Title: Removal of low-level radioisotopes from waste water by aerobic methods of treatment
CITATION PDF VIEWER THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00098227/00001
 Material Information
Title: Removal of low-level radioisotopes from waste water by aerobic methods of treatment
Physical Description: xii, 162 leaves. : illus. ; 28 cm.
Language: English
Creator: Lawrence, Charles Hillman, 1937-
Publication Date: 1963
Copyright Date: 1963
 Subjects
Subject: Sewage -- Analysis   ( lcsh )
Water -- Analysis   ( lcsh )
Water -- Pollution   ( lcsh )
Radioisotopes -- Industrial applications   ( lcsh )
Sanitary Engineering thesis Ph. D
Dissertations, Academic -- Sanitary Engineering -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Thesis: Thesis -- University of Florida.
Bibliography: Bibliography: leaves 157-161.
General Note: Manuscript copy.
General Note: Vita.
 Record Information
Bibliographic ID: UF00098227
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000572219
oclc - 13770766
notis - ACZ9362

Downloads

This item has the following downloads:

PDF ( 3 MBs ) ( PDF )


Full Text

REMOVAL OF LOW-LEVEL RADIOISOTOPES
FROM WASTE WATER BY AEROBIC
METHODS OF TREATMENT









CHARLES HILLMAN LAWRENCE


A DISSERTATION PRESENTED TO THE GRADUATE ODUNCEL OF
THEF UNIVERSITY OF FLORIDA
IN PARTIL FULFILLMENT OF THEF REQUIREM6ENTS FOR THE
DEGREEb OF DOCTOR OF PHIOSOPHY








UNIVERSITY OF FLORIDA
December, 1963


I











































































__


The anchor expresses appreciation to his graduate committee,

Professor F. N. Gilcreas, Chairman, Dr. A. P. Black, Professor G. B.

MIorgan, Professor J. E. Kiker and Professor T. deS. Furman, whose

kind help and constructive criticisms were invaluable in conducting

this study and in the preparation of this thesis.

Special appreciation is extended to Professor G. B. Haorgan, who

not only gave generously of his thme and knowledge as a committee

member but also whose photography adds much to the presentation of

this work.

Gratitude is expressed to the staff of Phelps Laboratory for

providing the facilities and helping with many of the laboratory

analyses that wFere required in conducting this tweestigation.

Appreciation is extended to Mr~s. Marjorie D~u~ez who devoted many

hours toward editing and typing the manuscript.

Recognition and appreciation is extended to the U.. S. Publiic

Health Service whose support under the Aublic Realth Training Program

made this study possible.

The author owes his deepest appreciation to his wife and family

for their patience and encouragement throughout this academic phase

of life.


ACKNOULEDGHENTS


















TABLE OF CONTENTS


Page


ACKNOILEDG;HENTS . .. .. . .. ... ... . .. ii

LIST OF TABLES ... .. ... .. .. .. .. . .. .. v

LIST OF FIGURES .. ... . .. ... .. .. .. .. .. viii

ABSTRACT ................... ......... x

CHAPTER

I. INTRODUCTION .. .. .. .. .. .. . 1

II. LITERATURE REVIEP .. .. .. .. .. .. .. ... 5

III. PURPOSE AND SCOPE ... ... .. .. .. .. .. 15

nV. DESCRIPTION OF EXERIMENTAL UNITS .. .. .. . 20

V. PROCEDURE ................... .... 40

VI. DISCUSSION OF OBSERVATIONS .. .. ... .. . ... 49

VII. SU~nNEY AND CONCLUSIONS .. .. .. .. .. . ... 64

APPENDICES

A. CHEMICAL ANALYSIS OF LDEMSTONE FILLER MBDIUn .. .. 69

B. CALCULATION OF CONCENTRATION OF RADIOACTIVE MATERIAL
PRESENT AT SELECTED LEVES OF RAD ICTIVfiT .. .. 70

C. STATISTICS OF COUNTING RADIOACTIVE SAMPUES .. .. .. 72

D. TABULATED DATA -- REMOVAL OF SELECTED RADIONUCLIDES BY
PRIMARY SEDIMENTATION .. .. .. .. . . 74

E. TABULATED DATA AND GRAPES -- 15EIKTML OF SELECTED RADIO-
NUCLIDES BT TRICKLING FILTRATION AND SECONDARY
SEDIMENTATION .. ... .. .. .. .. ... . 82


iii














APPENDICES Page

F. TABULATED DATA AND GRAPHS -- REMOVAL OF SELECTED
RADIONUCLIDES BY LAGOONING .. .. .. .. . ... .. 132

G. TABULATED DATA -- RESULTS OF CHEMICAL AND BIOCHEMICAL.
ANALYSES. . . . .. .. . . 143

LIST OFREFERENCES ........... - ..........- 157

BIOGRAPHICAL'SKETCH.. ......... ......--- -- 162

















LIST OF TABLES


Table Page

1. CHARACTERISTICS OF SELECTED RADIONUCLIDES .. .. . ... 18

2. RADIONUCLIDE DOSING DATA .. .. .. .. .. .. ... 41

3. SUMMARY OF REMOVAL EFFICIENCIES ACHIEVED BY TRICKLING
FILTRATION AND SECONDARY SEDIHENTATION UNDER EQUILIBRIUM
CONDITIONS . ... .... .. ... .. . . 53

4, SUMMARY OF REMOVAL EFFICIENCIES AND BUFFERING FACTORS
OBTAINED BY LAGOONING .. .. .. .. ... .. .. .. 59

5. REMOVAL OF P-32 BY PRIZIARY SEDIMENTATION ... .. .. 74

6. REMOVAL OF I-131 BY PROMAKE SEDIMENTATION . .. . .. 75

7. REMOVAL OF K-42 BY PRIMARY SEDIMENTATION .. .~ . .. 76

8. REMOVAL OF Ce-141, 144 BY PRIMARY SEDIMENTATION . ... 77

9. REMOVAL OF Fe-59 BY PRIMAKE SEDPMENTATION .. ... .. 78

10. REMOVAL OF Co-58 BY PRIMAKE SEDIMENTATION .. .. .. 79

11. REMOVAL OF Sr-89 BY PRIMARY SEDP1ENTATION .. .. .. . 80

12. REMOVAL OF MFP BY PRIMARY SEDIMENTATION .. .. .. .. 81

13. REMOVAL OF P-32 BY TRICKLING FILTRATION . .. ... .. 82

14. REMDVAL OF I-131 BY TRICKLING FILTRATION . ... . .. 83

15. RENDVAL OF K-42 BY TRICKLING FILTRATION .. .. .. .. 84

16. REMDVAL OF Ce-141, 144 BY TRICKLING FILTRATION . .. .. 85

17. REMOVAL OF Fe-59 BY TRICKLING FILTRATION .. .. .. .. 86

18. REMDWAL OF co-58 BY TRICKLING FILTRATION .. .. .. .. 87

19. REMOVAL OF Sr-89 BY TRICKLING FILTRATION .. . .. ... 88

20. REMOVAL OF MFP BY TRICKLING FILTRATION . .... . .. 89


I





Table Page

21. ACTIVITY OF P-32 IN FILTER SLOPES . .. .. .. .. ... 98

22. ACTIVITY OF I-131 IN FILTER SLOPES .. .. .. .. .. 99

23. ACTIVITY OF K-42 IN FILTER SLIMES .. .. ... ... 100

24. ACTIVITY DF Ce-141, 144 IN FILTER SLIMES .. .. .. .. 101

25. ACTIVITY OF Fe-59 IN FILTER SLIDES . .. .. ... .. 102

26. ACTIVITY DF Co-58 IN FILTER SLIMES .. .. .. .. .. 103

27. ACTIVITY OF Sr-89 IN FILTER SLIMES .. .. .. ... 104

28. ACTIVITY OF MFP IN FILTER SLIMES ... .. .. .. .. 105

29. RENDVAL DF P-32 BY SECONDARY SEDIMENTATIONJ .. .. .. 114

30. REEDWAL OF I-131 BY SECONDARY SEDIMENTATION . .. .. .. 115

31. REEDVAL OF K-42 BY SECONDARY SEDIMENTATION .. .. .. 116

32. REMDVAL OF Ce-141, 144 BY SECONDARY SEDIMENTATION . ... 117

33. REMOVAL OF Fe-59 BY SECONDARY SEDIMENTATION .. .. .. 118

34. RENBDVAL OF Co-58 BY SECONDARY SEDIMENTATION . ... .. 119

35. REMOVAL OF Sr-89 BY SECONDARY SEDIMENTATION .. .. .. 120

36. RENDVAL OF MFP BY SECONDARY SEDINENTATION .. .. ... 121

37. ACTIVITY OF P-32 IN SECONDARY SLUDGE .. .. .. .. .. 124

38. ACTIVITY OF I-131 IN SECONDARY SLUDGE . ... .. 124

39. ACTIVITY OF K-42 IN SECONDARY SLUDGE .. .... .. 125

40. ACTIVITY OF Ce-141, 144 IN SECONDARY SLUDGE . .. .... 125

41. ACTIVITY OF Fe-59 IN SECONDARY SLUDGE .. .. .. ... 126

42. ACTIVITY OF Co-58 IN SECONDMDE SLUDGE . .. ... . .. 126

43. ACTIVITY OF Sr-89 IN SECONDARY SLUDGE .. .. ... .. 127

44. ACTIVITY OF MFP IN SECONDARY SLUDGE . ... ... .. 127













Table Page

45. REHDELAL OF P-32 BY IAGOONING .. .... .. .. .. 132

.46. RENDELLL OF 1-131 BT ILAGOOING .- . ... .. .. . .. 133

47. Bl>KOYAL OF Ce-141, 144 BT LAGOON1INGC .. .. .. ... 133

48. READELLt OF Fe-59 BY LAGO0NiNG ... . ... . . . 134

49. REPIDELL OF Co-58 BT LAGOONIN~G . .... .. .. .. .. 134

50. RgEHOlML OF Sr-89 BT IAGOONING ... .. .. .. .. .. 135

51. REMBELL OF MFF BY LAGDONING . ... .. .. . 35

52. PRIMARY SEDTHER~T TION BAISINO DhZA .. .. .. .. ... 143

53. TRBICKLING FILEE DATIA (BOD in ag/1) .. ... .. .. 145

54. TRICKLING FILE DATA (Percentage Reduction in BOD) .. 147

55. TBIRICKLG FILSEBR BAth (Ttal Nitrogen in ag/1) .. .. .. 149

56. TRICKLING FILER DATA (Percentage Reduction in Total
Nitrogen) .. .. .. ... ... .. .. .. . .. 151

57. TRICKLING FIL2ER D1ATA (Nitrates in ag/1) . .. .. .. 153

58. TRICKLLING FILTER DATA (Percentage Nitrification) . .. .. 155


vii
















LIST OF FIGURES


Figure Page

1. GENERAL VIEW OF THE EXPERPIMNAL. PRPIARY SEDTHENTATION
BASIN ... .. ... .. .. .. .. . -. .. 22

2. .SECTIONAL VIEW OF THE PRICDIRY SEDIHENTATION BASIN
ISOTOPIC DOSING DEVICE .. ... .. .. .. .. .. 24

3. GENERAL VIEW OF THE EXPERIMENTAL TRICKLING FILTER .. 31

4. DOSING DEVICES USED IN THE APPLICATION OF SEWAGE AND
RADIDISOTOPES TO THE EXPERIMNTALL TRICKLING FILTER .. 33

5. GENERAL VIEW OF THE EXPERINENTAL. LAGOON .. .. ... 37

6. AVERAGE REMDVAL OF SELECTED RADIONIDCLIDES BY PRIMARY
SEDIMENTATION .. .................. 51

7. RELATION OF BOD, NITRATIES AND TOTAL NITROG;EN WITH DEPTH
INIFILTER................... ..... 62

8. BEENDVAL OF P-32 BY TRICKLING FILTRATION .. ... .. 90

9. REEDWAL OF I-131 BT TRICKLING FILTRATION .. . ... 91

10. REMOVAL OF.K(-42 BY TRICKLING FILTRATION .. .. .. .. 92

11. RENJDVAL OF Ge-141, 144 BY TRICKLING FILTRATION . ... 93

12. REMDVAL OF Fe-59 BY TRICKLING FILTRATION . .. ... 94

13. REMORAL OF Co-58 BY TRICKLING FILTRATION . .. ... 95

14. RENPDVAL OF Sr-89 BY TRICKLING FILTRATION .. .. .. 96

15. REN3CDRAL OF MIFP BY TRICKLING FILTRATION .. .. .. .. 97

16. ACTIVITY OF P-32 IN FILTER SLIMES . ... .. .. .. 106

17. ACTIVITY OF I-131 IN FILTER SLINES .. . .. 107

18. ACTIVITY OF K-42 IN FILTER SLIDES .. .. .. .. .. 108

19. ACTIVITY OF Ce-141, 144 IN FILTER SLINES .. . ... 109













Figure Page

20. ACTIVITY OF Fe-59 IN FILTER SLINES . .... . .. .. 110

21. ACTIVITY 07 Co-58 IN FILTER SLINES .. ... .. . .. 111

22. ACTIVITY OF Sr-89 IN FILTER SLIDES . ... .. ... 112

23. ACTIVITY OF MFP IN FILTER SLICES .. ... .. .. .. 113

24. RENDVAL OF P-32, I-131, K-42, AND Ce-141, 144 BY
SECONDARY SEDIMENTATION .. .. .. .. ... . . 122

25. REMOVAL OF Fe-59, Co-58, Sr-89, AND MFP BY SECONDARY
SEDIME~NTA1ION . .. .. . .. . ... . 123

26. ACTIVITY OF P-32, I-131, AND Co-58 IN SECONDARY SLUDGE . 128

27. ACTIVITY OF K-42 IN SECONDARY SLUDGE .. . . 129

28. ACTIVITY OF Ce-141, 144 IN SECONDARY SLUDGE .. . 130

29. ACTIVITY OF Fe-59, Sr-89, AND HFP IR SECONDARY SLUDGE . 131

30. RENDVAL OF P-32 BY LAGOONING . .. . . .. .. 136

31. REMOVAL OF I-131 BY LAGOONINlG . . . .. . 137

32. REMBOVAL OF Ce-141, 144 BY LAGOONING .. .. .. . 138

33. REMOVAL OF Fe-59 BY LAGOON1ING .. .. .. . . . 139

34. 252290. DF Co-58 BY LAGOONING .. .. .. .. .. . 140

35. RENDVAL OF Sr-89 BY LAGOONING . . . .. .. . 141

36. REMOVAL OF MFP BY LAGOONING .. . .. .. .. . 142












Abstract of Dissertation Presented to the Graduate
Council in Partial Fulfillaent of the Requirements
for the Degree of Doctor of Philosophy


REHDVALI OF LOW-FLEVEL RADIOISOTOPES FROR YASTEg
RATHER aT saEOBIC BTHsoDs OF TREA'DeNT

By

Charles Hillaan Lawrence

December, 1963


Chairman: Professor F. W. Gilcreas
major Department: Civil (Sanitary) Engineering


This investigation evaluated the removal of low-level radionuclides

from waste water by a complete sewage treatment plant operating under

field conditions. A pilot shee treatment plant employing primary

sedimentation, trickling filtration, and lagooning was utilized. These

processes were subjected to a series of eight experiments involving

phosphorus-32, todine-131, potassium-42, ceriurm-141, 144, iron-59,

cobalt-58, strontion-89, and mixed fission products.

ELhe results indicated that primary sedimentation was relatively

ineffective in removing colloidal and dissolved radionuclides from

sewage. After two hours of continuous isotopic dosing, the effluent

activity approached equlbrium conditions and the average rate of

removal for all materials investigated stabilized at approximately

9 per cent.

TIhe effectiveasess of the trickling filtration process in the

treatment of low-level wastes was 10mited to the ability of the filter

to remove the radioactive components from the main waste stream and to













concentrate them in the solids leaving the filter in a settleable form.

All radionuclides experienced significant uptakse in the filter but, in

some cases, extensive re-entrainment occurred before final removal could

be effected. Consequently, the treatment efficiency of the over-all

process was controlled by the removal accomplished by secondary

sedimentation. The following treatment efficiencies were observed under

equillbrium conditions: 60 to.70 per cent for ironr-59 and cobalt-58;

40 to 50 per cent for ceriumn-141, 144 and mixed fission products;

approximately 25 per cent for potasstum-42 and strontium-89; and less

than 5 per cent for todine-l11 and phosphorus*32.

Uptake studies indicated that the removal of low-level radianuclides

within the filter resulted from the concentration of these materials by

the anogleal slimes present throughout the unit. The various rates of

removal with respect to time were comparatively high during the initial

dose:: but gradually decreased to equilibrous conditions which, for all

materials investigated, were attained after approximately 96 doses.

All rates of removal with respect to depth decreased somewhat exponentially

with increasing depth of medium. Optiman filter depth was six feet,

The concentration of radioactive materials by the zoog1eal slices

resulted fran the action of three mechanics, (a) absorption of the

radionuclides by the microbiota in the slime layer, (b) ion exchange

reactions involving the radioisotopes in the vastaestream and the stable

elements associated with the filter solids, (c) adsorption and physical

trapping of the radioactive materials in and on the altae layer.

Absorption and ten exchange appeared to be comparatively ineffective and

highly reversible, especially for radioactive materials present in their












solable form. Adsorption and physical trapping were indicated to be

efficient and relatively irreversible for colloidal radianuctides.

Lagoon studies indicated that the long detention time and intimate

algal-bacterial contact provided by this process were effective in

dilating, delaying and, in most cases, substantially removing usings"

of low-level radioactive materials. The basin had an effective detention

thme of twro days and achieved the following removals approximately

90 per cent for CcrIum-141, 144 and iron-59; 69 per cent for strontiuma-89;

50 to 60 per cent for phosphorus-32, cobalt-58, and aimed fission

products; and less than 1 per cent for todine-131.

The mechanisms indicated to be effective in the removal of

radioactive materials by lagooning were precipitation by chemical,

physical, and biological means and ion exchange reactions Lawolving the

sulspended radionuclides and the stable materials retained in the basin.

Trvalent materials in their colloidal form and divalent elements

biologically significant in trace amounts wrere removed most effectively.

















CHAPTER I


INTRODUCTION


Nith the discovery of X-rays by Roentgen in 1895 and of naturally

occurring radioactive materials by Becqueral in 1896, the Nluclear Age

was born. These events caused a sensation among physicists but aroused

little interest in any other area. Twenty-four years later, it was

announced that radioisotopes could be produced artificially. This gave

renewed interest to the physicists and chemists but elsewhere radio-

activity still seemed to be a scientist's toy with little, if any,

practical application. Widespread interest in this new science was not

initiated until 1942, when the first reactor was built and put into

operation ~by Fermi and co-workers under the West Stands of Stagg Field

at the University of Chicago. The success. of this operation gave the

young field of nuclear science an impetus that shows no signs of

diminishing. These events gave rise to a new source of power -- both

stationary and mobile -- and to a source of radioisotopes both of which

have had a profound effect on industry, medicine and research.

The Lapact of this new technology upon the activities of man can

best be, illustrated by the use of a few statistics. In late 1955, there

were 42 nuclear reactors known to be operating in the world with 29 of

these in the United States (1). Twenty more were under construction,

with nine of these in this nation (1). In 1960 there were almost 100

reactors in various stages of design and construction in the United













States alone (2). At+ that time, the U. S. Navy had approximately 61

seagoing reactors either existing or authorized as power plants for an

aircraft carrier, a cruiser, a destroyer, and numerous submarines (2).

On addition to these reactors, it is expected that in the near future

almost every major college and university in the United States will have

reactors for research and instructional purposes and with the azhaustion

of fossil fuels, nuclear reactors will assume an increasing importance

as a source of power. It has been estimated that by 1980, 65 per cent

of all power plants will be operating on nuclear power (1).

As impressive as these figures may seem, they are not as phenomenal

as chose illustrating the growth in radioisotope usage in the' past 17

years. In ~1946, the first year the Atomic Energy Commission (AEC) made

radioisotopes available to the civilian economy, there were only 86 users

of these materials. The Oak Ridge National Laboratory, the principal

supplier of radioisotopes in the United States, made 281 shipments

totaling 8 curies (3). By 1959, a total of 78,598 shipments had been

made to approximately 5,200 organizations and individuals licensed by

the AEC (4). These shipments represented 537,781 curies of radioactivity

(4). In 1962 about 1,100 shipments per month vere sent to 2,700 users

throughout the United States and 57 foreign countries (5).

There is reason to believe that even though the growth of the use

of nuclear energy has been great, the surface of the application of this

new tool has just been scratched. Myriad uses are in the research and

developmental stage while others have yet to be realized or explored.

However, we cannot accept the assets that nuclear technology offers to

us unless we also assumae the responsibility for the Liabilities which

we know to exist.













In practically all cases where radioisotopes are used, radioactive

wastes are produced. As evidenced by the above figures, the treatment

and safe disposal of these wastes could easily become the major problem

which faces the Atomic Age. The extent to which we can safely dispose

of our radioactive wastes could very well limit our exploration of this

new science.

Aside from being a new problem for which we have no backlog of

experience, radioactive waste disposal has certain features heretofore

unencountered in the practice of waste treatment. For example, it is not

possible, by normal physical or chemical means, to destroy or appreciably

alter the property of radioactivity as we can the noxious properties of

other pollutants. Furthermore, the maxhamn permissible levels for

various radionuclides in waste effluents are several orders of magnitude

lower than those for inactive contarminates. However, the most insidious

property of this relatively new waste is that the biological effects of

exposure to ionizing radiation, even at low levels, can be somatically

and genetically cumulative and irreversible (6, 7, 8).

There are two alternatives in dealing with radioactive wastes,

narmely, (a) concentration and containment, and (b) dilution and dispersal.

Concentrated or high-level wastes usually come La anall volumes and the

methods of disposal, even though expensive, are quite effective;

consequently these wastes pose no serious public health problems.

Dilute or low-level wastes come in large volumes and are usually

discharged into the environment. It is the disposal of these wastes

that is causing an increasing concern in the field of public health and

placing an increasing burden on sanitary engineering.













The future release of low-level wastes by dilution into the

environment must be carried out with caution and under strict controls.

Even though the level of activity in the waste may be well within what

is considered safe limits, it can be concentrated physically, chemically,

and biologically in some phase of the environment, thus posing a health

hazard to this or future generations. To prevent the possibility of

such an occurrence, no effort should be termed excessive.















CHAPTER II


LITERATURE REVIEW


Throughout history man has been concerned with, and often plagued

by, the wastes from his activities. In order to protect his health,

comfort, and. property he has been forced, often belatedly, to take

remedial steps leading to the treatment and safe disposal of these

detrimental products. The coming of the Atomic Age has once again

presented this necessity; however, the incurable results will not allow

us to wait until the situation becomes critical to take remedial steps.

The magnitude of the problem of radioactive waste disposal is not

alarming until viewed in the light of present world activities and ~the

predictions of future capabilities. It has been predicted that by 1965

the United Kingdom alone will be deriving 6,000 megawatts from nuclear

power reactors (9). This annual capacity, which is scheduled to increase

in subsequent years, will require the fission of 6 to 8 tons of uranium-

235 and will produce an equivalent weight of fission products which

will have an associated radioactivity of 109 juries (9). In the United

States it has been estimated that the nuclear power industry will have

produced about 3 x 109 curies of radioactivity in 27 x 106 liters of

solution by 1970 and 6 x 1010 curies in' 11 x 108 liters of solution by

the year 2000 (10). Disturbing as these figures are, it must be

remembered that they are estimates for merely the power reactors of

only two countries. These figures must be augmented by the tastes fran





all other reactors of all types in all countries as well as by the wastes

from the rapidly expanding and diversified uses of radioisotopes in

practically all disciplines of science. The escape of a small fraction

of this activity as low-level wastes -- a highly probable occurrence --

could easily result in billions of gallons annually.

Since it is physically and economically impractical to concentrate

low-level wastes, dilution into the enviromnent is the only alternative.

One of the most common and convenient methods of carrying this out is by

discharge ~into the severs (11, 12). Nevertheless, research concerning

the ability of sewerage systems to receive and dispose of radioactive

tastes has not been sufficient to permit formulation of comprehensive

standards. Consequently, the legal limits of disposal of radioactive

wastes in this manner are those outlined in Randbook 69 (13) for

occupational exposure to various radionuclides in water. Admittedly,

the values contained therein were not primarily intended for use in

waste disposal, but they are well founded and offer a reasonable degree

of safety until more applicable guide-lines can be developed.

Other than these limits, it is quite difficult to locate concrete

information concerning the types and quantities of radioactive vastes

that can be safely discharged into the severs. Neal (14) states that

the discharge of liquids to the severs is safe if the average concentra-

tion of radioactivity in the severr does not exceed 10- microcuries per

milliliter and if the transient concentration does not: exceed 10-1

microcuries per milliliter. He further states that tilese limits can be

relaxed if the radioactivity is due solely to a nuclide of low toxicity.

The Radio Corporation of America Service Company (15) gives some slightly













more specific information. Their recommended daily 10mits of discharged

activity per million gallons of sewage are:

"1. One millicurie of stroncium-90 or polonium-210.

2. One hundred millicuries of any radioactive material having a

half-life of less than 30 days.

3. Ten millicuries of any other radioactive material."

These recommendations are rather brief and seem to be based more on

ruiles-of-thurmb than on the chemical, physical, or biological properties

of the wastes or the ability of the sewage treatment plant to remove

any fraction of the radioisotopes.

Once radioactive wastes are discharged to a sewerage system, the

slimes in the plumbing and severs provide the initial biological contact.

Talboys (16), in a laboratory study of the retention of iodine-131 by

bacterial slimes in drains, found that even though this isotope is not

metabolized by the organisms in the slimes, small quantities are retained

by physical adsorption and are subject to removal through successive

flushing. He calculated that any hazard to sever workers exposed to

sewage bearing this isotope, would be quite low. Reid (17) made similar

findings whien~ studying the sorption and metabolic uptake of phosphorus-32

by bacterial slimes.

Considerable attention has been given to the effects of radioactivity

on the organisms responsible for the biological treatment of sewage.

Dobbins et al. (18), using oxygen utilization as a criterion for measuring

oxidation rates in domestic sewage, found that these rates were not

affected by phosphorus-32 in concentrations up to 1 millicurie per liter

and only a small reduction in the rate of oxygen utilization was observed








-8-


at 10 millicuries per liter. Iodine-131 in concentrations up to 10

millieuries per liter produced a decrease in the rate of oxygen utiliza-

tion which resulted in a reduction in the total oxygen demand of about

10 per cent by the seventh day.

The relative ease with which sludge digestion can be reduced to a

small scale has induced considerable experimentation with this treatment

process. Babbitt et al. (19), in laboratory studies with phosphorus-32,

iodine-131, sulphur-35, and calcium-45 found that 100 millicuries per

liter had no measurable effects but 200 millicuries per liter gave a 17

per cent reduction in gas. At the lower concentration, phosphorus was

found primarily in the sludge phase, about 75 per cent of the iodine was

in the liquid phase and about 90 per cent of the sulphur was found to be

concentrated in the solids.

Phosphorus-32, iodine-131, and sulphur-35 were also used by

ERarmeson and Dietz (20) in their study of the effects of radioactive

substances on sludge digestion. They found that 110 millicuries per

liter had no apparent effects and 200 millicuries per liter were required

to produce inhibitory effects. They also found that phosphorus and

sulphur tended to concentrate in the sludge while iodine was more

concentrated in the liquid.

Grune et al. (21, 22), using carrier-free iodine-131, could detect

no significant difference in the gas production of their laboratory

digestors when dosed with up to 300 millicuries per liter. At 600

millicuries per liter a significant reduction occurred in the reaction-

velocity-d'onstant but the ultimate gas production, volatile solids

reduction, and concentration of volatile acids were not affected.












In further studies using carrier-free phosphorus-32, they found signifi-

cant gas reductions at 200, 400, and 800 millicuries per liter. At the

higher dose, a decrease in volatile matter and a tenfold increase in

volatile acids were noted.

Primary treatment processes have received relatively li title

investigation with respect to their ability to treat radioactive wastes.

Belcher (23), in a laboratory investigation concerned with some of the

radioisotopes of interest in the medical profession, found that not more

than 5 per cent of the influent activity was removed from domestic sewage

when subjected to sedimentation.

Secondary treatment processes, on the other hand, have been involved

in several -investigations. Using laboratory scale trickling filters

dosed with domestic sewage, Belcher (23) found that when bromine-82,

iodine-131, sodium-24, phosphorus-32, and cobalt-60 were added to the

sewage the concentration of radioisotopes in the effluent rose to an

apparently steady value after 16 hours. The proportions of the radio-

isotopes removed were 6, 5, 13, 77, and 79 per cent, respectively.

Nevall et al. (24) conducted laboratory investigations on the

removal of plutonium from laundry wastes. They compared a trickling

filter with chemical precipitation and concluded that the trickling

filteer, operating at a 15 to 1 recirculation ratio, gave effective

removal and the resulting sludge volume was only about 4 per cent of

that produced by chemical treatment of these wastes.

Gloyna and Geyer (25), using a synthetic laundry waste and rotary

tubes, simulated an 8-foot trickling filter loaded at 8 million gallons

per acre per day. They found that the slides retained 40 per cent of













the applied cerium-144 and 20 per cent of the applied phosphorus-32.

They concluded that the primary factors which control the removal of

radioactivity by microorganisms are ph, viability of the organisms, type

of isotope, toxicity of the waste to the aderoorganisms, and the ratio

of stable to radioactive isotopes.

Carter (26), using 2-inch diameter laboratory filters dosed with

savage containing carrier-free iodine-131, found that a 6-foot filter

had a removal efficiency of 85 per cent with most of the removal

occur-ring in the first 3 feet. This removal efficiency was found to be

fairly stable at dosing rates from 2 to 6 million gallons per acre per

day.

In a laboratory study using a synthetic waste and a trickling

filter 5 1/2 inches in diameter by 4 feet deep, Klein et al. (27)

concluded' that trickling filters could remove 70 to 85 per cent of the

gross beta activity due to mixed fission products. They also found

that the removal of phosphorus-32 was highly dependent upon the concen-

tration of the stable phosphorus in the waste. In this respect, they

reported that the removal of phosphorus-32 was as low as 20 per cent

at a stable phosphorus content of 6 1/2 milligrams per liter and as

high as 88 per cent when the stable phosphorus content dropped to

1 65/100 milligrams per liter.

Radioactive laundry tastes have also been studied by Wiederhold (28)

who, using a trickling filter constructed from two 30-gallon drums,

concluded that trickling filters not only gave satisfactory removal

of the applied alpha and beta activities but also removal of organic

materials that interfere with subsequent chemical coagulation and flocen-

lat ion.












In treating radioactive laundry tastes of pH 3.0 to 5.0, BOD 200 to

800 milligrams per liter and beta activity of 180 disintegrations per

minute per milliliter on single and two-stage laboratory trickling

filters, Dobbins (29, 30) found the sludge to contain 200 times the

activity of the raw waste. These studies indicated that 90 per cent

of the gross activity of mixed fission products was removed at loadings

of 250 pounds of BOD per acre-foot per day but that removal decreased

with increasing loading rates. It wjas observed that the sludge activity

was essentially independent of the organic loading rate but was dependent

on the activity level of the vaste. The percentage removal of the

various elements were: cerium, 97 3/10; ruthenium, 79 1/10; strontium,

69 4/10; yttrium, .86 7/10; and zirconium-niobium, 79 1/2.

Fowler et al. (31) in studying the retention time of trickling

filter slimes with rubidium, found that adsorption did take place but

was inherently reversible. They observed a slow leaching of the activity

from the filter for 37 hours after dosing occurred.

Activated sludge treatment as a means of radioisotope removal from

liquid wastes was suggested by Ruchhoft (32) as early as 1949. Later,

he and Setter (33) developed an activated sludge from synthetic sewage

for the treatment of radioactive wastes. In subsequent laboratory work

(34), they concluded that the activated sludge process is not efficient

in removing isotopes that are not utilized by, or readily absorbed on

biological floc (e.g. iodine-131), nor is it efficient for removing

radioisotopes that are isotopically diluted with their stable counter-

parts (e.g. phosphorus-32). They did find, however, that the process

gave good removal of plutonium even in the presence of organic sequester-

ing agents.













Belcher (23), as a result of his laboratory research, concluded that

the uptake of sodian~-24 and bromine-82 by activated sludge from sewage

is very slight. In both cases the proportion removed in a 6-hour

aeration period was about 10 per cent.

Kaufnani et al. (35, 36, 37), in their laboratory scale investigations

of the removal of radioisotopes by the activated sludge process, arrived

at the following conclusions.

1. Of the three isotopes studied, strontium-89 experienced the greatest

removal with iodine-131 showing intermediate removal and phosphorus-

32 undergoing the least removal.

2. The removal of radioisotopes, such as the three aboye, depends on

carrier concentration and on the concentration of other isotopes

that exhibit chemical similarity or interference.

3. Batch studies show greater removal than those employing continuous

flow and the removal increases with increasing solids.

4. With slugs of radioisotopes, greater removal is observed with high

solids content but, with continuous radioisotope flow, the converse

is true.

Plutonium bearing laundry waste, in a mixture with settled domestic

sewage, was treated by the activated sludge process by Reading and

co-workers (38). Using 20-liter bottles as aeration units, they found

good removal with long aeration periods followed by filtration of the

effluent. They also observed a high concentration of plutonium io the

zoogleal mass of sludge even when the raw feed was low in radioactivity.

This would necessitate special handling of the excess sludge.













Eden et al. (39), in their laboratory scale investigation of

activated sludge, found that equilibrium between the activities of the

liquid and solid phases was reached after 16 hours aeration. They

obtained removals of 95 per cent for plutonium-239, 89 per cent for

iodine-131, 42 per cent for strontium-90 and ruthenium-106, and 32 per

cent for cesium-134.

In studying the efficiency of sand filters for removing low-level

activity from laboratory tastes, Gemmell (40) observed 98 per cent

removal of the activity for the first 16 dosings (4 days), 70 per cent

removal for the next 10 dosings (2 1/2 days) and only 20 per cent after

37 dosings (9 days). Of the activity absorbed in the bed, 90 per cent

was found in the top 3 inches, 8 per cent in the next 9 inches and the

remaining 2 per cent was located in the lower 5 feet.

Eden- et al. (39), using slow sand filters on the laboratory scale,

found that plutonium-239 and cerian-144 were effectively removed but

iodine-131, strontium-90, and ruthenium-106 experienced a rapidly

decreasing removal efficiency with increased dosing.

Evaluation of the effectiveness of oxidation ponds (lagoons) on the

removal of various radionuclides, has also been the object of investi-

gations on the laboratory scale. Steel and Gloyna (41, 42) found that

iodine-131 was not removed to any great extent but appreciable removal

of mized fission products was experienced. The removal of phosphorus-32

and strontium-89 was found to be dependent upon the concentration of

stable counterparts and chemically similar isotopes.

Gloyna at al. (43), in their experimental work, obtained very low

removals of cesiulm-137 and iodine-131; however, they did find that







-14-


35 per cent of the applied strontium-89 could be removed by a single

laboratory lagoon and up to 80 per cent could be removed by three

lagoons in series. Mixed fission products were found to collect in the

slime and slndge with slow release back to the liquid phase. It was

found that the algae, under optinuum conditions of light, temperature,

pH and nutrients, could remove as much as 95 per cent of the influent

cerium- 141.

berman and Gloyna (44), in summarizing the investigations on the

removal of radioisotopes by oxidation ponds, reached the following

general conclusions.

1. Oxidation ponds can be used effectively to concentrate, delay- and,

possibly, remove radioisotopes from waste streams especially when

the concentration of radioactivity is near the maxirmum permissible

concentration (HIPC).

2. Intermittent slugs of low-level amounts of radioisotopes can be

diluted and, in many cases, removed by the long detention tiums

utilized in oxidation ponds.

3. Where climatic conditions are favorable, oxidation ponds can be

economical both as a BOD reduction device and for treating low-level

radioactive wastes.















CHAPTER III


PURPOSE AND SCOPE


The literature seems to indicate that appreciable work has been

done in the general area of the removal of radioisotopes by sewage

treatment processes. However, upon closer inspection it is apparent

that, for the most part, this work was carried out on a laboratory scale

under exactly controlled conditions and only a few isotopes were used in

investigating a single phase of treatment. In most cases laundry waste,

or a synthetic waste of some type, was used as the vehicle. In a

sizable portion of these studies, interest was centered on the effects

of the radioisotopes on the treatment process rather than the action of

the treatment process in removing the radioisotopes from the vaste stream.

Careful inspection of the experimental results shows that, in some cases,

appreciable disagreements and even contradictory conclusions have

resulted from similar investigations. One case in point is the

ability of trickling filters to remove iodine-131. Carter (26) reported

a removal efficiency of 85 per cent while the value recorded by Belcher

(23) was only 5 per cent.

Unfortunately, conditions developed in the laboratory using small

scale units operating under completely controlled conditions are

incompatible with conditions prevailing in the field. Such laboratory

results may be valid for indicating general trends or for comparison

purposes but they can be grossly misleading when projected to large-scale


-15-










































































_ __


-16-


field operations. There are probably few other fields of science where

these statements hold more truth than in the field of waste treatment.

The prevalence of laboratory investigations of the various aspects

of biological treatment of radioactive wastes and the virtual nonexistence

of their large scale counterparts, has been noted (45). As pointed out

previously, the savage treatment plant is rapidly becoming the focal

point for the disposal of practically all of the low-level radioactive

wastes from our urban activities. Ip view of this, there is a pressing

need for initial pilot scale research utilizing an entire sewage treatment

plant operating under true field conditions free from the inherent

inadequacies of laboratory scale research and synthetic wastes. It was

this need that provided the purpose for this investigation.

More specifically, the purpose of this investigation was to render

an evaluation of the effects of a complete sewage treatment plant

operating under actual field conditions on sewage that has been

contaminated with a representative spectrum of radioisotopes in low-level

amounts. Of primary interest was not only the fate of the radioisotopes

but also the underlying procedures responsible for their removal.

To achieve this goal, a pilot size sewage treatment plant employing

a standard rate trickling filter and a lagoon was utilized. In order to

facilitate the investigation on this scale and to comply with the

restrictions on the use of radioactive materials and the discharge.of the

resulting wastes to the receiving streams, it was decided that this

study be conducted with relatively short half-life radioisotopes. This,

however, in no way 10mits the scope of this investigation since numerous

such radioisotopes, representing practically the entire range of





-17-




radionuclides, are readily obtainable. The radioisotopes selected were

not only representative of the periodic table but also representative of

the significant fission products as well as being among those considered.

most biologically hazardous.

The radionuclides chosen, along with some of their more important

characteristics, are listed in Table 1. In this tabulation, the

information concerning maximum permissible concentrations and critical :

organs was obtained from the Federal Register (46), handbook 69 (13),

and Radiation Mb~nitoring (47). Data concerning the other characteristics

were obtained from the Badiolog~ical Health Randbook (18).


























rl

C

u
ra

rr
e
~




.r
err


v,
I
o


x

N


j
ct

O
O

Ir

O
U



O


O co



o

o,

o
P
rl e
r o
a o
P
0)
r)

~ a
x
~Z -1
o E
B'
O


a h
P. ct
C)
io C
P)


a,







s s


0


P "
h
C rr



"e 4


o
Is 01
r
ct rr
C m


c
o r~
u ~-t


~ c~ar



n i~
~ CB

~ lcl
p, IDL~
a caor
ra



B


PB
o


PD
Y

O
Do

o


a
o



r
D



U
o

o




c
o~sc~
T~C(
ooC
PDrlr(
-lr
ru



a
u
r
bD


p


a

,,

,,
coa
~r~
boa

PSa

,,
i'
e~e~-lclo,


Ctu~rc




j0 Y
cl~
1
.e
,o
w~~
OQ1:
LL3
a,
a-ct 5
~Eirl
~lb


d






a



I,
Orl


"c8

Ur
~pl




o
*U
LIU~
i~cae
~ro
o~~




o


x





o












P1


aB

,r

.z




,U

~Yt






o


x


01
C
o
rs


u,
1
o


x

N




I
I





0)

P

o
ca




















o
o

v


r-C
O
~7i





iP


~1

P
w








oc







~1
ra


o







a







o


I
I luI


a


I
u
ra








h
rr
oD
ct
v

O

N


hh
prss
NID
mel
vv

ur~
vr~n







B
,,


















y


O


91
u








h
rz
0

v




0


hh

00
~?rCI
vv

iOJ


00






i U1



















o


a,










Cch

03

aDcu
vv
m
rl~l~
\ONPI

OOL1
O

hC~
B-~PPh
~mis
-o
ooroo
vvv


~prn

ooo



la


i o







m
o

oD


h
R

v

L~ O
N r(

O O

"
hhl~
~~ro
o~
~ruo
vv

c~~ao
n~C~

000


























o


rl
ru Im
n I ct
iii
PI. I c~





















M












oc







eC



MI




EC
00






Cll




1C


gaW
M we

cmE

**4 1.s
dS4
4 M e
MM M
& 4
MS
ggy
U 0
' **
0 &


a 0
Eo
Li
3 5
o



L0



to
5






O







4






h b
4 us

O


A
h0 ~

-n <9
\O0 I
SGNW
Mvvv






: B

e


a
& '0
.'!
a


LI




1 *~ O
IDO 4






0 Iv



0

o

0 V



mi
to t$




st l



40 0 0 40.V
v o 4o
* *
0 0.

+ e
an

ha-o +



ft lo


O o\c 9
vv I M


O

X






O






P.



O


J


















a

1

I


















CH~APTERI IV


.DESCRIPTION OF EXPERIMENTAL UNITS


Introduction

All experimental units and laboratory facilities used in this

investigation are located at the Earle B. Phelps Laboratory for Sanitary

Engineering Research at the University of Florida at Gailnesville. This

laboratory is not only active in waste treatment research but also in

environmental radiation surveillance and the teaching of sanitary science.

At present the pilot sewage treatment plant, operated by the staff of

this laboratory, consists of a primary sedimentation basin, an Imhoff

Cank, an extended aeration unit, two trickling filters, numerous sand

filters, two sludge digesters and a lagoon. These units are arranged so

that they can be operated independently or in practically any conceivable

series and under a wide range of loading conditions. Collectively, they

have a treatment capacity of approximately 60,000 gallons per day. For

'---'- --C'-- ir u== decided to employ those units

under standard loading rates.

The sewage is received at the research laboratory's pilot plant

from the University of Florida campus and included drainage from

dormitories, classroom and laboratory buildings, cafeterias, family

housing units, fraternities, sororities, a milk processing plant, and

the J. Hillis Miller Health Center. It is received at the pilot plant


-20-














at a uniform rate from the campus sewage treatment plant after it has

been screened, comminuted, and degritted. As expected, the strength of

the sewage was found to vary markedly throughout the day and also

throughout the week. Because of the short flow time in the mains, the

savage reaching the plant was normally fresh.


Primary Sedimnentation Basin

The function of a primary sedimentation basin is to provide, in the

initial phases of sewage treatment, a relatively quiescent state so that

those suspended particles having a higher specific gravity than the

liquid phase will settle under the influence of gravity. Thus, the pri-

mary purpose of such a unit is to reduce the solids load on succeeding

treatment processes thereby increasing the treatment efficiency while

reducing maintenance. Most sedimentation basins are designed an a

continuous flow basis and are equipped with any one of a variety of

sludge collection and removal devices. Under normal loading rates, such

treatment units can remove 50 per cent of the influent suspended solids

and 35 per cent of the applied BOD.

The basin employed in this investigation (Figure 1) is rectangular
Tesettling cmarcaent: rs 14 Eee r n rengen, r reer: In n wrus nu
aen infuent: eacrsrouxon cox as werr as rnlluenr atar srrxaus ....

The settling compartment is 12 feet in length, 4 feet in both width and

depth and has a free-board of 1 foot. The effluent from this compartment

flows over a 4-foot long notched weir which leads to a collection trough.

From here it enters a 4-inch diameter pipe leading to an outfall in a

reinforced concrete dosing tank. It was at this outfall that the primary

effluent samples were taken.








-22-


Pig. 1.- General view of the experimental priarynr sedimentation
basin.







-23-


The unit is equipped with two sludge collection hoppers having a

combined capacity of 338 gallons thus giving the basin a total capacity

of 1,778 gallons. For the course of this investigation, this unit

received sewage at the approximate rate of 15 gallons per minute.

Calculations yield a theoretical detention time of 96 minutes, a surface

loading rate of 450 gallons per square foot per day and a theoretical

horizontal velocity of 1/10 of a foot .per minute.

Withdrawal of sludge is accomplished by means of a hydrostatic

pressure of 3 feet. The withdrawal pipes are 4 inches in diameter with

the flow controlled by shear gates located in receiving hoppers adjacent

to the unit.

The dosing device (Figure 2) used in the application of radioisotopes

to this unit was composed of a 55-gallon steel drum equipped with a

polyvinyl chloride discharge line attached to the bottom of a weighted

float. The latter, which was 5 inches in diameter by 3 1/2 inches deep,

projected 1/2 inch above the surface of the liquid in the drum, thus

providing a constant hydraulic head of 3 inches above the intake of the

discharge line. The discharge line itself was 1/4 inch in diameter and

3 1/2 feet long with its lower end attached to a 1/4-inch diameter valve

which passed through the wall of the drum, flush with the bottom.

The discharge of the apparatus as described above would be a function

of the depth of the liquid in the drum. In order to eliminate this

dependency, an air relief line was placed in the discharge line 5 inches

down stream from the intake. This line was composed of a short piece of

1/4-inch diameter polyvinyl chloride tubing connected to the discharge

line through a glass "T" and projected vertically through the surface of

the liquid.








-24-


Scale: 1" =6"


Fig. 2.- Sectional view of the primary sedimentation
basin isotopic dosing device.








-25-


This apparatus was calibrated to deliver a uniform discharge of 1

quart per minute over a span of 45 gallons, starting with the drum full

and continuing to within 6 inches of the bottom. The solution containing

the radioisotopes was added to the basin influent as it entered the

distribution box at the head of the unit. The thorough mixing occurring

at this point insured a complete distribution of the isotopic solution

throughout the incoming sewage before it entered the sedimentation zone

of the unit.

In order to facilitate the dosing and representative sampling of

both the primary sedimentation basin and the trickling filter and to

prevent the radioisotopes in the settling tank effluent from entering the

other units before they could be systematically investigated, it was

decided to operate the primary sedimentation basin on a line independent

of the other units being investigated.


Standard Rate Trickling Filter

Trickling filters are applicable for secondary treatment of wastes

susceptible to aerobic biological processes. They have been used with

success on domestic sewage, industrial wastes and mixtures of industrial

and domestic wastes. They have the ability to recover from shock and

toxic loads and to provide good performance with a minimum of skilled

technical supervision. Probably no other biological treatment process

is so versatile in its application or so dependable in its performance.

These units are normally 6 to 8 feet deep and have stone medium

2 to 4 inches in diameter. They are commonly round in plan and have

some type of rotary distribution for applying the sewage to the surface













of the bed. Collection of the treated effluent requires an under-drain

system which, due to frequent sloughing of solid material from the filter,

usually leads to a secondary sedimentation basin. Standard rate trickling

filters receive hydraulic loadings of 1 to 4 million gallons per acre

per day and under normal conditions, a 6-foot~ filter should remove 80

to 85 per cent of the applied BOD.

The action occurring in such a unit can be described briefly as the

biochemical sorption of the complex organic matter present in savage,

carried out by allowing the sewage to come in contact with the microar-

ganisms active in its degradation. The means of contact is usually

provided by the distribution of primary treated sewage over the top of

a unit containing a coarse medium, the surface of which is coated with

a viscous jelly-like matrix of microorganisms called zoogleal slimes.

As the sewage trickles down through the bed, it passes over the surfaces

of these slimes in a relatively thin film. It is here that the colloidal

and dissolved organic matter is removed from the liquid phase, used as

a source of energy by the biota in the slimes and replaced in the

liquid phase by their stable metabolic products.

It is appropriate that the underlying theory of the stabilization

of organic matter by trickling filters should be presented at this point,

especially since it is expected that this theory will find considerable

application in discussing the ability of a filter to remove radioisotopes.

The early theories concerning: the phenomenon of purification by

trickling filters were generally based on the process of absorption.

In the light of later developments in the chemistry of colloids, the

true mechanism appears to be that of adsorption. Based on this premise,













Buswell (49, 50) developed a more comprehensive theory explaining the

action of these units. His work, which represents the presently

accepted theory, has been summarized by Metcalf and Eddy (51) and by

Fair and Geyer (52) as follows:

"1. In the surface film of liquids, the concentration of dissolved

matter tends to change in such a way as to decrease surface tension.

If, therefore, a substance dissolving in a liquid increases the

surface tension of the solution, the film concentration of the

substance tends to become less; if it decreases the surface tension,

its film concentration tends to become greater. (Most salts and all

strong bases increase the surface tension of water; but, ammonia and

nitric and hydrochloric acids decrease it.) Substances in the

colloidal state are believed to act in a similar way and there are

found in sewage colloidal soaps and proteins that tend to concentrate

in a surface film. These changes in film concentration are not

restricted to the air-liquid interface, but seem to apply also to

the interface between the bacterial slime and the liquid. The

extent of the interface or contact surface is, therefore, important.

"2.- At the jelly-sewage interface the following occurs:

a) The substances concentrating at the interface are adsorbed to

the contact surfaces and thus removed from the sewage being~

filtered ;

b) The adsorbed substances are attacked by the enzymes and living

organisms present in the slime;

c) As rapidly as these substances are removed by digestion or

direct absorption into the living cells, others come to the

interface and further removal is effected;













d) In the presence of air, the products of decomposition of organic

matter are chiefly carbon dioxide, nitrates, and a humus-like

residue. The gas escapes .. nitrates, being salts, increase

the surface tension of water and therefore pass from the

interface into the flowing sewage; the humus-like residue must

either be removed .. or sloughed off from time to time. .

It is an important fact that -the humus .. settles readily,

unlike the colloidal matter from which it largely originated."

This summnary omits a very important hypothesis that was proposed by

Buswell. This hypothesis was that the rate of purification is directly

related to the law of mass action. Simply, this law states that the rate

at which a reaction occurs is in direct and constant proportion to the

concentration of the reactants. Incorporation of this law into the

above summary yields the presently accepted theory of trickling filter

operation.

In summaryv the action of a trickling filter can be described as

follows: removal of colloidal and dissolved material by adsorption on

the zoogleal surfaces; oxidation of the organic material by the biota

which constitutes the zoogleal mass; resolution and sloughing of the

oxidized material and its passing from the filter. The removal of

organic -material by adsorption on the bacterial jelly seems to be a

concentration phenomenon, with the rates of removal and oxidation being

dependent on the rate of oxygen transfer, temperature and the surface

area involved.

The filter used in this study is 8-feet deep and has an inside

diameter of 6 1/2 feet, thus giving a surface area of 33 18/100 square













feet and a medium volume of 9 6/10 cubic yards. The filter tank is

constructed of 3/8-inch steel plates, circular in plan, with a sloping

concrete bottom covered with formed tile under-drains which lead to a

4-inch diameter effluent line. This line outfalls into a 12-inch

diameter semi-circular trough leading to the secondary sedimentation

basin.

The sampling ports consist of short 6-inch diameter nipples, which

are welded to the steel shell of the filter.. There are 16 of these

nipples, w ich are aligned in pairs in order to support, on the inside

of the filter, two facing 4-inch steel channels separated by 3/4 of an

inch and extending across the filter. These channels have triangular

shaped cuts in their flanges to facilitate the passage of sewage, They

are positioned-so as to form a 3 1/2-inch by 3 1/2-inch opening through

which liquid and slime samples may be taken without being obstructed by

the medium. Each part has a small metal bar welded horizontally across

the middle of the opening. Each pair of bars supports a flattened 1-inch

diameter aluminum conduit cut the length of the channel and used for

mounting the glass slides employed in sampling the filter slimes.

Sampling ports are located at the 1/2 and 1 foot depths and at each foot

thereafter for a total depth of 7 feet. The samples representing the

B-foot depth are taken at the point where the filter effluent empties

into the secondary influent trough. In order to prevent short-circuiting

of the sewage as it passes through the filter, all channels are placed

in different vertical planes.

Liquid samples were collected at the various sampling ports by

means of aluminum sampling troughs, which are semi-circular In shape,













3 inches wide and 8 feet long. At one end of the trough is an outlet

nipple onto which a length of 3/4-inch diameter garden hose is connected

to allow the continuous filling of the 600-milliliter beakers in which

the samples were collected. A general view of the filter showing the

ports and the equipment used in sampling appears in Figure 3.

The medium used in the experimental filter is a native limerock

furnished to the U~niversity of Florida by the West Coast Rock Company

of Fort Myers, Florida.a These heavy and fairly uniform stones have an

average size of 4 inches, which exceeds the maximum value given in the

"Sewerage Guide" of the Florida State Board of Health. The stones have

porous and irregular surfaces that provide an excellent foundation for

the growth of the zoogleal slimes. In order to prevent the formation of

open pockets under the channels, to hold settling to a minimum and to

insure even distribution of sewage throughout the filter, the medium

was hand-placed. This limerock is performing excellently as a filter

medium and has shown no evidence of settling or deterioration after

almost 5 years of use.

The sewage being treated by this unit receives primary sedimentation

in an Imboff tank before being discharged into a large reinforced

concrete receiving tank. From here the sewage is pumped at a constant

rate by a centrifugal pumap to an elevated dosing chamber. Part of the

flow coming into this chamber flows over an adjustable veir into a

bell siphon chamber, the head on this weir being kept constant by twe

large overflows that return the excess sewage to the receiving tank.



aA complete chemical analysis of this material appears in Appendtz A.







-31-


Fig. 3.- General view of the experimental trickling filter.














The sewage is then siphoned to a distribution box from which it flows

over a series of adjustable weirs, one of which leads to the filter being

Investigated. Mechanically driven rotary distribution arms operating at

a rotation rate of 1 revolution per: minute provide a uniform distribution

of the sewage over the filter medium.

For the course of this investigation, the bell siphon cycle was

maintained at a constant 7 3/4 minutes which was divided into a 2 3/4-

minute dosing period and a S-minute resting period. The distribution

weir was adjusted to send approximately 17 gallons per cycle to the

filter. This corresponds to a hydraulic loading rate of 4 1/10 million

gallons per acre per day.

The device used in the application of radioisotopes to the influent

of this unit was basically composed of a. float switch, a-Sligma Motor pump

and a holding tank. The float switch was mounted on a vertical support

bolted to the wall of the bell siphon chamber and the float was allowed

to fluctuate with the liquid level in this chamber. The pump, powered

by a 1/20-horsepower electric motor operating through a gear box, was

housed on a platform over the distribution weirs. The holding tank,

which was located adjacent to the pumap housing, was constructed from a

14-gallon polyethylene carboy equipped withi a bottom drain connected to

a 3/16-inch diameter rubber tube. The shielding for this container was

provided by a 1/8-inch thick steel tank, 15 inches in diameter by 30

inches deep and equipped with a twist-lock lid. The rubber tubing

connected to the bottom of the carboy projected through the bottom of

the steel tank, extended through the pump, and terminated on the down-

stream side of the veir which dosed the filter. The arrangement of these

units is shown in Figure 4.








-33-


Fig. 4.- Dosing devices used in the application of sewage
and radioisotopes to the experimental trickling filter.













As the level of the sewage in the siphon chamber rose to the point

at which dosing started, a stop on the float staff, acting through the

float switch, started the electric motor which operated the pump. The

latter pumped the isotopic solution from the holding tank to the sewage

being sent to the filter. The turbulence provided by the drop from the

weir to the filter influent~ line along with the mixing occurring in the

influent line and' the distributor arm nozzles, provided a complete

distribution of the isotopes throughout the sewage. As the level of the

sewage in the siphon chamber dropped to the point where the siphon was

broken, a second stop on the float staff switched off the pump.

This dosing device was calibrated to deliver approximately 3150

milliliters of isotopic solution per dosing cycle. Under the installation

and operating conditions used, the discharge of the pump was independent

of the liquid level in the holding tank.

The device described above permitted the application of a fairly

small but reasonably uniform dose of radioisotopes to only that portion

of the sewage going to the unit under investigation and only during that

part of the cycle that the unit was actually receiving savage. The

transfer of the isotopic solution from the holding tank to the sewage was

carried out with an externally applied pumping device operating on a

completely closed system equipped with readily accessible and easily

replaced component parts.


Secondary Sedimentation Basin

The function of secondary settling tanks and the basic principles

by which they operate are practically identical to those of primary







-35-





settling tanks, Generally, design criteria for sedimentation tanks apply

equally well to both types of basins. The principal difference between

the two units is the type of suspended solids encountered.

The effluent from trickling filters contains large quantities of

settleable organic matter, particularly when the filter is undergoing

the process of "unloading." This material is more putrescible, has a

Higher oxygen demand and is lighter and more flocculent than the sludge

from primary tanks. Generally, sedimentation of the filter effluent to

remove this material is required; consequently, secondary sedimentation

is commonly considered part of the over-all process of stabilization by

trickling filters. As a result of this, treatment criteria for this

unit are usually integrated into a single set of values for the complete

process.

The secondary sedimentation basin used in this investigation was

constructed from a section of precast concrete pipe 5 feet in diameter

and 4 feet long. The sedimentation zone has a liquid depth of 2 feet

and a free board of 6 inches, the latter being provided by the bell of

the pipe. Sludge collection is carried out in a conical shaped hopper

that accounts for the lower 2 feet of the basin. The trickling filter

effluent enters the unit through a 4-inch diameter pipe which passes

through the sedimentation zone to the center of the basin where it

empties into a 12-inch diameter down-draft tube that acts as a submerged

inlet and an influent baffle. From here the liquid rises up through

the sedimentation zone and over an annular overflow weir which is 2 feet

in diameter and concentric with the down-draft tube. The secondary

effluent is then collected in a channel behind the veir and allowed t~o












































































___~


leave the basin through a 4-inch diameter pipe. The unit is equipped

with a pump for sludge removal and has a theoretical detention time of

2 hours in the sedimentation zone.

En accordance with the concept that thle secondary settling tank is

part of the trickling filter process, this unit was investigated in

conjunction with the filter. Bothl units were dosed simultaneously and

sampled concurrently. The radioisotopes reaching the settling tank

during any one dose were the same ones leaving the filter during the

same dose with no additional activity being added and with no operational

changes. In this manner both mutually dependent units were investigated

without violating the unity of the process or the continuity of treatment.




Lagoons or stabilization ponds are relatively shallow basins built

for purposes of treating raw, primary or secondary wastes by storage

under conditions that favor natural biological treatment, and accompanying

bacterial reduction.' When used to treat secondary effluent, as was the

case in this investigation, they are frequently called "polishing ponds"

-- the name arising from the fact that they provide the finishing

treatment in cases where a high degree of stabilization is desired before

the effluent is discharged to the receiving stream. Used in this

capacity, they can furnish an effluent having a low BOD and coliform

bacterial content and a dissolved oxygen content often in excess of

saturation.

The unit used in this investigation (Figure 5) has an effective

length of 23 1/2 feet and an effective width of 12 feet. It is of




































































Fig. 5.- General view of the experimental lagoon.













masonry construction with 19 equally spaced around-the-end baffles, each

11 feet long and turned width-wise in the basin. Essentially, this

forms a channel 1 foot wide, 2 feet deep and over 200 feet long.

A Hoyno worm-type pump supplied secondary effluent to this unit

through a 1-inch diameter line, the intake of which was located just in

front of the effluent weir of the secondary sedimentation basin. By use

of a timer, the 3/4-horsepower electric motor that operated the pump

was allowed to run 1 minute out of every 3. This gave the lagoon an

average influent of 1/2 of a gallon per minute which corresponds to a

theoretical detention time of 4 3/4 days. To prevent back-siphoning

through the pump and to provide a representative influent sampling

point, an air gap was provided between the influent line and the surface

of the liquid in the influent channel of the lagoon. Control of the

liquid level-in this basin was provided by a V-notch weir at the

effluent end. This weir also functioned as the effluent sampling point.

In keeping with the role of this unit as a polishing device, it was

decided that no additional isotopes would be added to the influent of

this basin. True field conditions dictate that not only the amount but

also the physical and chemical characteristics of the isotopes in the

influent of this unit be identical to those in the effluent of the

secondary sedimentation basin.

Since the primary and secondary units used in this investigation

wFere operated on two separate lines with each line being dosed at

different times, only half of the total flow through this portion of

the pilot plant was contaminated with radioisotopes at any one time.

This gave an isotopic dilution factor of 1 to 1 when these two flows








-39-


were combined. An additional dilution of 1 to 1 was obtained when this

combined flow was added to the effluent from the other units of the

pilot plant. The effluent from the entire pilot plant was then allowed

to enter an underground conduit wh~ere-it was diluted with surface

drainage having a dry weather flow in excess of 80,000 gallons per day.

The addition of the effluent from the campus sewage treatment plant to

this stream resulted in a further dilution of 10 to 1. Thus, the

effluents from the units under investigation were diluted to less than

1 part in 80 before being discharged to a 1-acre restricted use pond.

This dilution factor plus the use of short half-life radioisotopes in

low-level amounts, prevented the development of any radiation hazards

even if there had been no removal or buffering action by the units under

investigation.

















CHAPTER V


PROCEDURE


The radioactive materials used in this investigation were arranged

in eight experiments with three replications each. Six of these

experiments were concerned with individual radioisotopes, one experiment

was carried out with a mixture of two isotopes of radio-cerium and the

final experiment was conducted using mixed fission products. In order

to minimize the accumulation of activity within the treatment units,

these materials were arranged for investigation in order of increasing

physical half-life; however, the chemical characteristics of some of

the selected radionuclides precluded rigid adherence to this scheme and

minor modifications were required. The materials used, the order of

their application, their chemical form and influent concentrations are

shown in Table 2.

In order to determine the proper dosing duration, the location of

representative sampling points and an adequate sampling frequency for

each unit and to evolve a systematic sample processing procedure, an

intensified and extended sampling program was conducted during the

initial run of the first experiment. The results of this preliminary

study indicated that equilibrium of the effluent activity was reached

within 2 hours in the primary sedimentation basin, within 12 hours in

the trickling filter and secondary sedimentation basin and within 6 days

in the lagoon. On the basis of this information, a week was allowed


-40-












TABIE 2


RADIONUCLIDE DOSING DATA


a Approximate b
Experiment Radionuclide Chemical Forma Influent Concentrations
(pc/ml)

1 P-32 PO4 in dilute HC1 10 80
2 I-131 I- in basic Na2SO0 20
3 K-42 KC1 in dilute HC1 10 200
4 Ce-141,144 CeCly in dilute HC1 100
5 Fe-59 FeC13 in dilute HC1 30
6 Co-58 CoC12 in dilute HCI 45
7 Sr-89 SrC12 in dilute H01 100
8 MFP Nitrates in dilute RNO3 50


aFor dosing purposes, all radioisotopes were diluted with tap water and
the pH was adjusted to correspond to that of the original solution.

bCalculations expressing the influent concentrations in milligrams per
liter are illustrated in Appendix B.



for each of the three replications of each experiment and an additional

week of normal operation was provided between experiments in order to

substantially eliminate the preceding radioactive materials from the

treatment units. The detailed sampling procedures applied to the

individual units are outlined in the following sections.


Primary Sedimentation Basin

Immediately preceding each run, influent flow measurements were

made, influent and effluent background samples were taken and the dosing

solution was prepared and assayed. After dosing started, effluent

samples for radiological analysis were taken every 5 minutes for the

first 30 minutes then at 10-minute intervals for the next 2 1/2 hours.













Trickling Filter

Six days prior to the start of each run, six glass slides were

attached to each of the eight holding plates which were then inserted

into their respective sampling ports. Immediately preceding each run,

three of these slides from each port were removed, allowed to drain well

and the accumulated biological growth was transferred to 100-milliliter

beakers with the aid of a clean rubber policeman and 4 milliliters of

distilled water.

Liquid samples for radiological analysis were taken from the filter

influent, the 2-, 4-, and 6-foot ports and the filter effluent at time

zero and at the and of 2, 4, 8, 12, and 24 hours of isotopic dosing.

At this time, the three glass slides remaining in each of the eight

) sampling ports were removed and processed as described above. All

preliminary liquid samples were 600 milliliters in volume and in order

to eloninate any variations between individual doses, these samples

were all collected during the same dosing cycle. Proper evaluation of

the filter per se required the removal of the settleable material from

all liquid samples taken from the various ports. This was accomplished

by providing the preliminary samples with 1 hour of quiescent

sedimentation before the final samples were decanted into 100-milliliter

beakers.

Secondary Sedimentation Basin

Liquid samples for radiological analysis were taken from the

influent and effluent of this unit at time zero and after 2, 4, 8, 12,

and 24 hours of filter dosing. Representative samples of secondary













sludge for each of these times were obtained by allowing 600 milliliters

of the basin influent to undergo quiescent settling for 1 hour. At this

time, 3 milliliters of the settled material were removed with a dropper

and transferred to a 100-milliliter beaker.




The long detention time and buffering capacity of this unit permitted

a less intensified sampling frequency but required an extended sampling

duration. It was found that the action of this unit could be adequately

described by taking influent and effluent samples for radiological

analysis every 24 hours starting simultaneously with the filter dosing

and continuing for 6 days.


Sample Preparation

All liquid samples except for those from experiments 2 and 3 were

prepared for counting by the following method. After obtaining the

samples as described above, 50 milliliters of each were transferred with

a graduated cylinder to clean 100-milliliter beakers and allowed to

evaporate to dryness in a 103o C forced-air drying oven. The residue

obtained was transferred from the beakers onto planchets by successive

washing and scrubbing with a clean rubber policeman and distilled water.

'TwJo drops of 2N hydrochloric acid were added to the first of the four

wash waters. The residue on each planchet was then evaporated to

dryness under heat lamps.

All sludge and slime samples except for those from Experiment 2

were prepared for counting by transferring the samples directly to dried

and tared planchets and evaporating them to dryness under heat lamps.













After counting, these planchets were stored in a desiccator for at least

12 hours before the final weights were taken.

The instability of iodine in acid or -weakly basic solutions at

elevated temperatures required modification of the sample drying

procedure. For this experiment, all liquid samples were made basic to

phenophtalein with 2N sodium hydroxide before being placed in the 103o C

oven. After drying, the residues were transferred from thle beakers to

the planchets by normal washing procedures, omitting the 2N acid in the

first wash. The planchets were then allowed to evaporate to dryness in

a 700 C oven before counting. The sludge and slime samples for this

experiment were collected in the previously described manner, made basic

by the addition of two drops of 1/2DN sodium hydroxide and transferred

to the pre-weighed planchets. They were then dried at 700 C and counted

by the normal procedure..

The short half-life of potassium-42 (Experiment 3) necessitated the

elimination of the lengthy evaporation time required by the liquid

samples before their residue could be transferred. It was found that

two half-lives could be saved between the sampling and counting stages

by transferring exactly 4 milliliters of each sample directly to their

respective planchets and evaporating them under the heat lamps. Even.

though low count rates were obtained with these small samples, the

reproducibility obtained by this method was as good as that which would

have been obtained by the normal method and only 1/4 the quantity of

isotopes was required.







-45-


Counting Technique

For Experiment 1 all samples were placed on copper planchets having

a sample deposit area of 8 square centimeters and subjected to gross

counting in a Nuclear-Chicago automatic counting system having an

efficiency of 35 per cent for thallium-204. This counting sequence was

composed of an end window proportional counter, a Model C-110 B sample

changer and a Model 186 scaler. The counter was operated at 2150 volts

and supplied with "PR" counting gas under slight pressure. For the most

part, this system was operated on a pre-set count mode with the counting

times being recorded on a Model C-111 B printing timer.

Prior to Experiment 2, a Baird-Atomic automatic counting system

became operational and since it allowed considerable flexibility in

operation, it was used for this and all subsequent experiments. This

system, which had an efficiency of 40 per cent for thallium-204,

consisted of a Model A-227 gas flow end window proportional counter,

a Model 750 sample changer and a Model 132 scaler. All samples were

prepared on stainless steel planchets 5 centimeters in diameter and

subjected to gross counting at 2050 volts using "PR" counting gas

supplied under low pressure. This system was also operated on a pre-set

count basis and the counting times were recorded on a Clary print-out

timer.

In order to eliminate as much counting variability as possible,

all samples taken from the same treatment unit and having related

sampling times were grouped into sets and counted during the same

counting sequence. All samples were counted at least twice with a

background determination included in each counting run. For purposes













of assessing the normality of operation of the instrumentation, no less

than two uranium standards were included in each counting operation.

Since all samples from the same experiment were placed on the same

type and size planchet and counted on the same instrument, no corrections

for geometry or backscatter were necessary. The use of a systematic

handling procedure and relative counting techniques eliminated the need

for all counting corrections except background and decay, the latter

being required for Experiment 3 only.

The activity of all liquid samples was reported in counts per

minute per 50 milliliters with the exception of the corresponding data

Erom Experiment 3 which were based on a sample volume of 4 milliliters.

To gain maximan reproducibility and minimum variability, the activity

of all sludge and slime samples was reported in counts per minute per

milligrarm of dry solids.

Both counting systems could be operated automatically, which was

the method of choice. however, the activity level of various samples

differed widely, thus the attainment of ideal counting statistics would

require mannal operation in cases where fast counts would introduce time

errors and where long counts would not be compatible with efficient use

of the equipment. As a compromise between these extremes, the Nuclear-

Chicago instrument was operated so as to obtain minimum counting times

of 30 minutes for background samples and minimum total counts of 4000

for faster samples. In the latter case, no counting time of less than

5 minutes was recorded.

The Baird-Atomic system provided greater flexibility of operation

in that it allowed background samples to be counted for total counts of













900 while the faster samples were counted for 9000 counts. This was

accomplished by an auxiliary circuit which stopped the count at 900 if

the activity of the sample w~as less than 150 counts per minute. Here

again, the minimum counting time for background samples was 30 minutes

while the faster samples were counted for at least 5 minutes.

Counting statistics applicable to .the above counting conditions can

be found in Appendix C.


Chemical and Biochemical Sampling

In order to evaluate the major parameters of treatment plant

performance and to illustrate that the plant employed in this investigation

was indeed operating under normal field conditions and attaining typical

treatment efficiencies, the two major units -- the primary sedimentation

basin and the trickling filter -- were subjected to a chemical and

biochemical sampling program at the end of each run.

The sampling program applied to the primary settling tank was

carried out by taking 1-hour composite samples from the influent and

effluent of the basin. These samples, which were 1 gallon in volume,

were analyzed for BOD and suspended solids.

The trickling filter was evaluated by obtaining samples from the

influent, all ports and the effluent. The samples were composite over

at least three dosing cycles and were. 1 gallon in volume. In keeping

with the concept that secondary sedimentation is an integral part of

the trickling filter process, all preliminary samples were allowed

1 hour quiescent sedimentation before the final samples were taken.

These samples were then analyzed for BOD, nitrates, and total nitrogen.








-48-





All chemical and biochemical analyses were conducted in accordance

with the procedures outlined in Standard Methods for the Exarmination of

Water and Wastewater (53) .
















CHAPTER VI


DISCUSSION OF OBSERVATIONS


General Considerations

In this study, relative counting techniques were utilized and a

comparative analysis of the data was employed. Consequently, it was

not necessary to correct the observed counts to absolute units of

radioactivity. Since all radioactive samples from the same experiment

were counted under virtually identical conditions in the same instrument,

the relation between the observed activity and the true disintegrations

was essentially constant. Application of an appropriate correction

factor would have changed the absolute values of these data but would

not have altered the relative magnitude of the established relationships.

The chemical forms and influent concentrations of the radioisotopes

used in each experiment are tabulated in Table 2. In preparing these

materials for dosing, the pH of each solution was adjusted so as to

maintain the solubility of the radionuclides. Upon dosing, however,

this solution was diluted into sewage having an average pH of 7.8. The

characteristics of these materials in dilute solutions having slightly

basic pH values indicate that all radioisotopes used, except cerium,

iron, and cobalt which are known colloid formers, remained in their

ionic form.

All experimental studies conducted during this investigation were

undertaken at levels of activity that could be reasonably expected under


-49-





actual field conditions. Even though relatively high counting rates were

often produced, the concentrations of radioactive materials were still

very law. This is illustrated in Appendix B which gives the influent

concentrations (in ag/1) of the radionuclides used in each experiment.

Examination of these values indicates that the addition of radioactive

materials in the concentrations used did not appreciably alter the

nature or amount of soluble or insoluble solids present in the waste.


Removal by Primary Sedimentation

Tabulated data from the series of studies concerning this unit are

contained in Appendix D. inspection of these data permits two conclusions

to be drawn. The first is that after the effluent activity approached

equilibrium conditions, very little removal of soluble or colloidal

radionuclides was accomplished by this treatment process. The steady

state removal values varied from near 0 to 15 per cent with most falling

between 5 and 10 per cent. The highest values recorded were obtained

in the potassium-42 experiment but it is believed that this apparent

increase in treatment efficiency resulted from the physical decay of

this short half-life isotope rather than from actual removal by the unit.

The second conclusion is that all removal patterns were quite

similar and, within the ranges investigated, seemed to be independent of

the amount as well as the chemical and physical properties of the

radionuclides utilized. Due to these similarities, the removal patterns

from all experiments were averaged and the results are presented

graphically in Figure 6. Nbtle the particular shape of this curve is a

function of the design and operation of the basin investigated, it is



























































































I I IO O l l O O l i


C
O
O *-



~o




.0


u











*00 C




08 r


"c .-


0




o


la













characteristic of the effluent patterns from this type of unit. In

general, this figure indicates that after approximately 2 hours of

continuous isotopic dosing, the effluent activity approached equilibrium

conditions and that once these conditions were attained, the rate of

removal stabilized at approximately 9 per cent.

The principal action occurring in treatment units of this general

type is the physical removal of settleable solids by gravitational

sedimentation. Since the nature of the radioactive materials used in

this investigation did not permit them to be readily removed in this

manner, the mechanism of removal appears to have been the sorption of

the radionuclides by the settleable solids inherent in the waste. The

operational characteristics of this treatment process and the nature

and amount of settleable solids normally present in a waste of this type,

indicate that the efficiency of this proposed mechanism would be low

for colloidal and dissolved radioisotopes. This is substantiated by

the observed data.


Removal by Trickling. Filtration

Basic data and graphs concerning the experimental studies conducted

on the trickling filtration and secondary sedimentation processes are

contained in Appendix E. The various treatment efficiencies attained

by these units operating under equilibrium conditions are summarized

in Table 3. In studying Figures 16 through 23 and 26 through 29, it

should be remembered that the observed activities (in c/m/mg) were

dependent, to a large extent, on the influent concentration as well as

the physical half-life of the radioactive material investigated.
























Average Percentage Average Percentage
Radionuclide Removal by Various Removal in Secondary
Depths of Filter Mledium Sedimentation Basin
2' 4' 6' 8'

K-42 15 35 45 49 27

Sr-89 24 27 37 42 23

I-131 26 42 53 61 3

P-32 32 36 43 46 0.4


MFP 40 48 61 63 40


Fe-59 46 SS 72 65 70

Co-58 48 66 80 81 64

Ce-141, 144 57 63 78 81 48


TABLE 3


SUMMARY OF REMOVAL EFFICIENCIES ACHIEVED BY
TRICKLING FILTRATION AND SECONDARY SEDIMENTATION
UNDER EQUILIBRIUM CONDITIONS





Since these conditions varied from one experiment to another, these figures

should be used only in making comparisons and observing general trends.

The trickling filter data represented graphically in Figures 8

through 15 permit several general observations to be made. One of the

most significant of these is that all radioactive materials investigated

experienced some degree of removal by this unit. Figures 16 through 23

not only substantiate -the fact that this removal did occur but also

indicate that the observed uptake resulted from the concentration of

these materials by the zoogleal slimes present throughout the filter.

Considering the presently accepted theory of trickling filter operation,

the extent of the slime-liquid interface available for transfer within

this unit and the relatively low concentration of radioactive materials

used, it is understandable how such a removal could be obtained.

Another general trend recognizable in Figures 8 through 15 is that

most removal patterns exhibited a high initial uptake followed by a

somewhat asymptotic approach to equilibrium conditions. This is a

fairly common characteristic of most chemical and biological systems

and results from the gradual satisfaction of a comparatively high

initial uptake capacity being superiuposed on a steady rate of removal.

A noted exception to this general behavior occurred during the

phosphorus-32 experiment and was observed to coincide with a noticeable

sloughing caused by a sharp, early morning rise in both the organic

loading rate and the ambient temperature.

All filter uptake patterns indicate that the various rates of

removal reached their equilibrium values approximately 12 hours (96

doses) after isotopic dosing started. This conclusion is supported by







-55-


the action occurring in the secondary sedimentation basin. Figures 24

through 29 show that, in general, the secondary sedimentation removal

patterns and the activity of the secondary sludge, both of which depend

on the action occurring in the filter, had attained their steady state

conditions within 12 hours. These observations seem to indicate that the

achievement of equilibrium conditions was a function more of the number

of doses applied than of the physical and chemical characteristics of

the radionuclides investigated.

The filter uptake patterns also indicate that the rate of removal

with respect to depth generally decreased throughout the filter. This

is illustrated in Table 3 which summarizes the various removal

efficiencies observed after 24 hours of dosing. This table shows that

in all experimental studies undertaken, the highest removals per increment

of depth were obtained in the first 2 feet of medium and, in most

experiments, this portion of the filter accomplished over half of the

uptake attained by the entire unit. The middle 4 feet gave intermediate

treatment while no appreciable removal was realized by the lower 2 feet

of the filter bed. The activity of the filter slimes, shown graphically

.in Figures 16 through 23, express general agreement with this uptake

pattern .

This somewhat expOneHtial rate Of removal is understandable since

the uptake of soluble and colloidal radionuclides by this treatment

process is dependent on the sorptive capacity of the zoogleal slimes

present at the various depths in the filter and the concentration of

radioactive materials available for removal at each level. Both of these

factors were observed to decrease with increasing depth of filter medium.













A careful study of Table 3 indicates that by ranking the various

materials investigated according to their corresponding degrees of

removal, it is possible to distinguish two definite groups, separated

by mixed fission products (MFP). The first group, which contains

potassiumo-42, strontium-89, iodine-131 and phosphorus-32, experienced

an1 uptake of approximately 50 per cent by an 8-foot filter. The second

group, which contains tron-59, cobalt-58, and cerium-141, 144,

experienced a comparable removal in the first 2 feet of medium and

almost twice this value in the full 8-foot depth. Mixed fission

products, which contain representative members of both groups, gave

intermediate treatment. The treatment efficiencies obtained by the

secondary sedimentation basin not only confirm this general division

but also provide an indication of the nature and effectiveness of the

action occurring in the filter.

Correlation of the various removal patterns and treatment

efficiencies obtained in both~ the trickling filter and secondary

sedimentation basin with the physical and chemical characteristics of

the radioactive materials investigated, indicates that the mechanisms

of uptake in the filter can be classified into three general categories.

The first of these concerns the radionuclides that are significant in

cell metabolism. In this case, the effective mechanism of removal

appears to be the absorption of the radioactive materials by the

microorganisms present in the sougleal slime layer. The radionuclides

in this category have to compete with their stable counterparts in the

removal process; therefore, the uptake efficiency is dependent on the

concentrations of stable isotopes present in the waste. Since sewage





-57-


normally contains comparatively high concentrations of the elements

essential in cell metabolism, the isotopic dilution factor of this

waste is relatively high. Consequently, the potential uptake capacity

of metabolically significant radionuclides by the trickling filter

process is somewhat low. This is illustrated by the phosphorus-32

uptake data summarized in Table 3. This table shows that in the presence

of 5 to 7 milligrams per liter of stable orthophosphates, the experimental

filter used in this investigation accomplished a relatively low uptake

of 46 per cent.

The low removal of phosphorus-32 obtained in the secondary

sedimentation basin indicates that as the filter slimes gradually

sloughed off (due to continuous replacement procedures) and passed

from the filter, the radiophosphorus which had undergone preliminary

removal by the viable slimes in the unit was re-entrained in the waste

stream and was no longer associated with settleable solids. This leads

to the general observation that the over-all process of trickling

filtration and secondary sedimentation was relatively ineffective in

removing this radionuclide from sewage.

The second category of uptake mechanisms concerns the radioactive

materials that are present in the vaste in their soluble form but are

not significant in cell metabolic processes. In this case the uptake

mechanism appears to be that of ion exchange. The radionuclides subject

to removal in this manner must not only compete with their stable

counterparts but also with all other elements that have similar ionic

properties or chemical behavior. This indicates that the isotopic and

chemical dilution resulting from the wide range of stable materials














































































____ __


-58-


normally present in sewage, would limit the efficiency of this uptake

mechanism. This is substantiated by the potassium-42, strantium-89,

and iodine-131 data shown in Table 3. The relatively low removals

indicated in this table are understandable since these materials had

to compete with their chemically similar counterparts -- sodium, calcium,

and chlorine -- present in the sewage. The low removal efficiencies

obtained by secondary sedimentation indicate a re-entrainment similar

to that explained above and lead to the same general conclusion

concerning the ability of this treatment sequence to effectively remove

these radionuclides from sewage.

The third general category of uptake mechanisms concerns the

non-metabolically significant radionuclides that are present in the

waste in their colloidal form. Here, the indicated modes of removal

are adsorption and physical trapping of these materials on and in the

zoogleal slime layer. According to the presently accepted theory of

trickling filter operation, this uptake mechanism should be relatively

effective in removing colloidal matter from the waste stream. This is

supported by the iron-59, cobalt-58, and cerium-141, 144 data summaarized

in Table 3. As pointed out previously, these materials experienced a

higher uptake than that indicated for the other radionuclides investigated.

The comparatively high removal obtained by secondary sedimentation

indicates that this uptake mechanism was effective in removing these

colloidal radionuclides from the waste stream and associating them with

the filter solids that eventually reached the secondary sedimentation

basin in a settleable form.













Removal by Lagooning (Polishingi Pond)

The tabulated data concerning this series of investigations are

contained in Appendix F. Pertinent data derived from the influent and

effluent activity patterns shown in Figures 30 through 36 are summarized

in Table 4. In determining the various percentages of removal shown in

this tables, the total activity going into the basin over each 20-day

study period was compared to the total activity leaving the basin during

the same period. Since these activities were proportional to the areas

under their respective influent and effluent curves, the indicated

removal values were obtained by determining and comparing the appropriate

areas.


TABLE 4


SUMMARY OF REMOVAL EFFICIENCIES AND BUFFERING
FACTORS OBTAINED BY LAG00NING


Radionuclide Removal Efficiency Buffering Factora
(Percentage)

I-131 0 3.1

P-32 54 6.6

Co-58 55 3.3

HFP 58 7.0

Sr-89 .69 9.7

Fe-59 86 13.

Ce-141, 144 93 15.


aRatio of peak influent activity to peak effluent activity, averaged
over all three dosing sequences.





-60-


Inspection of Table 4 and Figurea 30 through 36 indicates that the

relatively long detention time, the intimate algal-bacterial contact and

the high dilution factor provided by this treatment process was effective

in delaying, buffering and, in most cases, appreciably removing low-level

"slugs" of the radionuclides investigated. The evident correlation of

the buffering factors with the removal efficiencies points out that the

ability of this unit to buffer "slugs" of radioactivity was not only

dependent on the design and operation of the basin but also on the

extent of the removal obtained within the unit. As indicated in the

above table, the observed buffering factors varied from a minimum of 3.1

for I-131 to a maximum of 15 for Ce-141, 144. The lower value, which

was obtained under the conditions of zero removal, indicates the

dilution factor of the basin.

The various influent and effluent activities observed represent

the total amount of radioactivity entering and leaving the basin

regardless of chemical or physical form or biological association;

therefore, the various removal efficiencies indicated in Table 4

represent the actual removal occurring within the unit. Since the

half-lives of the indicated radionuclides were relatively long compared

to the observed median detention time (2 days) of the basin, radioactive

decay had no appreciable effect on these removal, efficiencies. These

considerations indicate that the observed removals resulted from the

deposition of the radionuclides within the unit. In view of this, the

indicated mechanisms of removal are precipitation by chemical, physical,

and biological means and ion exchange reactions involving the radio-

nuclides entrained in the waste stream and the stable materials retained

in the basin.







-61-


The effectiveness of these mechanisms operating under the conditions

of prolonged detention and intensive biological contact, is illustrated

by the various removal efficiencies obtained. Except in the case of

I-131, which exhibited a positive aversion to removal by these processes,

all radionuclides investigated, especially colloidal cerium and iron,

experienced significant removal.


Chemical and Biochemical Analyses

Investigational data concerning the chemical and biochemical

parameters of treatment plant performance are tabulated in Appendix G.

The trickling filter data summarized in Tables 54, 56, and 58 are

presented graphically in Figure 7.

Inspection of Table 52 indicates that during the course of this

investigation, the pilot plant influent contained, on the average,

135 milligrams per liter of suspended solids and had an average BOD

equal to 170 milligrams per liter. The pronary sedimentation data

indicate that the unit used in this investigation accomplished an

average BOD reduction of 28 per cent and an average reduction in

suspended solids of 41 per cent. Both of these values fall within

reasonable limits of operation for basins of this type.

Tables 53 through 58 show that the filter utilized in this study

achieved average reductions in BOD and total nitrogen of 89 and 84 per

cent, respectively, while effecting an average nitrification of 67 per

cent. The various curves in Figure 7 indicate that the major portion

of the observed treatment occurred within the first 5 feet of filter

medium. These observations are within the ranges of normal operation






































Q
L)
~I

W







O
\D O
J


u



E
O
M
VI O
LI
O Y
O ~
ru

i
E m
5 ;1
cr 3
J L)
O
E s
E
c~ m
o
0
m
5
O
O
a L)
-e
r


a
o
m


c
N
e
o

L,
a







te


p
N
Lu


oo







QM u
19 o

DC E S




I


000000 000
o~m~~o~n-t~~u







-63-





and are in general agreement with the results of prior investigations

conducted on this unit by Hagan (54), Vitaret (55), and Priede (56).

En general, the primary sedimentation basin and trickling filter

employed in this investigation were observed to be operating under

normal field conditions and attaining typical treatment efficiencies

throughout the course of the experimental work. The presence of

radioactive materials in the waste stream in the amounts used in this

investigation had. no apparent effects of these treatment processes.














































































~


CHAPTER VII


SUMMARY AND CONCLUSIONS


This investigation was concerned with evaluating the removal of

low-level radionuclides from waste water by a complete sewage treatment

plant operating under actual field conditions. In making this evaluation,

a pilot size treatment plant employing primary sedimentation, trickling

filtration, and lagooning was utilized. These treatment processes were

subjected-to a series of eight experiments involving phosphorus-32,

iodine-131, potassium-42, cerium-141, 144, iron-59, cobalt-58,

strontium-89, and mixed fission products.

Based on the results of the various radiological, chemical and

biochemical determinations made during these experiments, the following

conclusions have been drawn.:

1. Primary sedimentation is relatively ineffective as a process for

removing colloidal and dissolved radionuclides from sewage. After

equilibrium of the effluent activity is established, removals of

less than 10 per cent can be expected.

2. The effectiveness of the trickling filtration process in the

treatment of low-level wastes is limited to its ability to remove

the radioactive components from the main vaste streak and to

concentrate these materials in a relatively small volume of solid

natter which, after passing from the filter, can be removed by

sedimentation. Even though significant removal may occur within













the unit, the uptake mechanism may become reversible and the materials

preliminarily removed in the filter may become re-entrained La

essentially their original form. Consequently, the treatment

efficiency of the over-all process of trickling filtration is

reflected in the removal accomplished by secondary sedimentation.

The approximate over-all removals that can be expected under the

conditions of normal plant operation are: 60 to 70 per cent for

iron-59 and cobalt-5i8; 40 to 50 per cent for cerium-141, 144 and

mized fission products; approximately 25 per cent for potassium-42

and strontium-89; and less than 5 per cent for iodine-131 and

phosphorus-32.

3. -The uptake of low-level radionuclides within a filter results from

the concentration of these materials by the soogleal slimes present

throughout the unit. The rate of removal with respect to time is

comparatively high during the initial doses but gradually decreases

to equilibrium conditions. The attairnment of stable uptake

conditions is more a function of the number of doses applied than

of the characteristics of the radioactive materials in the waste.

Plants employing shorter dosing cycles than 7 minutes can expect to

achieve equilibrium conditions in less than 12 hours (96 doses).

The rate of removal with respect to depth decreases somewhat

exponentially with increasing depth of medium. The optimum filter

depth' is 6 feet.

4. The concentration of radioactive materials by the zoogleal slimes

in a trickling filter results fran the action of three removal

mechanisms, (a) absorption of~the radionruclides by the microbiota







-66-


in the slime layer, (b) ion exchange reactions involving the radio-

isotopes in the waste stream and the stable elements associated with

the filter solids, (c) adsorption and physical trapping of the'

radioactive materials on and in the zoogleal slime layer. The

effectiveness of these uptake mechanisms is a function of the

chemical and physical properties of the radionuclides and the

concentration of their stable counterparts and chemically similar

materials in the waste. As a result of the isotopic and chemical

dilution provided by sewage, the mechanisms of absorption and ion

exchange are relatively ineffective and highly reversible; consequently

soluble radionnelides are not effectively removed. Colloidal

radionuclides, being more amenable to removal by these mechanisms

especially by adsorption and physical trapping, are efficiently and

effectively removed.

5. The comparatively long detention time and intimate algal-bacterial

contact provided by lagoons are effective in diluting, delaying

and, in most cases, substantially removing "slugs" of low-level

radioactive materials. Basins employing effective detention times

of 2 to 3 days can azpect to attain the following removals:

90 per cent for cerium-141, 144 and iron-S9; 70 per cent for

strontium-89; 50 to 60 per cent for phosphorus-32, cabalt-58 and
mixed fission products; and less than 1 per cent for iodine-131.

6, The mechanisms effective in the removal of radioactive materials

by lagooning are, (a) precipitation by chemical, physical, and

biological means, (b) ion exchange reactions involving the .







-67-




suspended radionuclides and the stable materials retained in the

basin. These mechanisms are most effective in removing trivalent

materials in their colloidal form and divalent elements biologically

significant in trace amounts.

7. Savage treatment plants operating under normal field conditions are

able to receive and dispose of low-level radioactive wastes with no

apparent decrease in treatment efficiency or changes in operational

procedure required.





































APPENDICES





APPENDIX A


CHEMICAL ANALYSIS OF LPMESTONE FILTER MEDIUM


Percentage by Weilhta

0.14 i 0.03

1.52 i 0.14

trace (<0.01)

0.35 i 0.04

3.14 i 0.12

42.62 i 0.41

8-48 i 0.22

36.42 i 0.14

1.88 i 0.10

1.78 + 0.04


Constituent

I120 (103o C)

CO2 (6000 C)

PO

Mg +

Combined Oxtides

Ca

Silica

CO3
SO

Fe


average results of three stones picked at random.


-69-

















APPENDIXB


CALCULATION OF CONCENTRATION OF RADIOACTIVE MATERIAL
PRESENT AT SELECTED LEVELS OF RADIDACTIVITI


The concentrations of radioactive materials present in low-level

wastes are usually very small. When the level of activity in picocuries

per milliliter is known for a particular radioisotope, its concentration

per milliliter may be calculated using the following relationship:

2.2 x A


where N is the number of unstable atoms present per milliliter, A is the

level of activity in picocuries per milliliter and A is the disinte-

gration constant obtained by dividing 0.693 by the appropriate half-life

T, expressed in minutes.

To express this concentration in terms of milligramns per liter, N

anst be multiplied by the proper atomic weight in grams, divided by

Avogadro's number then mu~ltiplied by -106. Arrangement of these

calculations into a single equation yields:

Con. (g/1 =A(pgaml) x 2.2 x T~min) x N~W(fms) x 106
0.693 x 6.023 x 1023(atoms/mole)

Indicated calculations for the activity levels used in this

investigation have been made and the results are tabulated below.








-71-


Activity
(pc/ml)

10 80

20

10 -200

100

30

45

100

50


Concentration
(mgi/1)

3.5 x 10-11 2.8 x 10-9

1.6 x 10-1

1.7 x 10-1 3.3 x 10-1

2.8 x 10

6.0 x 10-1

1.4 x 10-

3.6 x 10-


Radionuclide

P-32

I-131

K-42

Ge-141, 144

Fe-59

Co-58

Sr-89

MPP

















APPENDIX C


STATISTICS OF CDUNTING RADIOACTIVE. SAMPLES


Data obtained from most counting processes are known to follow a

Poisson distribution, an outstanding property of which is that its

standard deviation, 6. ,is the square root of its mean, /y

Unfortunately, in most experimental work, the true population mean is

an unknown quantity. In such cases, the best estimate of 70 can be

obtained by making a number of observations, N, and calculating their

mean 5. The best estimate of r- symbolized by drN), can then be

obtained by taking the square root of N.

However, in counting radioactive samples, it is not the standard

deviation of the cotal count that is of concern but rather the standard

deviation of the count rate, R', where





In this expression, N represents the observed count recorded in time t.

Since the accuracy of any count rate increases with increasing time of

observation, the desired standard deviation must not only be a function

of the observed count: rate but also a function of the time over which

this rate was determined. Applying the usual statistical methods for

propagation of error to the Poisson distribution:













In actual practice, all counting instruments have a background

counting rate, B, which contributes to the gross counting rate, R .

The sample counting rate, R, can be calculated as follows:


R =Ro- B

Applying the statistical methods for propagation of error yields:

Ro B
q-(R) =(t 2


where tl and t2 are the times over which gross and background counting

rates were determined.

Using gross counts of 4,000 and 9,000 observed over a minimum

counting time of 5 minutes and a background of 15 counts per minute

observed over a minimum time of 30 minutes, the following standard

deviations and associated counting errors may be calculated.


a-(R) =.(0 12.6 c/m e = 1.96 x 12.6 = 24.7 c/m



p-(R) = (1 = 19.0 c/m e = 1.96 x 19.0 = 37.2 c/m

















TABULATED DATA -- REMoVAL OF SELECTED
RADIONUCLEDES BY PRIMARY SEDIMENTATION


TABLE 5


REMOVAL OF P-32 BY PRIMARY SEDIMENTATION


Time Run la Run 2b Run 3c A~verage
in Eff. % Eff. X Eff. %
Minutes c/m Removal c/m Removal -c/m Removal Removal

0 3.47 -- 2.49 -- 6.80 -
5 1.57 99.79 2.41 99.94 6.35 99.69 99.8
10 2.75 99.64 7.52 99.81 7.13 99.65 99.7
15 6.26 99.18 266.0 93.41 299.5 85.18 92.6
20 245.6 67.86 836.3 79.27 691.7 65,78 71.0

25 346.6 54.64 1621. `59.83 985.5 51,24 55.2
30 428.8 43.89 2027. 49.78 851.6 57.87 50.5
40 518.0 32.21 2280. 43.49 1483. 26.61 34.0
50 568.6 25.59 2445. 39.42 1394. 31.04 32.0
60 601.4 21.29 2579. 36.20 1124. 44.38 34.0

70 597.6 21.79 2706. 32.97 1606. 20.54 25.1
80 651.27 19.48 2847. 29.45 1628. 19.48 22.8
90 631.8 17.32 3177. 21.28 1560. 22.84 20.5
100 699.8 8.42 -- -- 1633. 19.21 13.8
110 -- -- -- -- 1782. 11.82 11.8

120 687.0 10.09 -- -- 1750. 13.40 11.8
130 707.6 7.40 -- -- 1857. 8.12 7.76
140 684.6 10.41 -- -- .1893. 6.34 8.38
150 -- -- -- -- 1864. 7.77 7.77
'160 -- -- -- -- 1809. 10.51 10.5

170 -- -- -- -- 1857. 8.12 8.12
180 -- -- -- -- 1816. 10.17 10.2


alnfluent activity was 764.1 c/m.

blnfluent activity was 4035 c/m.

Cfnfluent activity was 2021 c/m.


APPENDIX D


-74-























Time Run La Run 2b un 3c Average
in Eff. % Eff. % Eff. % %
Minutes c/m Removal -c/m Removal c/m Removal Removal


0 1.11 -- 1.43 -- 1.75 -
5 1.17 99.62 1.56 99.57 1.83 99.45 99.6
10 2.25 99.27 5.25 98.56 9.40 97.16 98.3
15 21.77 92.96 71.82 80.26 73.15 77.93 83.7
20 59.29 80.83 85.30 76.55 103.9 68.66 75.3

25 80.36 74.01 115.4 68.28 118.7 64.19 68.8
30 193.0 37.S7 192.2 47.17 143.0 56.85 47.2
40 183.2 40.75 229.7 36.84 185.3 44.11 40.6
50 196.8 36.36 278.4 23.47 212.4 35.93 31.9
60 199.1 35.60 303.1 16.67 223.3 32.63 28.3

70 216.3 30 .05 316.9 12.89 247,8 25.25 22.7
80 252.1 18.49 278.4 23.47 239.8 27.66 23.2
90 231.3 25.17 287.4 20.98 235.4 28.99 25.0
100 249.1 19.46 320.2 11.98 243.5 26.54' 19.3
110 261.6 15.41 323.5 11.06 268.0 19.15 15.2

120 250.0 19.16 308.4 15.23 263.8 20.41 18.3
130 273.3 11.63 308.0 15.32 287.4 13.31 '13.4
140 278.0 10.10 338.1 7.05 294.0 11.31 9.79
150 273.7 11.49 331.7 8.83 301.4 9.07 9.80
160 269.8 12.76 325.8 10.43 297.5 10.25 11.2

170 279.1 9.75. 312.2 14.17 297.9 10.13 11.4
180 272.5 11.86 324.8 10.70 287.8 13.19 11.9


-75-


TABLE 6


REMOVAL OF I-131 BY PRIMARY SEDPMENTATION


alfluent activity was 309.2 c/m.

blnfluent activity was 363.8.c/m.

cInfluent activity was 331.5 c/m.

























Time Run 1 Run 2a Run 3b Average
in Eff. % Eff. Eff. Z Z
Kinutes c/m Removal c/m Removal c/m Removal Removal


0 -- -- 0.69 -- 0.00 ---
5 -- -- 0.77 97.40 0.00 100.0 98.7
10 -- -- 1.52 94.87 0.00 100.0 97.4
15 -- -- 3.23 89.10 7.92 87.85 88.5
20 -- -- 8.21 72.29 15.49 76.24 74.3

25 -- -- -- -- 23.11 64.55 64.6
30 -- -- 13.55 54.27 23.94 63.28 58.5
40 -- -- 14.73 50.29 25.09 61.51 55.9
50 -- -- 17.97 39.35 36.06 44.68 42.0
60 -- -- 18.73 36.79 33.89 48.01 42.4

70 -- -- 19.27 34.96 41.36 36.55 35.8
80 -- -- 17.32 41.55 45.73 29.85 35.7
90 -- -- 20.18 31.89 49.02 24.80 28.4
100 -- -- 21.22 28.38 47.30 27.44 27.9
110 -- -- 19.88 32.91 48.61 25.43 29.2

120 -- -- 21.12 28.72 48.15 26.14 27.4
130 -- -- 25.24 14.82 52.90 18.85 16.8
140 -- -- 23.75 19.84 57.93 11.14 15.5
150 -- -- 26.08 11.98 55.09 15.49 13.7
160 -- -- 25.63 13.50 59.02 9.47 11.5

170 -- -- 25.96 12.39 59.87 8.16 10.3
180 -- -- 25.58 13.67 57.81 11.32 12.5


a~nfluent activity was 29.63 c/m.

blnfluent activity was 65.19 c/m.


TABLE 7


REMDVAL OF K-42 BY PRIMARY SEDIMENTATION
















TABLE 8


REMIDVAL. OF Ce-141, 144 BY PRIMARY SEDPIENTATION

51m Rn a Rn b un 3c Average

in Eff. % Eff. % Eff. I %
H~inutes c/m Removal c/m Removal c/m Removal Removal

0 5.94 -- 1.87 -- 6.94 --
5 3.95 99.90 2.08 99.96 4.07 99.92 99.9
10 32.79 99.15 3.63 99.93 8.72 99.82 99.6
15 797.4 79.26 413.7 91.68 163.7 96.69 89.2
20 1783. 53.63 1240. 75.06 1205. 75.63 68.1

25 2192. 42.98 1597. 67.89 2566. 48.09 53.0
30 2294. 40.33 2603. 47.66 2967. 39.97 42.6
40 2277. 40.79 3236. 34.94 2808. 43.19 39 .6
50 2464. 35.91 3587. 27.88 2448. 30.23 31.3
60 2665. 30.68 3370. 32.24 3332. 32.58 31.8

70 2618. 31.89 3645. 26.71 3345. 32.32 30.3
80 3017. 21.53 3784. 23.91 3690. 25.33 23.6
90 2939. 23.56 4023. 19.12 3752. 24.08 22.2
100 2817. 26.74 4464. 10.24 3952. 20.05 19.0
110 3247. 15.54 4532. 8.88 3817. 22.78 15.7

120 3187. 17.12 4356. 12.42 3768. 23.76 17.8
130 3516. 8.55 4464. 10.24 4158. 15.87 11.6
140 3475. 9.62 4335. 12.85 4187. 15.29 12.6
150 3379, 12.11 4005. 19.48 4293. 13.14 14.9
160 3435. 10.66 4212. 15.31 4278. 13.44 13.1

170 3357. 12,68 4293. 13.69 4399. 11.01 12.5
180 3475. 9.62 4789. 4.52 4272. 13.56 9.23


alnfluent activity was 3845 c/m.

blnfluent activity was 4974 c/m.

clnfluent activity was 4943 c/m.























Time Run 11 Run 2b Run 3C Average
in Eff. %1 Eff. % Eff. 7. 1
Minutes c/m Removal c/m Removal c/m Removal Removal

0 6.92 -- 3.19 -- 1.22 -- -
5 10.03 98.27 4.40 99.04 0.63 99.90 99.1
10 23.89 95.88 2.75 99.40 2.70 99.56 98.3
15 195.0 66.38 43.46 90.55 28.93 93.65 83.5
20 248.0 57.25 114.0 75.22 113.0 81.56 71.3

25 288.5 50.26 177.5 61.41 256.5 58.13 56.6
30 243.3 40,81 213.0 53.69 302.2 50.68 48.4
40 255.3 38.75 272.2 40.81 378.6 38.21 39.3
50 428.2 26.18 322.8 29.80 382.2 37.62 31.2
60 415.3 28.39 301.9 34.35 415.6 32.16 31.6

70 437.2 24.61 351.2 23.63 401.5 34.47 27.6
80 422.0 27.27 375.0 18.44 472.2 22.92 22.9
90 460.2 20.65 414.3 9.92 512.3 16.38 15.7
100 454.8 21.58 445.5 3.12 559.8 8.63 11.1
110 515.4 11.15 413.7 10.04 549.1 10.38 10.5

120 532.0 8.27 427.0 7.16 526.0 14.15 9.86
130 493.9 14.85 403.5 12.25 591.1 3.51 9.87
140 553.3 4.60 401.6 12.67 543.4 11.31 9.53
150 522.9 9.84 427.5 7.04 588.5 3.94 6.94
160 550.5 5.09 403.5 12.25 563.1 8.09 8.48

170 521.4 10.11 395.8 13.94 549.6 10.30 11.4
180 525.7 9.36 421.7 8.29 530.1 13.48 10.4


TABLE 9


RENGVALL OF Fe-59 BT PRPIARY SEDIMENTATION


aInfluent

blnfluent

Clnfluent


activity was 580.0 c/m.

activity was 459.9 c/m.

activity was 612.6 c/m.























Time Run la Run 26 Run 3c Average
in Eiff, r Eff. % Eff. Z %.
Minutes c/m Removal c/m Removal c/m Removal Removal


0 2.65 -- 2.44 -- 1.36 ---
5 2.61 99.15 1.75 99.33 2.58 99.26 99.2
10 2.82 99.08 5.18 98.01 1.59 99.54 98.9
15 38.24 87.51 29.67 88.61 8.00 97.71 91.3
20 88.43 71.13 77.22 70.37 73.21 79.00 73.5

25 125.3 59.10 105.5 59.52 132.4 62.01 60.2
30 138.5 54.76 145.9 44.01 173.8 50.16 49.6
40 133.8 56.31 148.9 42.87 165.5 52.52 50.6
50 154.9 49.42 172.2 33.93 186.9 46.40 43.2
60 179.9 41.26 188.9 27,49 208.6 40.17 36.3

70 181.7 40.68 196.6 24.56 240.0 31.16 32.1
80 206.9 32.44 221.7 14.94 244.7 29.81 25.7
90 220.5 28.01 232.1 10.92 266.2 23.65 20.9
100 256.0 16.40 231.9 11.02 287.2 17.63 15.0
110 267.6 12.61 243.0 6.77 296.3 15.01 11.5

120 261.4 14.64 223.7 .14.17 296.3 15.01 14.6
130 271.4 11.39 232.8 11.66 315.9 9.39 10.8
140 276.0 9.87 231.6 11.13 302.6 13.21 11.4
150 264.9 13.50 241.7 7.25 300.1 13.91 11.6
160 289.9 5.33 250.4 3.90 326.2 6.44 5.22

170 290..8 5.06 255.6 1.91 327.9 5.95 4.31
180 277.6 9.34 241.6 7.28 321.2 7.87 8.16


TABLE 10


RENDVAL OF Co-58 BY PRIMARY SEDPIENTATION


aInfluent activity was 306.2 c/m.
b
Influent activity was 260.6 c/m.

CInfluent activity was 348.6 c/m.

























Time Run 1 Run 2a Rhun 3b Average
in Eff. %Eff. % Eff. I %
Minutes c/m Removal .c/m Removal c/m Removal Removal


0 -- -- 17.81 -- 4.15 --
5 -- -- 20.85 99.49 4.33 99.79 99.6
10 -- -- 18.61 99.54 44.13 97.90 98.7
15 -- -- 555.8 86.36 410.8 80.44 83.4
20 -- -- 870.5 78.63 817.3 61.08 69.9

25 -- -- 1279. 68.60 1176. 44.00 56.3
30 -- -- 1649. 59.51 1311. 37.57 48.5
60 -- -- 1876. 53.94 1385. 34.05 44.0
50 -- -- 2317. 43.11 1423. 32.24 .37.7
60 -- -- 2648. 34.99 1480. 29.52 32.3

70 -- -- 2655. 34.81 1652. 21.33 28.1
80 -- -- 2713. 33.39 1619. 22.90 28.1
90 -- -- 2889. 29.07 1740. 17.14 23.1
100 -- -- 2889. 29.07 1815. 13.57 21.3
110 -- -- 3026. 25.71 1837. 12.52 19.1

120 -- -- 3200. 21.43 1888. 10.10 15.8
130 -- -- 3501. 16.04 1921. 8.52 11.3
160 -- -- 3950. 3.02 1837. 12.52 7.77
150 -- -- 3674. 9.80 1968. 6.29 8.04
160 -- -- 3734. 8.32 1860. 11.43 9.87

170 -- -- 3886. 4.59 1892, 9.90 7.24
180 -- -- 3833. 5.89 2000. 4.76 5.33


-80-


TABLE 11


RENDOVAL OF Sr-89 BY PRPIARY SEDIMENT~ATION


alnfluent activity was 4073 c/m.

blafluent activity was 2100 c/m.
























a b c
Time Ru~n 1 Run 2 Run 3 Average
in Eff. 7. Eff. ;b Eff. % %
Minutes c/m Removal c/m Removal c/m Removal Removal

0 9.63 -- 3.70 -- 3.60 -
5 12.25 99.40 31.67 98.37 ~ 3.78 99.80 99.2
10 139.6 93.18 185.9 90.43 61.40 96.72 93.4
IS 644.0 68.52 295.5 84.79 112.3 94.00 82.4
20 730.4 61.37 583.1 69.99 480.4 74.34 68.6

25 912.1 55.42 736.3 62.10 700.1 62.60 60.0
30 1004. 50.93 936.3 51.81 906.7 51.57 51.4
40 1310. 35.97 1051. 45.91 1060. 43.38 41.8
50 1344. 34.31 1377. 29.13 1143. 38.94 34.1
60 1681. 17.84 1333. 31.40 1198. 36.00 28.4

70 1768. 13.59 1388. 28.56 1301. 30.50 24.2
80 1734. 15.25 1375. 29.23 1450. 22.54 22.3
90 1727. 15.59 1499. 22.85 1598. 14.64 17.7
100 1668. 18.48 1578. 18.78 1488. 20.51 19.3
110 1724. 15.74 1897. 2.34 1637. 12.55 10.2

120 1675. 18.13 1778. 8.49 1619. 13.51 13.4
130 1700. 16.91 1699. 12.56 1694. 9.51 13.0'
140 2040. 0.29 1647. 15.23 1833. 2.08 5.87
150 2022. 1.17 1778. 8.49 1687. 9.88 6.51
160 1938. 5.28 1764. 9.21 1747. 6.68 7.06

170 1885. 7.87 1807. 7.00 1760. 5.98 6.95
180 1834. 10.36 1796. 7.57 1830. 2.24 6.72


-81-


TABLE 12


REMOVAL OF MFP BYT PRIMARY SEDPIENTATION


alnfluent

blnfluent

cInfluent


activity was 2046

activity was 1943

activity was 1872

















TABULATED DATA AND GRAPHS -- REMOVAL OF SELECTED
RADIONUCLIDES BY TRICKLING FILTRATION AND SECONDARY SEDIN~ENTATIDE


TABLE 13


REMDVAL OF P-32 BY TRICKLING FILTRATION



Depth Time Run 1 Run 2 Run 3 Average
in in Net 1 Net 1 Net % I
Feet Hlours c/m Removal c/m Removal c/m Removal Removal

0 5.46 -- 38.76 -- 0.92 -- --
2 5.56 -- 42.80 -- 19.46 -- --
4 0 5.08 -- 32.96 -- 24.09 -- --
6 3.65 -- 32.08 -- 31.31 -- --
8 4.91 -- 32.86 -- 21.04 -- --

0 249.0 -- 2002. -- 2331. -- --
2 216.8 12.93 1824. 8.91 2490. 0.00 7.28
4 2 183.3 26.39 1224. 38.85 1759. 24.54 29.9
6 148.4 40.38 1225. 38.81 1454. 37.60 38.9
8 115.7 53.52 1062. 46.97 1333. 42.81 47.8

0 213.6 -- 3568. -- 2601. -- --
2 195.5 8.47 3303. 7.42 3109. 0.00 5.30
4 4 191.0 10.62 3229. 9.49 2620. 0.00 6.70
6 145.2 32.03 2229. 37.52 1994. 23.35 31.0
8 116.6 45.42 2153. 39.65 2012. 22.63 35.9

0 232.5 -- -- -- 3362. -- --
2 193.5 16.70 -- -- 3254. 3.20 9.95
1 8 190.8 17.92 -- -- 2707. 19.46 18.7
6 147.6 36.51 -- -- 2247. 33.17 34.8
8 119.1 48.79 -- -- 2082. 38.07 43.4

0 415.7 -- 2511. -- 3480. -- --
2 279.6 32.73 1835. 26.92 2774. 20.29 26.6
4 12 240.9 42.06 1679. 33.13 2634. 24.31 33.2
6 233.0 43.94 1484. 40,91 2175. 37.49 40.8
8 220.2 47.03 1397. 44.39 2055. 40.94 44.1

0 452.0 -- 2573. -- 3323. -- --
2 270.1 40.09 1605. 37.61 2076. 19.49 32.4
4 24 277.6 38.55 1534. 40.40 2320. 30.20 36.4
6 237.2 47.53 1436. 44.20 2037. 38.70 43.5
8 209.5 53.66 1409. 45.24 2052. 38.26 45.7


APPENDIX E
























Depth Time Run 1 Run 2 Run 3 Average
in in Net Z Net Z Net % 7.
Feet Bours c/m Removal c/m Removal c/m Removal Removal

0 1.39 -- 0.13 -- 0.00 -- --
2 3.78 -- 3.76 -- 0.00 -- --
4 0 9.42 -- 3.33 -- 0.62 -- --
6 5.49 -- 4.18 -- 1.94 -- --
8 6.34 -- 2.55 -- 1.45 -- --

0 430.3 -- 402.4 -- 361.9 -- --
2 228.6 46.86 208.3 48.24 177.8 50.86 48.7
4 2 192.4 55.29 175.9 56.27 140.2 61.27 57.6
6 164.6 61.75 142.8 64.50 128.8 64.40 63.6
8 134.1 68.84 124.0 69.17 123.2 65.97 68.0

0 401.5 -- 378.3 -- 357.9 -- --
2 218.1 45.69 206.4 45.43 216.4 39.54 43.6
4 4 187.9 53.19 175.1 53.70 174.2 51.32 52.7
6 148.9 62.91 147.2 61.10 149.7 58.18 60.7
8 134.1 66.59 132.5 64.97 129.3 63.87 65.1

0 497.3 -- 329.2 -- 426.0 -- --
2 325. 0 34.65 221.6 32.69 285.1 33.09 33.5
4 8 243.4 51.01 163.0 50.49 218.0 48.83 50.1
6 206.0 58.57 139.0 57.77 190.2 55.34 57.2
8 187.2 62.36 121.8 63.02 165.0 61.26 62.2

0 409.6 -- 349.6 -- 354.9 -- --
2 287.5 29.81 247.8 29.13 252.4 28.88 29.3
4 12 214.4 47.67 195.2 44.19 208.2 41.33 44.4
6 176.2 56.98 172.6 50.63 161.4 54.53 54.0
8 153.7 62.48 156.0 55.39 132.9 62.56 60.1

0 435.7 -- 343.2 -- 427.0 -- --
2 321.5 26.21 262.1 23.63 305.4 28.49 26.1
4 24 258.8 40.60 200.8 41.50 238.3 44.20 4.
6 203.4 53.32 172.1 49.85 183.7 56.97 53.4
8 173.5 60.18 140.5 59.06 156.2 63.42 60.9


-83-


TABLE 14


REMDOVAL OF I-131 BY TRICKLING FILTRATION

























Depth Time Run 1 Run 2 Run 3 Average
in in Net 9. Net % Net I X
Feet Hours c/m Removal c/m Ramoval c/m Removal Removal

0 0.11 -- 0.00 -- 0.00 -- --
2 0.79 -- 0.00 -- 0.00 -- --
4 0 1.02 -- 0.00 -- 0.09 -- --
6 0.53 -- 0.00 -- 0.00 -- --
8 0.53 -- 0.00 -- 0.00 -- --

0 452.6 -- 19.21 -- 13.17 -- --
2 321.0 29.07 12.11 36.96 9.24 29.84 32.0
4 2 275.5 39.12 11.15 41.96 8.30 36.98 39.4
6 231.0 48.97 8.84 53.98 6.42 51.25 51.4
8 194.6 57.01 8.88 53.77 6.60 49.89 53.6

0 582.8 -- 23.08 -- 15.11 -- --
2 477.8 18.02 17.37 24.74 11.85 21.58 21.4
4 4 367.1 37.01 14.35 37.82 9.53 36.93 37.2
6 349.4 40.04 12.05 47.79 8.32 44.94 44.3
8 257.0 55.90 11.80 48.87 7.29 51.71 52.2

0 317.4 -- 27.56 -- 13.91 -- --
2 279.3 12.02 23.65 14.19 11.11 20.13 15.4
4 8 212.5 33.06 18.70 32.15 9.75 29.91 31.7
6 187.2 41.03 15.14 45.07 7.66 44.93 43.7
8 158.6 50.03 12.69 53.96 7.10 48.96 5.

0 -- -- 13,08 -- 16.30 -- --
2 -- -- 11.25 13.99 13.38 17.91 16.0
4 12 -- -- 9.14 30.12 11.10 31.90 31.0
6 -- -- 7.87 39.83 9.12 44.05 42.0
8 -- -- 5.88 55.04 8.81 45.95 50.5

0 -- -- 15.62 -- 9.64 -- --
2 -- -- 13.72 12.16 7.88 18.26 15.2
4 24 -- -- 10.30 34.06 6.19 35.79 36.9
6 -- -- 8.27 67.06 5.58 42.12 44.6
8 -- -- 7.21 53.84 5.40 43.98 48.9


TABLE 15


RENDAL OF K-42 BY TRICKLINGC FILTRATI~ON
























Depth Time lu~n_ 1 un 2 Run 3 Average
in in Net % Net % Net X Z
Feat Houns c/m Remo~val c/m Removal c/m Removal Removal

0 2.19 -- 10.14 -- 34.56 --
2 3.30 -- 17.81 -- 42.59 -- -
4 0 0.87 -- 20.94 -- 37.04 -
6 ~ 3.00 -- 23.31 -- 27.15 --
8 1.73 -- 26.21 -- 34.67 -

0 2324. -- 3882. -- 3600. --
2 931.7 59.92 1226. 68.43 1389. 61.41 63.2
4 2 580.3 75.03 1205. 68.95 1057. 70.65 71.5
6 429.4 81.53 723.5 81.36 622.4 81.60 81.5
8 .221.8 90.46 414.4 89.32 316.6 91.21 90.3

0 3359. -- 3047. -- 3950. -
2 1263. 62.39 965.2 68.32 1480. 62.53 64.4
4 4 857.9 74.46 729.6 76.05 970.9 75.42 75.3
6 624.3 81.41 532.6 82.52 644.0 83.70 82.5
8 467.4 86.09 487.8 83.99 345.9 91.24 87.1

0 3361. -- 4375. -- 3118. ---
2 1500. 55.37 1539. 64.83 1185. 61.99 60.7
4 8 907.1 73.01 1143. 73.88 862.4 72.34 73.1
6 670.1 80.07 786.7 82.02 491.4 84.24 82.1
8 530.4 84.22 612.5 86.00 359.2 88.48 86.2~

0 2997. -- 4486. -- 4021. -- --
2 1342. 55.21 1713. 61.81 1488. 63.00 60.0
4 12 798.9 73.34 1170. 73.91 974.2 75.77 74.3
6 644.1 78.51 807.0 82.01 730.2 81.84 80.8
8 544.3 81.84 673.4 84.99 520.6 87.05 84.6

0 2721. -- 3143. -- 3065. -- --
2 1495. 45.04 1098. 65.07 1224. 60.07 56.7
4 24 802.8 70.49 1058. 66.33 1066. 65.23 63.4
6 631.0 76.81 712.6 77.33 636.8 79.23 77.8
8 630.5 76.83 620.6 80.26 422.9 86.20 81.1


-85-


TABLE 16


REMOVAL OF Ce-141, 144 BT TRICKLING FILTRATION
























Depth Time Run 1 Run 2 R~un 3 Average
in in Met 1Net % Net % %
Feet Rours c/m Removal c/m Removal c/m Removal Removal

0 2.40 -- 3.81 -- 5.47 -- --
2 4.99 -- 6.0* -- 5.21 -- --
4 0 6.81 -- 6.63 -- 6.0 -- --
6 5.93 -- 7.17 -- 6.47 -- --
8 10.94 -- 19.33 -- 18.44 -- --

0 287.1 -- 237.3 -- 282.7 -- --
2 127.6 55.57 105.2 55.68 136.1 51.88 54.4
4 2 77.18 73.11 69.93 70.54 89.51 68.34 70.7
6 43.67 84.79 37.18 84.35 42.41 85.00 84.7
8 41.70 85.47 50.28 78.82 50.04 82.30 82.2

0 6.8 -- 312.2 -- 264.4 -- --
2 173.3 52.48 147.5 52.75 131.9 50.11 51.8
4 4 119.9 67.12 96.38 69.13 92.48 65.03 67.1
6 65.26 82.11 59.53 80.93 64.20 75..72 79.6
8 57.84 84.14 66.15 78.81 65.65 75.17 79.4

0 364.1 -- 340.1 -- 287.6 -- --
2 174.8 49.18 178.4 47.54 149.8 47.91 48.2
4 8 150.9 56.16 124.0 63.55 111.6 61.21 60.3
6 92.72 73.06 86.03 74.71 79.02 72.53 73.4
8. 92.09 73.24 69.16 79.67 71.65 75.09 76.0

0 227.6 -- 220.2 -- 198.3 -- --
2 134.7 40.81 127.6 42.04 99.49 49.82 44.2
4 12 109.4 51.94 94.83 56.93 73.69 62.84 57.2
6 58.96 74.09 67.03 69.56 48.72 75.43 73.0
8 60.74 73.31 62.35 71.,68 55.59 71.96 72.3

0 213.1 -- 227.3 -- 191.8 -- --
2~ 119.6 43.85 136.0 40.15 88.61 53.79 45.9
4 24 94.31 55.74 95.49 57.99 77.34 59.67 57.8
6 50.20 76.44 60.00 73.60 65.66 65.76 71.9
8 71.50 66.45 83.62 63.21 66.36 65.40 65.0


TABIE 17


REHDVAL OF Fe-59 BY TRICKLINYG FILTRATION
























Depth Thme Rlun 1 Run 2 Run 3 Average
in in Net Z Net % Net %; Z
Feet Hours c/m Removal c/m Removal c/m Removal Removal

0 1.73 -- 3.72 -- 2.93 -- --
2 6.45 -- 6.66 -- 6.33 -- --
4 0 5.59 -- 4.97 -- 6.55 -- --
6 5.35 -- 4.92 -- 5.88 -- --
8 5.24 -- 8.08 -- 6.77 -- --

0 161.2 -- 165.6 -- 162.3 -- --
2 72.62 54.95 74.69 54.89 71.07 56.22 55.4
4 2 54.69 66.07 55.02 66.77 43.90 72.96 68.6
6 24.92 84.54 27.35 83.48 25.03 84.58 84.2
8 22.97 85.75 25.57 84.56 20.71 87.24 85.9

0 184.1 -- 173.6 -- 194.2 -- --
2 88.50 51.94 82.16 52.67 97.01 50.06 51.6
4 4 68.82 62.63 54.16 68.80 57.76 70.26 67.2
6 34.16 81.45 36.49 78.98 35.59 81.68 80.7
8 34.30 81.37 28.05 83.84 29.36 84.88 83.4

0 179.2 -- 178.3 -- 196.1 -- --
2 80.85 54.90 82.23 53.88 99.54 49.25 52.7
4 8 58.52 67.35 53.58 69.95 80.50 58.96 65.4
6 40.66 77.32 38.14 78.61 43.45 77.85 77.9
8 33.80 81.14 31.99 82.06 42.58 78.29 80.5.

O 167.2 -- -- -- \200.0 -- --
2 97.34 41.78 -- -- 111.0 44.50 43.1
4 12 59.61 64.35 -- -- 67.04 66.48 65.4
6 38.44 77.01 -- -- 40.77 79.61 78.3
8 33.82 79.77 -- -- 33.39 83.30 81.5

0 132.7 -- 177.7 -- 144.2 -- --
2 84.75 36.13 80.49 54.70 69.44 51.84 47.6
4 24 51.14 61.46. 55.32 68.86 45.58 68.39 66.2
6 29.17 78.02 27.01 84.80 30.90 78.57 80.5
8 30.64 76.91 31.13 82.48 23.83 83.07 81.0


TABLE 18


REMOVAL DF Co-58 BY TRICKLING FILTRATION

























Depth Time Run 1 Run 2 Run 3 Average
in in Net. 1X Net Z Net % %
Feet Bours c/m Removal c/m Rlmoval c/m Removal Removal

0 2.69 -- ~5.26 -- 5.40 -- --
2 9.32 .-- 63.08 -- 84.10 -- --
4 0 5.82 -- 48.58 -- 63.93 -- --
6 4.43 -- 52.48 -- 62.53 -- --
8 3.80 -- 31.48 -- 48.11 -- --

0 1686. -- 1814. -- 1554. -- --
2 628.0 .62.75 1055. 41.84 791.9 49.04 51.2
4 2 465.1 72.41 688.8 62.03 623.2 59.90 64.8
6 216.4 87.16 297.2 83.62 323.7 79.17 83.3
8 120.0 92.88 222.9 87.71 226.6 85.42 88.7

0 ,.1376. -- 2444. -- 1918. -- --
2 802.5 41.68 1440. 41.08 1082. 43.59 42.1
4 4 584.7 57.51 908.6 62.82 809.6 57.79 59.4
6 356.2 74.11 585.5 76.04 437.8 77.18 75.8
8 232.3 83.12 484.1 80.17 366.5 80.89 81.4

0 1550. -- 2102. -- 1633. -- --
2 929.5 40.03 1221. 41.91 1254. 23.21 35.0
4 8 802.5 48.23 1117. 46.86 1053. 35.52 43.5
6 566.5 64.03 702.8 66.57 670.1 58.97 63.2
8 472.4 69.52 579.0 72.45 655.4 59.87 67.3

0 1490. -- 2225. -- 1842. -- --
2 1040. 30.20 1552. 30.25 1441. 21.77 27.4
4 12 764.1 48.72 1338. 39.87 1095. 40.55 43.0
6 691.9 53. 56 1034. 53.53 981.8 46.70 51.3
8 661.6 55.60 1072. 51.82 812.7 55.88 54.4

0 1540. -- 2196. -- 1714. -- --
2 1143. 25.78 1609. 26.73 1397. 18.50 23.7
4 24 1060. 31.17 1589. 27.64 1329. 22.46 27.1
6 919.3 40.31 1243. 43.40 1229. 28.30 37.3
8 847.5 44.97 1183. 46.13 1095. 36.12 42.4


TABLE. 19


REMDWAL OF Sr-89 BY TRICKLING FILTRATION




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs