The objective of this study was to investigate the adsorption kinetics of As (III) on iron Hydroxide (III). The physicochemical parameters considered during our experiments are iron Hydroxide (III) weight, pH and contact time. Three kinetic models of sorption were investigated: pseudo-first-order model, pseudo-second-order model and the intra-particle diffusion model. The results show that these adsorption regimes are based on the equilibrium concentration of arsenic. We observed that the adsorption based on the metal retention capacity In the presence of interactions between the arsenic and different groups of the matrices. Pseudo-first-order model is relatively fast, so the arsenic (III) was adsorbed as a monodentate complex. However, the slower pseudo-second-order model indicates that the arsenic forms a bidentate complex with the hydroxide iron (III).
