Strategies for Chromium Bioremediation of Tannery Effluent

Pollution of the environment by toxic metals results largely from industrial activities, although sources such as agriculture and sewage disposal also contribute to some extent (Nriagu and Pacyna 1989). Toxic metallic species, once mobilized into the environment, tend to persist, circulate, and eventually accumulate at different trophic levels in members of the food chain. Ultimately, metal pollutants pose a serious threat to the environment, and affect plants, animals, and humans (Olson and Foster 1956; Reidske 1956; Sauter et al. 1976; Levis and Bianchi 1982; Mance 1987; Xing and Okrent 1993). Metal pollutants eventually affect ecosystem function, and impose an economic and public health burden. The problems associated with wastewater disposal in developing countries can generally be attributed to lack of adequate treatment/management policies, coupled with ineffective legislation on the part of entrusted governmental agencies (The Environmental Protection Act 1991; Oboh and Aluyor 2008). Environmental awareness has grown among consumers and industrialists in recent decades, and more recently has culminated in legal constraints being imposed on emissions; such constraints have increasingly become more strict necessitating cost-effective emission control (Gadd and White 1993).