Combined pollutions of arsenic (As) and copper (Cu) are common in water bodies near mines, non-ferrous metal smelting and power plants. This study investigated the effect of Cu(II) on the absorption and speciation of As(V) by microalgae. We compared the absorption and speciation of arsenic by microalgae (mainly Cyanophyta and Chlorophyta) when exposed to single As(V) with that exposed to As-Cu co-exposure in laboratory. The results showed that in the case of single As(V) exposure, the inhibitory effect of As(V) on microalgae was primarily affected by the exposure time, instead of the concentration of As(V) in the water solution. Compared with single As(V) exposure, the presence of Cu(II) under As-Cu co-exposure promoted the absorption and accumulation of As(V) by algae. The combination effect of As and Cu on algae was antagonistic instead of synergistic within the tolerance range of algae to them. In the presence of Cu(II), more monomethylarsonous acid (MMA) and dimethylarsinous acid (DMA), which are volatile organic arsenic compounds, were produced in algae compared with the control. The finding that Cu(II) can mediate the absorption and speciation processes of arsenic in algae has significance in possible bioremediation of arsenic pollution in aquatic environment.

矿山，有色金属冶炼和发电厂附近的水体中常见砷和铜的综合污染。这项研究调查了铜（II）对微藻对As（V）的吸收和形态的影响。我们比较了微藻类（主要是蓝藻和绿藻）在单一As（V）暴露下的砷的吸收和形态与在实验室中暴露于As-Cu共同暴露的砷的形态。结果表明，在单次As（V）暴露的情况下，As（V）对微藻的抑制作用主要受暴露时间的影响，而不是水溶液中As（V）的浓度。与单次As（V）暴露相比，As-Cu共暴露下Cu（II）的存在促进了藻类对As（V）的吸收和积累。在藻类对它们的耐受范围内，砷和铜对藻类的联合作用是拮抗的而不是协同的。与对照相比，在铜（II）的存在下，藻类中产生了更多的单甲基亚砷酸（MMA）和二甲基亚砷酸（DMA），它们是挥发性有机砷化合物。Cu（II）可以介导藻类中砷的吸收和形态形成过程的发现对水生环境中砷污染的可能生物修复具有重要意义。