Transport and Natural Attenuation of Emerging Contaminants in Groundwater

Emerging Contaminants (ECs) encompass a wide array of substances, including microplastics, pharmaceuticals and personal care products (PPCPs), pesticides, per- and polyfluoroalkyl substances (PFAS), and hydrocarbon additives such as MTBE and ETBE. These compounds, often originating from human activities, are of particular concern due to their persistence in the environment and potential adverse effects on human health and ecosystems. The interaction between surface water and groundwater becomes increasingly critical when polluted surface waters contribute to aquifer recharge through lateral transfer or percolation processes. In this context, PPCPs present a notable challenge. Once released into wastewater, they are poorly removed during treatment, and their presence in groundwater can be exacerbated by sewer pipe failures that allow direct discharge of contaminants into the surrounding environment. The integration of data from different phases of the project has led to significant progress in understanding the dynamics influencing groundwater contamination by emerging contaminants. The interaction between surface and groundwater, particularly in the context of surface waters vulnerable to anthropogenic pollution, proves to be a crucial factor, as these waters can influence groundwater through lateral transfer and/or infiltration processes. In this framework, both microplastics and personal care products (PCPs) present significant challenges, as wastewater treatment plants have proven ineffective in removing them. Moreover, the domestic use of these compounds exacerbates the contamination risk in case of sewer pipe failures, leading to direct release into the soil. Both the discharge of wastewater into surface water bodies and sewer pipe failures are therefore determining factors in the risk of groundwater contamination. The study of the biodegradability of these substances remains an evolving field of research, requiring further studies and in-depth exploration. The conclusions of this work underscore the urgency of addressing, from multiple fronts, the challenges posed by emerging contaminants, emphasizing the increasing need to develop analytical techniques that lower the detection limits for these substances, as well as effective methodologies for their removal from wastewater, in order to implement more effective monitoring and management strategies for the protection of groundwater.