Removal of Nickel by Natural and Magnetically Modified Bentonite

Abstract

Bentonite with its unique structural properties is a valuable material for environmental application. Its sorption properties are usually improved by different ways of modification. In this work, the modification by iron oxide particles was used with the aim to prepare a magnetic sorbent with enhanced sorption properties. The removal of nickel from aqueous solutions by the natural and magnetically modified bentonite was studied in batch adsorption-equilibrium experiments. The initial concentration of nickel in model solution was in the range 5–1,000 mg/L. Sorption experiments were carried out at pH 5.5, the sorbent concentration of 2 g/L and at the ambient temperature (25°C). The quantity of element in model solution was determined after the equilibrium time of 24 h by the atomic absorption spectroscopy (AAS). The experimental data were fitted with Langmuir, Freundlich and Redlich–Peterson isotherms. The sorption capacities of the natural and modified bentonite were compared.