title: Sulfur and oxygen isotope tracing in zero valent iron based In situ remediation system for metal contaminants.
abstract: In the present study, controlled laboratory column experiments were conducted to understand the biogeochemical changes during the microbial sulfate reduction. Sulfur and oxygen isotopes of sulfate were followed during sulfate reduction in zero valent iron incubated flow through columns at a constant temperature of 20±1°C for 90 d. Sulfur isotope signatures show considerable variation during biological sulfate reduction in our columns in comparison to abiotic columns where no changes were observed. The magnitude of the enrichment in δ(34)S values ranged from 9.4‰ to 10.3‰ compared to initial value of 2.3‰, having total fractionation δS between biotic and abiotic columns as much as 6.1‰. Sulfur isotope fractionation was directly proportional to the sulfate reduction rates in the columns. Oxygen isotopes in this experiment seem less sensitive to microbial activities and more likely to be influenced by isotopic exchange with ambient water. A linear relationship is observed between δ(34)S and δ(18)O in biotic conditions and we also highlight a good relationship between δ(34)S and sulfate reduction rate in biotic columns.
authors.affiliation: BRGM, Metrology Monitoring Analysis Department, Orléans, France. kumar@cerege.fr
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.forename: Romain
authors.initials: R
authors.lastname: Millot
authors.forename: Fabienne
authors.initials: F
authors.lastname: Battaglia-Brunet
authors.forename: Philippe
authors.initials: P
authors.lastname: Négrel
authors.forename: Ludo
authors.initials: L
authors.lastname: Diels
authors.forename: Jérôme
authors.initials: J
authors.lastname: Rose
authors.forename: Leen
authors.initials: L
authors.lastname: Bastiaens
mesh_terms: D052918:Environmental Restoration and Remediation / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D008670:Metals / Q000032:analysis / Q000737:chemistry*; D010103:Oxygen Isotopes / Q000032:analysis; D013460:Sulfur Isotopes / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D008670:Metals; D010103:Oxygen Isotopes; D013460:Sulfur Isotopes; D014874:Water Pollutants, Chemical