High performance removal of phenol from aqueous solution by magnetic chitosan based on response surface methodology and genetic algorithm

Abstract

The magnetic chitosan was prepared and characterized using FT-IR, SEM, and XRD techniques. The adsorbent was used for uptake of phenol in water. The sorption was modeled based on central composite design (CCD) - response surface methodology (RSM) method for independent variables pH, time, adsorbent dosage and phenol concentration; suggesting a quadratic polynomial model with p-value < 0.001, R2 = 0.9983 and adjusted R2 = 0.9963. The optimization of input factors was conducted using both CCD-RSM and Algorithm Genetic (GA). The obtained results were the same, where the optimum level of pH, time, adsorbent dosage, and phenol concentration for CCD-RSM technique were 3, 50 min, 0.96 g/L and 15 mg/L, and for GA technique were 3, 50 min, 1 g/L and 15 mg/L. In this condition, maximum removal was 97% for both CCD-RSM and GA. The isotherm and kinetic studies of adsorption process illustrated that adsorption of phenol onto magnetic chitosan corresponded Freundlich isotherm and Intraparticle diffusion kinetic models. The maximum adsorption capacity was approximately 51.68 mg∙g−1. Thermodynamic studies identified exothermic nature of adsorption. It was concluded that magnetic chitosan is a potential and promising adsorbent in adsorption process of phenolic pollutants and similar compounds from aquatic environments.