Use of anodic stripping voltammetry in predicting toxicity of copper in river water.
The labile concentration and toxicity of Cu as influenced by alkalinity and different concentrations of ethylenediaminetetraacetic acid (EDTA) and naturally derived fulvic acid (FA) were determined by bioassays carried out in the culture media for Daphnia magna (D. magna). The labile concentration of Cu was obtained by differential pulse anodic stripping voltammetry with a double-acidification method (DAM-DPASV). Changes in water alkalinity did not affect the labile concentration of Cu, but increase in alkalinity did reduce the mortality of D. magna. In the presence of EDTA and FA, both labile concentration of Cu and mortality were reduced. By excluding Cu-carbonate complexes from the labile concentration, a bioavailable concentration of Cu ([Cu*]) was obtained and was used to predict the acute toxicity of Cu on D. magna. For natural waters, the labile concentration of Cu was measured by DAM-DPASV, and [Cu*] was calculated using MINTEQ A2 software (developed by the U.S. Environmental Protection Agency) based on the anion composition of waters. This procedure was tested for waters and sediment elutriates sampled from the Le An River (Jiangxi Province, China) that were severely polluted by the discharges from a copper mine. The results showed that [Cu*] was a good indicator for Cu toxicity and could be used under field conditions.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Haidian District, Beijing, China. wangzj@mail.rcees.ac.cn
Zujian
Z
Wang
Shengbiao
S
Huang
Qing
Q
Liu
D000818:Animals; D001578:Benzopyrans / Q000737:chemistry; D001682:Biological Availability; D002614:Chelating Agents / Q000737:chemistry; D003300:Copper / Q000737:chemistry* / Q000633:toxicity*; D003621:Daphnia; D004492:Edetic Acid / Q000737:chemistry; D004784:Environmental Monitoring; D005544:Forecasting; D006863:Hydrogen-Ion Concentration; D008906:Mining; D014873:Water Pollutants / Q000633:toxicity*
D001578:Benzopyrans; D002614:Chelating Agents; D014873:Water Pollutants; D003300:Copper; D004492:Edetic Acid; C005023:fulvic acid