A critical assessment of widely used techniques for nitrate source apportionment in arid and semi-arid regions

V Re; S Kammoun; E Sacchi; R Trabelsi; K Zouari; I Matiatos; E Allais; S Daniele

doi:10.1016/j.scitotenv.2021.145688

A critical assessment of widely used techniques for nitrate source apportionment in arid and semi-arid regions

Sci Total Environ. 2021 Jun 25:775:145688. doi: 10.1016/j.scitotenv.2021.145688. Epub 2021 Feb 6.

Authors

V Re¹, S Kammoun², E Sacchi³, R Trabelsi², K Zouari², I Matiatos⁴, E Allais⁵, S Daniele⁶

Affiliations

¹ Department of Earth Sciences, University of Pisa, Via S. Maria 53, 56126 Pisa, Italy; Laboratory of Radio-Analyses and Environment, National School of Engineers of Sfax, BP1173, 3038 Sfax, Tunisia; Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30170 Venezia-Mestre, 40123 Venice, Italy. Electronic address: viviana.re@unipi.it.
² Laboratory of Radio-Analyses and Environment, National School of Engineers of Sfax, BP1173, 3038 Sfax, Tunisia.
³ Department of Earth and Environmental Sciences, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy.
⁴ Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Centre, PO Box 100, A-1400 Vienna, Austria.
⁵ ISO4 s.n.c., Via Valperga Caluso 35, 10125 Torino, Italy.
⁶ Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30170 Venezia-Mestre, 40123 Venice, Italy.

PMID: 33621868
DOI: 10.1016/j.scitotenv.2021.145688

Abstract

The assessment of nitrate pollution origin using stable isotope techniques is a fundamental prerequisite for the application of sustainable groundwater management plans. Although nitrate pollution is a worldwide groundwater quality problem, existing knowledge on the origin of nitrate pollution in arid and semi-arid regions is still scarce. Using the example of the Grombalia aquifer (NE Tunisia), this work summarizes the main strengths and constraints of multi-isotope techniques targeting at nitrate source identification and apportionment The results highlighted that, even in the case of well-established methodologies, like those of isotope hydrogeochemistry (δ¹⁵N_NO3, δ ¹⁸O_NO3 and δ ¹¹B) and mixing modelling for source apportionment, it is fundamental to take into account regional and local end-members to avoid biased data interpretation and to fully exploit the potential of such accurate tools.

Keywords: Groundwater; Hydrogeochemistry; Isotopes; Mixing models.