exahange capacity before much of the radioisotopes can be adsorbed. 
It is necessary to neutralize the acid wastes. 
Neutralizing Acid Wastes: To neutralize the acid with NaOH 
for adsorption defeats the purpose of the process because the Na ion 
is just as bad as the H ion. Ion permeable and semi-permeable membranes 
in conjunction with an electric current offer possibilities for by- 
passing chemical neutralization. The current drives the oppositely 
charged ions to oppositely charged terminals leaving the solution 
virtually neutralized. Aluminum nitrate can be treated much the same 
way. 
Activity Concentration in the Clay: As an indication of ultimate 
activities in the clay, about 45 mg. of pure sr? can be put in 1 gm. 
of clay. Since there are approximately 200 curies of activity per 
oe 45 mg. of ere will amount to roughly 10 curies per gram 
gm. of Sr 
of clay. If the isotope has a half-life of one year instead of 20 
as ee? has, and if the same amount of the isotope can be put on the 
clay, the initial activity will be 20 times as great as would be the 
case with ae With mixed fission products it is estimated that about 
10 curies of aged material can be adsorbed per gram of clay. 
Ruthenium causes trouble in the clay adsorption process by 
acting as an anion. It will pass through the cation exchanger, clay, 
but can be later collected on an anion exchanger. 
By firing the clay to about 800° C., the structure of the clay 
is altered and the adsorbed fission products become permanently attached. 
The resulting product is practically unleachable. Leaching from the 
flay in a flowing solution levels off with time and amounts to about 0.2%. 
(For a further discussion of the clay adsorption process, 
(es 
see Dec. 1954, "Nucleonics", 
