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Karst aquifers are essential drinking water sources, representing about 25% of the total available sources globally. Groundwater ecosystems consist of fissured carbonate rocks commonly covered with canopy collapse sinkholes. The open nature of karst aquifers makes them susceptible to rapidly transporting contaminants from the surface in dissolved and particulate forms. The principal aim of this review is to contribute to filling the gap in knowledge regarding major concerns affecting karst aquifers and understanding their vulnerabilities and dynamics. The principal groundwater pollutants of relevance are detailed in the present work, including well-known issues, such as the input of agriculture and its role in water quality. Emerging pollutants such as microplastics, still poorly studied in the groundwater systems, were also considered. Case studies for each typology of pollutant were highlighted, as their relative concerns for karst environments. Final considerations underlined an approach for studying karst environments more focused on understanding dynamics and links among different pollutants inputs and their drivers than on individual sources and impacts.

Recently modern methodologies allowed the improvement of conventional bioventing strategies in an engineering technology known as smart passive bioventing (S-PBv). The latter is an increasingly used application to reduce the concentrations of organic contaminants below the relative value of contamination threshold concentration (CSC). The S-PBv exploits the natural fluctuations of atmospheric pressure, which allow air to enter into the subsoil, to facilitate natural remediation processes. In this way, the efforts in terms of economics resources in the remediation process are minimised, the risk of pollutants volatilization is drastically reduced, and the degradation favoured by microorganisms is promoted. Our study aims to provide the essential information to plan a series of in situ tests (pilot test) to verify the applicability of this remediation technology, through the use of intelligent sensors designed and engineered using open-source hardware and software.