298 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
and ammonia gases which are collected and used again to regenerate 
the exchange resins in the bed. Thus, the costly chemicals used for 
regeneration are replaced by heat. Solar heat may be applicable. 
More information, such as the type of construction materials re- 
quired, durability or life of the exchange resins, etc., is essential 
before precise cost estimates can be made. 
Solvent extraction—The extraction of water from saline solutions 
by an organic solvent, to be recovered later from the extracted mixture 
of water and solvent by temperature change, has been found sufli- 
ciently promising for further research. One of the best solvents [44] 
so far found is N-ethyl-n-butyl amine, which extracts about 80 per- 
cent water at 30° C. and retains about 13 percent at the separation 
temperature of 75° C. The process is under development at Texas 
A. & M. College, and satisfactory laboratory equipment has now indi- 
cated the need for pilot-plant development which is being initiated. 
Biological action—Preliminary study of the desalting action of 
biological membranes has very recently led to a research under the 
United States program in which algae are to be grown in a basin of 
sea water to take up salt and later removed to a second basin for 
partial removal of the salt taken up [27]. Pure cultures of several 
hundred algae have been grown in synthetic sea water and tests are 
starting on determination of salt uptake. 
Use of nuclear energy.—Owing to the high cost of nuclear gener- 
ated electrical energy, it was originally felt that nuclear energy would 
probably not play an early role in saline-water conversion. How- 
ever, in 1957, the Office of Saline Water undertook a study of the 
possible use of low-temperature nuclear heat directly in evaporation 
processes. Following a preliminary investigation carried out by the 
Office of Saline Water [18], the U.S. Atomic Energy Commission, 
and the Fluor Corp. of Whittier, Calif., a design study is now being 
made of two nuclear-heated plants employing improved flash distilla- 
tion, one of 1 million gallons per day, the other of 20 million gallons 
per day. 
Substantial non-Federal research and development in desalting 
has been conducted in the United States by private industrial organi- 
zations. That work consists mainly of practical improvements in 
multiple-effect, flash, and vapor-compression distillation, and devel- 
opment of electrodialysis. The University of California [43] has 
carried out a research and development program in several fields in- 
cluding distillation, solar distillation, ion exchange, osmosis, and 
several exploratory researches. 
Saline-water conversion research and development outside the 
United States in general parallels and supplements that in America. 
In 1952 the OEKEC organized Working Party No. 8 to serve as an 
