Circular economy in membrane technology: recycled membranes and desalination by electrodialysis
Paper published in the Journal of Membrane Science
Membrane technology research group (IMDEA Water) in collaboration with the institute of polymer science and technology (CSIC) have published a new scientific paper in the Journal of Membrane Science. The objective of the study is the preparation of ion exchange membranes by using as mechanical support discarded reverse osmosis membranes. The resulting membranes have been deeply characterized in order to get a better knowledge of their properties. Moreover, the membrane performance has been tested for brackish water desalination (3g/L of total suspended solids) by electrodialysis. The polypropylene components from the discarded reverse osmosis module were also recycled as turbulence promoters and as end plates and compartments in the electrodialysis stack.

The use of the end-of-life membranes as mechanical support provide to the prepared ion exchange membranes of interesting properties, such as high permselectivity and good mechanical properties. In fact, these membranes could be an economical alternative in different processes such as waste water treatment, acid/alkali regeneration, water reuse, etc.
This study proposes a new management route for the discarded reverse osmosis membranes and it is an innovative example of indirect recycling where diverse recycling routes are proposed for the different plastic components of the membrane module (in this case, the membranes and the polypropylene components).
More information:
- Lejarazu-Larrañaga, A.; Molina, S.; Ortiz, J.M.; Navarro, R. and García-Calvo, E. (2019) Circular economy in membrane technology: using end-of-life reverse osmosis modules for preparation of recycled anion exchange membranes and validation in electrodialysis. Journal of Membrane Science. p. 117423. ISSN 03767388
This research is part of the INREMEM (Innovation in Membrane Recycling, Ref. CTM2015-65348-C2-1-R) national project and it is supported by the Spanish Ministry of Science, Innovation and Universities (MINECO) and co-financed by the European Regional Development Fund (ERDF). These entities have also support the predoctoral contract for training doctors (FPI, BES-2016-076244) and the program CTM2015-74695-JIN (AEI/FEDER, UE).