Application of the re-circulating tracer well test method to determine nitrate reaction rates in shallow unconfined aquifers
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| Title: | Application of the re-circulating tracer well test method to determine nitrate reaction rates in shallow unconfined aquifers |
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| Authors: | Burbery, Lee F.1,2 lee.burbery@esr.cri.nz, Flintoft, Mark J.1, Close, Murray E.1 |
| Source: | Journal of Contaminant Hydrology. Feb2013, Vol. 145, p1-9. 9p. |
| Subjects: | Groundwater tracers, Aquifers, Nitrates, Chemical kinetics, Volcanology, Petrology, Electrolytic reduction, Groundwater flow |
| Geographic Terms: | New Zealand |
| Abstract: | Abstract: Five re-circulating tracer well tests (RCTWTs) have been conducted in a variety of aquifer settings, at four sites across New Zealand. The tests constitute the first practical assessment of the two-well RCTWT methodology described by Burbery and Wang (Journal of Hydrology, 2010; 382:163–173) and were aimed at evaluating nitrate reaction rates in situ. The performance of the RCTWTs differed significantly at the different sites. The RCTWT method performed well when it was applied to determine potential nitrate reaction rates in anoxic, electro-chemically reductive, nitrate-free aquifers of volcanic lithology, on the North Island, New Zealand. Regional groundwater flow was not fast-flowing in this setting. An effective first-order nitrate reaction rate in the region of 0.09d−1 to 0.26d−1 was determined from two RCTWTs applied at one site where a reaction rate of 0.37d−1 had previously been estimated from a push–pull test. The RCTWT method performed poorly, however, in a fast-flowing, nitrate-impacted fluvio-glacial gravel aquifer that was examined on the South Island, New Zealand. This setting was more akin to the hypothetical physiochemical problem described by Burbery and Wang (2010). Although aerobic conditions were identified as the primary reason for failure to measure any nitrate reaction in the gravel aquifer, failure to establish significant interflow in the re-circulation cell due to the heterogeneous nature of the aquifer structure, and natural variability exhibited in nitrate contaminant levels of the ambient groundwater further contributed to the poor performance of the test. Our findings suggest that in practice, environmental conditions are more complex than assumed by the RCTWT methodology, which compromises the practicability of the method as one for determining attenuation rates in groundwater based on tracing ambient contaminant levels. Although limited, there appears to be a scope for RCTWTs to provide useful information on potential attenuation rates when reactants are supplemented to the aquifer system under examination. [Copyright &y& Elsevier] |
| Copyright of Journal of Contaminant Hydrology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 85173300 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Application of the re-circulating tracer well test method to determine nitrate reaction rates in shallow unconfined aquifers – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Burbery%2C+Lee+F%2E%22">Burbery, Lee F.</searchLink><relatesTo>1,2</relatesTo><i> lee.burbery@esr.cri.nz</i><br /><searchLink fieldCode="AR" term="%22Flintoft%2C+Mark+J%2E%22">Flintoft, Mark J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Close%2C+Murray+E%2E%22">Close, Murray E.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Contaminant+Hydrology%22">Journal of Contaminant Hydrology</searchLink>. Feb2013, Vol. 145, p1-9. 9p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Groundwater+tracers%22">Groundwater tracers</searchLink><br /><searchLink fieldCode="DE" term="%22Aquifers%22">Aquifers</searchLink><br /><searchLink fieldCode="DE" term="%22Nitrates%22">Nitrates</searchLink><br /><searchLink fieldCode="DE" term="%22Chemical+kinetics%22">Chemical kinetics</searchLink><br /><searchLink fieldCode="DE" term="%22Volcanology%22">Volcanology</searchLink><br /><searchLink fieldCode="DE" term="%22Petrology%22">Petrology</searchLink><br /><searchLink fieldCode="DE" term="%22Electrolytic+reduction%22">Electrolytic reduction</searchLink><br /><searchLink fieldCode="DE" term="%22Groundwater+flow%22">Groundwater flow</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22New+Zealand%22">New Zealand</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Abstract: Five re-circulating tracer well tests (RCTWTs) have been conducted in a variety of aquifer settings, at four sites across New Zealand. The tests constitute the first practical assessment of the two-well RCTWT methodology described by Burbery and Wang (Journal of Hydrology, 2010; 382:163–173) and were aimed at evaluating nitrate reaction rates in situ. The performance of the RCTWTs differed significantly at the different sites. The RCTWT method performed well when it was applied to determine potential nitrate reaction rates in anoxic, electro-chemically reductive, nitrate-free aquifers of volcanic lithology, on the North Island, New Zealand. Regional groundwater flow was not fast-flowing in this setting. An effective first-order nitrate reaction rate in the region of 0.09d−1 to 0.26d−1 was determined from two RCTWTs applied at one site where a reaction rate of 0.37d−1 had previously been estimated from a push–pull test. The RCTWT method performed poorly, however, in a fast-flowing, nitrate-impacted fluvio-glacial gravel aquifer that was examined on the South Island, New Zealand. This setting was more akin to the hypothetical physiochemical problem described by Burbery and Wang (2010). Although aerobic conditions were identified as the primary reason for failure to measure any nitrate reaction in the gravel aquifer, failure to establish significant interflow in the re-circulation cell due to the heterogeneous nature of the aquifer structure, and natural variability exhibited in nitrate contaminant levels of the ambient groundwater further contributed to the poor performance of the test. Our findings suggest that in practice, environmental conditions are more complex than assumed by the RCTWT methodology, which compromises the practicability of the method as one for determining attenuation rates in groundwater based on tracing ambient contaminant levels. Although limited, there appears to be a scope for RCTWTs to provide useful information on potential attenuation rates when reactants are supplemented to the aquifer system under examination. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Contaminant Hydrology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.jconhyd.2012.11.006 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 9 StartPage: 1 Subjects: – SubjectFull: Groundwater tracers Type: general – SubjectFull: Aquifers Type: general – SubjectFull: Nitrates Type: general – SubjectFull: Chemical kinetics Type: general – SubjectFull: Volcanology Type: general – SubjectFull: Petrology Type: general – SubjectFull: Electrolytic reduction Type: general – SubjectFull: Groundwater flow Type: general – SubjectFull: New Zealand Type: general Titles: – TitleFull: Application of the re-circulating tracer well test method to determine nitrate reaction rates in shallow unconfined aquifers Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Burbery, Lee F. – PersonEntity: Name: NameFull: Flintoft, Mark J. – PersonEntity: Name: NameFull: Close, Murray E. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 02 Text: Feb2013 Type: published Y: 2013 Identifiers: – Type: issn-print Value: 01697722 Numbering: – Type: volume Value: 145 Titles: – TitleFull: Journal of Contaminant Hydrology Type: main |
| ResultId | 1 |
