Metal precipitation in an ethanol-fed, fixed-bed sulphate-reducing bioreactor.

Authors :: Kousi P
Remoundaki E
Hatzikioseyian A
Battaglia-Brunet F
Joulian C
Kousteni V
Tsezos M
Source :: Journal of hazardous materials [J Hazard Mater] 2011 May 30; Vol. 189 (3), pp. 677-84. Date of Electronic Publication: 2011 Jan 26.
Publication Year :: 2011
Abstract: A batch upflow fixed-bed sulphate-reducing bioreactor has been set up and monitored for the treatment of synthetic solutions containing divalent iron (100mg/L and 200mg/L), zinc (100mg/L and 200mg/L), copper (100mg/L and 200mg/L), nickel (100mg/L and 200mg/L) and sulphate (1700 mg/L and 2130 mg/L) at initial pH 3-3.5, using ethanol as the sole electron donor. The reactor has been operated at the theoretical stoichiometric ethanol/sulphate ratio. Complete oxidation of ethanol has been achieved through complete oxidation of the intermediately, microbially produced acetate. This is mainly attributed to the presence of Desulfobacter postgatei species which dominated the sulphate-reducing community in the reactor. The reduction of sulphate was limited to about 85%. Quantitative precipitation of the soluble metal ions has been achieved. XRD and SEM-EDS analyses performed on samples of the produced sludge showed poorly crystalline phases of marcasite, covellite and wurtzite as well as several mixed metal sulphides.<br /> (Copyright © 2011 Elsevier B.V. All rights reserved.)