Emerging organic contaminants in karst groundwater: A global level assessment

Abstract

A quarter of the world's population uses groundwater from karst aquifers. A range of emerging organic contaminants (EOCs) are considered a potential threat to water resources and dependant ecosystems, and karst aquifers are the most vulnerable groundwater systems to anthropogenic pollution. This paper provides the first global compilation (based on 50 studies) of EOCs in karst aquifers and explores EOC occurrence and the use of EOCs to understand karst systems. Of the 144 compounds detected in the reviewed studies, the vast majority in karst groundwater are pharmaceuticals and pesticides. Maximum concentrations of compounds varied over five orders of magnitude, and nearly half of the detected compounds exceed 100 ng/L. Karst groundwater is shown to have lower frequency of detection and lower concentrations compared to surface waters and local shallow intergranular aquifers, but overall higher concentrations compared to other major aquifer types. A growing number of studies have demonstrated the utility of EOCs and some legacy compounds for groundwater quality assessment and as tracers for characterising karst systems. They can improve understanding of vulnerability, storage, attenuation mechanisms, and in some cases have been used to assist with catchment delineation. This is a growing research area for karst hydrogeology, and more research is needed to understand EOC contamination of karst aquifers, and to develop EOCs as tracers within karst to improve our understanding of this critical water resource.

Improvement of the KarstMod modeling platform for a better assessment of karst groundwater resources

“…Karst groundwater thus represents an unique opportunity to limit the increasing imbalance between growing demand and limited freshwater resource (Wada et al, 2016;Bierkens and Wada, 2019) in the present context of global change. However, karst aquifers are also particularly vulnerable to potential source of contamination, including emergent contaminants (Lukač Reberski et al, 2022), residues of phyto-sanitary products (Lorette et al, 2022) and wastewater (Doummar et al, 2021). Understanding the functioning of karst aquifers and developing operational tools to predict the evolution of freshwater resources is therefore a major challenge for the hydrological science community (Blöschl et al, 2019).…”

The Geological Characteristics of the Vadose Zone Influence the Impact of Treated Wastewater on the Groundwater Quality (SCA.Re.S. Project 2019–2020)

“…There is concern that the groundwater quality has deteriorated, and its suitability for drinking or irrigation has been threatened, as groundwater overexploitation and anthropic pressures on aquifers from urbanization, industrialization, intensive agriculture, and animal husbandry have increased in recent decades [3][4][5][6][7]. The groundwater quality is affected by anthropic activities that impact on its chemical and microbiological parameters, and by the geological features of the rocks that host the groundwater through their role in determining the vulnerability of the aquifer to contamination [8][9][10].…”

“…Some of the results of this project, concerning changes in the groundwater quality recharged by the treated wastewater that passed through fractured and karst vadose zone, have already been reported [9]. Numerous researchers have studied the flow of contaminants through karst soil [9][10][11][26][27][28] but few have studied non-karst soil [29][30][31].…”

Biotransformation of 17β-Estradiol through a Denitrifying Sludge

“…A pollutant group now attracting the attention of the scientific community is the emerging contaminants (ECs) [ 4 , 5 ]. ECs are a group of organic compounds of different chemical natures used in everyday products; this is why their presence in the environment is not necessarily new [ 6 , 7 , 8 ]. Currently, there are no regulations for many of these pollutants, or these are not entirely clear.…”