Desalination of sea- aand brackish water is a problem that has attracted widespread government attention and considerable engineering talent. Since the inception of the U.S. government's formal desalting program in 1952, when thermal distillation was the only method generally known, great progress has been made in the development of membrane processes for desalination. Reverse osmosis is the newest and most promising of these. This book covers the most significant aspects of the process in a collection of papers written by pioneers and experts in the field. The advent of commercial operation is imminent, and the information presented here is even more valuable for its timeliness.
Osmosis in simplest terms is an equalizing process: specifically, the flow of water through a semipermeable membrane from a solution of lesser salt concentration to one of greater salt concentration. In reverse osmosis, pressure is applied to the solution of lesser salt concentration so that this normal osmotic flow is arrested and then reversed. The principles of osmosis have been understood for decades, but the technical feasibility of large-scale operation was not established until the mid-1950's, when Professor C. E. Reid of the University of Florida and, independently, Professors S. Loeb and S. Sourirajan of the University of California at Los Angeles did some classic exploratory work on the process.
The pivotal problem has been the construction of a suitable pressure and yet afford a high degree of selectivity and permit a flow large enough to make the operation practical. The principal contribution of the University of California group was to develop one membrane that meets these requirements. This is the cellulose acetate membrane now in use in pilot desalination plants.
Desalination by Reverse Osmosis is an effort on the part of one group of interested technicians to share what they have learned about reverse osmosis. The book describes the process, reviews past work on reverse-osmosis membranes, discusses the engineering problems that must be solved before large-scale operation can be undertaken, and describes the pilot plants now in operation. As an introduction to a rapidly expanding field it should be of vital interest to technicians working with this and related processes. Although technical in nature, it is informative reading as well for an educated lay public alert to the urgency of this problem.
