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Luna M, Gastone F, Tosco T, Sethi R, Velimirovic M, Gemoets J, Muyshondt R, Sapion H, Klaas N, Bastiaens L. Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation. J Contam Hydrol 2015; 181:46-58. [PMID: 25971233 DOI: 10.1016/j.jconhyd.2015.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 04/15/2015] [Accepted: 04/19/2015] [Indexed: 06/04/2023]
Abstract
The paper reports a pilot injection test of microsized zerovalent iron (mZVI) dispersed in a guar gum shear thinning solution. The test was performed in the framework of the EU research project AQUAREHAB in a site in Belgium contaminated by chlorinated aliphatic hydrocarbons (CAHs). The field application was aimed to overcome those critical aspects which hinder mZVI field injection, mainly due to the colloidal instability of ZVI-based suspensions. The iron slurry properties (iron particles size and concentration, polymeric stabilizer type and concentration, slurry viscosity) were designed in the laboratory based on several tests (reactivity tests towards contaminants, sedimentation tests and rheological measurements). The particles were delivered into the aquifer through an injection well specifically designed for controlled-pressure delivery (approximately 10 bars). The well characteristics and the critical pressure of the aquifer (i.e. the injection pressure above which fracturing occurs) were assessed via two innovative injection step rate tests, one performed with water and the other one with guar gum. Based on laboratory and field preliminary tests, a flow regime at the threshold between permeation and preferential flow was selected for mZVI delivery, as a compromise between the desired homogeneous distribution of the mZVI around the injection point (ensured by permeation flow) and the fast and effective injection of the slurry (guaranteed by high discharge rates and injection pressure, resulting in the generation of preferential flow paths). A monitoring setup was designed and installed for the real-time monitoring of relevant parameters during injection, and for a fast determination of the spatial mZVI distribution after injection via non-invasive magnetic susceptibility measurements.
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Affiliation(s)
- M Luna
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - F Gastone
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - T Tosco
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - R Sethi
- Dipartimento di Ingegneria dell'Ambiente, del Territorio e delle Infrastrutture-Politecnico di Torino, corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - M Velimirovic
- VITO, Boeretang 200, 2400 Mol, Belgium; Department of Environmental Geosciences, University of Wien, Althanstrasse 14, 1090 Wien, Austria
| | - J Gemoets
- VITO, Boeretang 200, 2400 Mol, Belgium
| | | | - H Sapion
- SAPION, Oude Bevelsesteenweg 51, 2560 Nijlen, Belgium
| | - N Klaas
- VEGAS, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany
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