d e F h k in y
= = = = = = =
Q
=
V = V, = w = x
=
diameter of reactor, cm. constant, 2.71828 flow rate of solution, c m 3 per minute height of fixed bed, cm. constant, Equation 7 constant, Equation 7 equilibrium concentration of solute in solid phase, mg. P 0 4 3 -per gram quantity of solute in solid phase, mg. volumetric throughput, liters final volumetric throughput, liters weight of fixed bed, grams variable
Greek Letters T = constant, 3.1416 r = time Literature Cited American Public Health Association, “Standard Methods for the Examination of Water and Wastewater.” 12th Ed.. New York, 1965. Amundson, N. R., J . Phys. Colloid Chern. 54, 812-20 (1950). Bogoyavlenskii. A. F.. Belov. V. T.. Kozvrev. E. M.. Izv. Vysshikh Uchebn. Zaoedenii Khim.’ i K h h . Tekhnol.’3(4), 61&19 (1960). Churms, S. C , , J . S. African Chem. Inst., 19(2), 98-114 (1966). Cole, C. V., Jackson, M. L., J. Phys. Colloid Chem. 54, 128-55 (1950).
Colwell, C. J., Dranoff, J. S., A.I.CI2.E. J. 12, 304 (1966). Crank, J., “Mathematics of Diffusion,” pp. 121-47, Oxford Univ. Press., New York, 1956. SCI. TECHKOL. 2, 268-75 Dryden, F. D., Stern, G., ENVIRON. (1968). Edwards, G. P., Molof, A. H., Schneeman, R. W., J . Am. Water Works Assoc. 57, 917-25 (1965). Hach Chemical Company, “Water and Wastewater Analysis Procedures,” Catalog No. 10, Ames, Iowa, 1967. Hougen, 0. A., Marshall, Jr., R. W., Chem. Eng. Progr. 43, 197 (1947). Kar, K. R., J . Sci. Ind. Research (India) 17B, 175-8 (1958). National Bureau of Standards, “Tables of the Error Function and Its Derivative,” Applied Mathematics Series 41, U. S. Government Printing Office, Washington, D . C., 1954. Neufeld, R. D., M.S. thesis. Northwestern University. - , Evanston, Ill., 1968. Sinha, P. R., Choudhury, A. K., J . Indian Chem. SOC.31, 21119 (1954). Tien, Chi,Thodos, George, A.Z.CI1.E. J . 5, 373 (1959). Valentine, D. W., M.S. thesis, Northwestern University, Evanston, Ill., 1967. Weinberger, L. W., “Waste Treatment for Phosphorus Removal,” Lake Michigan Enforcement Conference, Chicago, Ill., February 1968. Yee, W. C., J. A m . Water Works Assoc. 58, 239-47 (1966). Receiced for reciew September 3, 1968. Accepted March 20, 1969. This study was made possible by the Piiblic Health Service Traineeship program.
Fractionation of Bomb-Produced Rare-Earth Nuclides in the Atmosphere Myint Thein,’ J. N. Beck, Horace Johnson, W. W. Cooper, M. A. Reynolds, R . S. Clark, J. 0. Baugh,2 and P. K. Kuroda Department of Chemistry, University of Arkansas, Fayetteville, Ark. 72701
a The phenomenon of atmospheric fractionation of fission
products occurs on a world-wide scale when fresh debris from a nuclear explosion travels eastward and circles the earth. Among the rare-earth radionuclides, lY and I4lCe were often depleted relative to other rare earths in fallout samples collected several days after the Chinese nuclear detonation of December 24, 1967. This is due to the existence of gaseous precursors in the mass 91 and 141 chains. Pronounced fractionation phenomena were also observed for fission products at mass numbers A = 89 (Sr), A = 131 (I), and A = 140 (Ba).
T
he fact that fresh debris from a single nuclear explosion travels eastward and circles the earth within a few weeks has recently been reported (Cooper and Kuroda, 1966; Kuroda, Miyake, et al., 1965; Thein and Kuroda, 1967). Fission products are highly fractionated in the so-called “hot” particles (Baugh, Yoshikawa, et al., 1967; Clark Yoshikawa, et ul., 1967; Rao, Yoshikawa, et al., 1966). Since large and small fallout particles are expected to travel Present address, Chemistry Department, Northeast Louisiana State College, Monroe, La. 71201. * Present address, Department of Chemistry, Boston College, Chestnut Hill, Mass. 02167.
at different velocities in the atmosphere, the fallout observed at different times and at different localities of the earth should reflect the particle size distribution in time and space. Thus. the effects of atmospheric fractionation of nuclear debris should be observable on a global scale. Knowledge of the global atmospheric fractionation of nuclear debris is essential in the understanding of the process of fallout from nuclear weapons tests. The atmospheric fractionation phenomena in local or closein fallout processes have been studied extensively by many investigators (Klement, 1965). The studies on world-wide fractionation phenomena are more difficult and require a single isolated nuclear test explosion so that it is possible to trace the movement of the fresh debris for a sufficiently lonc period, while the debris circles the earth at least once. It is also essential to make sure that the observed fractionation phenomena are not caused by secondary processes, such as fractionation due to incomplete dissolution of the samples. In the present study, we have measured a number of rare-earth nuclides, as well as Sr, Ba, Te, and I isotopes in rain collected at Fayetteville, Ark. The rare-earth nuclides are particular11 suited for this type of investigation, because they can not be easily fractionated under laboratory conditions. Experimental
For the radiochemical separation of the rare-earth nuclides from rain, 8 to 24 liters of rain samples were taken in each case. About 20 mg. each of Y, Ce, Pr, Nd, Sm, and Eu nitrates Volume 3, Number 7, July 1969 667
Nuclide 9 'Y l4lCe lrrCe 143pr 14iNd '4'Pm
49Pm l5lSm 13sm 155E~l l56Eu %r 9@Sr 1l5rnCd 129mTe 1311
132Te IdOBa b
Half-!ife 59d5 32.5d 285d 13.7d 11. Id 2.6~ 53h 9OY 47h 1.8y 15.2d 50.6d 28, 8y 43d 34d 8.05d 78h 12.8d
Table I. Fission Products in Rain a t Fayetteville, Ark. Concentrations in Rain (P.c.;I,)* 12-30-67
1-1-68
1-2-68
1-5-68
92 =k 7 115 + 12 44 i 4 400 I 30 198 = 18 4 . 8 =t0 . 6
135 i 9 230 = 30 78 i 8 1040 = 80 360 i 20 17.1 z 1 . 4
42 6 83 I 8 31 3 220 i 20 88 zt 6 7.4 i0.6
19 I 2 13 + 2 12 i 2 36 = 3 140218 120=14
-
-
-
96 =t 8 230 i 30 66 i 7 880 i 60 340 + 30 12.2 i 1 . 1 100 i 20 1 . 3 +C 0 . 3 22 i 5
-
1 . 6 =t0 . 2
-
-
-
4.5 = 0.5
-
2.5 1 0 . 3
*
3.8 0.5 24.8 i 1 . 7 4 . 5 2 i 0.16 -
10.6 = 0 . 3 30 = 3 13 i 2 180 i 20
5.6 i0.8 34 i 3 3.08 i 0.13 0.50 i 0.20 55.0 9.0 54 i 5 35 i 4 138 =t 14
*
* *
1-8-68
-
-
0.8
x
-
-
65 6 4 . 8 =t0 . 5 0.67 i 0.13 38 4 12.6 1.3 5.0 i 0.5 367 37
147 i 10 6 . 5 If 1 . 2 0 . 4 5 i 0.15 9.7 0.5 5.1 i 0.5
* *
*
-
0.1
46 I 2 3.43 i 0.52 -
1.9 i 0.5 -
-
263 It 26
154
=t
15
As of the d a t e of rainfall. y = years, tl = d.iys, h = hours.
were added to the sample. The solution was then evaporated to about 20 ml., transferred to a Teflon beaker, and further evaporated to a small volume. A 20-ml. portion of H N 0 3 was added to the solution and again evaporated to a small volume. The solution was then treated with 20 nil. of fuming H N 0 3 , 10 ml. of conc. IiCIOl and 10 ml. of conc. HF, and Table 11. Daily Variation of Large and Small Fallout Particles in the Ground-Level Air a t Fayetteville, Ark. Number of Particles in 3300 m3-of_Air _ Date Large (>2-3 p) Small (
