ABSTRACT
The world in this century is witnessing industrialization along with urbanization at an ever-increasing rate. This has resulted in the generation of large amounts of aqueous effluents with high levels of toxic pollutants, such as heavy metals and ionic dyes. Research on the use of biosorbents started in the late 1980s, and throughout the 1990s, major research in this field gained momentum (Wase and Wase, 2002). The use of biosorbents is an emerging field of research in environmental or bioresource technology processes. The uses of bioadsorbents have major advantages over the conventional processes that include high efficiency, low cost, minimal use of biological or chemical sludges, possibility of metal recovery after absorption, and regeneration of the bioadsorbent. A wide variety of microbial biomasses, both living and dead, have been investigated for biosorption properties. The microorganisms or the virgin biosorbents used usually lack specificity in metal binding that may cause difficulties in metal recovery and recycling. Genetic modification does provide a solution to this problem and results in enhanced properties in the biosorbents. These biosorption studies have been characterized through a variety of models.
