Distribución y comportamiento ambiental de contaminantes orgánicos emergentes en suelos afectados por la reutilización de aguas residuales / distribution and environmental behavior of emerging contaminants in soils affected by wastewater reuse

Resumen

This Doctoral Thesis is derived from the growing concern on the final fate, effects, and risks associated to the occurrence of new emerging contaminants in the environment, and has a particular emphasis on the terrestrial environment. In that sense, and in order to unravel potential hazards and possible alternatives for their elimination and/or future regulations, it is relevant to understand the different inputs, as well as the distribution, transport, and processes, by which these substances are affected. This Thesis seeks to improve the current knowledge on the sources (mainly wastewater treatment plants, or WWTPs), temporal and spatial distribution of pharmaceuticals and personal care products (PPCPs) in different environmental matrices, and, with a higher level of detail, in the vadose zone of the soil. Hence, a new analytical methodology was developed for the simultaneous extraction and detection of a broad spectrum of pharmaceutically active compounds, PhACs (including anti-inflammatories, antibiotics, antimicrobials, lipid regulators, etc.) at environmentally relevant concentrations (parts per billion, ppb). Several sampling campaigns were conducted to study the occurrence, levels, and temporal and spatial distribution of PPCPs in aquatic and terrestrial ecosystems from the Gulf of Cadiz, as well as the removal efficiency at Guadalete WWTP. Subsequently, the environmental behavior of PPCPs in soils affected by wastewater reuse was evaluated in situ and through laboratory experiments to characterize the most relevant processes (adsorption, aerobic and anaerobic biodegradation, and transport in soil columns). The results and discussion derived from this Doctoral Thesis were compiled in 7 manuscripts that present new scientific knowledge on the occurrence and final fate of emerging contaminants in ecosystems affected by the discharge and/or reuse of treated wastewater.