38 per cent was spent on distillation processes, 1 5 

 per cent on membrane processes, 13 per cent on 

 freezing processes, and 34 per cent on general 

 research. 



The general trend of OSW expenditures is 

 shown in Figure 1. Funding remainded at a low 

 level during the 1950's, but has been much more 

 substantial since 1960. 



The distillation processes which afford a user a 

 proven sea water desalting process are the most 

 technologically advanced.' These processes are 

 adaptable to production of water in small plant 

 sizes (1-5 mgd) as well as plants producing 

 hundreds of millions of gallons per day. At 

 present, major research emphasis in the field of 

 distillation is on the development of cor- 

 rosion-resistant materials that maintain their req- 

 uisite heat transfer properties, and the develop- 



ment of methods for minimizing or eliminating 

 compounds that increase corrosion and form scale 

 such as calcium sulfate. 



The Office of Saline Water has recently com- 

 pleted what is termed a "Universal" 2.5 mgd plant 

 design. The purpose is to develop a sound basis for 

 the procurement of high quality plants.* The heart 

 of this effort is the development of a performance 

 specification, procedures for procurement, and 

 recommended warranties for such a plant. 



The OSW also has a considerable effort in 

 developing large plant concepts, combination pro- 

 cesses (MSF-VTE and others), and supporting 

 development work. 



An aggressive research effort is being made in 

 the broad area of membrane processes. Major 

 emphasis is placed by the Office of Saline Water 

 on the reverse osmosis process which involves the 

 use of a permselective membrane which allows the 



J. A. Hunter, "Advances in Desalting Technology" 

 (International Conference on Water for Peace, Washing- 

 ton, D.C., May 1967). 



''Ibid. 



1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1955 1966 1967 1968 



Figure 1. Approximate expenditure breakdown of OSW activity since 1953 into major 

 process categories. 



VII-226 



