Occurrence and fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in an urban aquifer located at the Besòs River Delta (Spain).

Urban aquifers are at risk of contamination from persistent and mobile organic compounds (PMOCs), especially per- and polyfluoroalkyl substances (PFAS), which are artificial organic substances widely used across various industrial sectors. PFAS are considered toxic, mobile and persistent, and have therefore gained significant attention in environmental chemistry. Moreover, precursors could transform into more recalcitrant products under natural conditions.

Combination of multivariate data analysis and mixing modelling to assess tracer potential of contaminants of emerging concern in aquifers.

Collected evidence has shown that contaminants of emerging concern (CECs) in conjunction with more conventional tracers (major ions, nutrients, isotopes etc.) can be used to trace pollution origin in aquatic systems. However, in highly mixed aquifer systems signals obtained from conventional tracers overlap diminishing their potential to be used as tracers.

Contaminants of emerging concern in the urban aquifers of Barcelona: Do they hamper the use of groundwater?

Urban aquifers are an alternative to obtain freshwater, but they are frequently polluted by contaminants of emerging concern (CECs). Therefore, there is a need to ascertain whether CECs are a water management challenge as they might limit the use of groundwater as safe drinking water even at ng L concentration levels. To answer this question, it is required to evaluate human health-risk effects of measured CECs in the groundwater and to understand their behaviour at a field-scale.

Dynamics of nitrous oxide with depth in groundwater: Insights from ambient groundwater and laboratory incubation experiments (Hesbaye chalk aquifer, Belgium).

Aquifers under agricultural areas are considered to be an indirect source of nitrous oxide emission (NO) to the atmosphere, which is the greenhouse gas (GHGs) characterized with the highest global warning potential and acts as a stratospheric ozone depletion agent. Previous investigations performed in the Cretaceous Hesbaye chalk aquifer in Eastern Belgium suggested that the dynamics of NO in the aquifer is controlled by overlapping biochemical processes such as nitrification and denitrification. The current study aims to obtain better insight concerning the factors controlling the distribution of NO concentration along a vertical dimension in the aquifer, and to capture and quantify the occurrence of nitrification and denitrification processes in the groundwater system.

Isotopic composition of nitrogen species in groundwater under agricultural areas: A review.

This work reviews applications of stable isotope analysis to the studies of transport and transformation of N species in groundwater under agricultural areas. It summarizes evidence regarding factors affecting the isotopic composition of NO, NH and NO in subsurface, and discusses the use of B, O, C, S, Sr/Sr isotopes to support the analysis of δN values. The isotopic composition of NO, NH and NO varies depending on their sources and dynamics of N cycle processes.