Abstract: Polyamide-based thin film composite (TFC) membranes remain the gold standard in the desalination industry, while intensive research efforts are currently devoted to exceeding their inherent limitations. One such limitation is their inadequacy to remove trace solutes, including boron species. Boron levels are particularly high in the Mediterranean Sea, making irrigation a challenge for growing vital crops such as citrus fruits and nuts. This picture recently motivated us to explore the possibility of designing membranes for simultaneous boron removal and desalination. While most  existing efforts aiming efficient boron removal rely on surface modification of conventional TFC membranes, we evaluated different thin film nanocomposite (TFN) membrane designs considering their potential for achieving improved water flux and fouling resistance. However, this requires carefully selecting the type, functional group profile, and loading ratio of the nanomaterials alongside optimizing interfacial polymerization and post-treatment protocols. This presentation introduces our progress in embedding carbon nanotubes (CNTs), metal-organic frameworks, and zeolites into polyamide-based reverse osmosis membranes for improving boron and salt rejections and water flux. We achieved encouraging results with CNTs. In our parameter space, the dispersion homogeneity and geometrical alignment of CNTs inside the polymeric matrix stood out, in addition to more common parameters such as the thickness and crosslinking ratio of the selective layer. And full-atomistic molecular dynamics simulations helped us understand the impact of tip-functionalized CNTs on boron rejection further. Overall, we tackled critical challenges such as low reproducibility and reduction in salt rejection upon incorporating nanomaterials into polyamide membranes. This presentation will also introduce our parallel effort for utilizing commercially available desalination membranes for boron removal more effectively, which yielded a recently patented multi-stage process called Concurrent Desalination and Boron Removal (CDBR).

Biography: Prof. S. Birgül Tantekin-Ersolmaz received her BS degree in Chemical Engineering from Istanbul Technical University (ITU) and MS and PhD degrees in Chemical Engineering from the University of Colorado, Boulder. She has been a professor of chemical engineering at ITU since 1991. She also leads the membrane separation unit of the recently established ITU-SENTEK, The Center for Synthetic Fuels and Chemicals at ITU. She worked at the University of Texas, Austin, as a Fulbright Research Scholar for an academic year (1998-1999) and at the Chemical Engineering Department of the Virginia Polytechnic Institute and State University (Virginia Tech) as a visiting faculty member (undergraduate/graduate teaching) for 1.5 years (2012-2013). Her research interest lies in the cross-sections of molecular separations, porous materials, and polymeric membranes for energy and water applications, particularly in gas separations and desalination. In addition to research, Prof. Tantekin-Ersolmaz showed an exemplary commitment to engineering education. She was an Advisor to the ITU Rector between 1999-2004, with a focus on education quality management. And, she is one of the founding members of MÜDEK (Association for Evaluation and Accreditation of Engineering Programs), the engineering accreditation agency of Turkey, where she has served at different levels since 2007. Going beyond her home country, Prof. Tantekin-Ersolmaz also served in the European Network for Accreditation of Engineering Education (ENAEE) as an Administrative Council Member (2016-2019) and later as the Vice President (2019-2021).