The present work involves an investigation of the possible use of rice husk ash (RHA) for phenol removal from aqueous solutions. The study was realized using batch experiments. The surface area of RH increased from 7.1 up to 87.1 m2 g-1 after heat treatment. During the experimental part of this study, the effect of system variables such as burning temperature (300oC), burning time (1-4 hrs), pH (2-10) and initial phenol concentration (10-1000 mg l-1) on phenol removal were investigated. In addition, adsorption kinetics and adsorption isotherm studies were also carried out. The results show that RHA300(1h) has less removal efficiency compared to RHA300(4hrs). The investigation of pH effects indicates that maximum phenol removal can be obtained at pH 4 using RHA300 (4 hrs). It was found that, the sorption capacity increased from 0.96 mg g-1 to 45.2 mg g-1 by increasing the initial phenol concentration from 10 mg l-1 to 1000 mgl-1 using RHA300(4hrs). The adsorption isotherm is best fitted by the Freundlich model, while the adsorption kinetics is well described by the pseudo-second order and Elovich models. FTIR analysis shows that the –OH, C=C, C=O, Si-O-Si, Si-OH and –Si-H groups contribute to the adsorption of phenol onto the surface of adsorbent.
Phenol removal; Adsorption; Rice Husk; Sorption kinetics; Isotherm; Wastewater Treatment.