Cadmium (Cd) removal from aqueous solution using microwave incinerated rice husk ash (MIRHA)

Presence of heavy metals in aquatic systems has become a serious problem. Heavy metals can have adverse effects on environment as well as human health. As a result, much attention has been given to new technologies for removal of heavy metal ions from contaminated waters. This study uses Microwave Incinerated Rice Husk Ash (MIRHA), a locally available agricultural waste, for the removal of Cd (as a representative heavy metal) from synthetic wastewater by batch adsorption process. Influence of pH, initial metal concentration and contact time on Cd removal efficiency was studied. pH 4 was found to be optimum. The removal efficiency correlated with the initial metal concentration and contact time between adsorbent and adsorbate. Cd adsorption kinetics followed the pseudo-second-order model and implied chemisorption. Adsorption equilibrium of Cd can be well described by the Freunclich isotherm model.