were also high especially Cd, which indicated that they all have potential risk to environment.