Dr. Srinivasa Sourirajan was best known as the father of reverse osmosis and made many breakthroughs in clean energy. A former long-time researcher at the National Research Council of Canada (NRC), he passed away peacefully on February 20, 2022 at the age of 98.
A chemist originally from India, Dr. Sourirajan moved to Ottawa and joined the NRC in 1961. His major breakthrough in the way humans get access to drinking water made the NRC the world's centre for membrane research in the 1960s, attracting the best scientists from around the world. He pioneered the development of membranes collaborating with Sidney Loeb, a chemical engineer based in California, to make reverse osmosis (RO) commercially feasible. The Loeb–Sourirajan technique purified water by forcing high volumes of pressurized water through asymmetric, semipermeable membranes made of cellulose acetate—a natural plastic.
For 25 years, Dr. Sourirajan worked on reverse osmosis and ultrafiltration and inspired commercial and industrial use cases for several multinational companies. Today, the Loeb-Sourirajan RO technique influences thousands of RO plants for water purification and food processing. The filters are also used in environmental and medical applications like dialysis filters.
Following his retirement in 1986, he joined the University of Ottawa as the Director of the Industrial Membrane Research Institute. In 1991, he moved to Singapore to establish a membrane research laboratory at the National University of Singapore.
Dr. Sourirajan was an influential scientist who developed new scientific approaches to solve some of the world's most pressing social challenges. These include equitable global access to drinkable water and food supply, innovation in healthcare and medicine, and scientific breakthroughs on clean energy. He was a 3‑time Nobel Prize nominee in chemistry and the recipient of numerous awards and honors. His scientific legacy also includes contributions to new research methodologies and techniques that generated ground breaking data on geophysics, the development of unleaded gasoline to combat the growing problem of smog, and, most importantly, his invention of modern reverse osmosis using a cellulose acetate polymer with Sidney Loeb.
While in Ottawa and not at work, Dr. Sourirajan kept actively involved in building the city's Indian community.