Record Details
Fate of THMs in Columbia River basalts during aquifer storage and recovery
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Fate of THMs in Columbia River basalts during aquifer storage and recovery |
| Names |
Bertrand, Danelle
(creator) Wildenschild, Dorthe (advisor) Istok, Jonathan D (advisor) |
| Date Issued | 2010-04-14T18:07:42Z (iso8601) |
| Note | Graduation date: 2010 |
| Abstract | Use of basalt aquifers for aquifer storage and recovery (ASR) systems is increasing in the Pacific Northwest due to the large aerial extent of the Columbia River Basalt Group and the suitability of basalts as ASR reservoirs. However, the degradation of trihalomethanes (THMs), potentially carcinogenic disinfection by-products present in the majority of treated ASR source water, has not been quantitatively studied directly in basalt aquifers which have unique physical and geochemical characteristics. This study uses data from three basalt ASR systems in Oregon to calculate THM degradation rates corrected for dilution. Major ion concentration data was used to analyze dilution in the absence of external tracers and reaction rates were calculated based on first-order kinetics and residence times within the aquifer. Calculated total THM half-lives ranged over three orders of magnitude from approximately 20 to 8,000d. Overall, THM reaction rate trends were similar to those observed in non-basalt ASR systems with rates dependent on ASR redox conditions and higher reaction rates observed under more reducing conditions. Additionally, under anoxic and anaerobic conditions, higher reaction rates were observed for ASR cycles with higher TOC concentrations. Contradictory to results in non-basalt ASR systems, brominated THMs did not degrade more rapidly than chloroform in anoxic basalt ASR cycles. |
| Genre | Thesis/Dissertation |
| Topic | aquifer |
| Identifier | http://hdl.handle.net/1957/15438 |
