title: New approach in modeling Cr(VI) sorption onto biomass from metal binary mixtures solutions.
abstract: In the last decades Cr(VI) sorption equilibrium and kinetic studies have been carried out using several types of biomasses. However there are few researchers that consider all the simultaneous processes that take place during Cr(VI) sorption (i.e., sorption/reduction of Cr(VI) and simultaneous formation and binding of reduced Cr(III)) when formulating a model that describes the overall sorption process. On the other hand Cr(VI) scarcely exists alone in wastewaters, it is usually found in mixtures with divalent metals. Therefore, the simultaneous removal of Cr(VI) and divalent metals in binary mixtures and the interactive mechanism governing Cr(VI) elimination have gained more and more attention. In the present work, kinetics of Cr(VI) sorption onto exhausted coffee from Cr(VI)-Cu(II) binary mixtures has been studied in a stirred batch reactor. A model including Cr(VI) sorption and reduction, Cr(III) sorption and the effect of the presence of Cu(II) in these processes has been developed and validated. This study constitutes an important advance in modeling Cr(VI) sorption kinetics especially when chromium sorption is in part based on the sorbent capacity of reducing hexavalent chromium and a metal cation is present in the binary mixture.
authors.affiliation: College of Environmental Science and Engineering, Anhui Normal University, South Jiuhua Road, 189, 241002 Wuhu, China; Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Fiol
authors.affiliation: Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain. Electronic address: Isabel.Villaescusa@udg.edu.
authors.forename: Isabel
authors.initials: I
authors.lastname: Villaescusa
authors.affiliation: Applied Mathematics Department, Escola Politècnica Superior, Universitat de Girona, Mª Aurèlia Capmany, 61, 17071 Girona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Poch
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals; D008956:Models, Chemical; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion
keywords: Binary mixtures; Exhausted coffee; Kinetics model; Model validation