A study of Cr(VI) and NH⁴⁺adsorption using greensand (glauconite) as a low‐cost adsorbent from aqueous solutions

Abstract

Abstract This paper investigates the removal of Cr(VI) and NH 4+ from aqueous solutions using greensand (glauconite). The effects of adsorbent dosage, contact time, initial Cr(VI) and NH 4+ concentrations, and pH were investigated in batch experiments. The results show that these parameters influenced Cr(VI) and NH 4+ removal using glauconite considerably. Pseudo‐first‐order, pseudo‐second‐order and intraparticle diffusion kinetic models were applied to explain the kinetic data, and the pseudo‐second‐order model achieved good agreement. The equilibrium isotherm data are coordinated with the Freundlich, Langmuir models, Temkin and Dubinin–Radushkevich; the Freundlich model proved most best suitable. The removal efficiency of Cr(VI) and NH 4 + were 12.21 mg/g (54% at pH 3) and 19.24 mg/g (77.08% at pH 7). All in all, the results showed that the adsorption process on glauconite could be used as an effective method for removing Cr(VI) and NH 4+ from aqueous solutions.