The European Membrane Society (EMS) mourns the passing of Prof. Ora Kedem, who left us at the age of 101.

With profound respect and deep sadness, we honour the memory of one of the true giants of membrane science, water treatment, and desalination.

Prof. Jack Gilron and Prof. Yoram Oren, who were among those privileged to work closely with her during their careers’ highlight Ora Kedem’s pioneering work fundamentally shaped our field. Her groundbreaking theoretical contributions, rooted in irreversible thermodynamics, established the modern understanding of transport phenomena in biological and synthetic membranes. The Kedem–Katchalsky and Kedem–Spiegler models remain among the most cited frameworks in the membrane literature, continuing to guide both scientific inquiry and technological advancement.

Prof. Kedem’s scientific intuition was extraordinary. Based on flux data provided by Sid Loeb, she realized the asymmetric nature of the Loeb-Sourirajan cellulose acetate desalination membrane which was subsequently confirmed by imaging. Her research on ion transport in both pressure-driven and electro-driven membrane processes, as well as her extensive electrodialysis work at laboratory and pilot scale, played a central role in the development of desalination technologies used worldwide today.

Beyond her scientific brilliance, Ora Kedem was an institution builder in the truest sense. She helped establish the membrane research department at the Weizmann Institute, contributed to the founding of Ben-Gurion University of the Negev, and later built the Desalination and Water Treatment group at the Zuckerberg Institute for Water Research.
She was an inspiring mentor to generations of students, researchers, and colleagues, known for her generosity, sharp intellect, and unwavering commitment to scientific excellence.

Prof. Kedem’s achievements earned her numerous distinctions, including induction as an Honorary Member of the European Membrane Society—a testament to the lasting impact of her life’s work on the global membrane community.

The EMS extends its heartfelt condolences to her family, colleagues, and all who were touched by her remarkable life and scientific legacy. May we continue to be guided and inspired by her memory, her pioneering spirit, and her enduring contributions to science and society.

If you want to learn more about Prof. Ora Kedem and her great impact on membrane science please check the following website link