Potential of Rice Husk and Rice Husk Ash for Phenol Removal in Aqueous Systems

The potential of rice husk and rice husk ash for phenol adsorption from aqueous solution was studied. Batch kinetics and isotherm studies were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dose and pH. Adsorption equilibrium of rice husk and rice husk ash was reached within 6 hours for phenolic concentration 150-500 μg/L and 3 hours for phenol concentration 500-1300 μg/L, respectively. Kinetics of adsorption obeyed a first-order rate equation. The adsorption of phenol increases with increasing the solution pH value. The suitability of the Freundlich and Langmuir adsorption models of the equilibrium data was investigated for each phenol-sorbent system. The results showed that the equilibrium data for all the phenol-sorbent systems fitted the Freundlich model best within the concentration range studied. A comparative study showed that rice husk ash is very effective than rice husk for phenol removal. The studies showed that the rice husk ash can be used as an efficient adsorbent material for removal of phenolic from water and wastewater.