title: Assessment of potential positive effects of nZVI surface modification and concentration levels on TCE dechlorination in the presence of competing strong oxidants, using an experimental design.
abstract: Nanoscale zero-valent iron (nZVI) particles are efficient for the remediation of aquifers polluted by trichloroethylene (TCE). But for on-site applications, their reactivity can be affected by the presence of common inorganic co-pollutants, which are equally reduced by nZVI particles. The aim of this study was to assess the potential positive effects of nZVI surface modification and concentration level on TCE removal in the concomitant presence of two strong oxidants, i.e., Cr(VI) and NO3(-). A design of experiments, testing four factors (i.e. nZVI concentration, nZVI surface modification, Cr(VI) concentration and NO3(-) concentration), was used to select the best trials for the identification of the main effects of the factors and of the factors interactions. The effects of these factors were studied by measuring the following responses: TCE removal rates at different times, degradation kinetic rates, and the transformation products formed. As expected, TCE degradation was delayed or inhibited in most of the experiments, due to the presence of inorganics. The negative effects of co-pollutants can be palliated by combining surface modification with a slight increase in nZVI concentration. Encouragingly, complete TCE removal was achieved for some given experimental conditions. Noteworthily, nZVI surface modification was found to promote the efficient degradation of TCE. When degradation occurred, TCE was mainly transformed into innocuous non-chlorinated transformation products, while hazardous chlorinated transformation products accounted for a small percentage of the mass-balance.
authors.affiliation: Aix Marseille Université, CNRS, LCE, FRE 3416, Bâtiment Villemin, Europôle de l'Arbois, Avenue Louis Philibert, BP 80, 13545 Aix en Provence Cedex 4, France. Electronic address: delphine.kaifas@etu.univ-amu.fr.
authors.forename: Delphine
authors.initials: D
authors.lastname: Kaifas
authors.affiliation: Aix Marseille Université, CNRS, LCE, FRE 3416, Bâtiment Villemin, Europôle de l'Arbois, Avenue Louis Philibert, BP 80, 13545 Aix en Provence Cedex 4, France. Electronic address: laure.malleret@univ-amu.fr.
authors.forename: Laure
authors.initials: L
authors.lastname: Malleret
authors.affiliation: Aix Marseille Université, CNRS, CEREGE, UMR 7330, Europôle de l'Arbois, Avenue Louis Philibert, BP 80, 13545 Aix en Provence Cedex 4, France. Electronic address: kumar@cerege.fr.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Aix Marseille Université, CNRS, LCE, FRE 3416, Bâtiment Villemin, Europôle de l'Arbois, Avenue Louis Philibert, BP 80, 13545 Aix en Provence Cedex 4, France. Electronic address: fetimi.wafa_univ.mentouri@hotmail.fr.
authors.forename: Wafa
authors.initials: W
authors.lastname: Fétimi
authors.affiliation: Aix Marseille Université, CNRS, LISA, EA 4672, Avenue Escadrille Normandie Niémen, Case 451, 13397 Marseille Cedex 20, France. Electronic address: m.claeys-bruno@univ-amu.fr.
authors.forename: Magalie
authors.initials: M
authors.lastname: Claeys-Bruno
authors.affiliation: Aix Marseille Université, CNRS, LISA, EA 4672, Avenue Escadrille Normandie Niémen, Case 451, 13397 Marseille Cedex 20, France. Electronic address: michelle.sergent@univ-amu.fr.
authors.forename: Michelle
authors.initials: M
authors.lastname: Sergent
authors.affiliation: Aix Marseille Université, CNRS, LCE, FRE 3416, Bâtiment Villemin, Europôle de l'Arbois, Avenue Louis Philibert, BP 80, 13545 Aix en Provence Cedex 4, France. Electronic address: pierre.doumenq@univ-amu.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Doumenq
mesh_terms: D052918:Environmental Restoration and Remediation / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D054879:Halogenation; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D016877:Oxidants / Q000737:chemistry; D013499:Surface Properties; D014241:Trichloroethylene / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D016877:Oxidants; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D007501:Iron
keywords: Cr(VI); Experimental design; NO(3)(−); Nanoscale zero-valent iron particles; Surface modification; Trichloroethylene