Batch nickel removal from aqueous solution by sphagnum moss peat

The batch adsorption of Ni(II) onto sphagnum moss peat has been studied. The reaction was pH dependent, the optimum range being 4.0–7.0. Langmuir and Freundlich isotherms, established for various initial nickel concentrations and for a range of pH values, were used to obtain a single relationship between initial metal concentration, metal removal, and initial pH. The latter was found to control efficiency of nickel removal. Kinetic data suggested involvement of a chemical rate-limiting step, and a predictive relationship was derived relating nickel removal to peat dose. In comparison with other metals, nickel removal is poor, and possible reasons are discussed.