The concentration of magnesium in sea water is 
1,300 parts per million. By contrast bromine is 
only about 65 ppm, or one-twentieth that of 
magnesium. Yet the cost per pound of extraction 
of bromine is one-third less than magnesium 
despite the lower bromine concentration. These 
lower total costs for bromine are due to fewer 
processing steps and to lower power, labor, and 
capital equipment costs. Bromine is released di- 
rectly from sea water as an element while mag- 
nesium is not. Thus the experience with bromine 
encourages a belief that, if the technology can be 
developed, other elements with even lower concen- 
trations may be economically extracted from the 
sea. 
To obtain other elements from sea water, it will 
be necessary to modify current extraction tech- 
niques. For example, brines in desalting processes 
are reaching increasingly higher concentration 
ratios. Eventually this may permit economical 
recovery of additional chemicals. 
Attention should be given to the possibility of 
local concentrations in the ocean environment that 
may have future economic importance. For ex- 
ample, gold concentrations in sea water have been 
as high as 60 milligrams per ton, compared to an 
average sea water gold content of 0.04 mg per ton. 
More recently, attention has been focused on the 
hot spots at the bottom of the Red Sea, where 
bodies of stagnant or semi-stagnant waters have 
been found to contain zinc, copper, and other 
mineral constituents in concentrations ranging 
from 1,000 to 50,000 times normal. 
Extraction of elements directly from the sea 
using natural processes is another potential 
method. Some marine organisms concentrate trace 
elements in ratios as high as 100,000 to 1, as with 
vanadium. Lead is concentrated as much as 20 
million to 1 in certain fish bones. Biological 
concentration suggests future techniques of re- 
covering valuable trace elements. One could learn 
which organisms concentrate the desired elements 
best, culture them in sea water, harvest them, and 
extract the elements; or better yet, imitate the 
biological technique and synthesize it industrially. 
Recommendations: 
Further research and development on ion ex- 
change and biological techniques should aim at 
extracting elements with low concentration. 
Techniques for concentrating brines from de- 
salting plants will improve the possibility of 
by-product recovery. Hence the technology to 
permit commercial utilization of these techniques 
should be encouraged to allow recovery of chem- 
icals either now or projected to be in short supply. 
Examples include potassium compounds, uranium, 
and boron. 
Vil. DESALINATION 
Sea water can be used for human consumption 
if its saline content is reduced from 35,000 parts 
per million (ppm) to 1,000 ppm or less. However, 
the U.S. Public Health Service has established 
standards that good drinking water should not 
contain more than 500 ppm. The term desalting 
actually refers to more than just extraction of salt. 
It also encompasses removal of other impurities, 
such as those found in brackish inland water and, 
pollutants from waste water. Salt is one of the 
most highly soluble pollutants, and any process 
designed to remove salt from water usually re- 
moves other contaminants. 
In contrast with extraction of minerals from sea 
water, desalination has received much attention by 
the public and the Federal Government, especially 
through the establishment of the Office of Saline 
Water (OSW). Desalination is important because an 
adequate fresh water supply is essential for life— 
for drinking, cooking, cleansing, diluting, irriga- 
tion, industry, fish, wildlife, etc. Despite its 
recognized importance, the total effort in desalting 
has been small compared to many other research 
and development programs. 
The Honorable Stewart Udall, Secretary of the 
Interior, stated that:°° 
We are directing our efforts to the solution of two 
separate problems simultaneously. A way must be 
found to supply the water needs of large metropol- 
itan areas near the coast where conventional water 
is in short supply. Equally important, we need to 
develop a process that will improve the quality of 
brackish and minerally charged waters for inland 
communities at prices that will make this improve- 
ment economically feasible. 
3° Hearings before the Senate Subcommittee on Irriga- 
tion and Reclamation of the Committee on Interior and 
Insular Affairs, 89th Congress, First Session, on S. 24, 
May 1965, pp. 5, 9. 
VI-197 
