Monitoring induced denitrification during managed aquifer recharge in an infiltration pond

JOURNAL OF HYDROLOGY

卷:561

Article

Grau-Martinez, Alba¹  Folch, Albert^2,3  Torrento, Clara^1,4  Valhondo, Cristina^3,5  Barba, Carme^2,3  Domenech, Cristina¹  Soler, Albert¹  Otero, Neus^1,6 

[1] Univ Barcelona, Grp Mineral Aplicada & Geoquim Fluids, Dept Mineral Petrol & Geol Aplicada, SIMGEO UB CSIC,Fac Ciencies Terra, C Marti & Franques S-N, E-08028 Barcelona, Spain

[2] Univ Politecn Cataluna, Dept Civil & Environm Engn DECA, C Jordi Girona 1-3, ES-08034 Barcelona, Spain

[3] UPC CSIC, Associated Unit Hydrogeol Grp, Barcelona, Spain

[4] Univ Neuchatel, Ctr Hydrogeol & Geotherm, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland

[5] CSIC, Inst Environm Assessment & Water Res IDAEA, C Jordi Girona 18, ES-08034 Barcelona, Spain

[6] Generalitat Catalunya, Barcelona, Spain

关键词: Nitrate reduction;    Multi-isotope analysis;    Reactive layer;    Mixing zone;    Artificial recharge;    Field and laboratory experiments;   

DOI  :  10.1016/j.jhydrol.2018.03.044

来源: Elsevier

【 摘 要 】

Managed aquifer recharge (MAR) is a well-known technique for improving water quality and increasing groundwater resources. Denitrification (i.e. removal of nitrate) can be enhanced during MAR by coupling an artificial recharge pond with a permeable reactive layer (PRL). In this study, we examined the suitability of a multi-isotope approach for assessing the long-term effectiveness of enhancing denitrification in a PRL containing vegetal compost. Batch laboratory experiments confirmed that the PRL was still able to enhance denitrification two years after its installation in the infiltration pond. At the field scale, changes in redox indicators along a flow path and below the MAR-PRL system were monitored over 21 months during recharge and non-recharge periods. Results showed that the PRL was still releasing non-purgeable dissolved organic carbon five years after its installation. Nitrate concentration coupled with isotopic data collected from the piezometer network at the MAR system indicated that denitrification was occurring in the saturated zone immediately beneath the infiltration pond, where recharged water and native groundwater mix. Furthermore, longer operational periods of the MAR-PRL system increased denitrification extent. Multi-isotope analyses are therefore proved to be useful tools in identifying and quantifying denitrification in MAR-PRL systems. (C) 2018 Elsevier B.V. All rights reserved.

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