Use of natural products as biosorbent of heavy metals ó An overview

Industrial effluents loaded with heavy metals are a cause of hazards to human and other forms of life. Conventional methods such as precipitation, evaporation, electroplating, ion exchange, membrane processes, etc. used for removal of heavy metals from waste water however, are often cost prohibitive having inadequate efficiencies at low metal ion concentrations. Biosorption can be considered as an alternative technology which has been proved as more efficient and economical for removal of heavy metals from the industrial waste water. The most frequently used biosorbents are bacteria, fungi, algae and yeasts. But more recently, low cost natural products have also been searched as biosorbent. This paper presents an overview of the potential use of some natural products as biosorbent which could serve as a cost effective means of treating effluents charged with toxic heavy metals.