Removal of Hexavalent Chromium from Dilute Aqueous Solution by Coniferous Leaves

Abstract

Summary The ability of coniferous leaves to remove Cr(VI) from dilute aqueous solutions by physico-chemical adsorption and chemical reduction was investigated. Of 30 coniferous tree species tested, relatively high removal ability was found in Ginkgo , Larix , Pinus , Cryptomeria , Metasequoia , Taxodium , Thuja and Thujopsis spp. To search for optimum operation condition for treatment of wastewater containing Cr(VI), factors affecting Cr(VI) removal were studied using P. densiflora leaves. The extent of the removal was dependent upon the initial solution pH, contact time, temperature and initial concentration of Cr(VI) in solution. The Cr(VI) removal was mainly governed by the physico-chemical adsorption onto the substrate. The adsorption data were well fitted to the Freundlich isotherm.