Adsorption of Phenol by Activated Carbon Prepared from Waste Rice Straw by Chemical Activation with ( NH4 )2 HPO4.

Activated carbons, RS-1, RS-2, and RS-3, prepared from rice straw with ( NH₄ )₂ HPO₄ activation were used as adsorbents for removing phenols from aqueous solutions. The maximum adsorption capacities of phenol for RS-1, RS-2, and RS-3 were 163.9, 172.9, and 200.0 mg/g, respectively. The equilibrium data were analyzed by the Langmuir, Freundlich, and Temkin models. It displayed that Langmuir isotherm fitted to the results best. The dimensionless parameter R_L indicated the favorable nature of the adsorption of phenol. Otherwise, the kinetic rates were well explained by pseudo-second-order model. According to the results, activated carbon derived from waste rice straw can be a high-performance adsorbent for wastewater treatment. [ABSTRACT FROM AUTHOR]