The growing consumption of drugs and their incomplete removal at wastewater treatment plants has given rise to the appearance of these compounds in water bodies worldwide. According to their properties, some compounds may be retained on the soil, be degraded by microorganisms or travel long distances polluting water and associated ecosystems. The most persistent compounds can infiltrate and reach aquifers.
The PhD of Virtudes Martínez is about the "behaviour of drugs in the unsaturated zone," and focuses on determining the mid- and long-term risk of these compounds appearing in the aquifer. To achieve that, series of laboratory assays were carried out. These assays enabled us to identify which drugs qualitatively present a greater or lesser degree of persistence when in contact with soil, the processes most influential in the attenuation of each of the drugs during infiltration and which potential transformation products (PTs) are formed as a result of their biodegradation.
The application of these models allows us to predict the behaviour of substances under different scenarios, which will assist decision-making in the regulation of these compounds.