| Abstract: | Several important biogeochemical reactions are known to occur near the interface between aquifer and aquitard sediments. These reactions include O2 reduction; denitrification; and Fe3+, SO42-, and CO2 (methanogenesis) reduction. In some settings, these reactions occur on the aquitard side of the interface as electron acceptors move from the aquifer into the electron-donor-enriched aquitard. In other settings, these reactions occur on the aquifer side of the interface as electron donors move from the aquitard into the electron-acceptor-enriched, or microorganism-enriched, aquifer. Thus, the aquifer/aquitard interface represents a mixing zone capable of supporting greater microbial activity than either hydrogeologic unit alone. The extent to which biogeochemical reactions proceed in the mixing zone and the width of the mixing zone depend on several factors, including the abundance and solubility of electron acceptors and donors on either side of the interface and the rate at which electron acceptors and donors react and move across the interface. Biogeochemical reactions near the aquifer/aquitard interface can have a substantial influence on the chemistry of water in aquifers and on the chemistry of sediments near the interface. |
| Genre: | Article |
| ProdID: | 70022800 |
| Citation Author: | McMahon, P. B. |
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| Citation End Page: | 43 |
| Citation Issue: | 1 |
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| Citation Language: | English |
| Citation Larger Work Title: | Hydrogeology Journal |
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| Citation Number Of Pages: | 10 |
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| Citation Search Results Text: | Aquifer/aquitard interfaces: Mixing zones that enhance biogeochemical reactions; 2001; Article; Journal; Hydrogeology Journal; McMahon, P. B. |
| Citation Start Page: | 34 |
| Citation Volume: | 9 |
| Citation Year: | 2001 |
| Type: | citation/reference |
| Text: | Aquifer/aquitard interfaces: Mixing zones that enhance biogeochemical reactions; 2001; Article; Journal; Hydrogeology Journal; McMahon, P. B. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1007/s100400000109 |
| Date Other: | Mon, 1 Jan 2001 00:00 -0600 |
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