Impact of Sodium Humate Coating on Collector Surfaces on Deposition of Polymer-Coated Nanoiron Particles
- Author(s)
- Vesna Micic Batka, Doris Schmid, Nathan Bossa, Andreas Gondikas, Milica Velimirovic, Frank von der Kammer, Mark Wiesner, Thilo Hofmann
- Abstract
The affinity between nanoscale zerovalent iron (nano-ZVI) and mineral surfaces hinders its mobility, and hence its delivery into contaminated aquifers. We have tested the hypothesis that the attachment of poly(acrylic acid)-coated nano-ZVI (PAA-nano-ZVI) to mineral surfaces could be limited by coating such surfaces with sodium (Na) humate prior to PAA-nano-ZVI injection. Na humate was expected to form a coating over favorable sites for PAA-nano-ZVI attachment and hence reduce the affinity of PAA-nano-ZVI for the collector surfaces through electrosteric repulsion between the two interpenetrating charged polymers. Column experiments demonstrated that a low concentration (10 mg/L) Na humate solution in synthetic water significantly improved the mobility of PAA-nano-ZVI within a standard sand medium. This effect was, however, reduced in more heterogeneous natural collector media from contaminated sites, as not an adequate amount of the collector sites favorable for PAA-nano-ZVI attachment within these media appear to have been screened by the Na humate. Na humate did not interact with the surfaces of acid-washed glass beads or standard Ottawa sand, which presented less surface heterogeneity. Important factors influencing the effectiveness of Na humate application in improving PAA-nano-ZVI mobility include the solution chemistry, the Na humate concentration, and the collector properties.
- Organisation(s)
- External organisation(s)
- Duke University, University of Gothenburg
- Journal
- Environmental Science & Technology
- Volume
- 51
- Pages
- 9202-9209
- No. of pages
- 8
- ISSN
- 0013-936X
- DOI
- https://doi.org/10.1021/acs.est.7b01224
- Publication date
- 08-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 210001 Nanoanalytics, 104023 Environmental chemistry, 104002 Analytical chemistry, 210004 Nanomaterials
- Keywords
- ASJC Scopus subject areas
- General Chemistry, Environmental Chemistry
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/b3b6b6e1-32ee-41d8-979f-8ea015b50bbd