REMOVAL OF NICKEL (II) IONS FROM WASTE WATER USING LOW COST ADSORBENTS: A REVIEW

Due to rapid industrialization and urbanization in developing countries has increased the toxin levels in industrial effluent which rise the importance of water and waste water treatment. Very small concentrations of metallic ions present in water increase the health risks to human and animals. Though there are many treatment methods used for removal of heavy metals from waste water like chemical precipitation, membrane filtration, ion exchange, coagulation, flocculation, electrochemical treatment, adsorption and co-precipitation. Yet various researchers have studied that adsorption is a highly effective and economical technique for the removal of heavy metals from waste water and from ancient times activated carbon has extensively used as an adsorbent but it found to be an expensive material which triggered the need for synthesizing low cost adsorbents from Agro and horticultural wastes and by products such as coconut husk, tamarind fruit shell, saw dust, oil palm shell, cow bone charcoal and bagasse fly ash(sugar industry waste) etc., for the nickel removal from waste water. These Agro and horticultural wastes would have been the sources to pollute our environment. The removal of nickel ions from waste water using low cost adsorbents and utilization of Agro and horticultural wastes and by products to avoid environment pollution is discussed in this paper.