Nitrate attenuation potential of hypersaline lake sediments in central Spain: Flow-through and batch experiments

Denitrification in a hypersaline lake–aquifer system (Pétrola Basin, Central Spain): The role of recent organic matter and Cretaceous organic rich sediments

“…These poor statistical correlations can be explained due to differences in the climate conditions affecting volatilization before nitrification or mixing between different groundwater flow lines. Carrey et al (2014) point out the denitrification capacity of organic matter-rich sediment from the bottom of Pétrola lake and determined by laboratory experiments their isotopic fractionation (ε O = − 14.5‰; ε N = − 14.7‰). These values, which not differ significantly from those obtained by Carrey et al (2013) employing Utrillas sediments (ε O = − 11.6‰ and − 15.7‰; ε N = − 12.1‰ and −13.8‰), were used to quantify the amount of NO 3 − removed by denitrification at the field scale (up to 60%).…”

“…1). Previous laboratory work using different sediments from the basin showed the potential to promote NO 3 − attenuation at the field scale (Carrey et al, 2013(Carrey et al, , 2014. In these studies, the authors demonstrated the denitrification potential of sediments from the Utrillas Facies (a regional formation of Cretaceous age rich in organic matter and sulfides such as pyrite) and the lake bottom sediments.…”

“…To do so, NO 3 − attenuation processes in the basin are studied by means of chemical and multi-isotopic techniques to confirm the role of different electron donors in the basin. The results are discussed integrating laboratory experiments (Carrey et al, 2013(Carrey et al, , 2014.…”

Modeling biogeochemical processes and isotope fractionation of enhanced in situ biodenitrification in a fractured aquifer

“…Because of dilution, a 86 decrease in nitrate concentration cannot always be attributed to degradation. Monitoring the 87 changes in the nitrogen and oxygen isotope ratios of nitrate (δ 15 N-NO 3 -and δ 18 O-NO 3 -) allows 88 the degradation to be identified (Otero et al, 2009;Puig et al, 2013;Carrey et al, 2014) remaining, f; R s,0 is the initial isotopic composition of the molecule; and α is the kinetic isotopic 97 fractionation factor of the transformation process, which is often represented as the kinetic 98 isotopic enrichment factor ε (in permil, ‰), where ε = (α-1). 99…”

“…Because of dilution, a 86 decrease in nitrate concentration cannot always be attributed to degradation. Monitoring the 87 changes in the nitrogen and oxygen isotope ratios of nitrate (δ 15 N-NO 3 -and δ 18 O-NO 3 -) allows 88 the degradation to be identified (Otero et al, 2009;Puig et al, 2013;Carrey et al, 2014) and 89 therefore nitrate transformation and dilution to be distinguished. In EIB applications, this 90 distinction improves the characterization of the clean groundwater plume and allows nutrient 91 injection to be optimized, reducing treatment costs.…”