Techno-economic assessment of a membrane-based wastewater reclamation process

Reclaimed water plays a crucial role in the water cycle since it constitutes an effective way to improve the utilization of water resources and can help to cope with the water crisis. Membrane technologies for wastewater reclamation, especially ultrafiltration (UF) and reverse osmosis (RO), have received great attention in the past decades. In this work, an integrated prototype (2.5 m3/h) based on the combination of UF and RO was operated in Vuelta Ostrera municipal wastewater treatment plant, located in the proximity of an industrial hub, to obtain water with the required quality for being industrially reused complying with Spanish law and the needs of industrial users. The influence of the process variables on water recovery was studied. Filtration time, backwash cycles duration and frequency, and the addition (or not) of coagulant, were the main variables studied during UF operation, while the recirculation rate of the concentrate stream and the UF permeate quality were the main variables for RO operation. Finally, the economic evaluation pointed to important savings in the OPEX of the process, when compared to the prize that industrial users are currently paying for water.