Batch Studies of Adsorption of Phenol from Aqueous Solutions Using Rice Husk Ash

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. During the experimental part of this study, the effect of system variables such as burning temperature ( 400oC and 600oC), burning time (1-4hrs), adsorbent dosage (1, 5 and 10 gl-1), pH(2-10) , temperature (23oC and 40oC), and initial phenol concentration(10-1000mgl-1) on phenol removal were investigated. In addition, adsorption kinetics and adsorption isotherm studies were also carried out. The results show that RHA600 has less removal efficiency compared to RHA400 at 1,2,3 and 4hrs burning times. The investigation of pH effects indicates that maximum phenol removal can be obtained at pH 4 using RHA400, 1h. It was found that, the sorption capacity increased from 0.97 mg g-1 to 46.19 mg g-1 by increasing the initial phenol concentration from 10 mgl-1 to 1000 mgl-1 using RHA400, 1h; while a slight decrease on phenol adsorption capacity was observed as the temperature was increased from 23oC to 40oC. The adsorption isotherms are best fitted by the Freundlich model, while the adsorption kinetics is well described by Elovich model.