Adsorptive removal of chlorobenzene from wastewater using synthesized zeolite X: Equilibrium, kinetics and thermodynamics

The coal fly ash (CFA), obtained from Ontario Power Generation (OPG), was used to synthesize zeolite X (SZX). Zeolite SZX was used as adsorbent to remove the mono chlorobenzene from a simulated wastewater stream. Zeolite SZX was analyzed using XRD, FTIR, SEM, BET and XRF. To investigate the adsorption performance of chlorobenzene onto SZX zeolite by batch adsorption experiments, a series of tests were performed at different parameters, i. e., the temperature (298-318 K), contact time (0-5) hrs and initial concentration of chlorobenzene (100-300 mgL(-1)). In addition, the effect of adsorbent dose (0.03-0.20 g . L-1) was investigated. A maximum of 97.2% removal of chlorobenzene was obtained under these conditions. Langmuir and Freundlich models were applied to evaluate the equilibrium isotherms for the adsorption process. The collected data from the adsorption tests were well fitted to both Langmuir and Freundlich isotherms. The adsorption kinetics data were well defined by a pseudo-second-order kinetic model, R-2 value between (0.9889-0.9982). Thermodynamic analysis proved that this adsorption process was an endothermic (Delta H-0 was found as 31.6463 kJ/mol) and spontaneous process under these specified conditions. All in all, the results presented in this paper implied that the SZX zeolite is a promising adsorbent for elimination of chlorobenzene from wastewater.