Improvement in phenol adsorption capacity on eco-friendly biosorbent derived from waste Palm-oil shells using optimized parametric modelling of isotherms and kinetics by differential evolution

Abstract

Phenolic pollution is very common, and toxic and water-soluble compounds and their derivatives can have significant harmful effects on humans, aquatic life, and the environment. The adsorption method is the most efficient way of handling, but the high cost of biosorbents obstructs the feasibility of this approach. In this study, biomass waste derived from Palm-oil shells is synthesized as an eco-friendly biosorbent for phenol adsorption. A novel inverse modelling method based on differential evolution optimization (DEO) is used to estimate the isotherm and kinetic model parameters, which facilitates to identify the inherent mechanisms in the adsorption process for removing phenol from wastewater. The DEO based model parameters provides an accurate prediction that is very close to experimental data, thus resulting in higher regression coefficient, R2, and relatively low Pearson’s Chi-square, χ2& root mean square error (RMSE). Phenol adsorption found to be following Langmuir isotherm (R2 = 0.995; χ2 = 0.429; RMSE = 4.420) and Pseudo 2nd order kinetic model (R2 = 0.992; χ2 = 0.346; RMSE = 15.58). With a biosorbent size of 0.85 mm resulted in phenol removal efficiency of 98 %. For large scale industrial process, a design methodology is developed to estimate the amount of biosorbent (Palm-oil shell-based GAC) required to meet the desired phenol removal concentration.