title: Continuous removal of Cr(VI) from aqueous solution catalysed by palladised biomass of Desulfovibrio vulgaris.
abstract: Growth-decoupled cells of Desulfovibrio vulgaris NCIMB 8303 can be used to reduce Pd(II) to cell-bound Pd(0) (Bio-Pd(0)), a bioinorganic catalyst capable of reducing hexavalent chromium to less toxic Cr(III), using formate as the electron donor. Magnetic resonance imaging showed that Bio-Pd(0), immobilized in chitosan and agar beads, is distinguishable from the surrounding gel and is evenly dispersed within the immobilization matrix. Agar-immobilized Bio-Pd(0) and 'chemical Pd(0)' were packed into continuous-flow reactors, and challenged with a solution containing 100 microM Cr(VI) (pH 7) at a flow rate of 2.4 ml h(-1). Agar-immobilized chemical Pd(0) columns lost Cr(VI) reducing ability by 160 h, whereas columns containing immobilized Bio-Pd(0) maintained 90% reduction until 680 h, after which reduction efficiency was gradually lost.
authors.affiliation: School of Biosciences, The University of Birmingham, Edgbaston, B15 2TT, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: Humphries
authors.forename: K P
authors.initials: KP
authors.lastname: Nott
authors.forename: L D
authors.initials: LD
authors.lastname: Hall
authors.forename: L E
authors.initials: LE
authors.lastname: Macaskie
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D002857:Chromium / Q000737:chemistry* / Q000302:isolation & purification; D016969:Desulfovibrio vulgaris / Q000378:metabolism*; D010165:Palladium / Q000737:chemistry* / Q000378:metabolism*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D010165:Palladium