isotherms and mass transfer modeling of the adsorption of copper ions onto iron-activated carbon composite

This study utilized a composite of iron-activated carbon derived from waste date. the adsorbent, made by mixing iron sulfate in a specific way, was examined using x-ray diffraction (xrd) and scanning electron microscopy (sem). we used it to eliminate copper ions cu(ii) in pre-prepared solutions of copper sulfate. the equilibrium data were found to be better described by the freundlich model with r2>0.99, and the energy of mean adsorption was e=3.53 kj/mol adsorption kinetics were successfully fitted with a pseudo-second-order model. results indicated that the film and pore diffusion coefficients ranged within a specific value10-10 cm2/s, suggesting that pore diffusion is the rate-limiting step. this study highlights the importance of both external mass transfer and intra-particle diffusion in the adsorption of copper.