title: Field assessment of guar gum stabilized microscale zerovalent iron particles for in-situ remediation of 1,1,1-trichloroethane.
abstract: A pilot injection test with guar gum stabilized microscale zerovalent iron (mZVI) particles was performed at test site V (Belgium) where different chlorinated aliphatic hydrocarbons (CAHs) were present as pollutants in the subsurface. One hundred kilograms of 56μm-diameter mZVI (~70gL(-1)) was suspended in 1.5m(3) of guar gum (~7gL(-1)) solution and injected into the test area. In order to deliver the guar gum stabilized mZVI slurry, one direct push bottom-up injection (Geoprobe) was performed with injections at 5 depths between 10.5 and 8.5m bgs. The direct push technique was preferred above others (e.g. injection at low flow rate via screened wells) because of the limited hydraulic conductivity of the aquifer, and to the large size of the mZVI particles. A final heterogeneous distribution of the mZVI in the porous medium was observed explicable by preferential flow paths created during the high pressure injection. The maximum observed delivery distance was 2.5m. A significant decrease in 1,1,1-TCA concentrations was observed in close vicinity of spots where the highest concentration of mZVI was observed. Carbon stable isotope analysis (CSIA) yielded information on the success of the abiotic degradation of 1,1,1-TCA and indicated a heterogeneous spatio-temporal pattern of degradation. Finally, the obtained results show that mZVI slurries stabilized by guar gum can be prepared at pilot scale and directly injected into low permeable aquifers, indicating a significant removal of 1,1,1-TCA.
authors: VITO, Boeretang 200, 2400 Mol, Belgium; University of Antwerp, Department of Bio-Engineering, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. Electronic address: milica.velimirovic@univie.ac.at.
authors: Milica
authors: M
authors: Velimirovic
authors: Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy. Electronic address: tiziana.tosco@polito.it.
authors: Tiziana
authors: T
authors: Tosco
authors: VITO, Boeretang 200, 2400 Mol, Belgium. Electronic address: maarten.uyttebroek@vito.be.
authors: Maarten
authors: M
authors: Uyttebroek
authors: Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy. Electronic address: michela.luna@polito.it.
authors: Michela
authors: M
authors: Luna
authors: Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy. Electronic address: francesca.gastone@polito.it.
authors: Francesca
authors: F
authors: Gastone
authors: VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany; Department of Civil and Environmental Engineering, Western University, 1151 Richmond Street, London, ON, N6A 5B9 Canada. Electronic address: Cjestmir.deBoer@uwo.ca.
authors: Cjestmir
authors: C
authors: De Boer
authors: VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany. Electronic address: norbert.klaas@iws.uni-stuttgart.de.
authors: Norbert
authors: N
authors: Klaas
authors: SAPION, Oude Bevelsesteenweg 51, 2560 Nijlen, Belgium. Electronic address: hans.sapion@sapion.be.
authors: Hans
authors: H
authors: Sapion
authors: ISODETECT, Ingolstaedter Landstrasse, 1, D85764 München, Germany. Electronic address: eisenmann@isodetect.de.
authors: Heinrich
authors: H
authors: Eisenmann
authors: Höganäs AB, Bruksgatan 35, SE-263 83 Höganas, Sweden. Electronic address: Per-Olof.Larsson@hoganas.com.
authors: Per-Olof
authors: PO
authors: Larsson
authors: VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany. Electronic address: juergen.braun@iws.uni-stuttgart.de.
authors: Juergen
authors: J
authors: Braun
authors: Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture - Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy. Electronic address: rajandrea.sethi@polito.it.
authors: Rajandrea
authors: R
authors: Sethi
authors: VITO, Boeretang 200, 2400 Mol, Belgium. Electronic address: leen.bastiaens@vito.be.
authors: Leen
authors: L
authors: Bastiaens
mesh_terms: D001530:Belgium; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005685:Galactans / Q000737:chemistry*; D060587:Groundwater; D007501:Iron / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry*; D010865:Pilot Projects; D053149:Plant Gums / Q000737:chemistry*; D016062:Porosity; D014240:Trichloroethanes / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D014240:Trichloroethanes; D014874:Water Pollutants, Chemical; C024566:1,1,1-trichloroethane; D007501:Iron; C007894:guar gum
keywords: 1,1,1-TCA; CSIA; Direct push; Guar gum; In-situ remediation; mZVI