Adsorption of p-nitrophenol from aqueous solutions by Zr4+ activated carbon: Adsorption isotherm studies

Abstract

The dynamic adsorptive separation of p-nitrophenol from aqueous solution by newly modified coconut shell based granular activated carbon impregnated with Zr⁴⁺ has been studied. The adsorption behaviour is described by isotherm models of Langmuir, Freundlich and Dubinin-Radushkevich equations. The isotherm parameter shows loading of activated carbon with zirconium ions during stages of activation significantly improve the adsorption potential of activated carbon towards p-nitrophenol. Pore structure characteristics of the newly prepared granular activated carbon GACZR 1273 and GACOZR 1273 have been determined by nitrogen (N₂) gas adsorption isotherms data at 77K. Study shows each carbon has its own specific characteristics such as porosity, pore structure and surface area compared to their respective starting carbon GAC and GACO. The surface characteristics of carbon are directly related to the adsorptive removal of p-nitrophenol from aqueous solution under dynamic and equilibrium condition.