title: Reduction of hexavalent chromium in aqueous medium with zerovalent iron.
abstract: Hexavalent chromium, emanating primarily from the tannery and electroplating industries, can be reduced to the less toxic trivalent variety by several methods, including reduction with metallic iron. In the present work, electrolytic-grade iron dust was used to reduce chromium(VI) in the form of potassium dichromate. Loading of iron dust was varied from 0.5 to 1.0 g in 50 mL of solution; the pH of the medium was varied from 1.5 to 3.5; and the initial concentration of the dichromate solution was varied from 50 to 125 mg/L. Under the specified experimental conditions, maximum removal of the hexavalent chromium achieved was approximately 90% of its original value. The time-concentration data followed a pseudo-first-order kinetic model. The conversion and rate of reduction increased with an increase in iron loading and acidity of the medium, whereas an increase in the initial concentration of chromium(VI) caused a decrease in the reduction.
authors.affiliation: Department of Chemical Engineering, University of Calcutta, Kolkata, India.
authors.forename: Ratnadeepa
authors.initials: R
authors.lastname: Dutta
authors.forename: S Saker
authors.initials: SS
authors.lastname: Mohammad
authors.forename: Sampa
authors.initials: S
authors.lastname: Chakrabarti
authors.forename: Basab
authors.initials: B
authors.lastname: Chaudhuri
authors.forename: Sekhar
authors.initials: S
authors.lastname: Bhattacharjee
authors.forename: Binay K
authors.initials: BK
authors.lastname: Dutta
mesh_terms: D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D012995:Solubility; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D007501:Iron