Global patterns of nitrate isotope composition in rivers and adjacent aquifers reveal reactive nitrogen cascading
Journal
Communications Earth & Environment
ISSN
2662-4435
Date Issued
2021
Author(s)
Ioannis Matiatos
Leonard I. Wassenaar
Lucilena R. Monteiro
Jason J. Venkiteswaran
Daren C. Gooddy
Pascal Boeckx
Elisa Sacchi
Fu‐Jun Yue
Greg Michalski
Carlos Alonso-Hernández
Christina Biasi
Lhoussaine Bouchaou
Nandana V. Edirisinghe
Widad Fadhullah
Joseph R. Fianko
Alejandro García-Moya
Nerantzis Kazakis
Si-Liang Li
Minh T. N. Luu
Sakhila Priyadarshanee
Viviana Re
Asunción Romanelli
Prasanta Sanyal
Fredrick Tamooh
Duc A. Trinh
Wendell Walters
Nina Welti
Type
Resource Types::text::journal::journal article
URL Institutional Repository
Abstract
Remediation of nitrate pollution of Earth’s rivers and aquifers is hampered by cumulative biogeochemical processes and nitrogen sources. Isotopes (δ15N, δ18O) help unravel spatiotemporal nitrogen(N)-cycling of aquatic nitrate (NO3−). We synthesized nitrate isotope data (n = ~5200) for global rivers and shallow aquifers for common patterns and processes. Rivers had lower median NO3− (0.3 ± 0.2 mg L−1, n = 2902) compared to aquifers (5.5 ± 5.1 mg L−1, n = 2291) and slightly lower δ15N values (+7.1 ± 3.8‰, n = 2902 vs +7.7 ± 4.5‰, n = 2291), but were indistinguishable in δ18O (+2.3 ± 6.2‰, n = 2790 vs +2.3 ± 5.4‰, n = 2235). The isotope composition of NO3− was correlated with water temperature revealing enhanced N-cascading in warmer climates. Seasonal analyses revealed higher δ15N and δ18O values in wintertime, suggesting waste-related N-source signals are better preserved in the cold seasons. Isotopic assays of nitrate biogeochemical transformations are key to understanding nitrate pollution and to inform beneficial agricultural and land management strategies. © 2021, The Author(s).
Dataset(s)
Subjects
source identification
;
delta-o-18 values
;
dissolved-oxygen
;
lake winnipeg
;
land-use
;
groundwater
;
water
;
denitrification
;
delta-n-15
;
n-15
;
aquifer pollution
;
isotopic composition
;
land management
;
nitrate
;
nitrogen cycle
;
nitrogen isotope
;
river pollution
;
seasonal variation
;
water temperature