Monitoring the injection of microscale zero-valent iron particles for groundwater remediation by means of complex electrical conductivity imaging

Author(s)
Adrián Flores Orozco , Milica Velimirovic, Tiziana Tosco, Andreas Kemna, Hans Sapion, Norbert Klaas, Rajandrea Sethi, Leen Bastiaens
Abstract

The injection of microscale zerovalent iron (mZVI) particles for groundwater remediation has received much interest in recent years. However, to date, monitoring of mZVI particle injection is based on chemical analysis of groundwater and soil samples and thus might be limited in its spatiotemporal resolution. To overcome this deficiency, in this study, we investigate the application of complex electrical conductivity imaging, a geophysical method, to monitor the high-pressure injection of mZVI in a fieldscale application. The resulting electrical images revealed an increase in the induced electrical polarization (∼20%), upon delivery of ZVI into the targeted area, due to the accumulation of metallic surfaces at which the polarization takes place. Furthermore, larger changes (>50%) occurred in shallow sediments, a few meters away from the injection, suggesting the migration of particles through preferential flowpaths. Correlation of the electrical response and geochemical data, in particular the analysis of recovered cores from drilling after the injection, confirmed the migration of particles (and stabilizing solution) to shallow areas through fractures formed during the injection. Hence, our results demonstrate the suitability of the complex conductivity imaging method to monitor the transport of mZVI during subsurface amendment in quasi real-time.

Organisation(s)
External organisation(s)
Technische Universität Wien, Rheinische Friedrich-Wilhelms-Universität Bonn, Politecnico di Torino, SAPION bvba, Universität Stuttgart, Flemish Institute for Technological Research (VITO)
Journal
Environmental Science & Technology
Volume
49
Pages
5593-5600
No. of pages
8
ISSN
0013-936X
DOI
https://doi.org/10.1021/acs.est.5b00208
Publication date
04-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
104023 Environmental chemistry, 104002 Analytical chemistry, 105904 Environmental research, 210004 Nanomaterials
Keywords
ASJC Scopus subject areas
Chemistry(all), Environmental Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/monitoring-the-injection-of-microscale-zerovalent-iron-particles-for-groundwater-remediation-by-means-of-complex-electrical-conductivity-imaging(2085c488-69af-4f8d-845b-5c4aa4cef0ac).html