title: Biotreatment of Cr(VI) contaminated waters by sulphate reducing bacteria fed with ethanol.
abstract: Biological treatment of Cr(VI) contaminated waters was performed in fixed bed reactors inoculated with SRB (sulphate-reducing bacteria) growing on ethanol. Treatment efficiency was evaluated by checking chemical abatement of Cr(VI) and by ecotoxicological tests using the nematode Caenorhabditis elegans. A preliminary comparison between ethanol and lactate was performed, denoting that using ethanol, the same values of final sulphate abatement were obtained. In addition ethanol showed to be a substrate more competitive than lactate in kinetic terms. Fixed bed column reactors were continuously fed with a solution containing sulphates (3 g L(-1)), ethanol (1.5 g L(-1)) and Cr(VI) (50 mg L(-1)). At steady state the column inoculated with SRB removed 65 ± 5% of sulphate and 95 ± 5% of chromium. Bioactive removal mechanisms predominated over biosorption. Diminution of Cr(VI) toxicity was assessed by using the nematode C. elegans as a test organism showing that the survival of nematodes was 20% in the presence of the untreated influent and raised up to 53% when the nematodes were exposed to the treated effluent.
authors: Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy. francesca.pagnanelli@uniroma1.it
authors: F
authors: F
authors: Pagnanelli
authors: C Cruz
authors: CC
authors: Viggi
authors: A
authors: A
authors: Cibati
authors: D
authors: D
authors: Uccelletti
authors: L
authors: L
authors: Toro
authors: C
authors: C
authors: Palleschi
mesh_terms: D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D017173:Caenorhabditis elegans / Q000187:drug effects; D002857:Chromium / Q000302:isolation & purification* / Q000633:toxicity; D013431:Sulfates / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000633:toxicity
chemical_list: D013431:Sulfates; D014874:Water Pollutants, Chemical; D002857:Chromium