2026-04-17T05:58:43Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1553802025-12-05T14:32:28Zcom_2072_1057col_2072_478917col_2072_478923

00925njm 22002777a 4500 dc Torrentó, Clara author Palau, Jordi author Rodríguez Fernández, Diana author Heckel, B. author Meyer, A. author Domènech Ortí, Cristina author Rosell, Mònica author Soler i Gil, Albert author Elsner, M. author Hunkeler, D. author 2020-04-15T17:55:21Z 2020-04-15T17:55:21Z 2017-05-09 2020-04-15T17:55:22Z To use compound-specific isotope analysis for confidently assessing organic contaminant attenuation in the environment, isotope fractionation patterns associated with different transformation mechanisms must first be explored in laboratory experiments. To deliver this information for the common groundwater contaminant chloroform (CF), this study investigated for the first time both carbon and chlorine isotope fractionation for three different engineered reactions: oxidative C-H bond cleavage using heat-activated persulfate, transformation under alkaline conditions (pH ∼ 12) and reductive C-Cl bond cleavage by cast zerovalent iron, Fe(0). Carbon and chlorine isotope fractionation values were −8 ± 1 and −0.44 ± 0.06 for oxidation, −57 ± 5 and −4.4 ± 0.4 for alkaline hydrolysis (pH 11.84 ± 0.03), and −33 ± 11 and −3 ± 1 for dechlorination, respectively. Carbon and chlorine apparent kinetic isotope effects (AKIEs) were in general agreement with expected mechanisms (C-H bond cleavage in oxidation by persulfate, C-Cl bond cleavage in Fe(0)-mediated reductive dechlorination and E1CB elimination mechanism during alkaline hydrolysis) where a secondary AKIECl (1.00045 ± 0.00004) was observed for oxidation. The different dual carbon-chlorine (Δδ13C vs Δδ37Cl) isotope patterns for oxidation by thermally activated persulfate and alkaline hydrolysis (17 ± 2 and 13.0 ± 0.8, respectively) vs reductive dechlorination by Fe(0) (8 ± 2) establish a base to identify and quantify these CF degradation mechanisms in the field. Geoquímica Geologia isotòpica Geochemistry Isotope geology Carbon and chlorine isotope fractionation patterns associated with different engineered chloroform transformation reactions