Abstract

Water is a universal solvent that sustains life and there is an abundance on our planet. However, surface water has become increasingly polluted over the years due to anthropogenic activities. This has increased the cost of purifying surface water for domestic uses. Metal contaminants in surface water must be below the international accepted threshold limit, otherwise the water will not be safe to use for agriculture purposes and after purification, domestic purposes. Water purification can be achieved via synthetic and recently the use of natural selective adsorbents. There is a continual search for natural adsorbents because of its environmental safety, lost-cost preparation, compared to synthetic analogues. The natural adsorbents selected must also be sustainable, since life depends on a continuous supply of clean water. This paper survey research work done on selected adsorbents, with a view to its practical use worldwide. Amongst the adsorbents reviewed are grounded peanut shells, sugar cane residue (bagasse), activated carbon, rice husk, jack fruit leaf powder, coconut fibres, coconut shell, monkey thorn tree (Acacia galpinii), infused tea leves and even microorganism such as Agaricus macrospores.

Keywords:Surface water; Metal contaminants; Agriculture purposes; Selective adsorbents; Activated carbon; Rice husk; Coconut fibres; Infused tea leaves