RO pioneer dies at 91

Sidney Loeb, one of the original developers of the reverse-osmosis desalination process, died in his sleep on 11 December at the age of 91.

Loeb, together with Srinivasa Sourirajan, who is now 85 and lives in Ottawa, Canada, make the breakthrough that made today’s RO industry possible at the University of California at Los Angeles in 1959.

Loeb described it like this: “The commercial utility of reverse osmosis depends on combining adequate permeate flux (permeate rate per unit membrane area) with acceptably low permeate salinity (usually less than 500 ppm). These were simultaneously achieved by us in late 1959 by the attainment of a membrane with a very thin (micron or submicron) “skin” surmounting a relatively thick porous support layer. This anisotropic structure was verified by electronic microscopy at Gulf General Atomics in San Diego.

“In my opinion, such anisotropy is the seminal feature to the success of RO desalination, and has been a major contributor to the general surge of interest in and applications of membrane separation processes.”

The world’s first commercial RO system, which used the Loeb-Sourirajan tubular RO technology, was installed in Coalinga, California in 1965 providing potable water for the city.

The president of the International Desalination Association, Lisa Henthorne, issued this tribute on behalf of IDA:

“IDA would like to pass on our sincere condolences to the family of Sidney Loeb at his passing. As one of the early pioneers in our industry, we are deeply in gratitude for Sidney’s contributions to our field, his dedication to the industry and to his endearing spirit which inspired many of us over the years. The reverse osmosis industry which erupted from the early work of Sidney and his colleagues will have growing importance in our future water supply and the IDA would like to acknowledge the importance of Sidney’s work in this regard.”