title: Biogenic scorodite crystallization by Acidianus sulfidivorans for arsenic removal.
abstract: Scorodite is an arsenic mineral with the chemical formula FeAsO(4)*2H(2)O. It is the most common natural arsenate associated with arsenic-bearing ore deposits. In the present study we show that the thermoacidophilic iron-oxidizing archaeon Acidianus sulfidivorans is able to precipitate scorodite in the absence of any primary minerals or seed crystals, when grown on 0.7 g L(-1) ferrous iron (Fe(2+)) at 80 degrees C and pH 1 in the presence of 1.9 g L(-1) arsenate (H(3)AsO(4)). The simultaneous biologically induced crystallization of ferric iron (Fe(3+)) and arsenic to scorodite prevented accumulation of ferric iron. As a result, crystal growth was favored over primary nucleation which resulted in the formation of highly crystalline biogenic scorodite very similar to the mineral scorodite. Because mineral scorodite has a low water solubility and high chemical stability, scorodite crystallization may form the basis for a novel method for immobilization of arsenic from contaminated waters with high arsenic concentrations.
authors.affiliation: Subdepartment of Environmental Technology, Wageningen University, 6700 EV Wageningen, The Netherlands. paula.gonzalezcontreras@wur.nl
authors.forename: Paula
authors.initials: P
authors.lastname: Gonzalez-Contreras
authors.forename: Jan
authors.initials: J
authors.lastname: Weijma
authors.forename: Renata
authors.initials: R
authors.lastname: van der Weijden
authors.forename: Cees J N
authors.initials: CJ
authors.lastname: Buisman
mesh_terms: D041541:Acidianus / Q000378:metabolism*; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D001152:Arsenicals / Q000737:chemistry*; D001673:Biodegradation, Environmental; D008855:Microscopy, Electron, Scanning
chemical_list: D001152:Arsenicals; C548094:scorodite; D001151:Arsenic