Removal of Phenol from Water by Carbon Adsorbents Prepared by Pyrolysis of Sorghum and Millet Straws in Ortho Phosphoric Acid

The aim of this study is to determine the suitability of sorghum and millet straws as precursors for carbon adsorbents with capabilities for removing phenol from contaminated water. Phenol compounds react with chlorine in water to produce chlorophenols which have very low threshold odour concentrations in domestic water supply. Activated carbon adsorbents were prepared from millet and sorghum straws by chemical activation with phosphoric acid and used for the removal of aqueous phenol. The abilities of the carbon adsorbents to remove phenol from contaminated water were determined by aqueous phase phenol adsorption. Equilibrium concentrations of phenol were monitored, using Cole UV7504 Spectrophotometer at a wavelength of 269 nm. The adsorption data fitted the Freundlich isotherm and indicated multilayer adsorption of aqueous phenol on the carbon beds. The maximum adsorption capacities of the granular activated carbon from the cellulosic precursors were 80.36 and 82.34 mg/g of carbon from millet and sorghum straws respectively. The results suggest the suitability of the carbon adsorbents in community water detoxification protocols to remove phenol.