The selection of the most appropriate wastewater treatment for a certain scenario involves a decision making process of high complexity. Different sources of knowledge (scientific literature, databases, previous experiences…), variables (effluent composition, inhabitants’ equivalent, operation costs, location…) and objectives (fulfillment of legislation, resource recovery, energy valorization…), must be considered. For this reason, a great effort has been made during the past few years to systematize this decision making process in order to make it ease it and improve the results.

Environmental Decision support systems (EDSS) have proven to be powerful tools to face up this challenge: they manage huge volume of information by integrating databases and models, include expert knowledge from different sources, and present the information in a graphical user interface. LEQUIA research group from University of Girona has been a pioneer group in the application of decision support systems to the design of wastewater treatment plants (WWTPs). Thus, software Novedar_EDSS, developed within the framework of project Novedar_Consolider (Garrido-Baserba 2013), succeeded to overcome some of the limitations of former tools regarding both the extraction and management of information and its presentation.

Doctoral thesis “Decision support systems for the selection on sanitation systems” by Alba Castillo Llorens represents significant progress towards full integration of EDSS in the decision making process for the selection of water treatment alternatives. The author has worked on three main lines. Firstly, she has validated Novedar_EDSS with several real case studies, has adapted it to current market needs, and has integrated it with an optimization tool to conduct further evaluations. These three improvements upgraded the software in terms of utility and applicability. Secondly, Alba Castillo has studied the application of EDSS to industrial sanitation and has re-designed Novedar_EDSS for the food and beverage sectors. Finally, the researcher has also studied how EDSS can tackle the new circular economy paradigm, where WWTPs move from being facilities to remove pollutants to facilities to recover and valorize resources, as well as adapting to the new requirements in wastewater management.

The thesis, which has been directed by Dr. Manel Poch Espallargas, has been carried out in company AQUATEC, Proyectos para el sector del agua SAU  (group Suez) within the framework of the Industrial Doctorate Program from the Government of Catalonia.  Thus, collaboration between university and the private sector has been crucial to obtain relevant results at both the conceptual and applicability level.