Details of the work carried out by this research group at IMDEA Water
The membrane technology group (MEMTech), led by Dr. Eloy García Calvo, is a multidisciplinary team that studies the entire life cycle of membranes – from their preparation to its application in water treatment, the end of its useful life, and its recycling process.
Membrane technology refers to separation processes that use membranes that allow two phases to be separated by moving components selectively from one phase to another. There are different types of membrane processes depending on the driving force used in the separation process. MEMTech focuses on different processes: microfiltration, ultrafiltration, nanofiltration, reverse osmosis, membrane bioreactor, electrodialysis, and direct osmosis. The group aims to study these membrane technologies from a circular economy perspective. These are the specific objectives under the main four lines of research:
1) Preparation of new and second-generation membranes
This line of research focuses on the preparation of membranes using different methods such: as phase inversion, controlled evaporation of solvents, and interfacial polymerization. In addition, the modification of membranes by the coating immersion methodology is also studied for the preparation of more hydrophilic membranes, with less tendency to fouling and mono-selective membranes. This line of research is reinforced with the spectroscopic and morphological characterization of the membranes prepared using different techniques such as SEM, AFM; ATR, GPC, XPS, Z potential, and contact angle.
2) Implementation of membrane technology for water treatment
In his line of research, the group studies the treatment of wastewater, industrial and from desalination, through membrane technology. All these processes have different applications such as the elimination of micro(nano)plastics (MNPs) and the recovery of nutrients and valuable compounds in the regeneration of water for irrigation (high salinity water).
3) Membrane recycling
Sustainable membrane recycling processes are developed in this line of research. This line is based on a preliminary characterization of the discarded membranes (membrane autopsies), the study of the possibilities for its recycling and reuse, and their incorporation into the market in a circular economy context.
4) Cross-sectional study of membrane technology through life cycle analysis (LCA) and economic study
This line evaluates the environmental and economic impact of membrane processes and their recycling. Being a cross-sectional line, it is being used strategically to complement and reinforce the rest of the group's scientific objectives, thus bringing membrane technology closer to a circular economy, as required by the European Union.To achieve these objectives, the group is currently participating in several national projects:
The INREMEM 2.0 project (Grant RTI2018-096042-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by
ERDF A way of making Europe), in collaboration with the Universidad Complutense de Madrid, works on the combination of different hybrid systems based on membranes – Membrane Bioreactor (BRM), Nanofiltration (NF), Membrane Distillation (MD), and Electrodialysis (ED) – to treat wastewater with high saline content. This project intends to bring membrane technology closer to a circular economy. In addition, it focuses on the recovery of valuable compounds from wastewater, such as water, nutrients, and other salts, promoting a paradigm shift to consider wastewater as a resource by striving for zero liquid discharge (ZLD). On the other hand, it contributes to the effort of the European Union to create a "recycling society", by providing an alternative management route of reverse osmosis filtration membranes to continue treating water after they are discarded. http://inremem.simplesite.com/.
The µNanoCare project (Grant RTC2019-007261-5 funded by MCIN/AEI/10.13039/501100011033), in collaboration with Eurofins-IPROMA and FACSA, focuses on the quantification of MNPs in regenerated waters and agricultural ecosystems, and the evaluation of their environmental risk. The project is developing a novel analytical method for the identification and quantification of MNPs in different matrices. The sampling method is intended to be efficient, reliable, and affordable. Another objective is to evaluate the technologies currently applied in wastewater treatment systems, suggesting optimization improvements. Finally, the project will determine the destiny and concentration of MNPs in agricultural ecosystems where sludge is applied. Likewise, it will evaluate the exposure and potential risks that these particles pose both to aquatic and terrestrial organisms, and human health.
The nanoCLEAN project (Grant PID2019-111519RA-I00 funded by MCIN/AEI/10.13039/501100011033) “Quantification, treatment and environmental impact of MNPs in WWTPs”, aims to contribute to the evaluation and reduction of the impact of MNPs (MNPs) from urban wastewater treatment plants. The contamination level of MNPs in freshwater is estimated to be similar to that in the marine environment. However, there is a lack of standardized methods for sampling, identification, and quantification of small-sized MNPs, making it difficult to evaluate the discharge of wastewater treatment plants into the environment. NanoCLEAN has implemented a systemic method, where the efficient removal of MNPs through hybrid membrane systems (BRM-UF) is coupled with new sensitive sampling and quantification methods (Pyr-GC-MS). This is supported by the Life Cycle and Cost Analysis, where environmental impact and cost are assessed.
IMDEA Water participates in the thematic network for research on MNPs in the environment (EnviroPlaNet, Grant RED2018-102345-T funded by MCIN/AEI/10.13039/501100011033) since 2020. The network coordinates an interdisciplinary cluster of Spanish research groups working on plastic pollution issues. The aim is to improve the coordination of the groups in key aspects that currently pose an obstacle to research, such as the methodological dispersion of sampling and analysis, or the lack of consistency in toxicological and ecotoxicological studies.