dc.description.abstract
The end-of-life management of reverse osmosis (RO) membranes is an increasingly
important environmental and economic challenge in the water treatment sector. These
membranes, primarily used in desalination and water reuse processes, have a limited
lifespan of 3 to 5 years and are commonly discarded in landfills despite retaining part of their
functionality. In this context, the Osmo4Lives project, led by the LEQUIA research group at
the University of Girona, proposes a cascade recycling strategy to extend membrane
lifespan through chemical conversion treatments, adapting them for less demanding
applications such as nanofiltration (NF) and ultrafiltration (UF).
The main objective of this study was to evaluate the technical feasibility of RO membrane
cascade recycling through physicochemical characterization and analysis of their response
to chemical conversion and fouling. To achieve this, several experiments were developed:
first, commercial and converted membranes were characterized in terms of water
permeability and salt rejection. Then, controlled sodium hypochlorite treatments were
applied to reduce the selectivity of the polyamide layer. In addition, fouling experiments were
carried out using a synthetic solution rich in organic compounds to simulate real conditions,
and Chemical Oxygen Demand (COD) was measured to assess the quality of the permeate.
The results demonstrate that converted membranes can reach performance levels similar to
commercial ones, both in permeability and rejection. Furthermore, a consistent fouling
response was observed, with flow stabilization and a slight improvement in organic matter
retention. These findings confirm that membrane recycling is a feasible and promising
strategy, with the potential to support more sustainable water resource management within
the framework of the circular economy
