Acid mine drainage and the associated contaminants, including As and metals, are ongoing environmental issues. Passive remediation technologies have the potential to remove As from mine waste effluents. A series of laboratory column experiments was conducted to evaluate the effectiveness of varying mixtures of organic carbon (OC), zero-valent iron (ZVI), and limestone for the treatment of As, metals, SO42− , and acidity in groundwater from an abandoned gold mine. The onset of bacterially-mediated SO42− reduction was indicated by a decrease in Eh, a decline in aqueous SO42− concentrations coupled with enrichment of δ34S, and the presence of sulfatereducing bacteria and H2S. Removal of As was observed within the first 3 cm of reactive material, to values below 10 µg L− 1, representing > 99.9% removal. An increase in pH from 3.5 to circumneutral values and removal of metals including Al, Cu, and Zn was also observed. Synchrotron results suggest As was removed through precipitation of As-crystalline phases such as realgar and orpiment, or through adsorption as As(V) on ferrihydrite. The results indicate the potential for a mixture of OC and ZVI to remove As from acidic, mine-impacted water.
Bibliographical note© 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-
NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright
FunderNatural Sciences and Engineering Research Council of Canada , TERRE-NET (Grant Number: NETGP 479708-15 ) and the Ministry of Energy, Northern Development and Mines (ENDM). Synchrotron-based techniques were performed at Sector 20-ID of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357 . Additional synchrotron-based techniques were performed using beamline SXRMB at the Canadian Light Source, a national research facility of the University of Saskatchewan , which is supported by the Canada Foundation for Innovation (CFI), the Natural Sciences and Engineering Research Council (NSERC), the National Research Council (NRC), the Canadian Institutes of Health Research (CIHR), the Government of Saskatchewan, and the University of Saskatchewan .
- Acid Mine Drainage
- Permeable Reactive Barriers
- Water Treatment
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal
- Health, Toxicology and Mutagenesis