ABSTRACT

Hexavalent chromium, Cr(VI), is widely used in many industrial processes such as electroplating, wood preservation, etc. The chromium manufacturing industry produces a large quantity of solid and liquid waste containing hexavalent chromium. Cr(VI) compounds are highly water soluble, toxic and carcinogenic in mammals (Jeyasingh and Philip 2005). Cr(VI) as chromate and dichromate is considered one of the principal pollutants in the United States by the Environment Protection Agency (Polti et al. 2009). In contrast, trivalent chromium, Cr(III), is considered nontoxic as it precipitates at higher pH than 5.5 with the formation of insoluble oxides and hydroxides in soil and water systems (Jeyasingh and Philip 2005).