Bioremediation of Bauxite Residue (RED MUD) Using Microbes

Abstract

To meet the ever-growing demand of materials, the natural resources are being exploited to the fullest extent. As a result of which there is depletion of these valuable resources as well as accumulation of different types of wastes. Red mud is one such waste produced during alumina extraction from bauxite ore with concentrated NaOH at elevated temperature in the Bayer’s process, depending on raw material composition, red mud composition varies (Das et al., 1995). Aluminium is the most abundantly available metal and the third most plentiful element (8%). In the earth’s crust, next only to oxygen and silicon. It is light as metal, tough as an alloy, has good thermal and electrical conductivity, easy to fabricate, non magnetic in nature, has excellent resistance to many chemicals and is non toxic. Because of these outstanding properties aluminium and number of aluminium based alloys are finding growing application in various fields of consumer goods. The utility of the metal is enhanced by its tendency to form a stable adherent oxide that resists corrosion. The only economic ore of aluminium is bauxite, Al2O3.xH2O, which is always associated with silica, iron oxide, titanium dioxide and few other minor and trace impurities (Thakur et al., 1994)Bayer, a German scientist, in the year 1880 developed a method for producing alumina from bauxite by treating it with caustic soda (Fathi Habashi, 1995).