Adsorption of phenol and p-chlorophenol from aqueous solutions on the template-synthesized mesoporous carbon

摘要

The template-synthesized mesoporous carbon (TSMC) was prepared by nano-casting approach using KIT-6 as the template, sucrose as the carbon precursor, subsequently carbonized at the temperature of 900 degrees C and then removal of the template. Phenol and p-chlorophenol were selected as the objectives to research the adsorption ability of the TSMC towards phenols. The effects of adsorbent dosage, pH, contact time, initial concentration and temperature were investigated using a batch technique. The results showed that the TSMC had significant adsorption capacity on phenol (21.13 mg/g) and p-chlorophenol (44.111 mg/g) under the optimum conditions: the dosage of 0.2 g and 0.1 g for phenol and p-cholorophenol, the initial pH 6.80 and 6.70 for phenol and p-chlorophenol, respectively, the equilibrium time of 120 min, the solution concentration of 100 mg/L and the adsorption temperature of 30 degrees C. The adsorption kinetic studies demonstrated that the adsorption of phenols followed pseudo-second-order kinetic model. The best-fitted adsorption isotherm model was well fit using the Langmuir isotherm model. Besides, the thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The pi-pi interaction, the hydrophobic interaction, the molecular dimensions, H-bonding and Electrostatic interaction were the possible mechanisms for phenols removal.