A case study of urban wastewater reclamation in Spain: comparison of water quality produced by using alternative processes and related costs

In Spain, and particularly in the Valencia Region, the scarcity of water resources means that water resource exploitation must be optimized. In this light, reusing the large amounts of treated wastewater is a top priority, especially in agriculture, urban use and the irrigation of golf courses. Rincón de León wastewater treatment plant–water reclamation plant (Alicante, Spain) supplies reclaimed flow to a number of users according to the guidelines stated in the Royal Decree 1620/2007. Reclamation treatment includes: coagulation + flocculation + filtration (sand bed), ultrafiltration, ultraviolet disinfection and desalination (reverse osmosis). By combining these processes, three tertiary treatment alternatives were configured, and for each of them the quality of effluents, treatment costs, energy consumption and the uses of treated water were analysed. The results show that the quality of the water treated using the three alternatives is suitable for different uses. Moreover, the costs resulting from the tertiary treatment processes, their energy consumption and the final price of the treated water paid by farmers have been obtained.This study was partially financed by the Ministry of Education via the projects ‘Treatment of superficial water and wastewater by membrane technologies to obtain high quality effluents' (CTM2010-15348) and ‘Treatment and wastewater reuse for a sustainable management’ (CONSOLIDER) (CSD200644), as well as by the Ministry of Science and Innovation via the project ‘Quality of Aquifers and agricultural impacts' (DER2011-27765), and the Council for Education, Formation and Occupation of the Government of Valencia (ACOMP 2012/136)