Use of CAH-degrading bacteria as test-organisms for evaluating the impact of fine zerovalent iron particles on the anaerobic subsurface environment
- Author(s)
- Milica Velimirovic, Queenie Simons, Leen Bastiaens
- Abstract
The release of fine zerovalent iron (ZVI) particles in the environment after being introduced for in-situ treatment of compounds like chlorinated aliphatic hydrocarbons (CAHs) may raise questions toward environmental safety, especially for nanoscale materials. Classical single-species ecotoxicity tests do focus on aerobic conditions and are only relevant for the scenario when ZVI-particles reach surface water. Herein, we present an alternative approach where a CAH-degrading mixed bacterial culture was used as test-organisms relevant for the anaerobic subsurface. The impact of different ZVI particles on the bacterial culture was evaluated mainly by quantifying ATP, a reporter molecule giving a general indication of the microbial activity. These lab-scale batch tests were performed in liquid medium, without protecting and buffering aquifer material, as such representing worst-case scenario. The activity of the bacterial culture was negatively influenced by nanoscale zerovalent iron at doses as low as 0.05 g L
-1. On the other hand, concentrations up to 2 g L
-1 of several different types of microscale zerovalent iron (mZVI) particles stimulated the activity. However, very high doses of 15-30 g L
-1 of mZVI showed an inhibiting effect on the bacterial community. Negative effects of ZVIs were confirmed by H
2 accumulation in the batch reactors and the absence of lactate consumption. Observed inhibition also corresponded to a pH increase above 7.5, explicable by ZVI corrosion that was found to be dose-dependent. The obtained results suggest that low doses of mZVIs will not show severe inhibition effects on the microbial community once used for in-situ treatment of CAHs.
- Organisation(s)
- External organisation(s)
- Flemish Institute for Technological Research (VITO)
- Journal
- Chemosphere
- Volume
- 134
- Pages
- 338–345
- No. of pages
- 8
- ISSN
- 0045-6535
- DOI
- https://doi.org/10.1016/j.chemosphere.2015.04.068
- Publication date
- 05-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104023 Environmental chemistry, 104002 Analytical chemistry, 105904 Environmental research, 210004 Nanomaterials
- Keywords
- ASJC Scopus subject areas
- Pollution, General Chemistry, Health, Toxicology and Mutagenesis, Environmental Engineering, Environmental Chemistry
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/88e13927-533d-4797-9698-0510378b3c8d