The ability of rice (Oryza sativa) and pigeon pea (Cajanus cajan) husk to remove zinc and cadmium from aqueous solution
has been investigated. Several parameters that can affect metals uptake such as pH and metal concentration were
described. It has been found that the percentage of adsorption for both cadmium and zinc decrease with the increase in
metal ions concentration and increase with the increase in pH (in acidic range). Characterization of pigeon pea and rice
husks has revealed that it is excellent material for treating wastewaters containing low concentration of metal ions.