Adsorption of Cr(VI) using α-Fe2O3 coated hydroxy magnesium silicate (HMS): isotherm, thermodynamic and kinetic study

α-Fe2O3 coated hydroxy magnesium silicate (HMS) was prepared by the coprecipitation method and was used for the sorption of Cr(VI) from the aquatic environment. FT-IR, XRD, and SEM characterised the investigated composite. The influence of pH, shaking time, Cr(VI) concentration, and the temperature was investigated. The results obtained are fitted well with the pseudo-second-order kinetic model. Besides, Freundlich isotherm is adequate than the Langmuir isotherm. The adsorption was observed to be exothermic, spontaneous, and accompanied by increasing the system’s ran- domness. The adsorption of chromium attained equilibrium after 60.0 min. The maximum adsorption capacities of α-Fe2O3/HMS composite for Cr(VI) were 10.75 mg/g obtained at a pH of 2.