title: Application of zeolitic material synthesized from thermally treated sediment to the removal of trivalent chromium from wastewater.
abstract: Zeolitic materials were synthesized from thermally treated sediment by alkali treatment using different NaOH/sediment ratios. Characterization of the materials was done by XRD, FTIR, cation exchange capacity and specific surface area. Use of high NaOH/sediment ratio favored the formation of zeolite. The potential value of the zeolitic materials for the retention of trivalent chromium from water was examined. The maximum of Cr(III) sorption by the zeolitic materials, determined by a repeated batch equilibration method, ranged from 38.9 to 75.8 mg/g which was much greater than that of the thermally treated sediment (6.3 mg/g). No release of sorbed Cr(III) by 1.0M MgCl(2) at pH 7 was observed but Cr(III) desorption by ionic electrolyte increased with decreasing pH. The zeolitic materials could completely remove Cr(III) from wastewater even in the presence of Na(+) and Ca(2+) with high concentrations with a dose above 2.5 g/L. The pH-dependent desorption behavior and the high selectivity of zeolitic material for Cr(III) were explained by sorption at surface hydroxyl sites and formation of surface precipitates.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Rd., Minhang District, Shanghai, China.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Guan
authors.forename: Deyi
authors.initials: D
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: Xuechu
authors.initials: X
authors.lastname: Chen
authors.forename: Xinze
authors.initials: X
authors.lastname: Wang
authors.forename: Chunjie
authors.initials: C
authors.lastname: Li
authors.forename: Shengbing
authors.initials: S
authors.lastname: He
authors.forename: Hainan
authors.initials: H
authors.lastname: Kong
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000302:isolation & purification*; D019015:Geologic Sediments; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000517:prevention & control*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002857:Chromium; D017641:Zeolites