title: Cr(VI) removal from aqueous solution by dried activated sludge biomass.
abstract: Batch experiments were conducted to remove Cr(VI) from aqueous solution using activated sludge biomass. The effects of acid pretreatment of the biomass, initial pH, biomass and Cr(VI) concentrations on Cr(VI) removal efficiency were investigated. Proton consumption during the removal process and the reducing capacity of sludge biomass were studied. The results show that acid pretreatment could significantly improve Cr(VI) removal efficiency and increase Cr(VI) reducing capacity by 20.4%. Cr(VI) removal was remarkably pH-dependent; lower pH (pH=1, 2) facilitated Cr(VI) reduction while higher pH (pH=3, 4) favored sorption of the converted Cr(III). Lower Cr(VI) concentration as well as higher biomass concentration could accelerate Cr(VI) removal. Cr(VI) reduction was not the only reason for proton consumption in the removal process. Pseudo-second-order adsorption kinetic model could successfully simulate Cr(VI) removal except under higher pH conditions (pH=3, 4).
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
authors.forename: Qian
authors.initials: Q
authors.lastname: Yao
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D002857:Chromium / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D011522:Protons; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D012996:Solutions
chemical_list: D011522:Protons; D012722:Sewage; D012996:Solutions; D002857:Chromium; C074702:chromium hexavalent ion