Speciation of dissolved copper in human impacted freshwater and saltwater lakes

Abstract

China's natural waters are experiencing an increasingly anthropogenic perturbation widely including acidification and hypoxia, and toxic metals including copper (Cu) are subject to a series of reactions including chemical speciation and transformation. However, there is still little information available regarding such alterations of metal behaviors in China's natural waters. By using solid phase extraction technique, this study for the first time measured total dissolved Cu, and different Cu species: toxic labile Cu (referred to those free cupric ions and some weakly organic compounds adsorbed onto Chelex-100 resins), the organic refractory Cu (referred to those adsorbed onto C18 resins after passing through Chelex-100 resins), and residual Cu (obtained by subtracting labile and organic refractory fractions from the total) in a freshwater lake (the Lover) and a saltwater lagoon (the Yundang) in Xiamen, China. Our results demonstrated that both waters were characterized with relatively low levels of total dissolved Cu (5-10 nM), as a result of a net removal process dominated by particle adsorption and precipitation. Relatively high proportion of organic refractory Cu (as high as 50 %) was observed in the saltwater Yundang lagoon as a result of organic matter production and/or discharges followed by complexation nearby. On the other hand, the toxic labile Cu accounted for >40 % of the total dissolved Cu pool in these waters, and particularly the increased proportion of toxic labile Cu (as high as 70 %) occurred in the bottom sulfidic Lover Lake. Our study provides clear evidence that toxic labile Cu could be transformed under reducing environments such as deep sulfidic waters of the Lover Lake (Xiamen, China), and the releases of toxic labile metals are increasingly threatening nearby aquatic ecosystems.

Copper Inhibition of Triplet-Sensitized Phototransformation of Phenolic and Amine Contaminants

“…Copper, a ubiquitous transition metal in natural waters, is an essential element participating in many geochemical and physicochemical processes of environmental aquatic systems. − Copper is typically found in nanomolar concentrations in freshwaters (1.6–320 nM) − and estuarine and marine waters (3.9–160 nM) . Our results show that nanomolar concentrations of Cu are capable of inhibiting the triplet-sensitized phototransformation of a broad range of phenolic and amine contaminants in a weakly acidic solution in the presence of both a model photosensitizer, CBBP, and SRNOM, a natural photosensitizer.…”

Square Wave‐Anodic Stripping Voltammetric Determination of Copper at a Bismuth Film/Glassy Carbon Electrode Using 3‐[(2‐Mercapto‐Vinyl)‐Hydrazono]‐ 1,3‐Dihydro‐Indol‐2‐One

“…This intake leads to bioaccumulation in liver cells, damage in kidney and brain tissues, neurological disturbances, myocardium, hemolytic crisis, jaundice, Menke's syndrome and Wilson's disease . Evidence for conversion of toxic copper under reducing environments by releasing toxic labile metal ions and sulfidic waters have been reported . Thus, developing of highly sensitive and economical methods for trace determination of copper in complex matrices are desired .…”

“…Evidence for conversion of toxic copper under reducing environments by releasing toxic labile metal ions and sulfidic waters have been reported . Thus, developing of highly sensitive and economical methods for trace determination of copper in complex matrices are desired .…”