Optimization and application of zeolite derived from corncob for 2-chlorophenol removal from wastewater

Abstract

Four important factors (particle size, reagent ratio, contact duration, and temperature) were used in this study to optimize zeolite made from low-cost agricultural waste corncob. Alkali fusion techniques using full factorial design were used to accomplish this optimization. The optimized zeolite underwent comprehensive characterization using instrumental techniques including PXRD, FT-IR, and SEM. Four process variables were then used to enhance the optimized zeolite's ability to adsorb 2-chlorophenol in an aqueous matrix: pH (6–8), contact time (90–150 minutes), sorbent dosage (1–4 g), and temperature (30–60°C) using a full factorial design. Optimal adsorption of 82.85 mg/g removal of 2-chlorophenol was achieved at pH 8, temperature 60°C, contact time 90 minutes, and absorbent dosage of 1 g. Further analysis on this optimized alkali fusion material indicated that isotherm and kinetic data were effectively described by the Freundlich model and pseudo-second-order model, respectively. Thermodynamic analysis further indicated the endothermic nature of the adsorption process, with a positive energy of adsorption (∆H = 26.61 kJ/mol). Additionally, the optimized zeolite exhibited stability after three regenerative cycles using 0.5 M NaOH solution. These results reveal the potentiality of the optimized zeolite derived from corncob as an effective adsorbent for the removal of 2-chlorophenol in water.