Abstract

Water hyacinth (Eichhornia crassipes), has attracted significant attention as the world’s worst invasive aquatic plant due to its extremely rapid proliferation and congest growth, presenting serious challenges in navigation, irrigation, and power generation. Attempts to control the weed have proved to be costly with minimum results. However, the same plant has demonstrated an amazing ability to absorb and concentrate many toxic metals from aquatic environments. Consequently, research activity on utilization of the plant has been registered over the last few decades. This article reviews literature related to the utilization of E. crassipes in the biosorption and recovery of metals from aquatic environments. Availability in large quantities, high biosorption capacity, renewability and low cost determine the extent to which biosorbents can be adapted technologically. Sorption dynamics through classical and competitive models, effect of physical and chemical treatment, pH, temperature, initial metal concentration and biosorbent dose on metal removal by water hyacinth is discussed.        

Key words: Biosorption, heavy metals, precious metals, recovery, water hyacinth