A Large-Scale 3D Study on Transport of Humic Acid-Coated Goethite Nanoparticles for Aquifer Remediation

first_page settings Open AccessFeature PaperArticle A Large-Scale 3D Study on Transport of Humic Acid-Coated Goethite Nanoparticles for Aquifer Remediation by Milica Velimirovic 1,2 [OrcID] , Carlo Bianco 3 [OrcID] , Natalia Ferrantello 3, Tiziana Tosco 3, Alessandro Casasso 3 [OrcID] , Rajandrea Sethi 3,*, Doris Schmid 1, Stephan Wagner 1,4 [OrcID] , Kumiko Miyajima 5, Norbert Klaas 5, Rainer U. Meckenstock 6 [OrcID] , Frank von der Kammer 1 and Thilo Hofmann 1,* 1 Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria 2 Department of Chemistry, Atomic & Mass Spectrometry–A&MS Research Group, Campus Sterre, Ghent University, Krijgslaan 281-S12, 9000 Ghent, Belgium 3 Department of Environmental, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, corso Duca degli Abruzzi, 24-10129 Torino, Italy 4 Department of Analytical Chemistry, UFZ-Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany 5 VEGAS—Research Facility for Subsurface Remediation, University of Stuttgart, Pfaffenwaldring 61, 70569 Stuttgart, Germany 6 Environmental Microbiology and Biotechnology, University Duisburg-Essen, 45141 Essen, Germany * Authors to whom correspondence should be addressed. Water 2020, 12(4), 1207; https://doi.org/10.3390/w12041207 Received: 17 March 2020 / Revised: 10 April 2020 / Accepted: 16 April 2020 / Published: 24 April 2020 (This article belongs to the Special Issue Groundwater and Soil Remediation) Download PDF Browse Figures Review Reports Cite This Paper Abstract Humic acid-coated goethite nanoparticles (HA-GoeNPs) have been recently proposed as an effective reagent for the in situ nanoremediation of contaminated aquifers. However, the effective dosage of these particles has been studied only at laboratory scale to date. This study investigates the possibility of using HA-GoeNPs in remediation of real field sites by mimicking the injection and transport of HA-GoeNPs under realistic conditions. To this purpose, a three-dimensional (3D) transport experiment was conducted in a large-scale container representing a heterogeneous unconfined aquifer. Monitoring data, including particle size distribution, total iron (Fetot) content and turbidity measurements, revealed a good subsurface mobility of the HA-GoeNP suspension, especially within the higher permeability zones. A radius of influence of 2 m was achieved, proving that HA-GoeNPs delivery is feasible for aquifer restoration. A flow and transport model of the container was built using the numerical code Micro and Nanoparticle transport Model in 3D geometries (MNM3D) to predict the particle behavior during the experiment. The agreement between modeling and experimental results validated the capability of the model to reproduce the HA-GoeNP transport in a 3D heterogeneous aquifer. Such result confirms MNM3D as a valuable tool to support the design of field-scale applications of goethite-based nanoremediation.