Kinetics and thermodynamics of fluoride removal using cerium-impregnated chitosan

Abstract

The kinetics and thermodynamics of fluoride adsorption on cerium-impregnated chitosan (CIC) have been studied by the sets of experiments at various conditions (initial fluoride concentration, adsorption time and temperature). The characteristic of the adsorbent before and after fluoride adsorption was examined using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and energy dispersive spectrum (EDS) techniques. Adsorption of fluoride was strongly affected by pH. Pseudo-second order kinetic model best described the reaction rate, and the adsorption capacity calculated by using model equation, was consistent with the actual measurement. Isotherms for the adsorption of fluoride on CIC were developed and the equilibrium data fitted well to the Freundlich, Langmuir, Temkin and Dubinin-Radushkevich (D-R) isotherm. The adsorption isotherms were compared for six different error functions i.e., the sum of the squares of errors (SSE), sum of the absolute errors (SAE), the average ...