Efficient phenol removal from aqueous solution using iron-coated pumice and leca as an available adsorbents: evalution of kinetics and isotherm studies

Abstract

Searching for low cost, accessible, simple implementation, and environmentally friendly adsorbents has been one of the concern of researchers in recent years. Therefore, the aim of this study was to investigate the efficient phenol removal from a synthetic aqueous solution using iron-coated pumice and LECA as an available adsorbents. Bath adsorption experiments were carried out to evaluate the effects of the independent variables such as pH (3-5-7-9-11), initial concentration of phenol (10-50mg/L), contact time (10-60 min) and different concentrations of pumice and LECA (0.2-1 g/100 cc) on the phenol adsorption. The results of the experiments showed that there was a direct relationship between the phenol removal efficiency and increasing the contact time and the adsorbent dosage but it has reverse relationship with the increasing of pH and phenol initial concentration. The optimal condition of parameters for phenol removal were 200 rpm agitation speed, 0.6 g adsorbent dosage, 30 min contact time, and 20 mg/L initial phenol concentration. The study of isotherm and kinetic models showed that the experimental data of the phenol adsorption process were correlated with Freundlich (R2pumice=0.9749, R2LECA=0.9487) and Pseudo-second order (R2pumice=0.9745, R2LECA=0.9486) models. Based on this study’s results, the modified pumice and LECA have a high ability to remove the phenol compounds from aqueous solution.