An evaluation of the effectiveness of polyelectrolyte coagulant aids for the removal of radioactive isotopes by water tr...

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An evaluation of the effectiveness of polyelectrolyte coagulant aids for the removal of radioactive isotopes by water treatment processes
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Hannah, Sidney Allison, 1930-
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Table of Contents
    Title Page
        Page i
    Acknowledgement
        Page ii
    Table of Contents
        Page iii
    List of Tables
        Page iv
        Page v
    List of Figures
        Page vi
        Page vii
        Page viii
    Chapter 1. Introduction
        Page 1
        Page 2
        Page 3
    Chapter 2. Decontamination of water
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Chapter 3. Polyelectrolytes
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
    Chapter 4. Experimental materials and procedures
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
    Chapter 5. Discussion of results
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
    Chapter 6. Conclusions
        Page 42
        Page 43
        Page 44
    Appendices
        Page 45
    Appendix 1. Abbreviations used in tables and figures
        Page 46
    Appendix 2. Tables
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
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        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
        Page 77
        Page 78
        Page 79
        Page 80
        Page 81
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        Page 83
        Page 84
        Page 85
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
        Page 91
    Appendix 3. Figures
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
        Page 99
        Page 100
        Page 101
        Page 102
        Page 103
        Page 104
        Page 105
        Page 106
        Page 107
        Page 108
        Page 109
        Page 110
        Page 111
        Page 112
        Page 113
        Page 114
        Page 115
        Page 116
        Page 117
        Page 118
        Page 119
        Page 120
        Page 121
        Page 122
        Page 123
    List of references
        Page 124
        Page 125
        Page 126
        Page 127
        Page 128
        Page 129
    Biographical sketch
        Page 130
        Page 131
Full Text












An Evaluation of the Effectiveness of Polyelectrolyte

Coagulant Aids for the Removal of Radioactive

Isotopes by Water Treatment Processes











By
SIDNEY ALLISON HANNAH












A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY












UNIVERSITY OF FLORIDA December, 1962













ACKNOWLEDGMENTS



The author wishes to express his sincere appreciation to his committee chairman, Dr. A. P. Black, and to Professor F. W. Gilereas, co-sponsor of the investigation, for their guidance and assistance. Special thanks are also due the other members of his supervisory committee, Dr. W. S. Brey, Dr. J. M. Pearce, and Dr. H. E. Schweyer.

The author is very grateful to Mr. A. C. Printz, Jr., Professor G. B. Morgan, and the staff of the Phelps Sanitary Research Laboratory for their valuable assistance.

Gratitude is also expressed to the Office of Civil and Defense Mobilization whose financial support made this project possible.

























i














TABLE OF CONTENTS

Page

ACKNOWTEDJENTS......o.o...o ...........................o~ ii

LIST OF TABLE S........................ iv

LIST OF FIUE .. .o o...v!.

CHAPTER



II.* DECONTAMINATION OF WATER..... .......... 4

III. POLYELECTROLYTES.. ..*.*.*...... ****** 12

IV. EXPERIMENTAL MATERIALS AND PROCEDURES....* ....... 20

V. DISCUSSION OF REsULTS..o......................... 2?

VI.* CONCLUSIONS.o........................ 4.2

APPENDICES

I. ABBREVIATIONS USED IN TABLES AND FIOURS......... 46

II.* TABLES............................. 4.7



LIST OF REFERENCES................... .........***oooooooo~o~ 124

BIOGRAPHICAL SKETCH.....*.. .......... oo**. ........ .... 130













LIST OF TABLES

Table Page

1. CHARACTERISTICS OF SELECTED RADIOISOTOPES .............. 3

2. CHE4ICAL ANALYSES OF WATERS ............................ 23

3. SORPTION OF Cs137 FROM TAP WATER BY VARIABLE DOSAGES OF C48

4. THE EFFECT OF pH ON SORPTION OF Cs137 FROM TAP WATER Br KAOLINITE AND VOLCLAY. ............................. 49

5. THE EFFECT OF VARIABLE DOSAGES OF LIME ON REMOVAL OF Cs137 FROM TAP WATER WITH 1000 ppm ILLITE AND 25 ppm
FERRIC SULFATE................................... 50

6. REMOVAL OF Sr89 FROM WELL WATER WITH 188 ppm LIME, 35 ppm SODA ASH, ANDDIS-06........................... 51

7. REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCIAY AND VARIABLE DOSAGES OF COAGULANT AIDS................. 52

8. REMOVAL OF Sr89 FROM WELL WATER WITH LIME, SODA ASH, AND VARIABLE DOSAGES OF CLAYS................ .......... 55

9. REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCLAY AND VARIABLE DOSAGES OF LIME, SODA ASH, AND DIS-106.... 57 10. REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCLAY,
202 ppm LIME, 45 ppm SODA ASH, AND VARIABLE DOSAGES
OF N17 ........ ........................................... 58

11. REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCLAY,
202 ppm LIME, 45 ppm SODA ASH, AND VARIABLE DOSAGES OF

12. REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCLAY,
202 ppm LIME, 200 ppm SODA ASH, 10 ppm STABLE Sr, AND
VARIABLE DOSAGES OF N17 .............. ...... ........... 60

13. REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCIAY,
EXCESS LIME (402 ppm), EQUIVALENT SODA ASH (326 ppm),
10 ppm STABLE Sr, AND VARIABLE DOSAGES OF N17.......... 61



iv









Table Page

14. REMOVAL OF Pm'47 FROM TAP WATER WITH 60 ppm ALUM OR 36 ppm FERRIC SULFATE AND VARIABLE DOSAGES OF COAGULANT 15. R0OVAL OF Pm1'7 FROM WELL WATER WITH VARIABLE DOSAGES OF CIAYS.................................. ..... ..... 66

16. REMOVAL OF Pm7 FROM WELL WATER WITH VARIABLE DOSAGES OF LIME AND SODA ASH..................................... 67

17. REMOVAL OF Pm147 FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, AND VARIABLE DOSAGES OF COAGULANT AIDS.. 68 18. REMOVAL OF pX147 FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, 500 ppm CLAY, AND VARIABLE DOSAGES OF
COAGULANT AIDS........................................... 71

19. REMOVAL OF 1131 FRC WELL WATER WITH 100 ppm ACTIVATED CARBON, CHLORINE, AND VARIABLE DOSAGES OF ALUM OR FERRIC
SULFATE.................................... .............. 72

20. REMOVAL OF 1131 FRO4 WELL WATER WITH 100 ppm AQUA NUCHAR A, CHLORINE, AND VARIABLE DOSAGES OF COAGULANT


21. COAGULATION OF CONCENTRATED URANIUM SOLUTION WITH LIME AND ALUM................................................. 74

22. COAGULATION OF CONCENTRATED URANIUM SOLUTION WITH LIME AND FERRIC SULFATE.................... ...................75

23. REMOVAL OF URANIUM FROM WELL WATER WITH 30 ppm ALUM, KAOLINITE, AND COAGULANT AIDS. .... ..... ........... 76

24. REMOVAL OF URANIUM FROM WELL WATER WITH 25 ppm FERRIC SULFATE, KAOLINITE, AND COAGULANT AIDS .............o...... 78
25. REMOVAL OF URANIUM FROM WELL WATER WITH 202 ppm LWEE, 46 ppm SODA ASH, KAOLINITE, AND COAGULANT AIDS......... .. 80

26. SUMMARY OF TuRZDITY REDUCTION WITH COAGULANT AIDS ....... 82 27. SUMMARY OF ACTIVITY REMOVAL WITH COAGULANT AIDS.......... 87






V













LIST OF FIGURES
Hyre Pap Figure Page
1. SORPTION OF Csl37 FROM TAP WATER BY VARIABLE DOSAGES
OF CLAY..... ........... .......... ..... .............. ........ 93

2. THE EFFECT OF pH ON SORPTION OF Cs137 FROM TAP WATER BY 1000 ppm FULLERS EARTH OR 1000 ppm ILLITE................ 94e

3. REMOVAL OF Cs137 FROM TAP WATER BY 1000 ppm FULLERS EARTH OR ILLITE WITH VARIABLE DOSAGES OF N17................ 95
4. REMOVAL OF Csl37 FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, 1000 ppm FULLERS EARTH OR ILLITE, AND
VARIABLE DOSAGES OF DIS-106................................. 96
5. REMOVAL OF Cs137 FROM WELL WATER WITH 202 ppm LIME,
46 ppm SODA ASH, 1000 ppm FULLERS EARTH OR ILLITE, AND
VARIABLE DOSAGES OF "SiOz"................ ....*.. ** ......*..*.* 97

6. REMOVAL OF Cs137 FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, 1000 ppm FULLERS EARTH OR ILLITE, AND
VARIABLE DOSAGES OF CN..................................... 98

7. REMOVAL OF Cs37 FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, 500 ppm FULLERS EARTH, 500 ppm ILLITE,
AND VARIABLE DOSAGES OF CN................................ 99

8. THE EFFECT OF Mg ADDED AS MgC1 ON THE REMOVAL OF Cs137 FROM WELL WATER WITH LIME, SODA ASH, 500 ppm FULLERS
EARTH, AND 500 ppm ILLITE. ........... ...................... 100

9. THE EFFECT OF STABLE Cs ON THE REMOVAL OF Cs137 FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, AND
1000 ppm FULLERS EARTH OR 1000 ppm ILLITE................... 101

10. THE EFFECT OF SODA ASH DOSAGE ON REMOVAL OF Sr89 FROM
WELL WATER BY LIME-SODA SOFTENING......................... 102
89
11. REMOVAL OF Sr89 FROM WELL WATER WITH VARIABLE DOSAGES
OF C LAY **************************************. ............... 103

12. REMOVAL OF Pm7 FROM TAP WATER BY COAGULATION WITH
VARIABLE DOSAGES OF ALUM OR FERRIC SULFATE............... .. 104



vi








Figure Page
13. THE EFFECT OF pH ON REMOVAL OF Pml7 FROM TAP WATER WITH
60 ppm ALUM OR 36 ppm FERRIC SULFATE....................... 105
14. REMOVAL OF Pm 7 FROM WELL WATER WITH VARIABLE DOSAGES OF
CLAYS .................................................... 106
15. REMOVAL OF Pm7 FROM WELL WATER WITH 46 ppm SODA ASH AND
VARIABLE DOSAGES OF LIME.................................. 107
16. REMOVAL OF pm7 FROM WELL WATER WITH 202 ppm LIME, 46 ppm
SODA ASH, AND VARIABLE DOSAGES OF ACTIVATED SILICA......... 108 17. REMOVAL OF PI7 FROM WELL WATER WITH VARIABLE DOSAGES OF ACTIVATED CARBON........................................... 109

18. REMOVAL OF 1131 FROM WELL WATER WITH VARIABLE DOSAGES OF
ACTIVATED CARBON......................... ........ ...... 110
19. REMOVAL OF 1131 FROM WELL WATER WITH VARIABLE DOSAGES OF CHLORINE AND 50 ppm ALUM OR 40 ppm FERRIC SULFATE.......... 111 20. REMOVAL OF 1131 FROM WELL WATER WITH VARIABLE DOSAGES OF CHLORINE AND 100 ppm C-190-N ........................... 112
21. REMOVAL OF 1131 FROM WELL WATER WITH VARIABLE DOSAGES OF CHLORINE AND 100 ppm AQUA NUCHAR A......................... .13
22. REMOVAL OF 1131 FROM WELL WATER WITH VARIABLE DOSAGES OF CHLORINE AND 1000 ppm AQUA NUCHAR A....................... 114
23. REMOVAL OF 1131 FROM WELL WATER WITH 0.1 ppm CHLORINE AND VARIABLE DOSAGES OF AQUA NUCHAR A...................... 115
24. REMOVAL OF 1131 FROM WELL WATER WITH 100 ppm AQUA NUCHAR A, 202 ppm LIME, 46 ppm SODA ASH, AND VARIABLE DOSAGES OF
CHLORINE.................................................. 116
25. THE EFFECT OF VARIABLE ACTIVITY ON REMOVAL OF 1131 FROM WELL WATER WITH 0.1 ppm C12 and 100 ppm AQUA NUCHAR A...... 117 26. THE EFFECT OF STABLE I- ON REMOVAL OF 1131 FROM WELL WATER WITH 0.1 ppm Cla and 100 ppm AQUA NUCHAR A................. 118
27. THE EFFECT OF pH ON PRECIPITATION OF URANIUM WITH LIME AND SODIUM HYDROXIDE....................................... 119

28. COAGULATION OF DILUTE URANIUM SOLUTION WITH KAOLINITE AND ALUM OR FERRIC SULFATE E............................... 120



vii








Figure Page
29. REMOVAL OF URANIUM FROM DILUTE URANIUM SOLUTION WITH LIME AND KAOLITE...................................... 121

30. REMOVAL OF URANIUM FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, 500 ppm KAOLINITE, AND KELGIN W.......... 122 31. REMOVAL OF URANIUM FROM WELL WATER WITH 202 ppm LIME, 46 ppm SODA ASH, 500 ppm KAOLINITE, AND ACTIVATED
SILICA................................ee................. 123





































viii














I. INTRODUCTION



Radioactive contamination of our water supplies has increased

in recent years, paralleling the advances in nuclear technology and the growing uses for radioisotopes. These radioactive materials constitute a serious health hazard if present in significant concentrations and make the water unfit for many industrial processes. The discharge of radioactive substances is presently regulated by laws designed to ensure the safety of water users but abnormal conditions may result in dangerous levels of activity in the watercourses. In wartime, the widespread use of nuclear weapons would certainly result in severe contamination. Conventional water treatment processes have removed var7ing amounts of contamination depending on treatment Used, source and COMPOAtion of the activity,, and on other substances present in the water. The purpose of this investigation was to deter-mine the possible benefits of polyelectrolyte3 as aide to the conventional and specially modified treatment processes in water decontamination.

The major sources of radioactive water contaminants include the fallout from nuclear weapons explosions, wastes from production of radioisotopes or recovery of reactor fuel elements, and Wastes from individual users of isotopes. The chemical and physical properties Of the contaminants determine the extent to which they may be removed from water by a selected process. These properties in turn depend on the source of the contamination.


1 -






-2

Nuclear weapons detonated over land form melted silica spheres

which are only sparingly soluble in the pH range of natural waters (1,2). Uranium mill wastes, containing the radioactive daughter products of uranium disintegrations, hold 99 per cent of the most dangerous radioisotope, Ra226, in an insoluble form within the spent slims and sands (3). On the other hand, the chemical wastes will generally contain the radioelements in a soluble ionic form. Smaller fallout particles, which deposit downwind from a nuclear blast, may have volatile fission products condensed on their surfaces and thus cause considerable water contamination by solution of the activity (4). For complete decontamination, both the soluble and the insoluble activity must be removed.

Specific radioelements which enter the body are selectively

absorbed from the gastrointestinal tract and may then be generally distributed throughout the body fluids or may be concentrated in particular organs. The health hazard of a particular radioeloeent may be evaluated by considering the rate of absorption, the body distribution, the half life of the material, the nature and energy of the radiation, and the rate of excretion from the body. Maximum permissible conentrations (MPC) have been determined for many radioisotopes (5).

Five elements representing a potential hazard to water users

were selected for removal studies with polyelectrolytes. Their characteristics are presented in Table 1. With the exception of Pm1247, all are difficult to remove by ordinary coagulation.







3






TABLE 1

CHARCERISTICS OF SELECTED RADIOISOTOPES



Elemnt MPC(P.C/ml) Chemical. Form Critical Organ


Cs137_Ba137m 2 x 10O- CsCi in HCl Total body

p472 x 10-3 PmCl3 in HCU Gatrointestinal Tract

Sr 891x1 4 SrCl. in HU Bore

U238 4 x 10 -4 U02(N03)2-6 H20 Gastrointestinal Tract

1112 x 105 Nal in basiC Thyroid
NaSO3 soin.














II. DECONTAMINATION OF WATER



The radioactive elements present in fallout generally comprise less than one part per billion by weight of the total fallout (4). Much inactive material, consisting of weapon vehicle fragments and debris from the ground below the explosion, must be removed from the water in order to remove the activity. To be removed by conventional treatment processes, soluble activity must be precipitated or incorporated into another solid present in the water. The literature was reviewed to find the optimum conditions for decontamination.



Natural Decontamination


A number of natural processes serve to reduce the activity

before the water reaches the treatment plant. Such processes include sedimentation, ion exchange and sorption by silts and clays, and biological concentration by organisms in the streams. These often afford only temporary storage for activity and may result in surges of activity when high flows resuapend the solids. Concentration of radioactivity by natural agents is reviewed in OFSL-2557 (6).



Removal by Water Treatment Processes


Only those procedures which are readily adaptable to existing treatment plants were studied with polyelectrolytes. These include

4 -







5

ion exchange and sorption on solids, coagulation and precipitation, and lime-soda softening. Other processes such as distillation, evaporation, electrodialysis, electrolytic separation, solvent extraction, and freezeout have been studied by others for activity removal from wastes but they are impractical, at the present time, for treating the large volumes of water required for public consumption. Ion Exchange and Sorption on Solids

Clays and Minerals. Clays and minerals, which form natural ion

exchange systems, vary in their effectiveness for removing

radioactivity from water. Some of the radioelements are held

to the outside of the solid by surface valences while others

penetrate the lattice and bond internally. The solids should

be finely ground to increase the surface area and permit easier

access to the interior.

Christenson et al. (7) found that celite, kaolin, tuff,

and pumice would remove plutonium from laboratory wastes. Lacy

(8) slurried a mixed clay (montmorillonite and kaolinite) with

tap water containing radioisotopes and removed &4-95 per cent of Sr 90 -Y90 but only 5 per cent of 1131, Other investigators (9-13)

found that clays had a particularly strong affinity for cesium.

Strontium was usually taken up to a lesser degree.

Foreign ions in solution interfere with removal of radioelements by competing for the available sorption sites. Calcium

ion greatly depresses strontium uptake because of the chemical similarity of the two elements (10,139,14). Since hydrogen ions

also depress uptake, best removal of activity generally occurs

at high pH (899). Davey and Scott (15) showed that the presence







6

of sulfate ion decreased the amount of uranium adsorbed on clay.

Extruded montmorillonite was found to be a good column adsorbent but many cations could be leached out of the clay by continued passage of water (16). A comparison of slurry and column treatments showed that a single slurry treatment reached only 50 per cent of the clay saturation value reached in a column for the same activity (13)- The contact tim between the water and the solid should be as long as practical since equilibrium is very slowly attained with some isotopes (8,12).

Straub et al, (17) and Elia3s*n et al. (18) used clay in conjunction with alum and ferric chloride or ferric sulfate for removal of activity. Other common minerals found to have adsorptive properties for radioisotopes are Florida pebble phosphate (19) and limestone (20). Robinson (21) has compiled a bibliography concerning ion exchange minerals and disposal of radioactive wastes.

Ion Exchange Resins. The ion exchange resins commonly used for water softening will also remove radioisotopes from water. Either cation exchange resins or anion exchange resins may be required depending on the ionic form of the activity. Friend (22) removed greater than 99 per cent of Sr 89 and 131 from water with cation and anion exchange resins respectively and Downing et al. (23) removed greater than 97 per cent of Sr 89 with synthetic resins and aluminOAUCatS3.

It has been noted that activity continues to be removed by cation exchange resins long after their capacity for removing hardness has been exhausted (23,,24) but resin capacity for cesium






-7

is only about half that for hardness.* The water pH may affect

activity removal by influencing solubility or uptake of ions.

Interference due to complexing agents in reduced at low pH (25).

Batch-type treatment with ion exchange resins was found to be less efficient than column-type operations but equilibrium was

more readily accomplished (26).

Special Methods.* Lauderdale and Emmons (27) succeeded in

removing a mixed fission product from tap water by passing it

through two glass columns containing steel wool, burnt clay,,

activated carbon,, and mixed cation and anion exchange resins.

Lacy (28) and Lauderdale (29) slurried waters containing radioisotopes with metal dusts and removed up to 99.9 per cent of

the activity. Cs137 and 1131 were not effectively removed by

this process. Straub at al. (17) used activated carbon to

remove 1 131 Nerwell and Christenson (30) removed Plutonium

from laboratory and laundry wastes by adsorption on activated

carbon, activated sludge, and trickling filter organisms. Coagulation and Precipitation

Most coagulation studies have been carried out on radioactive wastes or on waters dosed with radioisotopes. With the exception of the cations above Periodic Group II, activity removals are usually poor with alum and iron salts unless supplementing procedures are Used.

Christenson et al. (7), Newell and Christenson (30), and

Pressman and Lindsten (31) used ferric chloride and lime to remove plutonium from water and also found alum to be effective but not as good as ferric chloride. Straub et al. (17) used alum and ferric chloride with clay and soda ash in jar tests to remove up to 98 per cent







8

of rare earths buit little Sr 89 or 1 131, Other investigators reported poor removals of strontium or iodine by coagulation (23,32,33,34). An overall removal of 70-73 per cent of mixed fission products, Simulating radioactive constituents remaining one month after a nuclear explosion, was obtained by coagulation with alum, lime, and sodium silicate in a pilot plant (35).

Eliassen et al. (18) and Kaufman et al. (34) removed more than 99 per cent of p32,. as the orthophosphate anion (PO, =), from water in coagulation tests with alum and ferric sulfate.* The primary mechanism of removal was found to be simple counterion adsorption rather than 1somorphous replacement in the floe structure.* Much of the p32 initially removed was desorbed with ti-me if the alum floe was allowed to age. Optimum removals of activity resulted under conditions Of good coagulation as evidenced by the rapid formation of large, easily Settleable floes and optimum turbidity removals.

Burbank et al. (36) Used alum and chlorinated copperas to remove radioactive particulate matter from water. Activity removal was maximum at the optimum pH of floc formation.* A small amount of turbidity was necessary to serve as nuclei for floe formation but quantities over 10 ppm were of little significance in removing particulate matter.

Phosphate coagulation has removed nearly 98 per cent of radiostrontium from water (17,33,37). For best results with this method,9 the pH Should be above 11.3 and the trisodium phosphate to lime ratio should exceed 2.2/1. The addition Of stable strontium aids in precipitation of strontium phosphate (38).

Auxiliary procedures for decontamination of 113l have used CuS3,,, AgNO3, and activated carbon with alum to remove up to 75 per cent of







-9

the activity (17). Carrier iodine with AgNO3 precipitated nearly 96 per cent of the 1131 (32). Sodium hypochlorite added before alum coagulation removed some 111but this may have been due to volatilization (32).

Lauderdale and Eliassen (39) and Bell et al. (40) found lower removals of gross natural fallout activity in municipal water treatment plants than had been obtained in laboratory tests for removal of synthetic fallout products. There were extreme daily variations in activity removal but a trend toward decreasing percentage removals with increasing age of the fallout products was observed.* Since the presence of turbidity, even in large amounts,, had no apparent effect on decontamination, it Was assumed that considerable self-purification had occurred during runoff and storage, leaving the Most difficultly separable fraction behind. There were no significant differences in removal between the different conventional treatment processes.* Over a period of time an average of 50-75 per cent activity removal my be expected (39).

Setter and Russell (141) removed 50-75 per cent of natural fallout products from rain, Cistern, and surface waters by jar teat coagulation. Junkina (42) reported removals of about 70 per cent of Columbia River activity by the Pasco, Washington,, treatment plant. Lime-Soda Ash Softening

With the exception of ion exchange, lime-soda ash softening is

the only conventional water treatment process which gives high strontium removals. Most Of the softening studies have,, therefore, included this element.

Eliassen et al.. (18) removed 74 per cent of Sr by lime-soda ash softening while Hoyt (43) removed 76 per cent of Sr with stoichioMetric






10
lime-soda ash dosages. Pressman and Lindsten (31) reported 97 per cent removal of Pu with the Armyr Mobile Water Purification Unit. Active phosphorus (32 ) was also removed during softening by precipitation as calcium phosphate (18,34). Cowser and Morton (44) reported good strontium removals using the softening process in a waste treatment plant. In a modified process, Goodgal et al. (45) removed 99 per cent of the Sr from water initially containing 41 ppm strontium nitrate by aeration at pH 12.2.* Strontium carbonate was precipitated by carbon dioxide in the air. Removals of 95 per cent of Y9go, 99 per cent of p32 and 94 per cent of mixed fission products by lime-soda softening have been reported (18,34,46).

Removal of strontium in lime-soda ash softening was shown to be due to formation of mixed crystals of strontianite andi calcium carbonate (46). Conditions promoting the removal of radiostrontium include the use of excess soda ash (23,43,46), high pH (43,46) high temperature (46),, excess lime with an equivalent amount of soda ash (43), and recirculation of preformed solids (46). Burbank et al. (36) found that up to 10 ppm added turbidity aided in lime-soda ash softening by providing nuclei for crystal formation and preventing the formation of poorly settling microorystals.

Good strontium removals are a function of high softening

efficiency. where water was not completely softened, Downing et al. (23) found a linear relationship between hardness removed and activity removed. Alexander at al. (47) in testing water samples from 50 cities throughout the United States found that municipal softening plants removed up to 75 per cent of the stable strontium.

In summary, the lime-soda ash softening process appears to be








the best general method of decontamination. It should be supplemented with clay and activated carbon for adsorption of hard-to-remove radionuolides. Coagulants and coagulant aids may be used to promote settling and improve clarification.













III. POLYELECTROLYTES



Polyelectrolytes, widely used as coagulant aids, are high

molecular weight polymers possessing such characteristics of simple electrolytes as electrical charges or ionizable groups. They may be naturally occurring products such as gelatin, starch, or vegetable gums or may be synthetic materials such as polyacrylamides or copolymers of vinyl acetate and maleic anhydride. Cohen et al. (48) list three classes of polyelectrolytes according to the charge on the polymer:

(a) negatively charged or anionic; (b) positively charged or cationic; and (c) compounds having both positive and negative charges called polyampholytes. To this list should be added a fourth, namely nonionic materials such as starch or guar gum. These materials are used in water treatment either alone or in conjunction with metal coagulants to improve clarification, to reduce the coagulant dosage required, to permit overloading of existing facilities, or to improve floc strength and filterability with consequent increase in filter runs.

The polymer molecules, which may be of colloidal dimensions, are surrounded by counterions of charge opposite that of the polymer molecules. This results in an uneven distribution of charges in solution such as in the clay-water system. Katchalsky (49) found that the activity of counterions in a polyelectrolyte solution decreased with increasing ionization of the polyelectrolyte because of their increased attraction to the polymer. The attraction of such charged polymers for


-12-







-13

ions increased rapidly with increasing valence of the ions.* The polyelectrolytes could thus hold radioactive ions.

Fuoss and Sadek (50) demonstrated the strong electrical interactions of polyelectrolytes by mixing dilute solutions of cationic and anionic polymers. Mutual precipitation occurred in concentrations as low as 10-8 molar in polyelectrolytes.

Clay particles in water have been shown to bear a negative

charge throughout the normal pH range used in water treatment (51). The addition of alum, however,, will reduce or reverse this change over much of the pH range. Cationic polymers could adsorb on negative clay particles because of electrostatic attraction while electrostatic repulsion should play a part where anionic polymers were used. Where enough alum or other metal coagulant to reverse the charge was present,, then these electrostatic forces would be reversed. Cohen et al. (4i8). using water of low turbidity, found the anionic polyelectrolytes to be effective only as aids to the metal coagulants. This electrical force picture does not, however, explain why the anionic aide alone will cause large floes to form in slurry concentrations of clay,

Michaels and Morelos (52) listed three Possible mechanisms for coagulation of clay with polyanions: (a) replacement of anionic groups of the clay with anionic groups of the polymer; (b) hydrogen bonding between the solid and the polymer; and (c) the formation of electrostatic bridges between the clay and the polymer by polyvalent cations. Working with slurry concentrations of clay, they concluded that hydrogen bonding between unionized carboxcyl or amide groups on the polymer chain and oxygen atoms on the clay surface was responsible for the adsorption of polyanions.






-14

Ruehrwein and Ward (53) treated montmorillonite with solutions of polycatiOs or polyanions and then subjected the clay to X-ray analysis. The interplanar spacing increased with the polycation, indicating adsorption on the faces of the layers, but remained the same for the polyanion. This procedure, however, did not eliminate the possibility of anion adsorption on the edges of the layers where anion exchange sites are known to occur. Kaolinite was found to adsorb a polyanion with the amount adsorbed being proportional to the polymer concentration up to a saturation value approximately equivalent to the cation exchange capacity of the clay. Added NaCl diminished the repulsive forces between the polymer molecules so that they could be more closely packed au the particle surfaces and adsorption therefore increased.

As in Cohen's work, Ruehrwein and Ward observed that polycations were effective coagulants alone while polyanions served as coagulant aids after a flocculating dose of a metal coagulant had been added. To explain their results, they postulated the formation of polymer bridges between particles. These bridges should form better when the particles are already flocculated, otherwise many of the polyelectrolyte molecules would adsorb completely on individual particles. The polymers also bond particles in the process of flocculation, thus reducing their dispersion by Brownian motion.

In neutral polymolecules, Brownian movement alone determines the molecular shape to be a random coil as the molecular segments rotate around the chemical bonds. In charged polyelectrolytes, the shape results from the equilibrium between Brownian coiling tendency and repulsion between the charged sites along the polymer chain. Fuoss (54) measured the changes in viscosity of a polyelectrolyte as it was diluted







15

and found that the more dilute solutions had much higher viscosities than would be extrapolated from the concentrated solutions.* This was attributed to a stretching out of the polymer chains from mutual repulsion of the charged sites. Katchaisky (4f9) similarly found that specific viscosities of polyelectrolyte solutions increased with the degree of ionization of the polyolectrolyte up to about 60 per cent, then leveled off. This was also said to be due to stretching of the molecules as the electrostatic field strength increased. The rates of change of viscosity showed that at very low ionization, the molecular chains were so tightly coiled as to be almost spherical. At between approximately 10-20 per cent ionization,, the molecules behaved as random flexing coils while at a high degree of ionization, they were fully extended and resembled rigid rods.

Michaels (55) performed controlled hydrolysis experiments on polyanions and concluded that there should be enough charged sites to extend the polymer chains sufficiently to permit interparticle bridging without increasing the charge density enough to interfere with adsorption an the negative clay particles.* Partial charge neutralization by a metal coagulant should increase polyanion adsorption by reducing the repulsive forces. The pH of the solution would be expected to affect the ionization of the polymer and thus affect the ad-sorption and coagulation. Black (56) summarized some of the mechanical aspects of coagulation with polyelectrolytes.

Black and Hannah (51) studied the effects of eight coagulant aids on the charge of clay particles treated with varying dosages of alum. Using electrophoretic techniques, the particle charges were found to vary with changing dosages of alum and aid but the degree of






16

clarification obtained could not be correlated with the final particle charge. The anionic polyelectrolytes would serve as aids to the metallic coagulants while the cationic polyelectrolytes would serve as sole coagulants. AUl of the polyelectrolytes could be made to either aid or inhibit coagulation by selection of dosages of alum or polyelectrolyte.

Black and Willems (57) found coagulant aids to be of value in

removing color from soft waters.* The lowest residual color was usually obtained where the combination of coagulant and aid neutralized the particle charge. However, the low pH used in color removal makes this process impractical for the removal of most radioisotopes from water.

Black and Christman (58) found both anionic and cationic aids to be of value in removing turbidity resulting from lime-soda ash softening. The charge of softening sludge particles was shown to be a function of the amount of Mg+ present in the water. Pure calcium carbonate was quite negative while pure magnesium hydroxide was slightly positive. Increasing amounts of Mgt-+ in a mixed sludge resulted in particle charges more Positive than magnesium hydroxide. Two anionic aids improved clarification of suspensions containing negative particles while increasing the negative charge, therefore adsorption could not be simply electrostatic attraction.

On the practical side,, Rice (59) listed three general methods by which coagulant aids work; they may increase the specific gravity of floc, the strength of floc, or the rate of coalescence of floe. They are particularly valuable in forming a rapidly settling floc in cold water where a metal coagulant alone is insufficient. Black at al. (60), using 17 different coagulant aids with alum to clarify clay suspensions, showed results ranging from great improvement in coagulation to complete







17

inhibition of coagulation. Wadsworth and Cutler (61) coprecipitated anionic and cationic polyelectrolytes on kaolinite and hematite ore pulp to increase the settling rates.

Tests by Cohen at al. (48) showed the effectiveness of one

anionic aid to be nearly Independent of pH, alkalinity, hardness, and turbidity. However, the optimum dosage of anionic aid increased linearly with the alum dosage. The pH range of alum flocculation was not extended by the anionic aid. A cationic aid was effective only in moderately mineralized water and allowed alum coagulation in the presence of such interferences as sodium tripolyphosphate and lignins. Algae, which are negatively charged, were also removed fromu water by the cationic aid.* This is potentially valuable in reducing contamination from organisms which are known to concentrate radioactive constituents. The nonionic aid tested was less effective than either the cationic or anionic aids.

Cowser et al. (62) studied the effects of eight coagulant aids on Oak Ridge National Laboratory radioactive waste effluent containing approximately 50 per cent of the activity associated with suspended solids. The most effective single aids for turbidity reduction, as determined by jar tests, were Hagan 50, Separan 2610, and Aerofloc 3000. Combinations of these aids with Hagan 18 gave further improvement. Plant trials showed that the combination of Hagan 50 and Hagan 18 would significantly reduce the effluent turbidity,, giving a better floe even at low temperature, although complexing agents, such as cleansers and decontaminating compounds, sometimes seriously Interfered with coagulation.

Newell and Christenson (30) found activated silica to be an aid







-18

to chemical flocculation of plutonium wastes where complexing agents such as citrates and phosphates were present. Hoyt (43) used sodium silicate to improve clarification with lime-soda softening and saw removals of Sr 9-Y 9 activity increase from 76 per cent without the aid to 79 per cent with the aid. Activated silica with alum gave no significant rmvlofS89or 113 in coagulation tests (23,32).
Rice (63) listed possible disadvantages of using the organic polyelectrolytes as a frequent shortening of filter runs with a resulting increase in backwash water requirements and the formation of a nonfilterable residual haze from colloidal aluminum oxide sol not already attached to the turbidity particles when the aid is added.

Johnson (64) photographically showed the effects of selected polyelectrolytes on floc formation In different types of water.

From a study of the behavior of many polyelectrolytes, certain procedures for their application become evident.

1. The aid must be applied in such a state that it may be

rapidly dispersed throughout the water. Mixing must be fast and

complete to ensure that all particles of turbidity come in contact with the polymer.

2. The order and time of addition of the coagulant and the aid

must be evaluated. It generally seems better to add the aid

shortly after the coagulant, although the reverse has been reported, particularly in softening with activated silica.

3. The dosages must be properly selected. An excess of aid may

saturate all adsorption sites with single polymer Molecules and

interparticle bridging will be prevented. The adsorbed polyelectrolytes will then repel each other and stabilize the







19

suspension. The use of an aid will sometimes permit a substantial reduction in the amount of coagulant required for satisfactory clarification.

4. The effectiveness of an aid must be evaluated for a particular water depending on its chemical and physical properties and on the particular treatment process employed. The many interacting variables which affect coagulation also affect the choice of aid.














IV. EXPERIMENTAL MATERIALS AND PROCEDURES


The basic experimental procedures for water decontamination

included coagulation with alum and ferric sulfate, softening with lime and soda ash, sorption on clays and activated carbon, carrier precipitation, and combinations of these treatments. Several coagulant aids of different types were used in conjunction with the basic treatments in an effort to increase the amount of radioactivity removed from water.



Materials


Alum

Alum used as coagulant was reagent grade aluminum sulfate represented by the formula A12(S0,)3"18 H20. Ferric Sulfate

Ferric sulfate was reagent grade powder analyzing 75.1 per cent Fea(SO3,)3. Dosages of ferric sulfate are reported as anhydrous Fe2(SO)1)3.

Lime

The lime used was reagent grade calcium hydroxide analyzing 98.0 per cent Ca(OH),.

Soda Ash

The soda ash was reagent grade sodium carbonate monohydrate. Dosages of soda ash are reported as anhydrous Na2C03.


1. Kaolinite. The kaolinite used was EPK-Edgar Plastic Kaolin
supplied by Edgar Plastic Kaolin Company, Edgar, Florida. A

20 -






21

data sheet is available with the chemical analysis and
properties (65).

2. Fullers earth. The fullers earth was regular Florex XXX
supplied by Floridin Company, Tallahassee, Florida. Definitive
data are listed in Floridin's general catalog (66).

3. Illite. The illite was grundite from Illinois Clay Products Company, Joliet, Illinois. It was reported to contain 65-75 per
cent illite.

4. Volclay. KWK Volclay was from American Colloid Company, Skokie, Illinois. It is a selected bentonite consisting of
90 per cent montmorillonite.

Coaxulant Aids

1. Purifloc N17. Purifloc N17 (Separan NP 10) is a product of Dow Chemical Company, Midland, Michigan. It is described as an
acrylamide type high molecular weight synthetic polymer having
active groups which are adsorbed onto solids in suspension,
bonding them together and drawing them into compact flocs (67).
The mechanism is said to be nonionic and irreversible.

2. DIS-106. This aid is also a product of Dow Chemical Company
and was particularly recommended for flocculation of solids in
softening processes. It has not been approved for use in the
treatment of potable water.

3. Nalcolyte 110. Nalcolyte 110 is a product of Nalco Chemical Company, Chicago, Illinois. It is described as a high molecular
weight complementary coagulant (68).

4. Kelain W. Kelgin W is a product of Kelco Company, New York,
N. Y. This aid is a polymer of the sodium salt of mannuronic
acid.

5. CjC 12H. CHC 12H is a product of Hercules Powder Company, Wilmington, Delaware. It is composed of sodium carboxymethylcellulose.

6. Caron CN. Ceron CN is also a product of Hercules Powder Company. It is described as a natural polymer derivative and
was found to be cationic (51). It is not approved for treatment
of potable water.

7. Jaguar WPB. Jaguar 4PB is a product of Stein, Hall and Company, Inc., New York, N. Y. Jaguar is a guar gum derived
from the guar seed and is described as a polysaccharide consisting of a complex carbohydrate polymer of galactose and mannose.
It is said to alter the electrokinetic properties of colloidal
suspensions by a hydrogen bonding effect (69).






22

8. Permtit 65. Permutit 65 is a product of the Permutit Company, New York, N. Y. It is described as a complex organic
compound having both cationic and anionic properties (70). It acts by being adsorbed on the floc particles. Distribution of
this coagulant aid was discontinued after completion of the
experimental work.

9. Activated Silica. The activated silica was prepared from
N Brand sodium silicate supplied by Philadelphia Zuartz Company,
Philadelphia, Pa., by treatment with ammonium sulfate (71).

10. Burtonite 78. Burtonite #78 is a product of the Burtonite Company, Nutley, N. J. It is a refined guar gum and has served
as a flocculant, filter aid, and flotation reagent for a variety
of materials.

11. Drewfloc. Drewfloc is described as an alkaline alumina solution containing an organic "promoter" or coagulation aid
plus a small amount of excess caustic for stabilization. It is
made by E. F. Drew & Company, Inc., New York, N. Y.

Activated Carbon

1. Aqua Nuchar "A". Industrial Chemical Sales Division, West
Virginia Pulp and Paper Company, New York, N. Y.

2. Nuchar C-190-N. Industrial Chemical Sales Division, West
Virginia Pulp and Paper Company, New York, N. Y.

3. Hardwood Retort Carbon. Forest Products Chemical Company,
Memphis, Tem.

4. Norit C., American Norit Company, Inc., Jacksonville, Fla.

Chlorine

A high-test calcium hypochlorite containing a minimum of 70 per cent available chlorine was used in the removal of 1131.

RadioisotopeS

The uranium was reagent grade uranyl nitrate hexahydrate. The other radioisotopes, as listed in Table 1, were obtained from Oak Ridge National Laboratory as carrier-free elements in acid or basic solutions.

Water

Most of the coagulation studies were made on Gainesville tap water with 5 ppm of added clay turbidity. Studies to evaluate the effect of lime-soda softening were made on a hard water from wells located near the laboratory. Analyses of the two waters performed by
standard methods (72) are given in Table 2. Dosages of hydrated lime and soda ash were usually the stoichometric quantities required for






23

complete softening and were, therefore, somewhat higher than the dosages which would be used in actual practice. However, undersoftening with lower dosages was sometimes used to detect the effects of lower pH.



TABIE 2

CHEMICAL ANALYSES OF WATERS



Parts per Million
Gainesville Wll
Constituent Tap Water Water


Total dissolved solids 147 391

Iron, Fe 0 0

Calcium, Ca 13 108

Magnesium, Mg 11 2.4

Sodium and potassium, Na+K as Na 4.3 1.1

Carbonate ion, CO3 17 0

Bicarbonate ion, HCO3 15 298

Sulfate ion, SO, 18 8.7

Chloride ion, Cl 20 21

Carbonate hardness as CaCO3 40 244

Non-carbonate hardness as CaC03 38 36

Total hardness as CaC03 78 280

pH 9.24 7.46







24



Procedures


Waters for activity removal studies were drawn into large polyethylene containers and thoroughly mixed with the selected radioisotope. With the exception of uranium, initial count rates were generally in the range 500 to 3000 cpm/ml. Where tap water was used, 5 ppm of finely ground kaolinite was added to the water to provide nuclei for floc formation.* After further mixing, 600 ml samples were pipetted into 1-liter pyrex beakers which were then placed on the jar test machines.* Twelve samples could be run at one time on the two units.

The paddle speed was set at 100 rpm and 1.00 ml samples were withdrawn from four beakers and placed in aluminum planchets for counting initial activity. Measured amounts of adsorbents, coagulants,

and coagulant aids were then added to the beakers and stirring was continued at 100 rpm.

All of the coagulant aids, with the exception of activated

silica and Drewfloc, were obtained as solids. These were dissolved or suspended in distilled water before use by stirring with a magnetic mixer. The coagulants and softening reagents were also made up as water solutions or suspensions. The carbons and clays were added as dry solids.

Where an adsorbent was Used or where the coagulant was added before the aid, two minutes mixing was allowed between increments to permit the adsorbent to wet or to give a floc time to form. Three minutes after the last reagent was added, the speed was reduced to


*Laboratory stirrer made by Phipps and Bird, Richmond, Va.






25

30 rpm and stirring Was continued for 30 Minutes permitting the floc to grow and incorporate the solids :in the water. At the end of the slow mixing period, the machines were stopped and the paddles were removed from the beakers.

After a one-hour settling period,, 1.00 ml samples were withdrawn from just below the water surfacs In the beakers and placed in planohets for counting the remaining unsettled activity. Fifty ml. samples were poured from each beaker at this time if final turbidities were to be measured. Ten ml samples were withdrawn and centrifuged at approximately 3200 rpm (10,000 fpm) for 15 minutes to remove suspended material; 1.00 ml samples of the supernatant were then taken for counting as an estimate of additional activity which might be removed by filtration. Hoyt (43) found that centrifugation and filtration gave comparable removals of activity.

The samples were dried under heat lamps and counted on Baird Atomic equipment, including a Model A-227 gas-flow proportional counter, Model 132 Scaler, and Model 750 automatic sample changer. Samples were timed for 900 or 3000 counts several times and results were averaged. Counting efficiency, as determined from a radium D and E standard previously calibrated by the National Bureau of Standards, was approximately 43 per cent. Because of the wide differences in types and energies Of emissions, no effort was made to calculate counting efficiencies of individual isotopes and activities are expressed :in cpm/ml. The counter was operated in the Geiger region at 2200 volts.

The measured counts were corrected for background and volume

change on addition of reagents and the percentage activity removed Was






26

calculated as follows: Per cent activity removed =


(cpm/ml)(elm)~ [600 +
(cI (cpm )b x 100



where i = initial activity (average of 4 samples)
f = final activity
b = background count
A = total volume in ml of aids and coagulants added to
the beaker sampled.

The per cent transmittance of turbidity samples was measured on a photoelectric colorimeter* using a red filter and 7.5 cm light path. Transmittance values were converted to A.P.H.A. turbidity units by means of a curve prepared with fullers earth standards measured on both the colorimeter and the Jackson Candle Turbidimeter. The pH of the remaining solution was measured on a Beckman Zeromatic pH Meter.

The preceding methods were generally followed for all isotopes. Special modifications and procedures are described in the discussions of individual isotopes.



















Lumetron Model 450, made by Photovolt Corp., New York, N. Y.














V, DISCUSSION OF RESULTS


The data are divided into five groups corresponding to the five radioisotopes studied. Common abbreviations used in the tables and figures are listed in the Appendix. Solid lines in the figures represent settled samples while broken lines show activities remaining in centrifuged saMPles. Values in parentheses in the tables are turbidities of the supernatant in settled samples.

In evaluating the significance of activity removals, the amount by which the initial activities exceed the maximum permissible concentrations (MPG) for water must be considered.* Where initial activities are high in relation to I4PC and efficiencies of decontamination processes are low, a given increase in per cent activity removed by a polyelectrolyte may not be nearly so significant as the same increase in per cent activity removed with a high efficiency process. If, for example,, 99.9 per cent of the initial activity must be removed to reach the MPG and two processes removed 99.0 per cent and 50.0 per cent of the activity respectively, an increase in removal of 0.9 per cent for both processes would be much more significant for the first process. In the one case, activities would be reduced from (10 x MPG) to the MPG value while in the other the change would be from, (500 x MPc) to (419 x MP). Percentage removals much greater than 99.9 per cent are often required in practice to reduce activities of liquid wastes to permissible levels.


27 -






28



Removal of Cs137Bal37M


Cesium is one of the alkali metals located in Group I of the periodic system. These elements are extremely reactive and form mostly soluble compounds.

Cs137, with a half life of 30 t 3 years (73), decays by

emission to Ba137m, which has a half life of 2.6 minutes and emits aradiation. Because of the different half lives, cesium would be the predominate active species present in an equilibrium mixture of the

two radioisotopes.

Coagulation of tap water containing Cs137 with variable dosages of alum and ferric sulfate removed only 0-10 per cent of the initial activity. The hydrous oxide floes are not good adsorbers for cesium. On the other hand the clays are quite effective for sorption of Cs137 from solution as shown in Figure 1 and Table 3. Illite and fullers earth both exhibited peak centrifuged removals of activity greater than 92 per cent at 1000 ppm dosages. The decreased pH (6.8) with 5000 ppm illite probably contributes to the lower activity removals with this dosage of clay. Reproducibility of results is shown by the duplicate illite runs. Where pH was varied with 0.5 N NaOH or HaSO,, centrifuged removals of activity generally increased with increasing pH but kaolinite and illite exhibited sharp drops in settled removals near pH 7 as shown in Figure 2 and Table 4.

The polyelectrolytes differed in their action on coagulation and activity removal with clays. Figure 3 shows that Parifloc NI?, which normally coagulates slurry concentrations of clay, reduced final






29

turbidities and consequently increased settled activity removals with 1000 ppm fullers earth or illite. Centrifuged removals, however, decreased slightly with all dosages of this aid. Activated silica interfered with coagulation of clay where an alum dosage of 17 ppm was optimum for turbidity reduction without any coagulant aid. Residual activities also increased with increasing dosages of activated silica. The alum with 1000 ppm fullers earth removed nearly 95 per cent of the activity. A dosage of 10 ppm ferric sulfate with clay gave activity removals comparable to alum. Nalcolyte 110, Kelgin W, and Jaguar WPB had little effect on activity removals with 1000 ppm fullers earth or illite and 10 ppm ferric sulfate. Nalcolyte 110 and Jaguar WdPB significantly reduced the turbidities while Kelgin W showed little improvement in coagulation under the test conditions.

Softening of well water with lime and soda ash did not remove

C3137. However, clays used in conjunction with lime-soda ash softening will remove almost 98 per cent of the activity. Table 5 shows steadily increasing activity removals with increasing dosages of lime. DIS-106, Ceron CN, and activated silica all reduced turbidity with lime, soda ash, and illite or fullers earth. Figures 4, 5, and 6 show removals of activity by settling generally increasing with decreasing final turbidity, but centrifuged removals have a slight downward trend with increasing dosages of these aids.

An anionic aid, Purifloo N1l, had little effect on either activity removal or turbidity when added after 1 ppm Ceron CN, a cationic aid. Ceron CN was of no value for increasing uptake of Cs137 by Volclay with lime and soda ash. It did increase activity removals by settling mixed illite and fullers earth, lime, and soda ash, and






30

did reduce the final turbidity. Figure 7, however, shows centrifuged activity removals to be nearly constant. Variations in the initial activity from 567 cpm/ml to 10,000 cpm/ml caused little change in percentage of activity removed by settling and centrifuging mixed illite and fullers earth, lime, soda ash, and 0.5 ppm Ceron CN.

Magnesium, added as MgCl2, increased settled activity removals but slightly decreased centrifuged removals with mixed illite and fullers earth, lime, and soda ash as shown in Figure 8. The final turbidity was reduced to 0 with 33 ppm added Mg; better clarification than with any of the polyelectrolytes. Lime and soda ash dosages were the stoichometric quantities required for complete softening including removal of the added magnesium.

Figure 9 shows that traces of stable cesium greatly inhibit removal of Cs137 from water by clays. Apparently the clays have a relatively low affinity for cesium or there are few lattice sites available for adsorption and exchange of this element.

An activated carbon, Norit C, with lime and soda ash, removed only 37 per cent of the activity in dosages up to 5000 ppm.

In summary, neither coagulation nor lime-soda softening alone will remove Cs137-Bal37m from water. Two clays, illite and fullers earth, are effective adsorbents for cesium but large dosages (1000 ppm) are required for good removal. For best results the pH should be held above pH 9.

The polyelectrolytes reduced suspended activity by aiding in clarification of clay slurries after softening but slightly reduced centrifuged activity removals. Minimum dosages of the coagulant aids which give satisfactory settling should be used to prevent interference






31

with activity uptake since the rapid formation of large flocs by higher dosages of aid decreases the surface area available for adsorption. Still higher concentrations of polyelectrolytes may coat the particles and prevent both adsorption and coagulation.



Removal of Sr89


Strontium is an alkaline earth metal located in Group II of the periodic system. These elements are somewhat less reactive than the alkali metals and generally form less soluble compounds.

Sr89 has a half life of 53 days (73) and decays byid emission. It may be readily precipitated as the carbonate or phosphate but an extremely high percentage removal is difficult to obtain.

Extensive coagulation tests using alum or ferric sulfate with variable dosages of seven polyelectrolytes failed to remove more than 30 per cent of the initial activity. Softening tests, using the lime dosage calculated for complete softening, gave steadily increasing activity removals with increasing dosages of soda ash as shown in Figure 10.

Table 6 shows that low dosages of DIS-106 slightly increased both settled and centrifuged activity removals with theoretical dosages of lime and soda ash. DIS-106, however, decreased activity removals with 100 per cent excess lime and soda ash equivalent to noncarbonate hardness plus excess lime. Theoretical lime dosages with both theoretical (35 Pui) and excess (200 ppm) soda ash dosages were not significantly improved in removal of Sr89 when used with Kelgin W, Nalcolyte 110, Jaguar WPB, Permutit 65, activated silica, CHC 12H, and






-32
Purifloc N17. Large dosages of aid almost always inhibited activity removal.

Figure 11 compares the effectiveness of the different clays in removing Sr89 from water. Volclay was better than the other clays but 5000 ppm Volclay removed only 66 per cent of the activity upon centrifuging. Purifloc N17, Kelgin W, Jaguar WPB, CMC 12H, and Nalcolyte 110 all gave good clarification when used with 5000 ppm Volclay as shown in Table 7. Permutit 65 was less effective as a coagulant while activated silica alone caused very high final turbidities. Some settled activities increased while others decreased with decreasing final turbidity. Centrifuged activities showed little tendency to change. Activity removals with kaolinite, fullers earth, and illite were not raised to practical levels by the coagulant aids. The effectiveness of any given polyelectrolyte was dependent on the type of clay and also on the order in which the aid and the clay were added to the contaminated water.

All four clays were found to be of some value as adsorbents for Sr89 with lime-soda softening although Volclay was the only one which removed more than 93 per cent of the activity. Removals of activity increased slightly when the settled softening sludge and clay were mixed with 5 ppm Purifloc N17 and then resettled and sampled as shown in Table 8.

Tables 9-11 show that DIS-106, Purifloc Ni7, and Kelgin W

slightly increased settled removals with lime, soda ash, and 5000 ppm Volclay. Final turbidities were quite high. Up to 99.5 per cent of the activity was removed by centrifuging samples containing 165 ppm soda ash in excess of calculated requirements.






33

Since the well water used for softening studies contained so

little magnesium, this element was added as MgCl, in special tests to determine its effect on removal of Sr89 With lime and soda ash dosages equivalent to the water hardness plus the extra magnesium,, activity removal was depressed slightly. Added magnesium increased settled activity removals and decreased final turbidities where 5000 ppm Voiclay was used with the same line and soda ash dosages. All samples thus treated contained 5 ppm DIS-106.

Low dosages of stable strontium had little effect on activity removal when used with theoretical lime and soda ash dosages and 5 ppm DIS-106. Variable dosages of Purifloo N17 with theoretical lime

dosages, excess soda ash, Volclay, and 10 ppm stable strontium raised settled activity removals from 93.5 per cent to 99.2 per cent with little change in centrifuged activity removals as shown in Table 12. Final turbidity was reduced from 1200 to 15 with 15 ppm N17. With excess lime, equivalent soda ash, Voiclay, and 10 ppm stable strontium,

5 ppm Purifloc N17 reduced turbidity from 325 to 11 but had little effect on activity removal as shown in Table 13.

In summary, neither coagulation nor softening alone were effective for removal of Sr 89from water. None of the polyelectrolytes significantly decreased the final activities with these Processes alone.

High dosages of Volclay with theoretical lime dosages and

excess soda ash gave the only activity removals greater than 99 per cent. The polyelectrolytes were of value here for reducing the turbidity and associated activity but centrifuged activity removals frequently decreased with decreasing final turbidity. The dosage of aid






4L

must reflect a balance between formation of floc large enough to settle but still small enough to have a large area for adsorption. There is a conflict in polyolectrolyto requirements between the porous clays, which may take up relatively large amounts of aid, and the crystalline sludge particles which need very little. Fractionation of the solids may thus occur upon coagulation leaving fine turbidity in suspension.



Removal of PM147


Promethium is one of the rare-earth or lanthanide elements.

Their characteristics and most stable oxidation state is +3, The ions have a strong affinity for cation exchange materials and this property

is used in their separation.

PM 147 has a half life of 2.6 years (73) and decays by 46

emission. Promethium has not been found in nature but Is a product of uranium fission,

Unlike cesium and strontium, promethium is effectively removed from water by coagulation. Figure 12 shows ferric sulfate to be more effective than alumt removing 99.1 per cent of the activity in a dosage Of 0 PPM. Settled and centrifuged activity removals without any coagulant were 36 per cent and 77 per cent respectively, indicating that the activity was either in a precipitated state or was associated with the 5 ppm kaolinite in the tap water.

Sulfuric acid and sodium hydroxide (0.5N) were used with the optimm alum and ferric sulfate dosages to determine the pH of best activity reduction. As shown in Figure 13, removals were highest near pH 7 but were relatively constant above this value.






35

Table l14 shows the effects of seven coagulant aids On removal of PX17with 60 pjxn alum or 36 ppm ferric sulfate. With alum, low dosages of Nalcolyte 110, Kelgin W. and Permutit 65 gave small increases In centrifuged activity removals.* Settled removals were somewhat erratic and did not necessarily parallel centrifuged removals. CMC 1211 and activated silica decreased centrifuged removals but Increased settled removals.* With ferric sulfate, Purifloc N17 and (24C 12H Increased centrifuged activity removals slightly. Dosages Of some coagulant aids for good coagulation were quite critical and floc size was not a good indication of activity removal to be expected. The order in which the aid and coagulant were added was also a factor in decontamination.

Table 15 shows all clays to be very effective in adsorbing
Pa 47 from water. Figure l14 shows activity removed by centrifuging clay dosed waters.* Purifloc N17, Kelgin W, and activated silica slightly reduced activity removals when used with 500 ppm clay and ferric sulfate or alum. Purifloc N17 and Jaguar WPB both increased floc size with clay but activity removals were greatly reduced. Settled activityr removals with~ fullers: earth and ferric sulfate remained essentially constant and centrifuged removals increased from 99.7 per cent to 99.8 per cent as initial activities were increased from 3100 cpm/ul to 33,000 C~m/ml.

In softening tests with variable amounts of lime and soda ash, as shown In Table 16, theoretical dosages of both reagents gave the best settled activity removal (95.4~ per cent) while the theoretical lime dosage with excess soda ash gave the best centrifuged removal (99.7 per cent). Figure 15 shows removal of p&147 from well water






36

with 46 ppm soda ash and variable dosages of lime.

Nine coagulant aids were used in softening the hard well water with theoretical dosages of lime and soda ash as shown in Table 17. Activated silica, shown in Figure 16, Was the only aid which satisfactorily reduced the turbidity and increased settled activity removals. Daily variations were noted in turbidities and settled removals where aids were not used but centrifuged removals all exceeded 97 per cent.

Table 18 shows that increasing dosages of Nurifloc Ni7 and

Jaguar WPB produced minimums in turbidities with lime, soda ash, and clay but steadily reduced activity removals. Where two different types Of solid surface eXist, one is likely to become saturated with polyelectrolyte before the other. Increasing dosages of coagulant aid may then be dispersing one solid while it is coagulating the other.

Figure 17 shows the reduction of activity in solution by Hardwood Retort Carbon. This material was not as effective as an equal weight of clay. Purifloc N1? flocculated carbon but did not predictably affect activities, while increasing dosages of Kelgin W caused activity removals to decrease with 250 ppm fullers earth and 250 ppm carbon.

In sumary, coagulation with alum and ferric sulfate or softening with theoretical dosages of lime and noda ash remove 95-99 per cent of Pm17 activity. Clay is useful for making high removals consistent and extends the range as high as 99.7 per cent. Although small dosages of some polyelectrolytes may decrease residual activity, accurate control of decontamination would be difficult since neither floc size nor final turbidity is indicative of activity removed. Activated silica was useful with lime and soda ash alone for both







37
decontamination and turbidity reduction.



Removal of113


Iodine is one of the halogens and is located in Group VII of the Periodic System. Iodide ion is easily oxidized to the free element by chlorine or hypochlorite and may be further oxidized to the iodate or periodate in alkaline solution. Most of the iodides are quite soluble in water.

111with a half life of 8.08 days (73) decays by both 1

and ?"'mia3ion with a wide range of energies. Because of the volatility of iodine at high temperature, it was necessary to dry all planchets with this isotope in air without the application of heat.

Coagulation with alum and ferric sulfate generally removed less than 10 per cent of the 1131 present. Aqua Nuchar A and C-190-N removed up to 59 per cent of 111but dosages as high as 5000 ppm were required as shown in Figure 18.

Figure 19 shows the improvement in activity removal by use of small dosages of chlorine (0.05 0.10 p) with alum and ferric sulfate. The chlorine dosage for optimum removal was quite critical and the maximum, efficiency was still only about 30 per cent. Similar results were obtained using chlorine with lime and soda ash or with 100 ppm. fullers earth.

Figure 20 shows the effect of smull dosages of chlorine on

removal of 113 with C-190-N. Over 80 per cent activity was removed by centrifuging with a chlorine dosage of 0.1 ppm. Figure 21 shows the effect of the order in which the chlorine and the activated carbon







38

are added to the water to be treated. When the carbon is added first, the peak removals are not obtained. Raising the carbon dosage from 100 ppm to 1000 ppm did not increase the per cent activity removed as shown in Figure 22. Using a fixed chlorine dosage of 0.1 ppm, activity removal with Aqua Nuchar A began to level off at a carbon dosage of 50 ppm an shown in Figure 23.

Varying the pH between 6.8 and 10.2 with sulfuric acid or

sodium hbydroxide had little effect on activity removal with 0.1 ppm chlorine and 100 ppm Aqua Nuchar A. Alum and ferric sulfate generally aided in coagulation of carbon and increased settled removals but slightly decreased centrifuged removals as shown in Table 19. Activity removals with chlorine, carbon, lime, and soda ash, shown in Figure 24, were lower than those with chlorine and carbon alone or with chlorine, carbon, and coagulants.

Figure 25 shows that the per cent of 113l removed with chlorine and Aqua Nuchar A tended to increase with increasing activity. Stable iodide in dosages greater than 0.05 ppm inhibited removal of 1l31 with fixed dosages of chlorine and Aqua Nuchar A as shown in Figure 26.

Table 20 shows that the coagulant aids used with chlorine and Aqua Nuchar A inhibited settled activity removals but left centrifuged removals practically unchanged. Activated silica with alum was of value in removing the carbon and activity by settling but centrifuged removals decreased.

In sumiary,, the only effective method found for removing 13

with materials generally available in water treatment plants involved chlorination followed by adsorption of liberated iodine on activated carbon.* The optimum chlorine dosages were quite small and had to be







39
selected by effects on activity removal alone since residuals were too =mall to be detected.* Chlorine requirements should also depend on other oxidizable materials in the water.

Normal prechlorination could not be used with iodine removal

because the residuals would generally exceed the critical dosages for activity removal.* Gainesville tap water could not be used for removal tests because Of its chlorine content.

Alum and ferric sulfate with low dosages of aids may be used to coagulate the carbon. Lim and soda ash or polyelectrolytes alone appear to inhibit removal of activity.

Although C-190-N gave slightly higher removals than Aqua

Nuchar A. the latter was preferred since it flocculated better and did not float on the surface. The clays alone were very poor decontazinants.



Removal of Uranium


Uranium is one of the actinide elements and is widely distributed in the earth's crust. The primary Isotope In natural uranium is U238 with smll amount of U3 and U234 Uranium initially decays by oL and -emission starting a long disintegration series which finally ends with stable lead.* Radium which is included in this series is one of the most dangerous isotopes when Ingested.

U28has a half life of 4.51 x 109 years (74), therefore relatively large amounts are required to give high count rates unless the working solutions are concentrated. Uranium forms insoluble salts With the alkali and alkaline earth metals indicating that lime-soda softening would possibly be an effective method for its removal.* Removal of







40

uranium was studied at two activity levels; in concentrated solutionsa containing approximately three grams of uranyl nitrate hexahydrate per liter, and in dilute solutions containing approximately 30 mg of uranyl nitrate hexahydrate per liter. With the concentrated solutions,

1 Ml sample were counted as with the other isotopes,, while 50 al settled samples only were concentrated and counted for the dilute solution.

The addition of both excess lime and caustic soda to a concentrated uranium solution reduced the count rate to background with

1.00 ml samples as shown in Figure 27. This is presumably due to precipitation of the insoluble uranates. For best results, the final pH should be greater than 11.0. The addition of sodium carbonate to a concentrated uranium solution caused a precipitate to form but this dissolved with excess soda ash because of complex formation.

Alum and ferric sulfate with reduced lime dosages increased activity removal by settling as shown in Tables 21 and 22. Voiclay had no apparent effect on precipitation of uranium from concentrated solutions with lime.

In the dilute solutions, the normal alkalinity of the water

precipitated much of the uranium. Alum and ferric sulfate coagulated the fine suspension and removed 70-75 per cent of the activity. A dosage of 500 ppm kaolinite increased activity removal with alum by about 5 per cent and gave more consistent results with ferric sulfate as shown in Figure 28. Figure 29 shows the effect of variable dosages of lime for precipitation of uranium from dilute solutions.* Almost 88 per cent of the activity was removed with 500 ppm kaolinite and







41

250 ppm lime at pH 10.9.

None of the group of eight coagulant aids was of value for

increasing activity removal with 30 ppm alum or with 500 ppm kaolinite and 30 ppm alum as shown in Table 23. No significant improvement was noted when the same coagulant aids were used with 25 ppm ferric sulfate or with 500 ppm kaolinite and 25 ppm ferric sulfate as shown in Table 24. Table 25 shows that the coagulant aids generally increased turbidity or decreased activity removal with lime and soda ash used alone or in conjunction with 500 ppm kaolinite. Exceptions were Kelgin W and activated silica, shown in Figures 30 and 31 respectively, both of which gave excellent turbidity reduction and some increase in activity removal.

In summary, uranium concentrations may be reduced well below the MPC by precipitation of the uranates with lime or caustic soda. In concentrated solutions, the uranium forms a heavy floc which settles readily.

In dilute solutions, alum and ferric sulfate were necessary to coagulate the uranium. The polyelectrolytes did not increase activity removal by coagulation but Kelgin W and activated silica aided in removal of activity with lime and soda ash.














VI. CONCLUSIONS


The effects of eleven polyelectrolyte coagulant aids on the

removal of turbidity and activity are summarized in Tables 26 and 27 respectively. These tables are subdivided into groups corresponding to the basic removal processes employed and polyslectrolytes are rated on arbitrary scales designed to separate then according to their relative efficiencies in each process.

The coagulant aids are primarily of value in removing from

water clay or other solids with which the activity might be associated. Improvements in removal Of soluble activity with the aids are generally small and will not yield a safe drinking water with conventional water treatment processes Unless initial activities are relatively low. The polyelectrolytes should give much greater benefits with actual fallout products which contain most of the activity in an insoluble form.

No coagulant aid was found which would be satisfactory for all

removal processes.* The type and dosage of coagulant or added turbidity are predominant factors in the selection of an aid. Dosages of many of the polyelectrolytes are quite critical and excessive amounts Will generally interfere with coagulation rather than aid it. Their effectiveness varies with the different radioisotopes.

For removal of the soluble activity which depends on adsorption by a solid, the minimum dosage of a coagulant aid that forms a floc which Will settle during the available retention time should be Used. Higher dosages will decrease the surface area of the solid, and

4f2 -






43

consequently, decrease the adsorption of activity. Some of the aids which give the best turbidity reduction thus increase the activity remaining in solution.

For removal of specific radioisotopes from water, the following basic procedures are recommended.* Those polyelectrolytes rated "A" in the tables for the given process should be tried to see which is best under local conditions.

1.* Cesium. Illite or fullers earth with lime and soda ash
dosages equivalent to the water hardness are Most effective for
removal of cesium.

2. Strontium. Volclay with theoretical lim dosages for
softening and excess soda ash are best for removal Of strontium.

3. Promethium. Good removals of promethium are obtained with
both alum andferric sulfate coagulation and with lime-soda
softening. Any of the clays are useful for broadening the
range of dosages giving good coagulation, and also appear to
adsorb s0om Of the promethium.

4. Ioin '* Small dosages of chlorine followed by adsorption of
liberated iodine 4th activated carbon have proved to be useful
for removal of 1131i from water.

5. Urnim Uranium is conveniently removed from water by
precip=tation with lime.* Alum or ferric sulfate may be used to
coagulate the suspension.

In an emergency situation, the best modified conventional process for water treatment would appear to be lime-soda softening in conjunction with clay treatment. Naturally Occurring soft waters should be treated with enough lime to bring the pH within the range of 10-11 and enough soda ash to precipitate the added calcium. Polyelectrolytes may be Used to reduce the turbidity. However, the clay and softening sludge should be allowed to contact the water as long as possible before the coagulant aid is added. Series operation of treatment units may be advantageous since the polymers should be thoroughly mixed with






44 -I

the water. Because of the many radioisotopes present in fallout and the different types of local clay which might be used, no specific polyelectrolyte can be recommended. The tables may be consulted to find those materials most likely to work in a given situation. In any case, jar tests should be used beforehand to determine the optimum dosage of polyelectrolyte needed to reach the minimum residual turbidity in the water.
























APPMEDICES














APPENDIX I


Akkrgviat1M nUed in Tailes aggnd iires

1I0 Initial Activity (cpu/al)

s Activity Removed by Settling

C Activity Removed by Centrifuging


-Clays

K Kalinite

FE Fuillers Earth

V Volclay

I Illite




106 =91-1.06

N17 Narif loo N17

110 Nalcolyte -10

W Kelgin W

12H1 GC12H

CN Caron CN

WPB Jaguar WPB

65 Permtit 65

"SiO," Activated Silica

78 Burtonite #78

D Drewfloc



46 -
























APPMMIX n TABIZS






-48





TABLE 3
SORPTION OF Cs137 FROM TAP WATER
BY VARIABLE DOSAGES OF CLAY


Per Cent Activity Removed by Settling I ppm Clay
Clay cpmdml pH 0 50 200 500 1000 5000

K 2844 8.8-7.9 0 0 19.4 16.3 39.2 73.7

FE 3047 8.6-8.4 9.0 32.9 60.9 77.1 86.0 61.0 V 3047 8.6-9.2 7.9 15.6 19.5 28.9 36.8 65.9
I 2844 8.8-6.9 29.2 34.9 52.5 57.1 58.6 78.0
I 3047 8.6-6.8 21.2 27.2 51.9 57.9 63.4 81.5






-49





TABLE 4

THE EFFECT OF pH ON SORPTION OF Csl37 FROM
TAP WATER BY KAOLINITE AND VOLCLAY


SPer Cent Activity Removed Clay pH cpmuml Settled Centrifuged

5.8 3416 83.4 85.9
7.0 3416 81.7 86.5
5000 ppm 7.5 3416 79.1 85.6
Kaolinite 8.1 3416 83.0 86.1
9.0 3416 83.5 87.8
9.8 3416 88.6 91.3

6.2 2957 52.2 78.4
7.0 2957 56.1 81.5
5000 ppm 7.9 2957 62.0 82.1
Volclay 8.5 2957 60.8 84.5
9.3 2957 66.6 85.0
10.1 2957 69.0 85.6





-50





TABLE 5
THE EFFECT OF VARIABLE DOSAGES OF LIME ON REMOVAL
OF Cs137 FROM TAP WATER WITH 1000 ppm ILLITE AND 25 pRu FERRIC SULFATE



ppm Settled Per Cent Activity Removed
Lime pH Turbidity Settled Centrifuged

0 6.8 20 91.8 92.1

5 7.1 14 92.7 93.5
8.5 7.2 13 90.3 92.7
14 7.8 22 92.1 94.2

20 8.5 17 95.5 94.4
35 9.3 15 96.2 95.4

50 9.5 11 95.6 96.8
80 10.1 9 97.1 97.9






51





TABLE 6
REMOVAL OF Sr89 FROM WELL WATER WITH 188 ppm LIME,
353 ppa SODA ASHt, AND DIS-106



ppM I Per Cent Activity Removed
106 Cpml pH Settled Centrifuged

0 653 10.1 77.3 83.0
0.1 653 10.1 81.2 84.1
0.3 653 10.2 81.7 84.3
0.5 653 10.2 78.9 82.3
1 653 10.2 81.0 81.7
5 653 10.1 79.8 82.1







TABLE 7
REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppa VOLCIAY AND VARIABLE DOSAGES OF COAGULANT AIDS


Per Cent Activity Removed
ppm Aid
Order of I 0 0.2 1 10
Aid Addition cpmml pH S C S C S C S C

N17 Aid + V 436 8.2 64.5 68.8 62.8 68.0 72.0 70.3 65.3 67.2
(69) (46) (12) (7)
N17 V + Aid 436 8.2 71.3 67.5 68.8 66.0 63.2 63.2
(54) (66) (9)


W Aid + V 310 8.2 65.9 67.6 69.8 69.8 73.8 69.8 67.3 73.1
(60) (49) (31) (18)
W V + Aid 310 8.2 73.6 75.2 75.7 73.4 75.0 75.7
(73) (44) (29)

WB Aid + V 1743 8.3 62.9 65.5 60.7 65.5 67.9 67.5 64.7 66.2
(54) (42) (39) (4)

WPB V + Aid 1743 8.3 67.7 67.0 57.8 62.7 67.2 65.9
(39) (32) (3)







TABLE 7 CONTINUED


Per Cent Activity Removed
pp.. Aid
Order of I 0 0.2 1 10
Aid Addition cpmml pH S C S C S C S C

12H Aid + V 1679 8.3 66.6 64.6 67.2 61.o 63.5 67.9 69.0 61.2

12H V + Aid 1679 8.3 63.0 70.1 64.4( 67.8 62.5 63.0


65 Aid + V 1743 8.3 63.7 66.8 68.0 62.2 68.4 63.3 64.8 65.3
(64) (54) (32) (49)

65 V + Aid 1743 8.3 67.6 64.3 66.0 65.1 67.7 65.7
(39) (37) (39)


0 0.5 5 25
110 Aid + V 1679 8.3 66.1 72.1 64.2 71.7 66.3 70.4 62.9 67.9
(78) (41) (21) (9)
11O V + Aid 1679 8.3 66.4( 67.0 63.2 64.7 66.7 62.2
(23) (ii) (3)







TABLE 7 CONTINUED


Per Cent Activity Removed ppm Aid
Order of I 0 5 25 100
Aid Addition cpm7uml pH S C S C s C S C

"Si0a" Aid + V 467 8.1-8.8 60.1 66.6 59.8 61.6 66.4 68.9 54.5 64.8
(78) (145) (450) ( o1150)
"SiOa" V + Aid 467 8.1-8.8 69.1 72.0 65.1 72.2 63.8 65.3
(300oo) (675) (1500)
,,i m ,,l i ,n i ,,, i ,i i H J,






55





TABLE 8
REMOVAL OF Sr89 FROM WELL WATER WITH LIME,
SODA ASH, AND VARIABLE DOSAGES OF CLAYS


Per Cent Activity Removed
PPM pp p Soda I No Aid 3 ym N17*
Clay Lime Ash cpmml pH S C S C

KAOLINITE

0 188 35 1466 9.7 79.1 81.9 76.8 82.3

100 188 35 1466 9.7 81.9 80.5 79.3 82.2
500 188 35 1466 9.7 81.0 80.5 80.5 80.0
1000 188 35 1466 9.7 78.7 82.9 81.1 82,8
2500 188 35 1466 9.6 82.8 83.5 85.6 84.5
5000 188 35 1466 9.2 81.7 85.4 86.3 87.2

FULLERS EARTH

0 188 35 1466 9.8 81.3 83.8 78.4 83.0
100 188 35 1466 9.6 80.2 85.6 81.6 83.7
500 188 35 1466 9.6 85.1 86.6 84.0 85.7
1000 188 35 1466 9.5 85.4 85.9 86.2 85.2
2500 188 35 1466 9.2 88.3 89.3 89.6 89.7
5000 188 35 1466 8.8 91.6 92.5 91.8 92.4






-56





TABLE 8 CONTINUED


Per Cent Activity Removed
ppm ppm Soda I No Aid 5 1=m N17*
Clay Lime Ash cpmiml pH S C S C
ILLITE

0 202 45 1377 10.4 77.7 78.6 79.0 81.6
100 202 45 1377 10.3 79.8 80.1 81.9 81.1
500 202 45 1377 10.2 83.5 84.? 84.5 83.8
1000 202 45 1377 10.1 84.6 87.2 87.3 89.9
2500 202 45 1377 9.6 89.2 89.8 90.3 89.6
5000 202 45 1377 8.7 90.0 90.9 91.0 91.0

VOLCLAY

0 202 45 1377 10.3 80.8 82.8 81.6 83.5
100 202 45 1377 10.2 83.9 86.2 85.6 85.0
500 202 45 1377 10.2 89.0 90.7 91.0 90.5
1000 202 45 1377 10.3 90.7 94.8 95.0 95.4
2500 202 45 1377 10.4 91.5 97.8 97.5 98.4
5000 202 45 1377 10.4 94.0 98.4 97.5 98.6

*After the normal mixing and settling periods, samples were
taken and 5 ppm N17 was added to each jar with 3 min. rapid
mix, 10 min. slow mix, and 20 min. settling before resampling.












TABLE 9
REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppi VOLCIAY
AND VARIABLE DOSAGES OF LIME, SODA ASH, AND DIS-106


ppm Per Cent Activity Removed
ppm ppi Soda I
106 Lim Ash c mFl pH Settled Ceatrifuged

0 117 0 1856 9.2 91.8 94.9
0.5 117 0 1856 9.2 94.0 96.1

5 117 0 1856 9.2 95.0 96.2
20 117 0 1856 9.2 95.1 95.6
0 188 35 1856 10.3 92.9 98.3
0.5 188 35 1856 10.3 96.2 98.4
5 188 35 1856 10.3 96.3 98.6

20 188 35 1856 10.3 96.8 98.6
0 188 200 1856 10.6 93.6 99.3
0.5 188 200 1856 10.6 98.2 99.4

5 188 200 1856 10.6 98.5 99.4
20 188 200 1856 10.6 98.7 99.5






M 58






TABLE 10
REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCLAY,
202 ppm LIME, 45 ppm SODA ASH, AND VARIABLE DOSAGES OF NI7



ppm Order of I Final Per Cent Activity Removed
N17 Addition opmml pH Turbidity Settled Centrifuged

0 1150 10.5 1200 93.4 98.6
1 Aid first 1150 10.3 950 94.0 98.2
2 Aid first 1150 10.3 750 95.6 98.7
5 Aid first 1150 10.3 200 98.0 99.0
1 Aid last 1150 10.4 1000 94.8 97.6
2 Aid last 1150 10.3 800 96.0 99.0
5 Aid last 1150 10.5 500 96.9





59






TABLE 11
REMOVAL OF Sr89 FROM WELL WATER WITH 5000 ppm VOLCLAY,
202 ppm LIME, 45 ppm SODA ASH, AND VARIABLE DOSAGES OF W



Order of I Final Per Cent Activity Removed
W Addition cpmml pH Turbidity Settled Contrifu

0 1150 10.5 1200 94.4 98.0
1 Aid first 1150 10.3 1200 95.6 97.4
2 Aid first 1150 10.6 1200 93.8 98.0
5 Aid first 1150 10.6 1200 97.6 97.1
1 Aid last 1150 10.4 1200 93.5 97.1
2 Aid last 1150 10.4 1200 94.0 98.0
5 Aid last 1150 10.5 1200 92.0 96.9








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-66




TABLE 15
REMOVAL OF P&147 FROM WELL WATER WITH VARIABLE DOSAGES OF CLAYS


Per Cent Activity Removed
PM Kaolinite Fullers Earth Illit. Volslay
Clay S C S C S C S C

0 6o.1 93.7 55.1 94.1 56.7 95.7 34.4 94.7
50 66.1 88.2 60.7 85.2 70.2 89.6 74.8 92.5
200 77.1 91.1 80.0 94.8 83.3 94.7 82.7 92.6
500 93.1 96.4 94.6 97.8 91.5 96.7 90.8 91.8
1000 94.6 98.5 95.9 98.9 94.5 97.8 94.1 96.o 5000 98.4 99.5 98.7 99.7 97.3 99.5 99.0 99.7






67





TABLE 16
RE24OVAL OF Pm147 FROM WELL WATER WITH VARIABLE
DOSAGES OF LIME AND SODA ASH


Per Cent Activity Removed
ppm ppm I
Lime Soda cpm~ml pH Settled Centrifuged


0 0 1861 7.8 17.8 56.0

202 0 1861 9.4 92.9 98.9

202 46 1861 9.8 95.4 99.5

101 46 1861 8.6 88.7 89.4

152 46 1861 8.9 89.8 99.5

250 46 1861 10.7 89.6 99.5

302 46 1861 11.1 76.6 96.1

202 100 1861 9.9 93.7 99.1
202 200 1861 10.3 92.4 99.7

302 187 1861 11.1 91.7 99.0

404 329 1861 11.5 84.2 95.8








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E- co co 00 co

r-4
0;

r-4 \0 \0 C- CN N N N N N

cl- cl-- r-4 H
co co 01\ 01%







10 10 U) 10
4-3 4J

+ +
9) to ?a r
14 4.) 4.> Cd 4J 0
4) g 0 0
r
+ eD + +
-0 Cd 10 10
0 0 0




0 0
10 r4 4
ri C 1 0 \AD
4 r









71








C C7, cv

co C- 00 C
co Cs-t C

cc
co H Z)
0
co U)
0 co




H
C; r-4
V-4 C
C-4
CC)
4-)



00 Cr-4 Ci


CN


ri co 00 0 1
(Y\ CN


OD cr)
C)l 11-1







0 LIN



0
CrN 1-4 H rc

4-)

r-4 H
r-4 0 0 0 r-i 0 0
0 Cd 0 0 0 co
V* : 4 U-N 4

C
r-4 r-I
:3:






72





TABLE 19
REMOVAL OF 1131 FROM WELL WATER WITH 100 ppm ACTIVATED CARBON, CHLORINE, AND VARIABLE DOSAGES OF ALUM OR FERRIC SULFATE


Per Cent Activity Removed
pPM ppm I Final
Alum Fe,(S04)3 (cpmml) pH Settled Centrifuged

C-190-N and 0.10 ppm Cl2

o 0 1448 8.2 61.5 73.7

15 0 1448 8.2 74.2 73.6

30 0 1448 8.0 80.8 72.4

0 10 1448 8.1 55.5 74.7

o 20 1448 8.0 55.1 70.5
Aqua Nuchar A and 0.075 ppm Cl2

0 0 1704 8.1 50.7 71.8
15 0 1704 8.1 67.3 71.7

30 0 1704 7.9 65.1 71.3
0 10 1704 8.0 66.4 70.4

0 20 1704 7.9 65.9 68.3








TABLE 20
REMOVAL OF 1131 FROM WELL WATER WITH 100 ppm AQUA NUCHAR A, CHLORINE, AND VARIABLE DOSAGES OF COAGULANT AIDS


Per Cent Activity Removed
Dosages of Aids (ppm)
ppm I 0 0.05 0.1 0.5 1 5
Aids Cl2 cpm~ml S C S C S C S C S C S C

N17 0.08 1780 62.1 71.7 58.4 70.7 55.5 65.1 53.7 67.1 54.5 65.4 47.1 69.2
110 0.10 1309 66.0 83.1 67.2 81.8 65.4 80.3 65.3 80.1 64.0 78.0 63.8 76.8

W 0.10 2147 67.4 80.6 62.7 80.5 62.3 80.2 63.2 78.4 63.2 79.7 65.0 80.1
CN 0.08 1455 65.3 76.3 64.4 76.7 67.1 76.9 64.6 79.4 64.8 76.1 65.1 77.4
WPB 0.10 2147 67.4 80.6 64.8 78.6 60.4 79.0 60.4 78.1 56.8 78.2 50.7 76.9
12H 0.10 1821 70.2 78.7 67.2 80.4 67.2 80.3 55.2 79.7 50.1 82.3 42.1 78.3
65 0.10 1821 70.2 78.7 66.5 80.3 64.0 80.5 60.6 78.4 51.7 77.7 25.9 77.8


0 1 3 5 15
"Si0n"+
30 ppm
Alum 0.10 1309 66.0 83.1 79.9 81.3 80.5 80.9 79.7 80.5 77.9 80.3 76.4 78.3






1






TABLE 21

COAGULATION OF CONCENTRATED URANIUM SOLUTION WITH LIME AND ALUM


Per Cent Activity Removed
I ppm ppm
(cpmml) Alum Lime pH Settled Centrifuged


3.96 x 102 0 410 9.0 99.1 99.5

3.96 x 102 15 410 8.8 99.3 99.5

3.96 x 10? 30 410 8.5 99.1 99.5

3.96 x 102 45 410 8.4 99.5 99.7
3.96 x 102 60 410 8.3 99.5 99.8
3.96 x 102 60 410 8.3 99.3 99.8
3.96 x 102 75 410 8.1 99.5 99.7






75





TABLE 22

COAGULATION OF CONCENTRATED URANIUM SOLUTION WITH LIME AND FERRIC SULFATE


Initial Per Cent Activity Removed
Activity ppm ppm
(cpM/ml) Fe2(SO)3 Lime pH Settled Centrifuged

3.96 x 102 0 410 9.2 99.3 99.8
3.96 x 102 10 410 9.0 99.3 99.8
3.96 x 102 20 410 8.8 99.5 99.8


3.96 x 1O2 30 410 8.6 99.7 99.7

3.96 x 102 40 410 8.3 99.7 99.5
3.96 x 102 50 410 8.0 99.5 99.8






76





TABLE 23
REMOVAL OF URANIM FROM WELL WATER WITH 30 ppm ALUM,
KAOLINITE, AND COAGULANT AIDS


Per Cent Activity Removed
I Dosages of Aids (ppm)
Aids Kaolinite pml 0 0.05 0.1 0.5 1 5

N17 2.86 73 75 75 73 72 68
N17 500 ppm 2.86 75 73 73 73 71 71

110 2.76 67 72 75 72 77 77
110 500 ppm 2.76 75 75 76 75 77 75

W 2.16 64 72 66 67 67 64
w 500 ppm 2.16 66 65 66 65 69 66

CN 2.38 66 67 66 65
C i 500 ppm 2.38 65 67 65 67 66 67

WPB 2.72 70 68 70 68 70
PB 500 ppm 2.72 75 73 74 74 77 71

12H 2.72 68 65 65 65 65 65
12H 500 ppm 2.72 71 71 70 72 65 67

65 2.22 61 62 67 62 64 66
65 500 ppm 2.22 64 57 62 64 61 66






-t77






TABLE 23 CONTINUED


Per Cent Activity Rmuoved I Dosages of Aids (ppm)
Aids Kaolinite cipx?ml 0 0.5 1.0 5.0 10) 15

"SiO2 2.18 56 58 58 58 58 55

"Si0l" 50OP~xn 2.18 56 .59 55 59 56






78




TABLE 24
REMOVAL OF URANIUM FROM WELL WATER WITH 25 ppm FERRIC
SULFATE, KAOLINITE, AND COAGULANT AIDS


Per Cent Activity Removed
I Dosages of Aids (ppn)
Aids Clay cpmml 0 0.05 0.1 0.5 1 5

N17 3.38 74 73 76 66 67 67
N17 500 ppm 3.38 76 76 73 67 70 68

110 3.22 73 73 75 75 76 70
110 500 ppm 3.22 74 75 74 76 73 73

W 3.38 74 74 73 76 71 71
W 500 ppm 3.38 74 75 74 73 74 73

CN 2.52 63 59 60 60 62 64
CN 500 ppm 2.52 63 60 58 55 61 58

WPB 3.16 71 71 72 72 71
WPB 500 ppm 3.16 72 73 73 75 75

12H 3.22 76 74 73 72 74 73
12H 500 ppm 3.22 72 71 76 76 77 73

65 2.44 65 63 63 64 62 61
65 500 ppmn 2.44 65 69 68 70 68 62






79





TABLE 24 CONTINUED


Per Cent Activity Removed I Dosages of Aids (ppm)
Aids Clay cpmml 0 0.5 1 5 10 15

"SioC" 2.18 60 56 59 55 57 55
"SiO,2" 500 ppm 2.18 59 66 59 59 59 954






80





TABLE 25
REMOVAL OF URANIUM FROM WELL WATER WITH 202 ppm LIME,
46 ppm SODA ASH, KAOLINITE, AND COAGULANT AIDS


Per Cent Activity Removed
I Dosages of Aids (ppm)
Aids Clay cpmml 0 0.05 0.1 0.5 1 5

N17 3.76 73(73) 7?(74) 69(80) 64(66) 61(71) 58(6?)
N17 500 P i 3.76 86(68) 81(80) 77(73) 66(51) 62(53) 63(53)

110 2.76 77(27) 77(28) 77(31) 77(29) 77(36) 67(54)
110 500 ppm 2.76 84(36) 86(44) 84(45) 81(46) 77(41) 74(38)

W 2.16 82(29) 82(27) 84(26) 83(13) 88(2) 89(0)
W 500 PM 2.16 91(38) 89(29) 92(26) 88(29) 86(18) 86(3)

CN 2.38 74(41) 75(38) 73(40) 74(42) 74(47) 73(64)
CN 500 ppm 2.38 79(62) 76(66) 79(64) 79(69) 77(71) 75(105)

WPB 2.72 59(31) 58(39) 59(39) 52(56) 51(71) 45(100)
WPB 500 ppm 2.72 66(5) 61(41) 65(46) 60(71) 60(71) 56(100)

12H 2.72 76(51) 74(69) 71(74) 66(92) 70(108) 63(125)
12H 500 ppm 2.72 82(73) 79(92) 81(100) 76(98) 75(90) 69(73)

65 2.22 66(42) 74(47) 73(47) 67(53) 67(51) 67(84)
65 500 pIm 2.22 78(71) 79(71) 81(74) 74(66) 75(73) 59(90)













TABIE 25 -CONTINUE


Per Cent Activity Removed
I Dosages of Aids (PPM)
Aids Clay cPK?2iJ 0 1 5 10 15 20

"Sioaff 3.04 58(18) 50(26) 50(00) 68(0) 75(l) 77(0)

"SiLOaf 500 P~n 3.04 67(56) 63(35) 63(26) 65(25) 77(3) 79(2)






-82





TABLE 26

SUMMARY OF TURBIDITY REDUCTION WITH COAGULANT AIDS'
Coagulation of Clay Alone

Aid Clay (ppm) A Turbidity Best Aid Dosage (ppm) Rating

N17 500 K 31-5 5 A
N17 500 K 44-11 10 B
Ni7 500 V 3-1 0.2 A
N17 500 V 69-7 10 A
NI7 500 FE 46-1 10 A
N17 1000 FE 39-21 1 B
N17 500 I 225-17 10 B
NI? 1000 I 700-80 5 B
w 500 K 66-13 1 B
w 500 V 60-18 10 B
W 500 FE 46-1 1 A
W 500 I 18o-13 1 B
12H 500 V 64-3 1 A
WPB 500 K 31-5 5 A
WPB 500 V 514-3 10 A
65 500 V 64-32 10 B
110 500 V 78-3 25 A
"SiO2" 500 K 92-900 0 U
-sio" 500 V 78-1500 0 U






83




TABLE 26 CONTINUED


Aid Clay (ppm) A Turbidity Best Aid Dosage (ppm) Rating

"Sio02" 500 FE 53-650 0 U
"SiOa" 500 I 180-1100 0 U



Coagulation of Added Clay with Ferric Sulfate or Alum

Coagulant Best Aid
Aid ppm Clay (ppm) A Turbidity Dosage (ppm) Rating

110 10 Fea(SO,)3 1000 FE 1-5 0 U
110 10 Fe(SO,)03 1000 I 38-14 1 B
W 10 Fe6,(SO,) 3 1000 FE 1-4 0 U
W 10 Fes(SO,) 3 1000 I 39-35 0.5 C
WPB 10 Fea(SO)3 1000 FE 2-0 0.5 A
WPB 10 Fea(SO4)3 1000 I 31-14 1 B
"Si02" 17 Alum 1000 FE 1-0 0.5 A
"Si02" 17 Alum 1000 I 11-73 0 U






-84





TABLE 26 CONTINUED

Coagulation of Softening Sludge from Theoretical Lime-Soda Ash Dosages

Aid A Turbidity Best Aid Dosage (ppm) Rating


106 26-140 0 U

N17 13-54 0 U

N17u 73-66 0.5 B

110 42-31 0.5 B

l11o 27-54 0 U

w 26-84 0 U

Wu 29-0 5 A

12H 26-110 0 U

12Hu 51-125 0 U

CN 16-14 0.1 C

CNu 41-40 0.1 C

WPB 24-39 0 U

WPBu 31-100 0 U

65 24-22 0.1 C

6u 42-E4 0 U

"Si02" 27-1 5 A

"SiO2" 18-0 0.5-5 A






85





TABLE 26 CONTINUED
Coagulation of Softening Sludge from Theoretical
Lime-Soda Ash Dosages and Added Clay

Aid Clay (ppm) A Turbidity Best Aid Dosage (ppn) Rating

106 1000 FE 44-14 0.5 B
106 1000 I 290-35 5 B
1Ni7 500 K 68-47 0.2 B
N17 500 V 46-10 0.5 A
N17 5000 V 1200-200 5 B
N17u 500 K 68-51 0.5 B
N171 5000 V 1200-15 15 B
N172 5000 V 325-11 5 B
110u 500 K 36-46 0 U

w 5000 V 1200-1200 U
W 500 K 38-3 5 A
12Hu 500 K 73-100 0 U
CN 1000 FE 40-3 1 A
CN 1000 I 240-26 1 B
CNu 500 K 62-105 o U
CN 500 I + 500 FE 87-17 1 B
WPB 500 K 36-28 1 C
WPBu 500 K 54-41 0.05 B
65u 500 K 71-66 0.5 C







-86






TABLE 26 CONTINUED



Aid Clay (ppm) A Turbidity Best Aid Dosage (ppm) Rating


"Si02" 1000 FE 39-43 0 U
"SiO a" 1000 I 215-29 5 B

"SiO,"u 500 K 56-2 20 A

1 ppm CN +

Variable 1000 FE 10-21 0 U

N17 1000 I 37-31 0.1 C


Ratings
A Coagulant aid improves coagulation and final turbidity is 10
or less.
B Coagulation is significantly improved but final turbidity is
greater than 10.
C Coagulation is slightly improved by one dosage of aid but the
turbidity difference is insignificant.
U All dosages of aid result in a higher final turbidity.

ATurbidity If the rating is A, B, or C, the first number is the turbidity without any aid while the last number is the
lowest final turbidity with the best aid dosage. If the
rating is U, the first number is again the turbidity without any aid while the last number is the highest
final turbidity with any dosage of aid used.

Superscripts
u These samples contained 30 ppm uranyl nitrate hexahydrate.
1 This sample contained 155 ppm excess soda ash and 10 ppm
stable strontium.
2 This sample contained 100% excess lime with equivalent soda
ash and 10 ppm stable strontium.






-.87






TABLE 27

SUMMARY OF ACTIVITY REMOVAL WITH COAGULANT AIDS

Coagulation of Clay Alone


Best Aid
Aid Isotope Clay (ppm) A Activity Dosage (ppm) Rating N17 Cs 1000 FE 90.4-93.4 S 0.1 B

N17 Cs 1000 I 69.4-88.4 S 1 B

N17 Sr 500 V 64.5-72.0 S 1 A

W Sr 500 V 65.9-75.7 S 1 A

W Sr 500 V 67.6-75.7 C 10 A

"SiO2" Sr 500 V 60.1-69.1 S 5 A



Coagulation with Ferric Sulfate or Alum


Coagulant Best Aid
Aid Isotope ppm A Activity Dosage (ppm) Rating

NI? Pm 36 Fez(SO)3 93.5-96.3 S 0.2 A
N17 Pm 36 Fe2(SO)3 99.1-99.5 C 1 A

110 Pm 60 Alum 94.2-97.2 S 5 A
110 Pm 60 Alum 98.3-98.7 C 0.5-5 A

W Pm 60 Alum 97.6-98.6 S 0.5 A

W Pm 60 Alum 98.6-99.3 C 1 A






-88





TABLE 27 CONTINUED


Coagulant Best Aid
Aid Isotope (ppm) A Activity Dosage (ppm) Rating

WPB Pm 36 Fe2(S30)3 99.2-99.4 S 0.5 A
WPB Pm 36 Fe,(SO,)3 99.8-99.9 C 0.5-1 A
12H Pm 60 Alum 92.5-98.3 S 5 B
12H Pm 36 Fe2(SO4)3 97.0-98.9 C 1 B
65 Pm 60 Alum 95.7-96.8 C 5 B

"Si02" Pm 60 Alum 90.9-95.1 S 15 B
110 U 30 Alum 67-77 S 1-5
W U 30 Alum 64-72 S 0.05



Coagulation of Added Clay with Ferric Sulfate or Alum


Coagulant Clay Best Aid
Aid Isotope (ppm) (ppm) A Activity Dosage (ppm) Rating

110 Cs 10 Fe2(304)3 1000 I 93.5-94.8 C 0.5 A
W Ca 10 Fe2(SO,)3 1000 I 95.1-96.6 C 5 B
JPB Cs 10 Fe2(SO,)3 1000 I 91.7-93.4 S 1 A

W Pm 36 Fe2(SO,)3 500 FE 98.8-99.3 S 0.5 B

"Si02" Pm 60 Alum 500 FE 96.3-99.1 S 0.5 B





89





TABLE 27 CONTINUED
Coagulation of Softening Sludge from Theoretical Lime-Soda Ash Dosages


Aid Isotope A Activity Best Aid Dosage (ppm) Rating

N17 Sr 64.o-8o.2 S 1 B

w Sr 81.3-85.5 C 1 B
WPB Sr 77.4-82.6 S 0.2 A

65 Sr 67.3-79.0 S 0.5 A

65 Sr 73.9-83.5 C 0.5 A

651 Sr 92.8-94.5 C 0.5 B
106 PR 95.4-98.5 S 5 B

W Pm 97.2-99.5 C 0.1 B

CN Pm 99.6-99.7 C 0.5 B

WPB Pm 98.1-98.6 C 0.1 A

"Si0" Pm 94.9-98.1 S 5 B

"SiO2" Pm 99.3-99.5 C 1 A

w U 82-89 S 5

65 U 66-74 S 0.05
"SiO 2 U 58-77 S 5






90





TABLE 27 CONTINUED

Coagulation of Softening Sludge from Theoretical
Lime-Soda Ash Dosages and Added Clay


Best Aid
Aid Isotope Clay (ppm) A Activity Dosage (ppm) Rating


106 Cs 1000 FE 92.5-94.7 S 0.1 A

106 Cs 1000 I 83.2-92.9 S 0.1 A

106 Cs 1000 I 96.5-97.9 C 0.1 A
"SiO2" Cs 1000 I 85.6-94.6 S 5 B

CN Cs 1000 FE 89.6-96.1 S 1-5 B

CN Cs 1000 I 83.3-95.8 S 5 A

CN Cs 1000 1 96.0-97.0 C 1 A

CN Cs 500 FE, 500 I 89.4-95.6 S 0.5 A

1 ppm CN +
Variable
N17 Cs 1000 FE 95.0-96.7 S 5 B

1062 Sr 5000 V 91.8-95.1 S 20 A
1062 Sr 5000 V 94.9-96.2 C 5 A

106 Sr 5000 V 92.9-96.8 S 20 A

1061 Sr 5000 V 93.6-98.7 S 20 A
1061 Sr 5000 V 99.3-99.5 C 20 A

N17 Sr 5000 V 93.4-98.0 S 5 A

N17 Sr 5000 V 98.6-99.0 C 2-5 A

N171,3 Sr 5000 V 93.5-99.2 S 5 B







91






TABLE 27 CONTINUED



Best Aid
Aid Isotope Clay (pjxi) A Activity Dosage (pp11) Rating


N173 4 Sr 5000 V 97.6-98.3 S 2 B

W Sr 5000 V 94.4j-97.6 S 5 B

N17 PM 500 V 96.7-97.5 S 0.2 B

"5i02" U 500 K 67-79 S 5


Ratings
A -Coagulant aid reduces residual activity from the basic decontamination process by at least 20%~ in either a settled or a
centrifuged sample and does not increase the resudual activity
in the corresponding centrifuged or settled sample.

B -Coagulant aid reduces residual activity from the basic decontamination process by at least 205p in either a settled or a
centrifuged sample but increases the residual activity in the
corresponding centrifuged or settled sample.

A Activity
The first number is the per cent activity removed by the basic
decontamination process without any aid while the last number is the
highest per cent activity removed with the best aid dosage. S and
C denote settled and centrifuged samples respectively.

Superscripts
1 Theoretical lime dosage and 155-165 ppxn excess soda ash used.
2 117 pjxn lime and no soda ash used.
3 Contains 10 pjpm stable Sr.
4 100% excess lime and equivalent soda ash used.

























APPSIM Ill

FlaUMCS