| Autor: |
Ziegler BA; Department of Geosciences, Virginia Tech , Blacksburg, Virginia, 24061 United States., McGuire JT; Department of Biology, University of St. Thomas , St. Paul, Minnesota, 55105 United States., Cozzarelli IM; U.S. Geological Survey , Reston, Virginia, 20192 United States. |
| Jazyk: |
angličtina |
| Zdroj: |
Environmental science & technology [Environ Sci Technol] 2015 Nov 17; Vol. 49 (22), pp. 13179-89. Date of Electronic Publication: 2015 Nov 05. |
| DOI: |
10.1021/acs.est.5b02341 |
| Abstrakt: |
Biodegradation of organic matter, including petroleum-based fuels and biofuels, can create undesired secondary water-quality effects. Trace elements, especially arsenic (As), have strong adsorption affinities for Fe(III) (oxyhydr)-oxides and can be released to groundwater during Fe-reducing biodegradation. We investigated the mobilization of naturally occurring As, cobalt (Co), chromium (Cr), and nickel (Ni) from wetland sediments caused by the introduction of benzene, toluene, ethylbenzene, and xylenes (BTEX) and ethanol mixtures under iron- and nitrate-reducing conditions, using in situ push-pull tests. When BTEX alone was added, results showed simultaneous onset and similar rates of Fe reduction and As mobilization. In the presence of ethanol, the maximum rates of As release and Fe reduction were higher, the time to onset of reaction was decreased, and the rates occurred in multiple stages that reflected additional processes. The concentration of As increased from <1 μg/L to a maximum of 99 μg/L, exceeding the 10 μg/L limit for drinking water. Mobilization of Co, Cr, and Ni was observed in association with ethanol biodegradation but not with BTEX. These results demonstrate the potential for trace-element contamination of drinking water during biodegradation and highlight the importance of monitoring trace elements at natural and enhanced attenuation sites. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
|
