History of Commercial RO

The original commercial reverse osmosis systems were designed for use on ships to produce fresh water during long voyages. These systems used high-pressure pumps to force water through membranes. The first membranes used for reverse osmosis were very thick, which made treatment systems quite large. These were suitable for industrial processes and large-scale treatment, but not for home use. Early reverse osmosis equipment was so large that even a moderate sized unit would not fit under a typical kitchen sink. In the early stages of commercial development of reverse osmosis several vexing problems were encountered. One of the more problematical ones was how to attach the membranes to a backing material without using adhesives that would coat the membrane and render it useless. In some cases the membranes fell off of the backing as soon as pressure was reduced. Under these circumstances the membrane tore when flow was restored in the unit.

A second difficulty encountered was the size of the membrane tubes themselves. The amount of fresh water produced is proportional to the surface area of the membrane and the pressure applied. One way to increase the rate of treatment is to increase the pressure on the membrane and hope that it does not tear or leak. The other is to increase surface area. This can be done by using many small tubes instead of one large tube as a membrane holder.

Both of these problems were solved with improved membranes, adhesives and the use of plastics. The results led to products that can be applied for home use, with pressures that can be expected from normal plumbing in households.