Pea (Pisum sativum L.) peel waste carbon loaded with zirconium: study of kinetics, thermodynamics and mechanism of fluoride adsorption

Pea peel waste carbon loaded with zirconium is used as an engineered biochar material for adsorption of fluoride from aqueous solution. The prepared adsorbent was characterized and the material degradation kinetics were studied using thermogravimetric analysis. Adsorption kinetics follow both pseudo-second order and intra-particle diffusion model. Optimization of algorithm yielded Freundlich isotherm as the best fitting equation. Increment in solution temperature thermodynamically favors fluoride adsorption. Fluoride adsorption remains unaffected in presence of specific co-ions. Adsorbed fluoride could be successfully leached using 0.001 N NaOH and reusability of the material was tested up to tenth cycle of continuous operation.