ADSORPTIVE REMOVAL OF 4-NITROPHENOL AND 2,4-DINITROPHENOL FROM AQUEOUS SOLUTION USING COMMERCIAL ACTIVATED CARBON

Abstract

Batch operation studies were carried out for the removal of hazardous and toxic chemical compounds 4-Nitrophenol and 2,4-Dinitrophenol from aqueous solutions. For both adsorhACes, predictive capability of three types of kinetic models and five types of adsorption uilibrium isotherms were investigated. Optimum adsorption conditions were determined with respect to contact time, pH, adsorbent dose, and adsorbate initial concentrations for both 4-Nitrophenol and 2,4-Dinitrophenol. The adsorption of both the adsorbates was found to be following pseudo-second order kinetic model with rate constants 0.0026 g mg-' min' and 0.00045 g mg-' min-', respectively. Among the five adsorption isotherm models examined, on the basis of calculation of various Statistical indices for 4-Nitrophenol and 2,4-Dinitrophenol it is justified that Koble-Corrigan and Sips adsorption isotherm models are best fitting model, respectively. Under optimum conditions, maximum removal efficiencies of 4-Nitrophenol and 2,4-Dinitrophenol were found to be 99 % and 99.4 % respectively. On the basis of the experimental results it was established that the AC was more compatible in the removal of both adsorbates at similar operating conditions. The study concluded that AC is an excellent and effective adsorbent for the removal of 4-Nitrophenol and 2,4-Dinitrophenol from industrial waste water because of its high efficiency and ease of availability.