विटामिन और खनिज

Trivalent Chromium: A Neglected Latent Contaminant

Abstract

Zhaohui Wang, Renlan Liu and Jianshe Liu

As the 21st most abundant element in earth’s crust, chromium has been extensively used in industrial activities such as paint pigments and leather tanning. As a consequence, there is a continual influx of chromium contaminants into the environment, thereby posing a serious environmental problem. Chromium exhibits a wide range of possible oxidation states, where trivalent chromium [Cr (III)] is most stable energetically, but Cr (III) and Cr (VI) are most commonly observed in aquatic environment. Cr (VI) species are of great environment concern due to their well-known toxicity, carcinogentic properties and high mobility in environmentally relevant media. Cr (III) is generally regarded as benign and even essential for human and animal, since trace amounts of Cr (III) is required for sugar and lipid metabolism.In this context, it is a common strategy in environmental remediation to reduce toxic Cr (VI) to Cr (III) by various redox reactions. Cr (III) is thought to be immobilized by precipitating into insoluble Cr (III) hydroxides