Sistema combinado dixestor-humidal seguido de fotodegradación para a depuración de augas residuais e contaminantes orgánicos emerxentes

Abstract

In Galiza, the current settlement pattern of population is characterised by its high geographical dispersion with settlements of up to 2000 inhabitants, representing 48% of total population. Thus, decentralised wastewater treatment emerges as a logical solution to address the sustainability problems of conventional systems, promoting nature-based solutions. These include constructed wetlands that, in combination with anaerobic digesters, achieve high performance in urban wastewater treatment in terms of conventional water quality parameters. To achieve advanced urban wastewater treatment, a compact three-stage system was presented in this thesis: anaerobic digester (pre-treatment), vertical flow constructed wetland (main treatment) and photodegradation (post-treatment). This combined system was mainly aimed at intensifying the removal of nitrogen, emerging organic pollutants and pathogens, with a surface area of no more than 1 m2/inhabitant equivalent. In addition, a new hybrid anaerobic digester design was tested to facilitate its integration in the combined digester- constructed wetland system, as well as several post-treatments based on heterogeneous photocatalysis. Finally, at both laboratory and pilot plant scale, a high-performance efficiency was obtained by the combined digester-constructed wetland- photodegradation system on the studied parameters.