Adsorption Studies of Phenol Using Thermally and Chemically Modified Rice Husk as Adsorbents

Most of the Phenols are hazardous substances and some are supposed to have carcinogenic activity. Thus it is necessary to remove Phenolics and other aromatics from the aqueous ecosystem. Traditional processes for the removal of Phenolics compounds are extraction, adsorption on granulated activated carbon, steam distillation, chemical and bacterial techniques. Literature survey show a number of methods like oxidation, ion exchange, reverse osmosis, electrochemical oxidation and adsorption. Phenol removal by process like, adsorption is the best method of choice as it can remove most of phenols in simple and easy way. In recent past; agricultural by-products such as, maize cob, date stone, apricot Stones, rice bran, and bagass pith have been extensively studied and used as adsorbents for the adsorption of hazardous substances from wastewater. In the present study we tried modified rice husks as potential adsorbents for the removal of Phenol from aqueous system. Batch mode studies were carried out. Isotherm data was generated and fitted in Freundlich and Langmuir equation to explain the phenomenon of adsorption. The adsorption capacities based on Langmuir model (Qm) of the 3 adsorbents were found to be 0.81 for raw husk (RH), 0.395 for the Grafted (G) and 2.306 mg/g for the Charred (C). The R² values were 0.92 for raw husk, 0.97 for grafted and 0.91 for charred husk. Based on Freundlich model the adsorption capacities (K) were 2.94, 2.29 and 1.25mg/g for Raw husk, grafted husk and charred husk. The R² values were found to be 0.72, 0.95 and 0.83 for the raw husk, grafted husk and charred husk respectively. Our result showed that modified rice husks could be used as potential adsorbents for Phenol removal from aqueous system.