LA— 11691-MS

DE90 003988

Characterization of Reactive Tracers

for C-Wells Field Experiments I:

Electrostatic Sorption Mechanism, Lithium

H. R. Fuentes

W. L. Polzer

E. H. Essington

B. D. Newman

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States

Government. Neither the United States Government nor any agency thereof, nor any of their

employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or

process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark,

manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views

and opinions of authors expressed herein do not necessarily state or reflect those of the

United States Government or any agency thereof.

Los Alamos National Laboratory

Los Alamos.New Mexico 87545
CONTENTS

LIST OF FIGURES vi

LIST OF TABLES viii

ABSTRACT 1

1.0 INTRODUCTION 2

2.0 TRACER SELECTION CRITERIA 5

3.0 LITHIUM 6

4.0 MATERIALS AND METHODS 13

4.1 Prow Pass Samples and J-13 Water 13

4.2 Procedures 18

4.2.1 Adsorption Kinetics 18

4.2.2 Desorption Kinetics 20

4.2.3 Equilibrium Adsorption 21

4.2.4 Equilibrium Desorption 21

4.2.5 Potentiometric Titration 21

4.2.6 Electrophoresis 22

4.2.7 Abrasion Effects 24

4.3 Models 26

4.3.1 Isotherms 26

4.3.2 Thermodynamics 30

4.4 Pre-experimental Geochemical Modeling 34

5.0 RESULTS AND DISCUSSION 37

5.1 Kinetics Experiments 37

5.2 Equilibrium 38

5.2.1 Sorption Calculations 38

5.2.2 Isotherm Evaluation 40

5.2.3 Thermodynamic Parameter Estimation 50

5.2.4 Deso-ption 60

5.3 Potentiometric Studies 63

6.0 SUMMARY AND CONCLUSIONS 71

ACKNOWLEDGMENTS 74

REFERENCES 76

APPENDIX A. ANALYTICAL INSTRUMENTATION 81

APPENDIX B. ESTIMATES OF LITHIUM ADSORPTION AND DESORPTION EQUILIBRIUM CONCENTRATIONS 85

APPENDIX C. EQUILIBRIUM CONCENTRATIONS AND MODELING VARIABLES ... . 95

APPENDIX D. STATISTICAL AND MODEL PARAMETER ESTIMATES FOR ISOTHERMS . 113
LIST OF FIGURES

Figure 1. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 25°C for an initial

concentration range of 1 to 2000 fig Li mL and a solid-to-liquid

ratio of 1:20. Adsorbed lithium is determined in two ways: (1)

based on measured lithium in solution (Li) and (2) based on a

combination of measured lithium and other cations in solution

(best estimate). Predicted lithium is based on the Modified

Freundlich isotherm 41

Figure 2. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 38°C for an initial

concentration range of 1 to 2000 fig Li mL" and a solid-to-liquid

ratio of 1:20. Adsorbed lithium is determined in two ways: (1)

based on measured lithium in solution (Li) and (2) based on a

combination of measured lithium and other cations in solution

(best estimate). Predicted lithium is based on the Modified

Freundlich isotherm 42

Figure 3. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 45°C for an initial

concentration range of 1 to 2000 fig Li mL and a solid-to-liquid

ratio of 1:20. Adsorbed lithium is determined in two ways: (1)

based on measured lithium in solution (Li) and (2) based on a

combination of measured lithium and other cations in solution

(best estimate). Predicted lithium is based on the Modified

Freundlich isotherm 43

Figure 4. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 25°C for an initial

concentration range of 1 to 150 fig Li mL" and a solid-to-liquid

ratio of 1:10. Adsorbed lithium is determined in two ways: (1)

based on measured lithium in solution (Li) and (2) based on a

combination of measured lithium and other cations in solution (best

estimate). Predicted lithium is based on the Modified Freundlich

isotherm 44

Figure 5. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 38°C for an initial

concentration range of 1 to 150 fig Li mL" and a solid-to-liquid

ratio of 1:10. Adsorbed lithium is determined in two ways: (1)

based on measured lithium in solution (Li) and (2) based on a

combination of measured lithium and other cations in solution

(best estimate). Predicted lithium is based on the Modified

Freundlich isotherm , 45

vi
Figure 6. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 45°C for an initial

concentration range of 1 to 150 fig Li mL~ and a solid-to-liquid

ratio of 1:10. Adsorbed lithium is determined in two ways: (1)

based on measured lithium in solution (Li) and (2) based on a

combination of measured lithium and other cations in solution

(best estimate). Predicted lithium is based on the Modified

Freundlich isotherm 46

Figure 7. Observed and predicted adsorption and desorption of lithium on

a Prow Pass suspension in J-13 well water at 38 C for an

initial concentration range of 1 to 2000 fig Li mL" and a

solid-to-liquid ratio of 1:20. Predicted lithium is based on the

Modified Freundlich isotherm 64

Figure 8. Observed and predicted adsorption and desorption of lithium on

a Prow Pass suspension in J-13 well water at 38°C for an

initial concentration range of 1 to 150 fig Li mL" and a

solid-to-liquid ratio of 1:10. Predicted lithium is based on

the Modified Freundlicb isotherm 65

Figure 9. Potentiometric titration of Prow Pass in suspension with

J-13 well water and NaClO. electrolyte at 38°C without the

addition of lithium 67

Figure 10. Potentiometric titration of Prow Pass in suspension with

J-13 well water and NaC104 electrolyte at 38°C with the

addition of 900 fig Li mL"1 68

Figure 11. Electrophoretic behavior of a colloidal suspension of Prow

Pass in J-13 well water and NaClO. electrolyte at 38°C

with the addition of 900 fig Li mL 69

Figure 12. Electrophoretic behavior of a colloidal suspension of Prow

Pass in J-13 well water and NaC104 electrolyte at 38°C

without the addition of lithium 70

vii
LIST OF TABLES

I. GENERIC CLASSIFICATION OF ADSORPTION PROCESSES 3

II. LITHIUM CHARACTERISTICS 7

III. LITHIUM BROMIDE CHARACTERISTICS 8

IV. J-13 VATER Bfc?(lRE AND AFTER EQUILIBRATION VITH PROV PASS MATERIALS (ng mL"J) 15

V. PHYSICOCHEMICAL CHARACTERIZATION OF PROV PASS TUFF SAMPLES (<500

) USED IN THE INVESTIGATIONS 16

VI. REGRESSION AND COMPARISON BETVEEN SIZE DISTRIBUTIONS BEFORE AND

AFTER TUMBLING 25

VII. PREDICTIONS FOR LITHIUM DISTRIBUTION IN PROV PASS AND J-13

VATER ADSORPTION EXPERIMENTS AT 38°C (Li = 2000 pg raL"1

AS LiBr) 36

VIII. A COMPARISON OF ESTIMATED PARAMETERS OF FOUR ISOTHERM MODELS FOR

THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL

VATER FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 2000 pg Li mL'1

AND A SOLID-TO-LIQUID RATIO OF 1:20 48

IX. A COMPARISON OF ESTIMATED PARAMETERS OF FOUR ISOTHERM MODELS FOR

THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13

VELL VATER FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 150

fig Li mL"1 AND A SOLID-TO-LIQUID RATIO OF 1:10 51

X. PARAMETER VALUES FOR THE ESTIMATION OF A THERMODYNAMIC EQUILIBRIUM

CONSTANT FOR THE LITHIUM ADSORPTION ON A PROV PASS SUSPENSION IN

J-13 VELL VATER AT THREE TEMPERATURES FOR THE INITIAL CONCENTRATION RANGE OF 1 TO 2000 pg Li raL'1 AND A SOLID-TO-LIQUID

RATIO OF 1:20 54

XI. THERMODYNAMIC CONSTANTS ESTIMATED FOR LITHIUM ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT THREE TEMPERATURES FOR AN

INITIAL CONCENTRATION RANGE OF 1 TO 2000 pg Li raL"1 AND A SOLIDTO-LIQUID RATIO OF 1:20 55

XII. PARAMETER VALUES FOR THE ESTIMATION OF THERMODYNAMIC EQUILIBRIUM

CONSTANTS FOR LITHIUM ADSORPTION ON A PROV PASS SUSPENSION IN

J-13 VELL VATER AT 38°C AND 45°C FOR THE INITIAL CONCENTRATION

RANGE OF 1 TO 150 jig Li mL"1 AND A SOLID-TO-LIQUID RATIO OF 1:10. 57

viii
XIII. THERMODYNAMIC CONSTANTS ESTIMATED FOR LITHIUM ADSORPTION ON A

PROV PASS SUSPENSION IN J-13 VELL WATER AT 38°C AND 45°C FOR

AN INITIAL CONCENTRATION RANGE OF 1 TO 150 fig Li raL"1 AND A

SOLID-TO-LIQUID RATIO OF 1:10 58

XIV. DATA USED IN THE CALCULATION OF EQUILIBRIUM CONSTANTS FOR

THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL

VATER AT THREE TEMPERATURES FOR THE INITIAL CONCENTRATION RANGE

OF 1 TO 150 ng Li ml'1 AND A SOLID-TO-LIQUID RATIO OF 1:20. ... 61

XV. EQUILIBRIUM CONSTANTS AND ENTHALPIES FOR THE ADSORPTION

OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL VATER AT

TEMPERATURES OF 25°C, 38°C, AND 45°C FOR THE INITIAL CONCENTRATION RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TOLIQUID RATIO OF 1:20 62

B-I. ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT 25°C FOR AN INITIAL

CONCENTRATION RANGE OF 1 TO 2000 fig Li mL'1 AND A SOLID-TO-LIQUID

RATIO OF 1:20 87

B-II. ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL

CONCENTRATION RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TO-LIQUID

RATIO OF 1:20 88

B-III. ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT 45°C FOR AN INITIAL

CONCENTRATION RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TO-LIQUID

RATIO OF 1:20 89

B-IV. ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT 25°C FOR AN INITIAL

CONCENTRATION RANGE OF 1 TO 150 fig Li mL'1 AND A SOLID-TO-LIQUID

RATIO OF 1:10 90

B-V. ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL

ix
CONCENTRATION RANGE OF 1 TO 150 /tg Li raL"1 AND A SOLID-TO-LIQUID

RATIO OF 1:10 91

B-VI. ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VELL VATER AT 45°C FOR AN INITIAL

CONCENTRATION RANGE OF 1 TO 150 fig Li ml" * AND A SOLID-TO-LIQUID

RATIO OF 1:10 92

B-VII. THE BEST ESTIMATE OF ADSORBED LITHIUM AS DETERMINED BY TVO

METHODS FOR THE DESORPTION OF LITHIUM FROM A PROV PASS SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 2000 fig Li ml"1 AND A SOLID-TO-LIQUID RATIO

OF 1:20 93

B-VIII. THE BEST ESTIMATE OF ADSORBED LITHIUM AS DETERMINED BY TVO

METHODS FOR THE DESORPTION OF LITHIUM FROM A PROV PASS SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 150 fig Li mL" * AND A SOLID- TO- LIQUID RATIO

OF 1:10 94

C-I. ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig raL'1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 25°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID

RATIO = 1:20 99

C-II. ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 25°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20 100

C-III. ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 /tg mL~

 ! RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 38°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID

RATIO = 1:20 101

C-IV. ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 38°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20 102
C-V. ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 45°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID

RATIO = 1:20 103

C-VI. ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 45°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20 104

C-VII. ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL"l RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 25°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID

RATIO = 1:10 105

C-VIII. ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL'1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 25°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:10 106

C-IX. ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 38°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID

RATIO = 1:10 107

C-X. ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL"

 J RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 38°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:10 108

C-XI. ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL'1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 45°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID

RATIO = 1:10 109

C-XII. ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 45°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:10 110

xi
C-XIII. DESORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL"1 RANGE OF

INITIAL LITHIUM CONCENTRATIONS IN SOLUTION AT 38°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20 Ill

D-I. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE LINEAR

ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV PASS

SUSPENSION IN J-13 VELL VATER FOR AN INITIAL LITHIUM

CONCENTRATION RANGE OF 1 TO 2000 fig Li mL"l AND A SOLID-TOLIQUID RATIO OF 1:20. 114

D-II. STATISTICAL AND MODEL PARAMETER ESTIMATIONS OF THE LANGMUIR

ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL VATER FOR AN INITIAL LITHIUM CONCENTRATION RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TO-LIQUID

RATION OF 1:20 115

D-III. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE FREUNDLICH

ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL VATER FOR AN INITIAL CONCENTRATION RANGE

OF 1 TO 2000 fig Li ml'1 AND A SOLID-TO-LIQUID RATIO OF 1:20 .. .116

D-IV. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE MODIFIED

FREUNDLICH ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV

PASS SUSPENSION IN J-13 VELL VATER FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 2000 fig Li mL"

 X AND A SOLID-TO-LIQUID

RATIO OF 1:20 117

D-V. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE LINEAR ISOTHERM

FOR THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13

VELL VATER FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 150

fig Li mL'1 AND A SOLID-TO-LIQUID RATIO OF 1:10 118

D-VI. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE LANGMUIR

ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL VATER FOR AN INITIAL CONCENTRATION RANGE OF

1 TO 150 fig Li mL'1 AND A SOLID-TO-LIQUID RATIO OF 1:10 119

D-VII. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE FREUNDLICH

ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL VATER FOR AN INITIAL CONCENTRATION RANGE OF

1 TO 150 fig Li mL"1 AND A SOLID-TO-LIQUID RATIO OF 1:10 120

D-VIII. STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE MODIFIED

FREUNDLICH ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV

xii
PASS SUSPENSION IN J-13 WELL VATER FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 150 fig Li mL~

 X AND A SOLID-TO-LIQUID

RATIO OF 1:10 121

xiii
CHARACTERIZATION OP REACTIVE TRACERS FOR C-VEILS

FIELD EXPERIMENTS I: ELECTROSTATIC SORPTION MECHANISM, LITHIUM

by

H. R. Fuentes, V. L. Polzer, E. H. Essington,

and B. D. Newman

ABSTRACT

Lithium (Li+) was introduced as lithium bromide (LiBr), as

a retarded tracer for experiments in the C-wells complex at

Yucca Mountain, Nevada Test Site, Nevada. The objective was to

evaluate the potential of lithium to sorb predominately by

physical forces. Lithium was selected as a candidate tracer oa

the basis of high solubility, good chemical and biological

stability, and relatively low sorptivity; lack of

bioaccumulation and exclusion as a priority pollutant in

pertinent federal environmental regulations; good analytical

detectability and low natural background concentrations; and a

low cost. Laboratory experiments were performed with

suspensions of Prow Pass cuttings from drill hole CE-25p#l at

depths between 549 and 594 m in J-13 water at a pH of

approximately 8 and in the temperature range of 25°C to 45°C.

Batch equilibrium and kinetics experiments were performed;

estimated thermodynamic constants, relative behavior between

adsorption and desorption, and potentiometric studies provided

information to infer the physical nature of lithium sorption.

Modeling of the equilibrium adsorption data indicates that

lithium adsorption can be effectively represented in the range

of 1 to 2000 ng ml' of initial lithium concentrations by the

following isotherms: Linear, Langmuir, Freundlich, and Modified

Freundlich. The Modified Freundlich is a general equation from

which the others can be derived. The applicability of these

isotherms to various flow regimes and influent conditions must

be verified in laboratory column and field experiments.

Thermodynamic estimates indicate that lithium adsorbs to

the Prow Pass in contact with J-13 water by a physical

(electrostatic) mechanism. Enthalpies of adsorption are in the

range expected for physical adsorption (<12 kcal mole" ) . These

results are supported by the reversibility between the

adsorption and desorption of lithium and by its behavior in

potentiometric studies. The potentiometric studies indicate

that lithium did not cause a shift in the zero point of charge,

which is indicative of physical sorption.

The characteristics of lithium in combination with the

analysis of the laboratory batch equilibrium experiments
indicate that lithium is a good candidate tracer for a field

test because it is expected to be only slightly retarded (a

retardation factor of about 2) and to exhibit reversibility, a

characteristic that should permit a better tracer recovery

within a reasonable period of time, depending on the design of

the field test. An advantage of adding Li+ as LiBr is the

simultaneous application of bromide, which is expected to behave

as a conservative tracer for flow characterization.

1.0 INTRODUCTION

This report is part of the laboratory investigations conducted by Los

Alamos National Laboratory (Los Alamos) as part of a study of Reactive Tracer

Experiments in the C-wells and other wells in the Yucca Mountain Vicinity,

Nevada. This study will provide information required by the Yucca Mountain

Project (YMP) to describe the saturated-zone hydrologic characteristics at

Yucca Mountain. The information is also required by the YMP geochemistry test

program to evaluate the applicability of laboratory data to field conditions.

Laboratory investigations are being conducted to identify and

characterize a group of tracers to be used in the C-wells field experiments at

Yucca Mountain. Ideally, each tracer should adsorb by one predominant

sorption mechanism, but various sorption mechanisms can actually occur

simultaneously (for example, ion exchange and molecular sieve in zeolites) or

sequentially (for example, film diffusion followed by ion exchange).

For this study two broad classes of sorption--physical and chemical--have

been defined (1) and are described in Table I. Physical adsorption is very

rapid (if not limited by diffusion rates), reversible, non-site-specific, and

with low heats of adsorption (<12 kcal mole ) (2). In contrast,

chemisorption is more site-specific and results in adsorption energies similar

to that of chemical bonding (>20 kcal mole ) (2). Vithin these two general

classes of adsorption, two major overall mechanisms are of concern in these

2
TABLE I

GENERIC CLASSIFICATION OF ADSORPTION PROCESSES

Characteristic

Enthalpy, AH

(kcal mole )

Changes in

vibration

frequency

Bond strength

Type of bond

Forces

Physical

Low

<12

Small (~0.l7.)

Veak; easily

reversible

Nonspecific and

reversible

Too weak to

cause physical

or chemical change

Process

Chemical

High

>20

Large

Strong; partially

or fully irreversible

Specific and

reversible

Strong enough to

cause physical and

chemical change

Intermediate

Low

(?)

Small to large

Veak; easily

reversible

Similar to

physical and

chemical

Similar to

physical and

chemical

change

Sources: References 1, 2.
investigations: electrostatic and chemical. Electrostatic adsorption

represents a physical adsorption where ions in solution migrate to a diffuse

layer (3,4) because of electrostatic attraction of ions to a surface of

opposite charge and because of the dispersive influence of diffusion forces.

Ion-exchange behavior is included in this definition if it is stoichiometric

and reversible. Chemisorption refers to those cases where forces as large as

those of chemical bonds hold the adsorbate (solute) to a site surface (3,4).

The sorption mechanism of a tracer can be inferred by several kinds of

data: enthalpy and zero point of charge (ZPC). The enthalpy of sorption can

be determined from isotherm data obtained at three temperatures. Enthalpy

values of <12 kcal mole" are indicative of physical (electrostatic) sorption

and those of >20 kcal mole" are indicative of chemical sorption. The ZPC can

be determined from potentiometric titrations of electrolyte solutions in

contact with the sorbent material and from electrophoretic measurements. If

the presence of the tracer displaces the ZPC, then chemical sorption is

indicated; if the ZPC is not displaced, then physical sorption is indicated.

The objective of the laboratory efforts is to characterize lithium (Li),

introduced as lithium bromide (LiBr), as a candidate tracer of the

electrostatic sorption mechanism for the field experiments. Laboratory batch

experiments were conducted to evaluate and to model the extent of lithium

adsorption to prepared samples from the Prow Pass Member of Yucca Mountain in

J-13 well water (groundwater from the Yucca Mountain vicinity used as

reference water in most geochemical investigations) by isotherms. In an

attempt to demonstrate the physical nature of the adsorption of lithium,

additional tests, including desorption in solutions of different ionic

strengths and potentiometric studies, were conducted.
2.0 TRACER SELECTION CRITERIA

The selection of a tracer that adsorbs predominantly by physical

adsorption was based on the following criteria:

• physicochemical properties,

• environmental regulations,

• detection, and

• cost.

The most important physical property is the reaction of the tracer with

the rock matrix. Bowever, the tracer should be sufficiently mobile to travel

from the injection well to the observation wells in a reasonable period of

time with reasonable groundwater flow rates. Thus, conventional tracers (5)

that migrate with groundwater velocities are not adequate. On the other hand,

the tracer must be stable so that other processes (for example, microbial

uptake, complexation, and volatilization) do not complicate the monitoring,

measuring, and modeling of the tracer. One criterion for the selection of

tracers is obtaining approval from environmental agencies (federal, state, and

local). Thus, chemicals included in major regulatory actions and their

amendments have not been considered. Organic compounds with significant

volatility and potential for complexation and compounds subject to

biotransformation have also been excluded. These constraints leave limited

choices. Radioactive tracers that offer advantages, for example, simpler

analysis and more realistic simulation of repository releases, have been

excluded from consideration for field tests because of their potential

rejection by regulatory agencies.
3.0 LITHIUM

Literature searches and consultations with experts indicate that lithium

as LiBr may satisfy most of the requirements discussed in Section 2.G. Tables

II and III contain information on lithium and lithium bromide. This

information includes physicochemical, thermodynamic, and toxicological

characteristics, as well as references to the more pertinent federal

environmental regulations. Lithium bromide dissolves and speciates into Li

and Br in water, thus producing two tracers, one reactive (nonconservative)

and one nonreactive (conservative). LiBr is soluble in water at sufficiently

high concentrations for easy use in field tests (i.e., hundreds of /jg mL ).

Lithium does not appear to form complexes that can complicate its chemistry

and analytical identification. Additionally, its low potential for microbial

conversion increases its traceability in laboratory and field studies.

As in the case of the rest of the alkali elements, lithium has a single

electron in the outermost energy level of its atom. This electron, which is

easily detachable, causes an extremely reactive chemical character. Because

of the small size of its atom and ion, the behavior of lithium is transitional

between the behavior of the alkali metals and that of the alkaline earth

metals. These groups present a high ionic potential (ratio of ion radius to

ion charge), which implies that lithium is expected to be highly soluble and

more easily weatherable (leachable) than transition metals, aluminum cations,

and oxyanions (15).

General information on lithium is available from a number of sources.

Thermodynamic data include enthalpy, entropy, and free energy of formations

for lithium and lithium species (16, 17, 18). Information on the distribution

of lithium in the lithosphere and in specific geochemical systems has also

been documented (19, 20).

6
TABLE II

LITHIUM CHARACTERISTICS

Physicochemical

Atomic number 3

Atomic weight 6.941

Specific gravity 0.53 at 20°C (solid)

Hydrated radius 3.4 A

Ionic radius 0.68 A

Heat of solution -17,500 cal g

Natural isotopes 6 (7.47. abundance), 7 (92.67. abundance)

Thermodynamic (Li ).

AG°f = -70.1 kcal mole"1 at 298.15K

AH°f = -66.6 kcal mole'1 at 298.15K

S° = 3.2 cal deg"1 mole"1 at 298.15K

Toxicity

• The lithium ion may injure kidneys, especially if sodium intake is limited.

• Effect of low concentrations on aquatic life is unknown.

• Waterfowl toxicity data: not available.

• Food chain concentration potential: none.

• CAS RN: 74 39-93-2, NIOSH No: OJ 5540000

Environmental Regulations

Lithium is not included in the Clean Water Act, the Resource Conservation and

Recovery Act, the Superfund Amendments Reauthorization Act or the Safe

Drinking Water Act. It is inventoried in the Toxic Substances Control Act.

Sources: References 6, 7, 8, 9, 10, 11, 12
TABLE III

LITHIUM BROMIDE CHARACTERISTICS

Phvsicochemical

Form

Molecular weight"

Melting point

Boiling point

Specific gravity

Solubility in 100 g water

White hygroscopic granular powder

86.85

550°C

1265°C

3.464 at 25°C

177 g at 20°C

202 g at 40°C

224 g at 60°C

Heat of solution

Hydration states

Six-fold coordination

11.4 cal mole" (water)

Mono, di, tri and penta hydrate

Bond length: 2.75 Angstrom

Thermodvnamic

4G°f = -94.95 kcal mole"1 at 298.15K

4H°f = -95.61 kcal mole"1 at 298.15K

S° = 22.9 cal mole"1 at 298.15K

Toxicitv

LD50 = 1,680 mg kg

-1 (tests with mice, subcutaneous)

• Large doses may cause CNS (central nervous system) depression. Chronic

adsorption may cause skin eruptions and CNS disturbances because of

bromide. May also cause disturbed blood electrolyte balance.

• CAS RN: 75 50-35-8; NIOSH No: OJ 5755000

Environmental Regulations

Lithium bromide is not included in the Clean Vater Act, the Resource

Conservation and Recovery Act, the Superfund Amendments and Reauthorization

Act (lithium chromate, lithium hydride and bromine are included), or the Safe

Drinking Vater Act. It is inventoried in the Toxic Substances Control Act.

Sources: References 6, 9, 10, 11, 12, 13, 14
Sorption information for lithium on soils and rocks is scarce. A survey

of the literature indicates a lack of pertinent investigations. The survey

used computer searches to inventory journals in the fields of environmental

science or engineering, soil chemistry, and geochemistry. This lack of

success may be because lithium is not an element of concern in agricultural

production and is not considered a contaminant according to environmental

regulations. Two references (21, 22) deserve mention because they constitute

recent summaries on the sorption of inorganic elements by materials of the

subsurface environment. The first summary (21) reviewed literature from

approximately 500 papers on cation exchange in soil systems. Selectivity

coefficients and estimated thermodynamic parameters were compiled for soils

and soil components in well-defined systems. Lithium was reported only as the

resident cation of Li-clays in exchanges with alkali and ammonium ions NH, in

solutions. The estimates of the excess free energy indicate that the exchange

favors the adsorption of all the ions over lithium. A second recent

bibliography was completed by the Energy Power Research Institute (EPRI) (22).

This bibliography contained over 350 references, published before February

1983, dealing with chemical and biological attenuation mechanisms for 21

inorganic elements; lithium was not included. This survey found that adequate

data exist to make quantitative estimates for only a few solutes and that

attenuation is expected to vary as a function of the chemical element and the

composition of the subsurface media. The above limited information on lithium

illustrates its lack of priority in sorption research.

Most available basic information on the adsorption of lithium by natural

adsorbents refers to its inclusion in studies to characterize differences of

behavior among ions. Investigations as early as 1922 showed low exchange of

lithium for barium and calcium in soils and high exchange of lithium for ions

9
with atomic weights higher than those of barium and calcium (23). Later

investigations (24) examined the influence of solution concentration and the

nature of the interacting ions on lithium adsorption. Selectivity sequences

are used to document the effects of ion characteristics or behavior on

adsorption preference of ions for an adsorbent. Such sequences included

valence, equivalent volume, polarizability, interactions with resident ions,

and complex formation.

Adsorption of lithium does not seem to involve a strong surface

interaction. For instance, some studies strongly suggest that lithium shows a

lower preference for natural ion exchangers than do the rest of alkali

cations, namely, sodium (NaT), potassium (K ), rubidium (Rb ) , and cesium

(Cs+)(25). Helfferich (26) reported that exchangers show the lowest

selectivity for lithium among most common cations. Other findings from

investigations with soils and tuff report a low adsorption of lithiurc (27,

28). Low adsorption can be an advantage for a reactive tracer because it will

result in lower retardation, which shortens breakthrough periods in field

tests.

The general order of preference of monovalent cations by smectites (29)

for the Group IA metal cations is

Cs+ > Rb+ > K+ ft NH4

+ > Na+ > Li+. (3.1)

This sequence indicates a greater attraction of less hydrated cations to the

interlayer of smectites. The less hydrated cations can more closely fit the

cavity of the smectite six-membered tetrahedral rings. The sequence is

explained at the molecular level (30) by the principle of hard and soft acids

10
and bases. Lithium is the hardest acid in the selectivity sequence, so it has

less ability to exchange its solvent water molecules for the oxygen ions (soft

base) in surface functional groups than do softer acids such as cesium.

A general selectivity sequence of most common cations by general-purpose

cation exchangers is the following (26):

B a2 + > Pb2 + > Sr2 + > Ca2 + > Ni2 + > Cd2+ > Cu2 + > Co2 + > Zn2^ > Mg2 + ,

> UD2

2 + > Tl+ > Ag+ > Cs+ > Rb+ > K+ > NH4+ > Na+ > Li+, (3.2)

This selectivity shows lithium with the lowest preference. In addition,

lithium is also the least strongly held cation on synthetic zeolites, compared

with most of the other alkali elements and with alkaline earth elements.

Eisenman (25) developed the concept of "equivalent anion" to explain

relative bonding strengths of cations in various types of exchangers. From

the combination of cation size, cation charge, "equivalent anion," and

hydration energies for the cations, predictions for the bonding energies of

the alkali elements were made for natural exchangers. The predictions,

expressed as free energies, compared fairly well with experimental

measurements. The analysis predicts the bonding energies of all alkali ions

to clays, zeolites, and feldspars. It predicts lithium to be the least

adsorbed ion in the presence of sodium, potassium, cesium, or rubidium.

The limited current toxicological information for lithium bromide

indicates that toxicity to aquatic life at low lithium concentrations has not

been demonstrated and that bioaccumulation in food chains is not expected.

The absence of regulatory concern in the major environmental acts suggests

that the use of lithium as a tracer should be feasible. This feasibility

11
could be ensured by the use of low concentrations and by effective recovery of

injected solutions. Of all the pertinent Federal acts, only the Toxic

Substances Control Act (TSCA) includes lithium as part of an inventory.

Lithium is not included in the 129 priority toxic pollutants (31). Although

regulations do not specifically address lithium, it has been known to occur in

groundwater, as reported by the Office of Technology Assessment (32).

Critical to the constraints set by regulations is the consideration of

groundwater quality standards defined by both State and local regulations in

Nevada that may apply to the Yucca Mountain area. The role of State and local

regulations is not discussed in this study.

Lithium in aqueous solutions can be determined by several conventional

analytical techniques. Of these (33, 34), spectroscopy (e.g., atomic emission

spectroscopy) and chromatography (e.g., ion chromatography) offer competitive

analytical costs and low limits of detection. Limits of detection can be at

least within the parts per billion range (ppb) but can be improved by

concentration techniques. The background concentration of lithium in J-13

water is low (about 0.05 fig mL ) compared with an operational range at least

two orders of magnitude higher. The cost of lithium bromide is low enough not

to be of any importance in tracer selection.

In summary, lithium as LiBr appears to be an excellent candidate tracer

for hydrogeochemical investigations in Yucca Mountain because of its stability

and weak adsorption. It may show enough adsorption to simulate the migration

of weakly reactive tracers in the subsurface. This low degree of sorptivity

has been demonstrated in intermediate-scale (caisson) experiments conducted

with unsaturated and saturated Bandelier Tuff (28). Estimates for lithium

retardation factors are slightly greater than one (up to about 1.3) when

experimental breakthrough curves (within 6 m of traveling distance from the

12
source) are fitted to a one-dimensional advective-dispersive equation (28).

Simultaneously, lithium may be more acceptable by regulatory agencies for use

in groundwater studies than other tracers, is detectable in the fig I range

by conventional analytical equipment, and is inexpensive. Currently available

equipment allows adaptation to continuous-flow monitoring, which speeds up and

improves the characterization of breakthrough profiles in the field.

4.0 MATERIALS AND METHODS

This section describes the Prow Pass samples and the J-13 well water used

in all of the investigations. Information about experimental procedures and

the application of geochemical modeling to experimental design is also

presented in this section.

4.1 Prow Pass Samples and J-13 Vater

Prow Pass material used in these experiments consisted of cuttings

collected from drill hole UE-25p#l about 630 m east of the C-wells complex.

Fifteen sets of cuttings from depths between 1800 and 1950 feet (549 and

594 m) were selected because they represent the Prow Pass Member, which is the

first geological barrier to radionuclide migration in the saturated zone (35).

The general mineralogical composition of these samples is dominated by

feldspars, quartz, and kaolinites, with small quantities of smectite, mica,

and hematite (36). An analysis of a washed sample of cuttings (see next

paragraph) showed larger percentages of feldspars, quartz, and cristobalite,

with small quantities of smectite and hematite (37). This difference cannot

be explained yet, but it may be related to variability of sampling. Compared

with other cuttings from the drill holes in the C-wells area, these samples

appeared to have the simplest mineralogic composition, helping to minimize

13
uncertainty in the laboratory but reducing the representativeness of the

results for field projections.

The 15 samples of cuttings were washed with distilled water and

composited to form sufficient material for the experiments. During drilling,

the cuttings may have become contaminated with overlying rock materials and

drilling material residues and additives that would interfere with the

experiments. Ass much of the contaminating residue and additives as possible

was removed by suspending the cuttings in distilled water and gently sonifying

and decanting the fines after a period of settling. Thirty such treatments

were necessary to remove the fine materials believed to contain the drilling

contaminants.

The Prow Pass material was then ground with a ceramic pulverizer to pass

a 500-fim stainless steel sieve. The ground material was conditioned with

eight successive J-13 water washes; key chemical constituents of the washes

were monitored for completeness of conditioning. Table IV summarizes the key

constituents of the J-13 water as collected and after the first and eighth

24-h equilibrations with treated Prow Pass samples. Based on the limited

change over the 8 days of treatment, it was concluded that pseudo-equilibrium

had been reached within the first 24 h of contact time. The data from the

eighth 24-h equilibration represent the background composition and are used as

a reference for experiments with J-13 well water and Prow Pass materials.

The <500-//m sample was used in all the experiments. Characterization of

the <500-/im fractions is given in Table V and includes specific surface area,

ion exchange capacity, mineralogy by x-ray diffraction, and particle size

classification.

Specific surface area was measured by three methods that gave different

results, as shown in Table V. The Brunauer-Emmett-Teller (BET) method

14
TABLE IV

J-13 VATER BEFORE AND AFTER EQUILIBRATION

VITH PROV PASS MATERIALS {fig mL" *)

Element

Al

B

Ba

Ca

Fe

X

Li

Na

Si

Sr

Cl

P O4

so4

HCO3

pH

Original

J-13

Vater

<0.03

0.13

<0.001

11.3

0.02

5

0.040

<0.010

0.01

44

30

0.040

7

<2.5

19

124

7.2

First

24-h

Equilibration

0.47

0.13

0.02

13.5

0.05

3

0.09

0.79

0.004

50

23

0.015

8

<2.5

23

~

b

"

b

Eighth

24-h

Equilibration

0.25

0.13

0.003

13.1

0.04

3.0

0.05

1.2

0.005

42.0

27.0

0.020

7

<2.5

19

b

b

C-wella

11

2

0.11

0.38

55

25

0.044

7

22

142

7.8

aSource: Reference 38.

Not analyzed.

15
TABLE V

PHYSICOCHEMICAL CHARACTERIZATION OF PROV PASS

TUFF SAMPLES (<500 fim) USED IN THE INVESTIGATIONS

Property Measurement

2 -1

Specific Surface Area (m g" ):

Quantachrome3, Brunauer-Emmett-Teller

Microtrac

Ethylene glycol monoethyl ether

Cation exchange capacity (meq 100 g" ):

Na+ acetate (pH 8.2)

Exchangeable cations (meq 100 g" ) :

3.46

0.19 ± 0.06

0.26 ± 0.12

16

C a2 +

M g2 +

Na+

K

+

Li+

X-ray diffraction (7i):

feldspar 60±7

cristobalite 15±1

hematite 1±1

Particle size classification |

sand 96

NH. acetate

(pH 7.0)

14

0.64

4.2

1.1

NDb

[7,)C:

silt 4

Na acetate

(pH 8.2)

7.2

0.44

1.8

0.0068

quartz 22±2

smectite 1±1

clay <0.3

aThis estimate was performed by Quantachrome Corporation (Syosset, NY) with a

quantasorb Jr.

bND - Not detected.

U.S. Department of Agriculture classification scheme.

16
measures the amount of nitrogen gas required to complete a monolayer of

nitrogen molecules absorbed by the exposed surface of the particle. The area

was estimated to be 3.46 m g . The ethylene glycol monoethyl ether (EGME)

method, similar in principle to the BET method, gave results lower than those

from the BET method (0.26 m g ) . This is understandable because the

adsorbing component, EGME, is much larger than the nitrogen gas molecule and

2 -1

cannot penetrate the small pores accessible to nitrogen. The 0.19-m g

value obtained with the Leeds and Northrup Microtrac is lower than that of the

EGME method although not significantly different, and is obtained during

measurement of particle size distribution using laser-based light reflectance.

The mean particle diameter of the ground samples was estimated by the

Microtrac to be about 50 pm. Assuming smooth spherical particles, the minimum

specific surface area calculated for 50-fiia particles at a density of 2.5 g

- 3 2 1

cm and 0.5 packing fraction is 0.05 ra g" . The choice of the value of

2 -1

surface area to be used in calculations will be between 0.05 and 3.46 m g

and will depend on the requirements of the specific computations.

Cation exchange capacity and exchangeable cations were measured on the

Prow Pass materials with NH.+ (pH 7.0) and Na+ (pH 8.2) as exchanging cations

in an acetate buffer system. Exchangeable cations were recovered upon

treating the NH.+-saturated Prow Pass material with Na+ acetate and the

Na+-saturated Prow Pass with NH4

+ acetate. Particle size classification of

the prepared Prow Pass material was determined by sieve analysis for fractions

greater than 44 /tm and by a Micromeritics Sedigraph 5000D Particle Size

Analyzer for the smaller fractions.

Vater from well J-13, a natural groundwater, was the primary solution.

This easily available water has been used as a standard water in sorption

tasks for the Yucca Mountain Project (YMP). Synthetic waters are the choice

17
for development of fundamental information for individual minerals and

tracers; however, natural groundwater was selected in an attempt to simulate

field conditions more closely and to meet time and resource limitations.

C-wells waters were considered but were not available for these

investigations. The composition of the J-13 water is not greatly different

from that of the C-wells water and thus should not affect results from these

laboratory investigations. Key components of J-13 and C-wells waters are

compared in Table IV. Before experimental use, the water was filtered to

<0.05 urn in order to remove potential colloidal particulates.

4.2 Procedures

Detailed procedures (DPs) have been formulated according to los Alamos

National Laboratory Quality Assurance Documents for the Yucca Mountain

Project, No. 88, Volumes I, II, and III, 1988. These DPs describe sorption

experiments, or activities supporting those experiments, that are being

performed in the assessment of tracers for the C-wells project. These

procedures were derived or modified from peer-reviewed published procedures.

Appendix A describes instrumentation used in the investigations.

4.2.1 Adsorption Kinetics

Two types of kinetics studies were performed: batch tube studies to

define minimum equilibration times; and controlled reactor studies to collect

data for (a) evaluating the role of film transfer and internal diffusion in

the laboratory experiments and (b) estimating activation energies.

The batch-tube method used 50-mL polyallomer centrifuge tubes with 2.0 g

of Prow Pass material, which was conditioned by mixing for 24 h with 38 ml of

J-13 water. After conditioning, 2 ml of tracer solution was added to each

tube, and mixing and timing were started immediately. The filled tubes were

18
mixed continuously by tumbling in a modified Patterson-Kelley blender. Three

replicates for each sampling time were maintained at a solid-to-liquid ratio

of 1:20 and at a controlled temperature of 38°C (±2°C) for the duration of the

experiment. The sampling times of 1 min, 0.5 h, 8 h, 24 h, 48 h, and 96 h

were expected to cover the time necessary for the system to attain

equilibrium.

Sampling involved centrifuging the tubes for 11 min at a relative

centrifugal force (RCF) of 900 and then filtering the supernatant through a

0.45-/im syringe filter. The sample was then split into two 20-ml polyethylene

vials. One vial was used for pH measurement and the other was acidified to 1%

nitric acid, stored at 4 C, and chemically analyzed. During sampling of the

first batch, bacteria growth was found in the tubes, so all subsequent

experimental materials were sterilized in a steam autoclave before being used

in the sorption experiments.

For the controlled reactor studies, ground and sieved Prow Pass material

and J-13 water were added to a tared glass beaker to make the final

solid-to-liquid ratio 1:20 or 1:10. The beaker and its contents were

autoclaved and the contents were transferred to the controlled reactor vessel

(a 500-ml glass kettle with baffles, a lid, and a mixing system with speed

control). Other adsorption experiments with the controlled reactors were

conducted at 25°C, 38°C, and 45°C, initial lithium solution concentrations of

15 and 75 /ig ml" , and at mixing levels of 700, 1000, and 1500 rpm; these

experiments extended over a period of 12 h with more samples withdrawn at the

beginning than at the end. As with the previous experiments, equilibrium was

reached within the first 2 h, confirming the adequacy of the 24-h standard

equilibration time. The reactor and contents were allowed to condition for

24 h at constant mixing and a temperature of 38 ± 2°C.

19
During mixing, an appropriate volume of tracer was added to the reactor;

reaction timing started immediately. Samples were taken by withdrawing

suspension from the reactor and filtering through a 0.45-/jm syringe filter.

Samples were acidified to 17, nitric acid, stored at 4°C, and chemically

analyzed. The pH was measured on a sample withdrawn from the suspension

before addition of the tracer and again after the last sample was taken.

4.2.2 Desorption Kinetics

Desorption kinetics was evaluated only for certain adsorption

experimental conditions. The desorption method was basically the same for the

batch tube and the controlled reactor studies; exceptions are noted below.

J-13 water was used as the desorbing solution. Experimental conditions, for

example, temperature, were maintained the same as in the adsorption step.

After the adsorption period in the batch tubes, the tracer solution was

removed by centrifuging and decanting. The tubes were weighed and the amount

of the entrained solution was determined. Samples of solution removed from

the tubes were collected and analyzed to determine the amount of the entrained

tracer. The solution phase in the controlled reactor was removed by vacuum

filtration. The solids were washed twice with distilled water to remove much

of the entrained nonsorbed tracer. A sample of the last wash was retained for

pH and chemical analyses to determine the amount of tracer remaining in the

reactor solution.

An amount of J-13 water was added to the tubes or to the reactor so that

the solid-to-liquid ratio was maintained. Timing and mixing were started

immediately after addition of the J-13 water.

Samples from the batch tubes were split as in the adsorption stage for pH

and chemical analyses. Samples were collected from the controlled reactors in

20
the same manner as in the adsorption stage; pH was measured on the last sample

collected. Sampling times were selected to monitor desorption kinetics for

periods up to 48 h for the batch tubes and 96 h for the reactors.

4.2.3 Equilibrium Adsorption

Equilibrium experiments were performed at 25°C, 38°C, and 45°C, with up

to ten initial tracer concentrations ranging from 1 to 2000 fig ml" . Section

4.2.1 describes the basic setup and the general procedure for both adsorption

and desorption. The main difference between the kinetics and equilibrium

experiments is that sampling in equilibrium experiments was only at the

beginning and end of the equilibration period. The typical sampling time for

equilibrium studies was 24 h after addition of the tracer.

4.2.4 Equilibrium Desorption

Desorption equilibrium was evaluated only for certain equilibrium

conditions. J-13 water was used as the desorbing solution. Section 4.2.2

describes the setup and procedure followed for equilibrium desorption.

4.2.5 Potentiometric Titration

Prow Pass material was suspended in electrolyte solutions of 0.005 or

0.1 M NaC104 in a ratio of 2 g solids to 40 g electrolyte. A second series of

samples was prepared in the same manner, but the electrolyte solutions

contained 900 fig ml" lithium as LiBr. Each sample was duplicated and the

experiment was conducted at 38°C. To each sample a small amount of

standardized 0.25 M HC104 or 0.25 M NaOH was added; treatments ranged from 0

21
to 3000 //L. The samples were mixed by tumbling for 6 h and were then

centrifuged, and pH was measured directly on the clarified supernatant.

Concurrently, a separate set of electrolyte samples was prepared similarly but

without Prow Pass solids. The pH measurements on these samples were used as

the reference in the following calculation to estimate the net adsorbed charge

(//moles m ) :

sQ = k(AH-AOH) or (4.1)

s0 = k(W a - [OH] - [H] + [OH] ) , (4.2)

where

S = net adsorbed charge (//moles m" )

AH = the amount of the added H+ consumed, //moles mL" ,

AOH = the amount of the added OH" consumed, //moles mL ,

[B] = the concentration of protons remaining after reaction with the

solid, //moles mL ,

[OH] = the concentration of hydroxide remaining after reaction with the

solid, //moles mL" ,

[H]r = the concentration of protons remaining in the electrolyte not

reacted with the solids, //moles mL ,

[0H]r = the concentration of hydroxide remaining in the electrolyte not

reacted with the solids, //moles mL" , and

- 2 k = system constant, mL m .

4.2.6 Electrophoresis

Electrophoresis refers to the movement of charged particles relative to a

stationary solution in an applied potential. The pH at which a colloid is

22
electrokinetically uncharged is referred to as the zero point of charge (ZPC).

If the ZPC is displaced by the addition of a tracer, then chemical sorption is

indicated; if not, then physical sorption is indicated. Electrophoretic

mobility of colloidal suspensions is used to determine the ZPC.

Electrophoretic mobility (EM) is a measure of the velocity of a colloid

in response to an electric field and is defined as the colloid velocity in

micrometers per second divided by the strength of the electrical field in

volts per centimeter. An EM run consists of timing the migration of a number

of particles over a measured distance under an applied voltage. Measurements

of EM were made with a Zeta-Meter 3.0 System.

The samples used for EM were the same ones used in the potentiometric

measurements, Section 4.2.5. The solids were resuspended in water and then

allowed a minimum of 10 h to settle. A portion of the sample (e.g., 1 mL)

that contained the desired particle size range (e.g., <2 pm) and proportion of

solids was retrieved from the solution after 10 h and placed in a separate

container. The remaining sample was then centrifuged at an RCF of 900 for

approximately 10 min to separate the majority of the particles from the bulk

liquid. The clarified liquid was then added to the 1 ml sample. This is

essentially the-method of reconstitution described by the manufacturer of the

Zeta-Meter 3.0.

Four samples were prepared by vacuum filtration through filter paper with

a pore diameter of 8 fim. This method proved to be time consuming, however,

and reconstitution was used for the remaining samples. EM results were

obtained on either reconstituted or filtered duplicate suspensions in which EM

values compared favorably: -2.578 with -2.563 and -2.641 with -2.743 /im cm per

volt second.

23
4.2.7 Abrasion Effects

Tumbling (or stirring) suspensions (tube or reactor) of soils and

geological samples may cause abrasion that could change the particle size

distributions and create new sorption surfaces or active sites. The degree of

abrasion of Prow Pass was evaluated by measurement of particle size

distributions on mixed and nonmixed materials. Data for the average mesh

sizes of 774 through 31 pm were applied to a model for particle size

distribution (39) that was used to fit the equation

Y = 1 - exp (x/xo )

n , (4.3)

where

Y = cumulative fraction of material by weight less than size x (x in

Urn),

x = characteristic particle size, fim, and,

n = constant specific to the sample and breakage conditions.

Linearization of Equation (4.3) followed by linear regression provided a

goodness of fit and an estimate of the constants. Table VI summarizes those

estimates and regression statistics. An F-test comparison of the regression

for the sample before tumbling and that after tumbling indicated that the two

size distributions were significantly different at the 99.57. confidence level.

Thus, reactor experiments may affect distribution of sizes, but further

evaluation is needed to estimate the variability in tracer response relative

to different particle size distributions.

24
TABLE VI

REGRESSION AND COMPARISON BETVEEN SIZE DISTRIBUTIONS

BEFORE AND AFTER TUMBLING

Statisticsa Sample before Tumbling Sample after Tumbling

R

2 0.945 0.978

C.V. 36.400 65.370

n 2.190 1.749

xQ 194.98 186.21

F-test F-calculated = 33.50 > F-tabulated (at 99.57. confidence

level) = 6.27; then the distributions are significantly

different.

a R = index of determination; C.V. = coefficient of variance; n, x =

constants in Equation (4.3).

25
4.3 Models

Evaluation of the suitability of lithium as a tracer of physical sorption

in field tests in the C-wells saturated zone included modeling with isotherm

and thermodynamic models. The isotherm models were used to determine the

extent of sorption and to provide information for the thermodynamic models.

The thermodynamic models were ased to estimate energies associated with the

mechanism of sorption.

4.3.1 Isotherms

Isotherms have been derived and used to represent sorptive behavior in a

variety of disciplines (2, 3, 40, 41). Three of the more commonly used

isotherms are the Linear, Langmuir, and Freundlich. These three models plus

the Modified Freundlich isotherm, a general isotherm from which the others can

be derived, were fitted to the equilibrium lithium concentrations.

The simplest and most widely used of the equilibrium sorption isotherms

is the linear relationship

S = KdC , (4.4)

where

S = concentration of solute sorbed by the solid,

C = concentration of solute in solution, and

K, = distribution coefficient.

This expression is widely used in transport models to describe the

sorption of reactive solutes by solids. One limitation is that the maximum

quantity of adsorption is not included. The distribution coefficient K. is

26
the ratio of retention of solute by the solid to the solute in solution and is

assumed to be independent of concentration. This is not always the case, and

conclusions drawn from modeling based on assumptions of linear sorption

behavior may not be valid.

Langmuir developed a quantitative model that has also been widely applied

to describe experimental data (42). The Langmuir equation was derived for the

sorption of gases on a solid surface. Nevertheless, it has been extended to

include the sorption of solutes by solids. The basic expression takes the

form

c kbC u

S = jrp-flj , (4.

where

k, b = empirical constants.

Linearization of Equation (4.5) provides the following transformation to

be fitted to the experimental data:

C/S = (l/b)C + 1/kb. (4.6)

In this expression, k is a measure of the strength of the sorption bond and b

is the maximum amount of the solute that can be sorbed by the solid (40).

This isotherm is based on the theoretical assumption that the sorption sites

are homogeneously distributed relative to energy potentials.

The Freundlich isotherm has the form

S = KCN , (4.7)

27
where

K,N = empirical constants.

Estimation of the constants is possible by the logarithmic transformation

of Equation (4.7) to

log S = N log C + log K. (4.8)

This expression is also very popular in the literature because of the

flexibility of the exponential function to fit experimental data. The

equation is a better representation of heterogeneous behavior.

The Linear and Langmuir isotherms assume that the energy of adsorption is

the same for all active sites on the adsorbent surface. However, the

assumption fails in many cases because either pure mineral or multimineral

adsorption sites interact with solutes at different energies (heterogeneity).

These differences among site energies require the identification of those

energy distributions that characterize the heterogeneity of a particular

adsorbent/solute interaction. Then, equations such as the Freundlich isotherm

are better modeling alternatives.

Sips (43) introduced and discussed an isotherm that suggests a

Gaussian-like statistical function that could represent the distribution of

site/solute interactions. This isotherm is based on the assumption that

localized adsorption occurs without interaction among sites and was presented

as an expansion of the conventional Freundlich isotherm. Sposito (44),

following the derivation obtained by Sips (43) and using a Langmuir isotherm

to define site/solute interactions, derived a similar Gaussian-like

statistical function that is regarded as a log-normal distribution of a

variable that defines the relative affinity of a solute for a solid phase.

28
The isotherm, referred to as Modified Freundlich, can be expressed as

cs—

mamax 1 + Kj^C

where

S = maximum available exchange capacity of solid phase and

KD, p = parameters that define the overall solute/solid phase

interaction.

If this isotherm applies, a more comprehensive representation of the

heterogeneity of the adsorption is gained from the meaning of K^ and p. These

two parameters can be found by regression analysis of a given set of sorption

data on the following expression transformed from Equation (4.9):

log g S _ s = P log C + log (K/) . (4.10)

max

The parameter p has been described (44) as a measure of how sharply

peaked, about an average value, is the statistical function for the

distribution of surface-binding energies at equilibrium. This parameter has

also been described by Crickmore and Vojciechowski (45) as the spread of the

statistical function for the distribution of adsorption-desorption rate

constants. The parameter Kn has been implicitly related (44) to an average

"distribution coefficient," or an average adsorption energy or affinity.

Crickmore and Vojciechowski (45), on the other hand, define IL as the ratio of

the reaction rate constants that represent simultaneous /?-order

adsorption-desorption rates. Both parameters, P and K^, are temperature and

pH dependent.

29
It is important to note that Equation (4.9) is the general isotherm from

which common isotherms can be derived based on the following conditions:

Linear isotherms (/? = 1, Kj/H/ < < 1), the langmuir isotherm (/? = 1), and the

Freundlich isotherm (0 < /? < 1, K D V < < 1).

4.3.2 Thermodynamics

The thermodynamic parameters used to evaluate sorption mechanisms are the

equilibrium constant (K ) , the free energy of sorption (AG°), the enthalpy of

sorption (AH0), and the entropy of sorption (AS0). Thus, the equilibrium

constant for ion exchange is based on the law of mass action (26) and can be

written as

-

 ZB ZA

aA • an

a B * aA

for the reaction

zfiA + zAB = zfi A + zAB , (4.12)

where

A, B = ion species of the binary system in solution,

A, B = the ion species in the solid phase,

a., a.. = the activities of A and B, respectively, in the solution phase,

*A' ^B

 = t^ie activities of A and B, respectively, in the solid phase, and

zA, zR = the valences of A and B, respectively.

30
Equation (4.11) can be expressed in terms of the following modified rational

equilibrium constant:

2 B

=

 Kr \

x

 Zfi C %k 7 H

such that I = \ • -V • -V-i (4-

14)

v

 A r B -v B

X B CA ^A

where

7 , 7g = the activity coefficients of A and B, respectively, in the

solution phase,

7», 7g = the activity coefficients of A and B, respectively, in the

solid phase,

C^, CB = the nolar concentrations of A and B, respectively, in the

solution phase, and

*A' ^B

 = ^ e e Quiva le n t fractions of A and B, respectively, in the solid

phase.

Therefore, the thermodynamic equilibrium constant can be expressed as follows

(26):

lnKe =

where

XR = z.n. + *-n_ (4

-

16)

31
and

n», n« are moles of A and B, respectively, in the solid phase.

The integral in Equation (4.15) can also be expressed in terms of its

components:

Q (^ Kr ) dxB = zfi jl In CA dxfi - zA j* In

A fi A j

+ ZA fQ

 ln GB

 diB • ZB fQ

 ln CA d*0 + ZA fQ ln 7B

 diB " ZB j j

 ln

 U diB

(4.17)

The integral in Equation (4.17) can be solved by several means, for example,

graphically or analytically.

The parameters of the Modified Freundlich equation can be substituted

into Equation (4.17) and the thermodynamic equilibrium constant may be

evaluated, if the components of the lodified Freundlich equation are converted

into the same units as those of Equation (4.17).

The Gibbs free energy of sorption AG can be determined from the

thermodynamic equilibrium constant (45) through the equation

AG° = -RT ln I , (4.18)

where R is the gas constant and T is the absolute temperature.

The enthalpy of sorption can be determined from the van't Hoff equation

(18, p. 348)

e _ AH ,, iO^

32
Integration ol Equation (4.19), with respect to temperature, gives

AH0 = In (KeT2 / KeT1 ) . I/[(T2 - T^/T^ ] . (4.20)

Equation (4.20) indicates that the equilibrium constant must be obtained at

two or more temperatures. If the equilibrium constant is obtained at more

than two temperatures, then AH0 can be determined from a plot of In Kg vs. j.

The slope of the plot is equal to -AH°/R.

The entropy of sorption AS0 can be determined through the relation

AG° = AH0 - TAS° . (4.21)

The thermodynamic equilibrium constant for sorption in which ion exchange

is not considered can be expressed as

Ko = If '

where

ai, a. are the activities of A in the solid and solution phases,

respectively.

Equation (4.22) can be expressed as

KQ = > A , (4.23)

33
where

7», 7. are the respective activity coefficients of A in the solid and

solution phases.

At infinite dilution, 71 and 7. equal unity. Thus the thermodynamic

equilibrium constant can be estimated from the values of C. and C. at infinite

dilution. A simpler technique is also available to estimate C. and Ci at

infinite dilution and to calculate an overall equilibrium constant between the

concentrations in the solid and in solution of the species or compound of

concern (46, 47, 48).

4.4 Pre-experimental Geochemical Modeling

The development of geochemical codes to predict chemical equilibria among

aqueous, solid, and gaseous components offers a new design tool for

investigators of sorption phenomena (49). The purpose of geochemical modeling

was fourfold:

a. to evaluate the; effect of lithium bromide addition on the chemical

2+ 2-

equilibria of major ions, e.g., Ca and C(L ;

b. to predict possible precipitation or dissolution of the major

mineral components of the Prow Pass sample and other components that

could be present in the field or that could appear as precipitates

during experiments;

c. to predict the effect of pH on the precipitation or dissolution of

the major mineral components of the Prow Pass samples; and

d. to investigate the distribution of the lithium ion among various

expected lithium compounds, e.g., LiOH, HJCQ*.

This study has used the geochemical code PHREEQE (50) as an aid in the

design of laboratory batch sorption experiments. This code was selected

because it is well documented and is in the public domain. The code includes

34
models for precipitation, dissolution, and adsorption, and is supported by a

thermodynamic data base that is easily expanded by the user.

The simulations used the composition of the J-13 well waters and focused

on the mineralogical components of the Prow Pass samples and other possible

precipitates that could appear during the experiments. The components, in

order of composition by weight, were feldspar, quartz, cristobalite, hematite,

and montmorillonite. Others were goethite, barite, calcite, analcime, and

magnetite.

The results of the simulations at 38 C predict that the addition of LiBr

in concentrations up to 2000 /ig ml" lithium does not significantly change the

equilibria of the major cations, Ca

 +, Mg +, Na+, or the major anions, SO. ,

CO, , and Cl • The addition of LiBr to J-13 well water is not expected to

affect the potential precipitation and solubility of Prow Pass and other

minerals. Also, added lithium is not expected to show an effect when the pH

is varied from 7 to 9.

The evaluation of the distribution of lithium among different species

suggests that >997. lithium will be present as the free ion Li+ between pH 7

and 9 (Table VII). The species studied were liDB, LiSO4~, Li2SD4, LiCl,

LiML, LinCOo, and LiBr. The equilibrium constants for these species were

derived from reported free energy values (18) and were included in the

thermodynamic data base of PHREEQE.

The conclusions from these geochemical simulations permitted a decrease

in the number of chemical analyses of ions in the experiments. The

simulations also supported the use of total lithium as a good measure of Li+

for lithium adsorption.

35
TABLE VII

PREDICTIONS FOR LITHIUM DISTRIBUTION IN PROV PASS AND J-13 VATER

Species

Li+

LiOH

LiSO4"

Li2SO4

LiCl

LiNOg

Li2CO3

LiBr

ADSORPTION EXPERIMENTS AT 38°C (Li

pH

1.4

6.6

3.3

7.0

1.4

2.2

4.4

8.4

7

X

X

X

X

X

X

X

X

10" 1

10"

 8

10'5

. 7

10"

 5

10"6

10"8

-4

Concentration

pH 8

1.4 x

4.6 x

3.3 x

7.0 x

1.4 x

1.1 X

2.9 x

8.4 x

= 2000 fig mL"

(mole L"l)

io-i

10"7

10"5

10"7

-5

10"

 5

_7

-4

iA s

pH

1.4

1.4

3.3

7.0

1.4

1.2

8.0

8.4

LiBr)

9

x 10" 1

xlO"6

x 10"

 5

x 10"

 7

x 10"

 5

x 10"

 5

x 10"7

X10-"

36
5.0 RESULTS AND DISCUSSION

This section presents the experimental results and their analysis and

interpretation. Emphasis is on modeling of the lithium data by isotherms and

estimation of thermodynamic constants. These constants--the relative behavior

between adsorption and desorption, and potentiometric studies--are used to

classify the controlling sorption mechanism as either physical or chemical.

5..t Kinetics Experiments

The kinetics experiments had two main objectives: first, to determine

minimum equilibration times; second, to provide data for (a) evaluating the

role of film transfer and internal diffusion and (b) estimating activation

energies.

Batch-tube kinetics experiments conducted at 38°C provided a first

measure of the minimum equilibration time needed for adsorption. Two initial

lithium solution concentrations, 5 and 250 fig ml , were used to estimate an

equilibration period. Although equilibrium was reached rapidly (about 2

hours), a 24-hour equilibrium period was selected as a standard for all

adsorption equilibrium experiments.

Desorption kinetics was evaluated for each of the above adsorption

experiments. The results indicate that most desorption ,(-7570 occurs within 6

hours, with additional desorption occurring through the 96-hour sampling time.

An analysis of the kinetics data from the controlled reactors has not

been performed for this report. The quality and quantity of the kinetics data

have not been evaluated for usefulness in estimating rates for film transfer,

particulate diffusion, or surface reaction. A general inspection of the data

suggests that it may be possible to model adsorption kinetics. However, the

lacK of sufficient observations during the first 12 hours makes the desorption

37
data inadequate for modeling of rates. Both adsorption and desorption

kinetics data appear to be of better quality for the controlled reactors than

for the batch tubes.

5.2 Equilibrium

Two sets of equilibrium experiments were performed at three temperatures

(25°C, 38°C, and 45°C; 38°C is the average temperature of the Yucca Mountain

aquifer water). One set was performed over an initial concentration range of

1 to 2000 fig mL and at a solid-to-liquid ratio of 1:20. The amount adsorbed

is based on the difference between the initial concentration and the

equilibrium concentration. Because adsorption was low, the difference in

concentration was minimal relative to the analytical error of concentration

measurements. In order to minimize the effect of the analytical error, the

solid-to-liquid ratio was increased to 1:10 (to increase the number of

potential adsorption sites per volume of tracer) and the initial concentration

range restricted to 1-150 fig mL to enhance the difference in concentrations

compared with the analytical error of concentration measurement. The other

set of experiments was performed over an initial concentration range of 1 to

150 fig ml" and at a solid-to-liquid ratio of 1:10. These experiments were

performed to determine the extent of sorption and to select suitable isotherms

that can be applied to transport modeling. Also, thermodynamiij parameters

were calculated from the sorption data at the three temperatures to help in

differentiating between physical and chemical sorption.

5.2.1 Sorption Calculations

The amount of lithium sorbed to the Prow Pass solid from J-13 well water

spiked with concentrations of lithium was determined from the difference in

38
concentration of lithium in the solution before equilibration and that in the

solution concentrations after equilibration. Preliminary evaluation of the

sorption data shows large variability at the high solution concentrations

after equilibration. The variability is attributed to experimental conditions

and to the error associated with the analytical data. For example, the

difference between the initial concentration of lithium and that after

equilibration can be shown to be within the analytical error of the measured

concentrations for the experimental conditions 1000 /igLi mL" initial

concentration, 20 mL of solution, 1 g tuff, 1120 fig Li g" maximum sorption

(CEC), and 37, analytical error. Thus the variability associated with that

difference is very large.

A different procedure, used to determine the amount of lithium iorbed, is

based on the assumption that the amount of lithium adsorbed is equal to the

amount of cations desorbed from the solid. The data obtained by the two

procedures are given in Appendix B (Tables B-I through B-III). The values

obtained by calculating differences in lithium concentration are higher at low

concentrations of lithium than those obtained by calculating the differences

in summed cations. Small differences existed between initial and equilibrated

concentrations of some of the individual cations. Those differences were well

within analytical error; thus large errors could occur. Some calculated

differences gave negative values. In those cases a sum of differences in

concentrations resulted in a lower summed concentration of desorbed cations.

The difference in lithium concentrations was used in the low-concentration

39
range and the difference in summed cations was used at the high-concentration

range for the best estimate of lithium sorbed.

5.2.2 Isotherm Evaluation

The four isotherms, Linear, Langmuir, Freundlich, and Modified

Freundlich, were used to model the two sets of equilibrium experiments

discussed above. Linear, langmuir, and Freundlich were used because of their

widespread use in modeling sorption and in the coupling of the sorption

isotherms to transport models. The fourth isotherm, the Modified Freundlich,

was used because of its theoretical implications. Appendix C compiles all the

data from the adsorption and desorption experiments used in the fitting of the

four isotherms.

The statistical data on the modeling of sorption by the four isotherms

indicate that the sorption data based on best estimates give the better index

of determination (R ) and coefficient of variation (CV). All four isotherms

o

gave R of >0.80. The CV were 55 percent or better. The Freundlich and

o

Modified Freundlich isotherms gave the best R and CV values, with the

Freundlich giving slightly better CV values. Detailed statistical and

isotherm parameter data are given in the Tables in Appendix D. Figures 1

through 6 show the results of modeling the data with the Modified Freundlich

isotherm. The regression of the best estimate data shows the best

variability. The modeling analyses indicate that the sorption of lithium can

be effectively represented by all four isotherms. However, the analysis of

the Modified Freundlich isotherm provides additional information on the

prediction of the extent and heterogeneity of sorption. This extent and

heterogeneity of sorption provides an insight into the transport of lithium in

40
X

a

&

3

0-

- 1 -

- 2 -

- 3 -

n

—

. o

—-

UObs.

U Pred.

Best Est. Obs.

Best Est Pred.

n

—i 1

a

-1 1

Log Cone.

2

mL~"')

Figure 1.

suspension

to 2000 fig

determined

based on a

estimate).

Observed and predicted adsorption of lithium on a Prow Pass

in J-13 well water at 25°C for an initial concentration range of 1

Li ml"1 and a solid-to-liquid ratio of 1:20. Adsorbed lithium is

in two ways: (1) based on measured lithium in solution (li) and (2)

combination of measured lithium and other cations in solution (best

Predicted lithium is based on the Modified Freundlich isotherm.

41
X

a

3 _

2

1 •

0-

-1 ••

2 -•

- 3

-1

D Li Obs.

—- U Pred.

O Beat Eat. Oba.

— Beat Eat. Pred.

o

Log Cone, (jiq m L

 1 )

Figure 2.

suspension

to 2000 fig

determined

based on a

estimate).

Observed and predicted adsorption of lithium on a Prow Pass

in J-13 well water at 38°C for an initial concentration range of 1

Li ml" and a solid-to-liquid ratio of 1:20. Adsorbed lithium is

in two ways: (1) based on measured lithium in solution (Li) and (2)

combination of measured lithium and other cations in solution (best

Predicted lithium is based on the Modified Freundlich isotherm.

42
V)

I

o

Q

2

1-

0 ••

- 1 -

- 2 -

- 3

O U Obs.

Li Pred.

O Best Est. Oba.

— Best Est. Pred,

- 1

Log Cone, {jjq mL~1~ )

1

Figure 3.

suspension

to 2000 ng

determined

based on a

estimate).

Observed and predicted adsorption of lithium on a Prow Pass

in J-13 well water at 45°C for an initial concentration range of 1

Li mL and a solid-to-liquid ratio of 1:20. Adsorbed lithium is

in two ways: (1) based on measured lithium in solution (Li) and (2)

combination ol measured lithium and other cations in solution (best

Predicted lithium is based on the Modified Freundlich isotherm.

43
I

en

I

2 -2+

o

o

1

•

o

——

Li Obs.

Lf Pred.

Best Est. Obs.

Best Est. Pred.

1 1 _

-1 0 1

Log Cone, (pq mL"

Figure 4. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 25°C for an initial concentration range of 1

to 150 /tg Li mL and a solid-to-liquid ratio of 1:10. Adsorbed lithium is

determined in two ways: (1) based on measured lithium in solution (Li) and (2)

based on a combination of measured lithium and other cations in solution (best

estimate). Predicted lithium is based on the Modified Freundlich isotherm.

44
I

x

a

XL

en

o

D Li Obs.

U Pred.

O Best Eat. Obs.

— Best Est. Pred.

Log Cone, (jiq m L ')

Figure 5. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 38°C for an initial concentration range of 1

to 150 fig Li mL*1 and a solid-to-liquid ratio of 1:10. Adsorbed lithium is

determined in two ways: (1) based on measured lithium in solution (Li) and (2)

based on a combination of measured lithium and other cations in solution (best

estimate). Predicted lithium is based on the Modified Freundlich isotherm.

45
I

V)

\

X

o

w

en

o

-1 •

—2-

- 3

D U Obs.

Li Pred.

O Best Est. Obs.

— Best Est. Pred

-1 1

Log Cone, (/ig ml_~ ')

Figure 6. Observed and predicted adsorption of lithium on a Prow Pass

suspension in J-13 well water at 45°C for an initial concentration range of 1

to 150 fig Li ml and a solid-to-liquid ratio of 1:10. Adsorbed lithium is

determined in two ways: (1) based on measured lithium in solution (Li) and (2)

based on a combination of measured lithium and other cations in solution (best

estimate). Predicted lithium is based on the Modified Freundlich isotherm.

46
laboratory column and field tests. A higher degree of heterogeneity {fl-value

in the Modified Freundlich isotherm approaches zero) implies that a wider

spectrum of retardation factors will occur in transport. This spectrum will

have an average extent of retardation as defined by the Kn-value of the same

isotherm. Consequently, the following analysis uses the Modified Freundlich

isotherm as a reference in predicting the behavior of lithium in transport.

The extent of sorption is related to any of the K parameters of the four

models, for example, K in the Freundlich isotherm and k in the Langmuir

isotherm. For a better understanding of the relative retardation of lithium

predicted by the four isotherms, the retardation parameters were normalized or

transformed to those of the linear isotherm, K., and the Modified Freundlich

isotherm, IL and /?.

The isotherm parameters K,, Kg, and 0 are given in Table VIII, along with

the transformations. The results indicate that all values of K. are 2 mL g"

or less; the Langmuir isotherm gives the highest values and the Freundlich

gives the lowest values. Retardation can be expressed by the following

equation

Rf = 1 + - p , (5.1)

where R^ is the retardation factor and is defined as the mean velocity of the

moving liquid relative to the mean velocity at which the tracer moves; />, is

the dry bulk density of the medium; and 9 is the volumetric moisture content.

In general, a K, of 2 or less indicates little sorption-caused retardation of

the tracer. Thus lithium appears to be a suitable tracer for the C-wells

field test because of low sorptivity.

47
TABIE VIII

A COMPARISON OF ESTIMATED PARAMETERS OF FOUR ISOTHERM MODELS FOR THE ADSORPTION OF

LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN INITIAL C^CENTRATION

RANGE OF 1 TO 2000 jag Li inL"1 AND A SOLID-TO-LIQUID RATIO OF 1:20

25°C 38°C 45°C

Linear

Iangnuir

Freundlich

Modified

Freundlich

0.43

2.0

3.3x10

0.98

-2

3.9X10

2.8X10

-3

3.0x10

8.9x10"

1.

1.

0.

0.

0

0

72

82

0.

1.

2.

0.

43

6

oxio"2

73

3.

2.

1.

6.

9x10 '

3xlO~3

8xlO~5

6xlO~4

1

1

0

0

.0

.0

.68

.77

0.

1.

1.

0.

27

2

0x10

33

-2

2.4X10

2.4X10

-4

-3

9.5x10

2.8x10

.-4

1.0

1.0

0.65

0.70

Transformations:

Linear: K

d

 = Kd

Freundlich: K K

1/N

'd S.

max

K

max

max

1/N

Langmuir: K. • Ids Modified Freundlich: Kd -
Based on theoretical considerations, the K« parameter is a measure of the

mean energy sorption of lithium, and the /? p?rameter i6 a measure of the

distribution or spread of individual energies about the mean. Thus under flow

conditions, IL is a measure of the sorption-caused retardation of the tracer

and 0 is a measure of the sorptive dispersion caused by the heterogeneity of

sorption; this dispersion is in addition to any hydrodynamic dispersion that

may occur. Thus the comparison of 1L and 0 parameter values in Table VIII for

the linear, Langmuir, and Freundlich isotherms (1 to 2000 fig Li mL ) can be

interpreted as follows.

1. The Freundlich isotherm underestimates retardation and overestimates

sorptive dispersion.

2. The Langmuir isotherm overestimates retardation and underestimates

sorptive dispersion.

3. The Linear isotherm underestimates both retardation and sorptive

dispersion.

The effects of overestimation and underestimation can only be inferred from

these analyses. Proper statistical discrimination analysis in combination

with column experiments is needed to identify the best isotherm under flow

conditions.

The statistical and modeling results for the concentration range 1 to 150

fig Li mL" and a solid-to-liquid ratio of 1:10 are given in Appendix D, Tables

D-V through D-IX, for the Linear, Langmuir, Freundlich, and Modified

Freundlich isotherms, respectively. The data are based on lithium analysis

and best estimates, as was the case in the range 1 to 2000 fig Li mL . The

results indicate that the statistics (R and CV) in general do not differ

greatly from the results for the l-to-2000-/jg-Li mL data set. Overall, the

best-estimate data, as determined from a combination of lithium data and the

49
summed cation data, can also be represented by the four isotherm expressions.

Table IX summarizes the estimated parameters for the four isotherms within

this concentration range. The parameters are also expressed in terms of K,,

Kp, and /?, in order to compare the expected outcomes of using specific

isotherms in transport modeling. As in the case of the l-to-2000-/zg-Li mL

data set, the interpretation given to these data is as follows.

1. The Freundlich isotherm underestimates retardation and overestimates

sorptive dispersion.

2. The langmuir isotherm overestimates retardation and underestimates

sorptive dispersion.

3. The Linear isotherm overestimates retardation and underestimates

sorptive dispersion.

A comparison of these results with those of the l-to-2000-/rg-Li mL" range

indicates that in both cases the Freundlich isotherm underestimates

retardation and overestimates sorptive dispersion. The Langmuir isotherm

model overestimates retardation and underestimates sorptive dispersion for

both cases. However, the overestimation of retardation appears significantly

greater for the 1- to-150- /ig- Li mL experiment than for the l-to-2000-^g-Li

mL experiment. The Linear isotherm overestimates retardation in the former

but underestimates retardation for the latter, even though the amount of

overestimation and underestimation appears to be small. Consequently, care

should be exercised when selecting an isotherm among several possible

alternatives, regardless of their relatively good correlation statistics.

5.2.3 Thermodynamic Parameter Estimation

Thermodynamic parameters were estimated for the lithium sorption of the

Prow Pass medium from J-13 well water for the concentration range of 1 to

50
TABLE IX

A COMPARISON OF ESTIMATED PARAMETERS OF FOUR ISOTHERM MODELS FOR THE ADSORPTION OF

LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN INITIAL

OMIC3ENTRATION RANGE OF 1 TO 150 M g Li iriL*"1 AND A SOLID-TO-LIQUID RATIO OF 1:10

25°C 38°C 45°C

K,

Linear

Langmuir

Freundlich

Modified

Freundlich

0

2

3

0

Transformations:

Linear:

Langmuir:

0

Kd

0

=

=

=

.87

.17

.7X10

.497

Kd

V

s!,

1

kb

k

1

-2

7.9x10 1.0 0.96 8.7x10

1.3X1O"2 1.0 2.06 1.2x10

3.6xlO~5 0.759 7.3xlO~2 6.6x10

4.5X104 0.777 0.806 7.3x10"

r

2

-5

1.0

1.0

0.831

0.852

1.24

2.77

3.7X10

0.662

-2

1.1X10

1.3x10"

3.3X10"

6.0X10"

-3

1.0

1.0

0.722

0.748

max

Freundlich: K,d

1/N

Smax max

1/N

Smax

N = &

Modified Freundlich:

Ln
2000 /ig li mL and a solid-to-liquid ratio of 1:20. The assumption in these

calculations is that lithium sorption can be modeled as pseudo-binary

ion-exchange sorption. During sorption, lithium replaced primarily calcium

and sodium ions. Typically, lithium was exchanged with calcium and sodium in

an equivalent ratio of 1.6:1 (Ca:Na) in the higher concentration region of

lithium and nearly the reverse in the lower concentration region. Therefore,

calcium and sodium are considered as a composite ion [ion B in Equation

(4.12)] in these calculations. The valence of the composite ion B was

estimated as follows.

At high concentrations,

1 f\ i

ZD = i—Ti~fi zn~ + T77~7t % » = 1.61 .

D l.+i.o ua l+i.o wa

At low concentrations,

1 R 1

Z B = 17+176 zNa + I+T78 zCa = 1>38<

Therefore average Zg is approximately 1.5. The integrated form of Equation

(4.18) was used to calculate the thermodynamic equilibrium constant.

e

 v D

+ zA (1 + vp -»-°) [In (-B;° + CB o ) - 1] - zA rp -

B-° [In C B o - 1]

CBo Tf> CBo

+ zA In 7B - Zg In 7A + zg In MA + zg In K^ , (5.2)

52
where

Zg = valence of the composite ion B;

z. - valence of lithium;

/? = isotherm parameter;

Cn = the initial concentration of composite ion B adsorbed expressed as

/jraoles B mL" solid;

Cg - the initial concentration of composite ion B in the solution phase

expressed as /anoles B mL" HgO;

r = solution-to-solid ratio expressed as mL H^O g solid;

p - solid density expressed as g solid mL" solid;

7B = (?Ca ^Na^ = activity coefficient of composite ion B;

7i = activity coefficient of lithium in solution phase;

1^ = molecular weight of lithium expressed as ftg Li /imole' Li; and

Kp = isotherm parameter expressed as mL jig Li;

The parameter values used to calculate the thermodynamic equilibrium constants

from Equations (4.19) through (4.22) are given in Table X. The estimated

values for the equilibrium constants (K ) , Gibb's free energies of sorption

(AG°), and enthalpy (AH0) are given in Table II. The results indicate that

the thermodynamic equilibrium constant decreases with an increase in

temperature, as does Gibb's free energy of sorption. The enthalpy of sorption

between 25°C and 38°C was estimated to be -5 kcal mole . However, the AH0

between 38°C and 45°C was estimated to be about -36 kcal mole . The -5 kcal

mole is more consistent with that expected with lithium, that is,

electrostatic or physical sorption. The 7°C difference between 38°C and 45°C

is small. Therefore, differences in equilibrium constants will be smaller

than when the temperature difference is great. In cases where small

53
TABLE X

PARAMETER VALUES FOR THE ESTIMATION OF A THERMODYNAMIC EQUILIBRIUM

CONSTANT FOR THE LITHIUM ADSORPTION ON A PROV PASS SUSPENSION IN

J-13 VELL WATER AT THREE TEMPERATURES FOR THE INITIAL CONCENTRATION

RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TO-LIQUID RATIO OF 1:20

25°C

38°C

45°C

0

0

0

0

.823

.775

.703

9

6

2

KD

.17x10"4

.90x10"4

.97x10"4

1

0.

0.

0.

Li

978

941

940

7

0.

0.

0.

Ca

787

783

781

0

0

0

7Na

.974

.939

.938

0

0

0

.876

.857

.856

zA = 1 ~p = 2.54 g solid mL"1 solid Cfio = 270.93 /zraole B mL solid

zfl = 1.5 r = 20 mL H20 g" * solid Cfio = 1.798 fimoles B mL"1 HgO

MA = 6.94 jig Li mole"1

Mfi = 33 (tg B fimole'1

54
TABLE XI

THERMODYNAMIC CONSTANTS ESTIMATED FOR LITHIUM ADSORPTION ON A

PROV PASS SUSPENSION IN J-13 VELL VATER AT THREE TEMPERATURES

FOR AN INITIAL CONCENTRATION RANGE OF 1 TO 2000 pg Li ml"1

AND A SOLID-TO-LIQUID RATIO OF 1:20

Ke

AG°

(kcal

AH0

(kcal

mole" )

mole" )

25°C

0.001954

3.7

-5.4

38

0.

4.

°C

0013

1

-35.5

45°C

0.00037

5.0

55
differences in equilibrium constants occur, the relative error is expected to

increase. Thus, estimated enthalpies (equation 4.20) are subject to more

error when temperature differences are small than when they are large. To

evaluate the -36 kcal mole estimate, the enthalpy from the l-to-150-/jg-Li

mlT experiment for 38°C and 45°C was calculated. The experimental design

differed in that the solid-to-liquid ratio was 1:10 instead of 1:20. The

effective valence of the pseudo-solute B was about 1.2, compared with 1.5 for

the first data set. The parameters used in calculating thermodynamic

constants are given in Table XII for the 38°C and 45°C data sets. The

thermodynamic constants are given in Table XIII. The equilibrium constant

value for 38°C is slightly higher than for the first data set (0,0303 compared

with 0.0239). This difference can be attributed to differences in the

effective valence of the pseudo-ion B. However, the AH0 estimated for the

38°C and 45°C data is -5 kcal mole" , which is the same as that for the 25°C

to 38°C data of the l-to-2000-/jg-Li mL"1 data set. It should be stated that

the method of calculating the enthalpy of sorption is sensitive to the error

associated with the estimate of the thermodynamic equilibrium constant. Small

errors in the equilibrium constants may result in large differences in

enthalpy estimates. For instance, in the case of equation 4.20, errors

associated with the natural logarithm of the ratio of the equilibrium

constants is multiplied by the large product of two absolute temperatures.

Thus, the above conclusions should be kept within the context of the trends

from a number of data sets; the average values of enthalpy should not be taken

as absolute.

A second approach in estimating the enthalpy of sorption was used to test

the above conclusions. The best-estimate data of the l-to-2000-/*m-Li ml

56
TABLE XII

PARAMETER VALUES FOR THE ESTIMATION OF THERMODYNAMIC EQUILIBRIUM CONSTANTS

FOR LITHIUM ADSORPTION ON A PROV PASS SUSPENSION IN J-13 VEIL WATER

AT 38°C AND 45°C FOR THE INITIAL CONCENTRATION RANGE OF 1 TO 150 fig Li mL"1

AND A SOLID-TO-LIQUID RATIO OF 1:10

38°C

45°C

ZA =

Z B =

1

1.2

0.

0.

852

748

7.

6.

i

3x10"4

0x10"4

7

0

0

P

r

Li

.978

.940

= 2.

= 10

54

mL

?Ca

0.783

0.781

g solid

^Og"1

0.

0.

ml"1

Ya

.939

.938

solid

solid

7

0

0

B

.857

.856

MA = 6.94 fig Li fimole'1 Cfio = 270.93 fimoles B raL"1 solid

Mg = 27 fig B fimole'1 C^Q = 1.798 pinoles B mL"1 H2 0

57
TABLE XIII

THERMODYNAMIC CONSTANTS ESTIMATED FOR LITHIUM

ADSORPTION ON A PROV PASS SUSPENSION IN J-13 VELL

VATER AT 38°C AND 45°C FOR. AN INITIAL CONCENTRATION RANGE OF 1 TO 150 ng Li mL"1 AND A

SOLID-TO-LiqUID RATIO OF 1:10

Constant 38°C 45°C

Ke

AG°

(kcal

AH0

(kcal

mole"*)

mole"1)

0.

2.

0093

9

-5.2

0.

3.

0077

1

58
concentration range experiments were used in this approach. The Freundlich

equation was used to show the relationship between the concentration of

lithium sorbed and the concentration in solution at equilibrium. The

parameter values for that equation are given in Appendix D, Table D-III. In

this approach the concentration of lithium adsorbed (Co) is expressed as /jg Li

s

ml" of solution in contact with the surface of the solid. This value can be

calculated from the equation (47, 48)

where

p is the density of water (g mL ) ,

H is the molecular weight of water (g),

2 -1

A is the cross-sectional area of water (cm molecule" ) ,

N is Avogadro's number,

2 -1

So is the surface area of the solid (cm g" ) , and

S is the specific adsorption (ing kg" ).

The cross-sectional area of water was calculated from the following equation

(46):

A = 1.091 x 10"i 6 [(I x lO2 4)^/?)"1]

2/3 . (5.4)

For the conditions of the lithium experiment, p = 1 g ml , M = 18 g, A = 105

x 10"1 5 cm2 molecule"1, S, = 34 600 cm2 g"1, and N = 6.02 x 102 3 ; therefore C

cl S

= 1015 x S.

Equation 5.3 was used to calculate C for a series of S values. Also, C

s e

was calculated for the same S values by inverting the Freundlich isotherm

59
data. Those results are given in Table XIV- From those data, In (C /C ) was

plotted against C and the curve was extrapolated to C -• 0; as C -^3 0,

S fa o

(C /C ) = a /a = K , where K is an equilibrium constant for the sorption

process.

The K values obtained from the sorption of lithium at the three

temperatures (25°C, 38°C, and 45°C) are given in Table XV, as are average

enthalpies calculated with Equation (4.19). The estimated average enthalpies

(based on trends) indicate that the mechanism of lithium sorption is physical

(electrostatic). The results are consistent with those yielded by the

assumption of ion exchange method.

5.2.4 Desorption

The objective of the desorption experiment was to evaluate the

reversibility of lithium sorption. Knowledge of the reversibility of lithium

sorption will help in determining models for the transport of lithium in the

field and in supporting a controlling sorption mechanism of lithium; the

electrostatic sorption mechanism is expected to show reversibility.

After the adsorption experiment, the solution was decanted and replaced

with J-13 water without lithium. Some lithium remained in solution after

decanting. The concentration of lithium in the remaining solution was

determined from analysis of an aliquot of the decanted wash solution. J-13

water was equilibrated with the solid containing adsorbed lithium. The

solution was then analyzed for lithium and other cations. Vith the

concentration of ions in the adsorbed and solution phases known, the amount of

lithium gained in solution was compared with the amount of cations (excluding

lithium) lost from solution, and a best estimate was obtained for the amount

of lithium sorbed after desorption equilibration. These results, given in

60
TABLE XIV

DATA USED IN THE CALCULATION OF EQUILIBRIUM CONSTANTS FOR THE

ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL WATER AT

THREE TEMPERATURES FOR THE INITIAL CONCENTRATION RANGE OF 1 TO 150

fig Li mL'1 AND A SOLID- TO- LiqUID RATIO OF 1:20

s

faglig"1)

4

25

100

250

375

500

(fig Li mL"1)

4.06xl03

2.54xlO4

1.02xl05

2.54xlO5

3.81xlO5

5.08xl05

25°C

0.96

12.2

83.6

298

522

780

C

(fig Li mL'1)

38°C

0.81

12.1

92.7

356

647

986

45°C

1.00

17.0

145

598

1120

1750

C is calculated by using Equation (5.3).

C is calculated using its relationship to S as modeled by the

Freundlich isotherm (see Section 5.2.3 for the relationship).

61
TABLE XV

EQUILIBRIUM CONSTANTS AND ENTHALPIES FOR THE ADSORPTION

OF LITHIUM ON A PROV PASS SUSPENSION IN J-13 VELL VATER

AT TEMPERATURES OF 25°C, 38°C, and 45°C FOR THE INITIAL

CONCENTRATION RANGE OF 1 TO 2000 fig Li mL 1 AND A

SOLID-TO-LIQUID RATIO OF 1:20

Ko

AH0

Constant

(Kcal mole )

25°C

7.81

0.09

(25°C-38°C)

38°C

7.85

-0.32

(25°C-45°C)

45°C

7.55

-1.12

(38°C-45°C)

62
Figure 7, indicate that desorption data follow the adsorption data in the low

concentration range, but in the high concentration range the amount of sorbed

lithium is higher for the desorption experiment than for the adsorption

experiment. This difference is attributed to the probability that equilibrium

was not reached in the desorption experiment because of the high concentration

of lithium in solution; that concentration in solution may reduce the rate of

outward diffusion.

To further substantiate these conclusions, the desorption data for the

l-to-150-/*g-Li ml experiment at 38°C were evaluated similarly. The results,

given in Figure 8, indicate that lithium concentrations in the desorption

experiment essentially follow those of the adsorption experiment over the

range of desorption concentrations. A statistical comparison of the Modified

Freundlich isotherms indicates a significant difference in the two regressions

at the 957i confidence level, but that difference is attributed to the

adsorption data at concentrations higher than those of the desorption data.

The above results indicate that the sorption of lithium is reversible and

hysteresis is not evident. The conclusion that lithium sorption is reversible

also supports the conclusion drawn from the enthalpy data: physical sorption

is the predominant mechanism for the sorption of lithium on the Prow Pass

matrix.

5.3 Potentiometric Studies

Potentiometric analysis of mineral surfaces can provide information to

permit understanding the mechanisms of sorption exhibited by a solute ion.

Data generated by titrating the solid material with potential-determining ions

(e.g., H+ and OH") may also be used with models to investigate further the

nature of solute interactions with the media (30).

63
I—I

r

w

i

s

CO Log

1

0

-1

- 2

- 3

-4

D

'" O

Adsorp. Obs.

Adsorp. Pred.

Desorp. Obs. n

Oesorp. Pred. ©/ ^

*y o

—i——i 1— 1

-1 1

Log Cone, (pjq

Figure 7. Observed and predicted adsorption and desorption of lithium on a

Prow Pass suspension in J-13 well water at 38°C for an initial concentration

range of 1 to 2000 fig li ml"1 and a solid-to-liquid ratio of 1:20. Predicted

lithium is based on the Modified Freundlich isotherm.

64
X

I

1.

2

3-

4-

D

. O

Adsorp. Obs.

Adsorp. Pred.

Desorp. Obs.

Desorp. Pred.

1 — i 1

-1 1

Log Cone, (jig mL" 1 )

Figure 8. Observed and predicted adsorption and desorption of lithium on a

Prow Pass suspension in J-13 well water at 38°C for an initial concentration

range of 1 to 150 pg Li ml"1 and a solid-to-liquid ratio of 1:10. Predicted

lithium is based on the Modified Freundlich isotherm.

65
Results of the potentiometric titrations are summarized in Figure 9 for

no lithium added and Figure 10 for lithium added. All four curves of s k

plotted against resultant pH show the same pattern. No clear intersections

are observed for the two electrolyte concentrations, and the low electrolyte

curves are almost always below the high electrolyte curves. The pH at which

the two electrolyte concentrations intersect is indicative of the ZPC. The

graphs do exhibit a character similar to those reported by other investigators

(51) in that the two electrolyte concentrations tend to converge and remain

almost indistinguishable below pH 9.

Results of the electrophoresis experiment are summarized in Figures 11

and 12 for the same samples generated in the titration experiment. Vhereas

the titration measurements were made on the whole sample (<500-/jm particle

diameter), electrophoresis was measured only on the colloidal fraction (<10-/jm

diameter). The colloidal fraction may represent the more reactive portion of

the sample. EM approached, but did not attain, a zero value. These results

support those of the potentiometric t.i.tration study.

In all cases, both methods indicated negatively charged particles. The

decrease in pH to 2 with the addition of acid was insufficient to neutralize

the negative surface charges on the particles. The curves do, however,

suggest that a ZPC may occur below pH 2. This finding agrees with published

ZPC data (41) for silicates (SilL), feldspar, and montmorillonite clay, all of

which have ZPCs near or below pH 2. These materials have been identified as

the major mineral constituents of the Prow Pass Member (36).

Small amounts of materials with higher ZPC may be present in the sample,

but their effect is obscured by the dominance of charges contributed by the

66
20

L

 10

0 •

o -10"

-20

O—O0.005MNaCI04

D—O0.1M NQC104

PH

14

Figure 9. Potentiometric titration of Prow Pass in suspension with J-13 well

water and NaC104 electrolyte at 38°C without the addition of lithium.

67
20

o -10-

- 20

0-- -

O—O0.005M NaCI04

D—D0.1M NaCI04

pH

8 10 12 14

Figure 10. Potentiometric titration of Prow Pass in suspension with J-13 well

water and NaC104 electrolyte at 38 C with the addition of 900 fig Li ml" .

68
E

u

o

o

n

a

- 2

- 3

- 5

O—O 0.005MNaCI04

• — D 0.1MNaCI04

6

PH

8 10 12

Figure 11. Electrophoretic behavior of a colloidal suspension of Prow Pass in

J-13 well water and NaC104 electrolyte at 38°C with the addition of

900 /ig Li m-l1

69
E

o

o

8

Ui

0

- 1

- 2

- 3

- 4

- 5

O — O 0.005MNaCI04

D — • 0.1MNaCI04

Cb-Q

NA -D—•

—f6

pH

8 10 12

Figure 12. Electrophoretic behavior of a colloidal suspension of Prow Pass in

J-13 well water and NaCllh electrolyte at 38°C without the addition of

lithium.

70
bulk sample. For example, in natural settings coatings on transmissive

fractures or on the bulk materials may be important in defining the sorption

mechanisms under hydrologic conditions. The electrophoresis and the titration

methods of determining ZPC both indicate the lack of a ZPC between pH 2 and 12

for the Prow Pass material in the presence or absence of added lithium.

6.0 SUMMARY AND CONCLUSIONS

This report includes the results from batch experiments that were

conducted to evaluate the potential of lithium, when added as lithium bromide,

as a reactive (nonconservative) tracer for tests in the saturated zone of the

C-wells subsurface in Yucca Mountain. The main objectives were to model the

extent of lithium sorption on Prow Pass suspensions in J-13 well waters and to

estimate thermodynamic constants that in combination with potentiometric

studies support the classification of lithium sorption either as physical or

as chemical.

Lithium (as lithium bromide) was considered a suitable candidate on the

basis of the following characteristics: high solubility, good chemical and

biological stability, and relatively low sorptivity; no suspicion of

bioaccumulation and exclusion as a priority pollutant in pertinent

environmental regulations; good analytical detectability and low natural

background concentrations; and low cost. Additionally, the literature

indicated that retardation by adsorption or by exchange with adsorbers is

lower than the retardation of most cations and that its recovery should be

reasonably fast (i.e., within the context of the C-wells pump-tracer tests).

Geochemical simulations performed before the experiments with the code

PHREEQE suggest that most of the lithium will remain in the form of free

lithium with onl* traces in the form of other species. The simulations also

indicate that in a pH range of 7 to 9 neither the stability of the mineral

71
components of the Prow Pass samples nor the potential for the formation of new

precipitates is significantly affected.

Although resource constraints prevented validation of the geochemical

code predictions, these simulations support the assumption that lithium

analysis is a measure of the lithium cation (Li+) concentration and thus can

be used for estimating concentrations for the isotherm parameters and

thermodynamic constants. These simulations also show, within the limitations

of the data base and computer code calculations, that precipitation or

dissolution did not significantly affect the concentration of lithium in

solution. This prediction supports the assumption that the removal of lithium

from solution was primarily due to sorption processes.

Biological activity in initial experiments was confirmed by the detection

of bacteria and substrates. This occurrence was minimized during subsequent

experiments by autoclaving containers and materials before each experiment.

Autoclaving was a compromise between having less control of the sorption

processes in these experiments and potentially changing the characteristics of

the experimental materials.

Abrasion of samples, caused by tumbling or stirring of suspensions, is a

concern because of the generation of more sorption area or active sites. The

ge, jration of more sorption area or active sites may affect sorption during

the performance of batch experiments. Abrasion effects could be important in

this study because of the significant, but small, difference between size

distributions before and after the contact period. Abrasion has not been

shown definitively to be a serious effect because significant differences

among replicated representative Prow Pass samples have not been estimated.

Nevertheless, this effect is difficult to exclude because of the nature of the

batch experiments, so its extent should be characterized.

72
The equilibrium sorption experimental data indicate that lithium sorption

can be modeled by the four isotherms: Linear, Langmuir, Freundlich, and

Modified Freundlich. However, theoretical considerations suggest that under

flow conditions the four isotherms will predict varied patterns of lithium

migration. The Modified Freundlich isotherm is a general isotherm, based on

theoretical considerations, and the others are special cases of this general

case. Therefore, the Modified Freundlich appears to be the best isotherm for

modeling migration of lithium under flow conditions. This conclusion needs to

be verified, however, by laboratory column experiments.

Lithium apparently adsorbs to the Prow Pass matrix from J-13 well water

by an electrostatic or physical mechanism. Sorption of lithium is easily

reversible, a condition consistent with the theory of electrostatic sorption.

Also, the enthalpy of sorption appears to be in the range consistent with the

enthalpies of physical sorption (<12 kcal mole" ) . Potentiometric and

electrophoretic studies were inconclusive because the ZPC could not be

determined within the design of the experiments. The electrophoretic results

suggest that the ZPC was at a pH less than 2, the lowest pH considered in

these experiments.

Some recommendations for future laboratory work are as follows.

1. Expand the temperature and pH range of the experiments for the

evaluation of the enthalpy of sorption.

2. Continue to analyze samples from sorption experiments for the tracer

of interest and for other constituents that will provide supporting

information on the sorption of the tracer.

3. Perform sorption experiments in binary systems as well as in a

system of J-13 well water. For example, determine the sorption

behavior of lithium in a calcium system and in a sodium system. The

73
thermodynamics of these systems should permit an extrapolation of

results to a system in which both calcium and sodium can control the

sorption behavior of lithium (e.g., J-13 well water system).

4. Dse additional rock samples as well as representative individual

minerals to increase the representativeness of the results for the

field tests.

5. Expand the effort to characterize kinetics to improve the

understanding of the relative control by physical or chemical

sorption processes.

6. Test the ability of the developed isotherms to predict the

breakthrough patterns obtained from column studies under various

velocities ar.d influent conditions.

The overall conclusion from the laboratory efforts is that lithium

bromide is a good candidate tracer for a field test in an environment where

the chemistry closely resembles the chemistry of the Prow Pass material in

contact with J-13 water and in the presence of dissolved oxygen within a

temperature range of 25-45°C and a pH range of about 8. Lithium is expected

to be slightly retarded (retardation factor of about 2) with good

reversibility. Its adsorption, as suggested by the thermodynamic constants,

falls in the category of physical adsorption.

ACKNOWLEDGMENTS

The authors wish to thank Dr. H. Gopala Rao, collaborator from Howard

University, for the calculation and interpretation of thermodynamic data.

Also, we wish to thank Dr. F. A. Tomei for characterizing the microbial growth

74
that was observed in our initial experiments. Key contributions have been the

analytical chemistry services performed by D. J. Hoard and G. E. Bentley,

CLS-1, and the particle size distribution analyses performed by J. Hunter,

MST-6. Finally, we thank Sylvia M. Gonzales for her efforts in maintaining

the quality assurance documentation and in word processing the manuscript.

75
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20. Carmichael, R. S. (ed.) 1982. Handbook of physical properties of rocks.

CRC Press, Boca Raton, FL.

21. Bruggenwert, I. G. I. and A. Kamphorst. 1982. Survey of experimental

information on cation exchange in soil systems. In: G. H. Bolt (ed.)

Soil chemistry, B. physicochemical models. Elsevier Scientific

Publishing Co., New York, NY.

22. EA-3356. 1984. Chemical attentuation rates, coefficients, and constants

in leachate migration, Volume 2: An annotated bibliography. Electric

Power Research Institute, Palo Alto, CA.

23. Gedroiz, K. K. 1922. On the adsorptive power of soils. In: R. D.

Barter (ed.) Adsorption phenomena. Van Nostrand Reinhold Soil Science

Series, New York, NY.

24. Schachtschabel, P. Von. 1940. Dntersuchungen iiber die sorption der

tonmineralien und organischen bodenkolloide, und die bestimmung des

anteils dieser kolloide an der sorption in boden. Kolloid-Beihefte.

51:199-276.

25. Eisenman, G. 1962. Cation selective glass electrodes and their mode of

operation. Biophysics 2:259-323.

26. Helfferich, I. 1962. Ion exchange. McGraw-Hill Book Company, Inc., New

York, NY.

27. Shainberg, I. and V. D. Kemper. 1967. Ion exchange equilibria on

montmorillonite. Soil Science 103:4-9.

28. Fuentes, B. R. and V. L. Polzer. 1987. Interpretative analysis of data

for solute transport in the unsaturated zone. Los Alamos National

Laboratory report NUREG/CR-4737, LA-10817-MS, Los Alamos, NM.

29. Talibudeen, 0. 1981. Cation exchange in soils. In: D. J. Greenland

and M. H. B. Hayes (eds.). The chemistry of soil processes.

Viley-Interscience, New York, NY.

77
30. Sposito, G. 1984. The surface chemistry of soils. Oxford University

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31. Sittig, M. (ed.) 1980. Priority toxic pollutants. Noyes Data

Corporation, Park Ridge, NJ.

32. OTA-0-233. 1984. Protecting the nation's groundwater from

contamination. Office of Technology Assessment, Washington, DC.

33. APHA, AVVA, VPCF. 1985. 16th 'Ed. Standard methods for the examination

of water and waste water. American Public Health Association,

Vashington, DC.

34. ASA, SSSA. 1982. 2nd Ed. Methods of analysis, Part 2. American

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35. Bish, D. L., D. T. Vaniman, F. M. Byers, Jr., and D. E. Broxton. 1982.

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secondary-phase thermal stability in tuffs. Los Alamos National

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36. Chipera, S. J. and D. L. Bish. 1988. Mineralogy of drill hole UE-25p#l

at Yucca Mountain, Nevada. Los Alamos National Laboratory report

LA-11292-MS, Los Alamos, NM.

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44. Sposito, G. 1980. Derivation of the Freundlich equation for ion

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78
45. Crickmore, P. J. and B. V. Vojciechowski. 1977. Kinetics of adsorption

of energetically heterogeneous surfaces. J. Chem. Soc. Faraday Trans.

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(4-amino-3,5,6-trichoropicolinic acid) on Panoche, Ephrata, and Palouse

soils: a thermodynaraic approach to the adsorption mechanism. Soil

Sci.Soc. Am. J. 37: 863-868.

48. IcCloskey, V. B. and D. E. Bayer. 1987. Thermodynamics of fluridone

adsorption and desorption on three California soils. Soil Sci. Soc. Am.

J. 51: 605-612.

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Process description and computer code selection. Energy Power Research

Institute, Palo Alto, CA.

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a computer program for geochemical calculations. U. S. Geological Survey

Water, Resources Investigations 80-96.

51. Parker, J. C , L. V. Zelazny, S. Sampath, and V. G. Harris. 1979. A

critical evaluation of the extension of zero point of charge (ZPC) theory

to soil systems. Soil Sci. Soc. Amer. J. 43:668-674.

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edition. SAS Institute, Inc., Cary, NC.

79
Appendix A

ANALYTICAL INSTRUMENTATION

81
A variety of analytical instruments have been used in measurements and

characterization of either liquid or solid samples. liquid samples were

analyzed on a routine basis by inductively coupled plasma-atomic emission

spectroscopy (ICP-AES) for cations with atomic weights less than 80, by

inductively coupled plasma-mass spectroscopy (ICP-MS) for cations with atomic

weights greater than 80, and by ion chromatography (IC) for anions. The pH of

solutions was measured with a Corning pH-Meter Model 130 (expanded pH-range)

with an Orion Combination Electrode (precision of *0.02 pH units).

Characterization of geological samples (Prow Pass cuttings) was accomplished

with a Siemens D-500 X-Ray Diffraction System (XRD). Unsuccessful attempts to

determine the presence or absence of surface lithium on Prow Pass material

were made with a x-ray photoelectron spectroscope (XPS). An alternative

approach to determine surface lithium was explored with cylindrical internal

reflection-Fourier transform infrared spectroscopy (CIR-FTIR). This effort

was discontinued after preliminary results did not prove immediately

successful.

Surface area analysis of the /row Pass samples was performed with a

Quantasorb Jr. instrument. The particle size distributions for the same

samples were obtained with various instruments: U.S.A. standard testing

sieves of stainless steel (V. S. Tyler, Inc.) up to 44 /*m (mesh 325), and a

Micrometritics Sedigraph 5000D Particle Size Analyzer for less than 44 /xra but

equal to or greater than 25 /im.

During the development of experimental procedures the appearance of

microbial growth motivated a simple characterization of the growth and organic

substrate. Growth was observed by an Olympus microscope (phase contrast and

82
fluorescence photomicrographs). Bacterial density was estimated by

adenosine-triphosphate (ATP) measurements with a Los Alamos Diagnostics Model

535Y Luminometer. Colloidal size distributions were determined with a flow

cytometer. Total organic carbon (TOC) analyses were performed on a Photochem

total organic analyzer for the determination of organic substrate.

Potentiometric studies comprised titrametric and electrophoretic

measurements. Titrametric measurements were made with a combination of a

Fisher Burette Model 394, a Fisher Titrate Stirrer Model 385, and a Fisher

Electrometer Model 380. Electrophoretic mobility measurements employed a Zeta

Meter 3.0 System.

Batch studies used both a modification of a Patterson-Kelley Twin Shell

Dry as a rotator (20 rpm) and 500-mL glass resin kettles. Mixing in the

kettles was accomplished with paddles turned by 6. K. Heller, GT 21-18

Stirrers.

Routine work also employed two Sartorious balances (Model 3704 with a

precision of 0.005 g, and Model 3713 with a precision of 0.005/0.05 g) , riffle

splitters and pulverizers for geological samples, and centrifuges for

liquid/solid separation. All experiments, tests, and measurements were

conducted in an environmental room with controlled temperature when a constant

temperature was required. The room temperature can be maintained to within

*1°C.
Appendix B

ESTIMATES OF LITHIUI ADSOiPTION

AND DESOtPTION EQUILIBilUl CONCENT1ATIONS

85
Appendix B is a compilation of data for the adsorption and desorption of

lithium on a Prow Pass suspension in J-13 well water at 25°C, 38°C, and 45 C.

Given data are based on two methods of evaluating adsorbed and desorbed

lithium. Best estimate values are also given and were used in the evaluation

of the selection of lithium as a tracer exhibiting physical sorptive

properties for the C-wells field tests. Tables B-I through B-III contain

adsorption data for experiments performed at an initial concentration range of

1 to 2000 fig Li mL and a solid-to-liquid ratio of 1:20. Tables B-IV through

B-VI show adsorption data for experiments performed at an initial

concentration range of 1 to 150 fig li ml" and a solid-to-liquid ratio of

1:10. Table B-VII shows desorption data for those experiments performed at

38°C at an initial concentration range of 1 to 2000 fig Li ml" and a

solid-to-liquid ratio of 1:20. Table B-VIII shows desorption data for those

experiments also performed at 38°C but at an initial concentration range of 1

to 150 fig Li mL" and a solid-to-liquid ratio of 1:10.

86
TABLE B-I

ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV PASS

SUSPENSION IN J-13 VEIL WATER AT 25°C FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 2000 /jg Li mL"1 AND A SOLID-TO-LIQUID RATIO OF 1:20

Targeted

Initial Concentration

(ng Li mL"1)

1

5

10

50

100

250

500

750

1000

2000

Adsorbed Lithium (fig g

Lithium Loss

from Solution

3.47

13.9

198

83.3

163

1010

0.0

174

590

555

Cations Gained

in Solution

0.0

83.3

10.4

65.9

115

281

319

392

888

604

1 Solid)

Best

Estimate

3.47

13.9

10.4

83.3

163

392

319

392

590

604

87
TABLE B-II

ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TWO METHODS AND

THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV PASS

SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TO-LiqUID RATIO OF 1:20

Targeted

Initial Concentration

(/ig Li mL" )

1

5

10

50

100

250

500

750

1000

2000

Adsorbed Lithium (fig g~

Lithium Loss

from Solution

2.78

18.7

21.9

101

221

72.9

10.4

201

378

2390

Cations Gained

in Solution

-29.5

-20.1

-30.5

50.0

126

153

367

423

494

605

1 Solid)

Best

Estimate

2.78

18.7

21.9

50.0

126

153

367

423

494

605

88
TABLE B-III

ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV PASS

SUSPENSION IN J-13 VELL VATER AT 45°C FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 2000 /tg Li mL"l AND A SOLID-TO-LIQUID RATIO OF 1:20

Targeted

Initial Concentration

(fig Li mL"1)

1

5

10

50

100

250

500

750

1000

2000

Adsorbed Lithium (fig g

Lithium Loss

from Solution

3.47

13.9

31.2

90.2

250

510

312

729

590

1040

Cations Gained

in Solution

45.1

6.94

13.9

111

132

90.2

208

219

243

500

1 Solid)

Best

Estimate

3.47

6.94

13.9

111

132

90.2

208

219

243

500

89
TABLE B-IV

ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV PASS

SUSPENSION IN J-13 VELL VATER AT 25°C FOR AN INITIAL CONCENTRATION RANGE

OF 1 TO 150 fig Li mL'1 AND A SOLID-TO-LIQUID RATIO OF 1:10

Targeted

Initial Concentration

{tig Li mL"1)

1

5

10

20

50

100

150

Adsorbed Lithium (/zg g

Lithium Loss

from Solution

1.80

4.51

11.1

18.0

-22.0

64.0

5.00

Cations Gained

in Solution

-5.58

5.60

15.5

29.0

74.9

67.0

111

1 Solid)

Best

Estimate

1.80

5.60

15.5

29.0

75.0

67.0

111

90
TABLE B-V

ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV

PASS SUSPENSION IN J-13 VPIL VATER AT 38°C FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 150 /ig Li raL" * AND A SOLID-TO-LttJUID RATIO OF 1:10

Targeted

Initial Concentration

(fig Li raL"1)

1

5

10

20

50

100

150

Adsorbed Lithium (/ig g

Lithium Loss

from Solution

1.90

12.5

21.0

50.0

110

127

195

Cations Gained

in Solution

-4.58

4.05

21.2

33.7

83.1

92.9

94.7

1 Solid)

Best

Estimate

1.90

4.05

21.2

33.7

83.0

93.0

95.0

91
TABLE B-VI

ADSORBED LITHIUM CONCENTRATIONS AS ESTIMATED BY TVO METHODS

AND THOSE CONSIDERED BEST ESTIMATES FOR ADSORPTION ON A PROV PASS

SUSPENSION IN J-13 VELL VATER AT 45°C FOR AN INITIAL CONCENTRATION RANGE

OF 1 TO 150 #g Li mL'1 AND A SOLID-TO-LIQUID RATIO OF 1:10

Targeted

Initial Concentration

{fig Li mL'1)

1

5

10

20

50

100

150

Adsorbed Lithium [fig g"

Lithium Loss

from Solution

2.59

10.6

19.7

56.0

14.5

175

190

Cations Gained

in Solution

-15.5

-5.00

5.11

21.6

103

99.6

129

1 Solid)

Best

Estimate

2.60

10.6

19.7

38.81

58.51

1371

1601

Values represent the mean of lithium lost and cations gained.

92
TABLE B-VII

THE BEST ESTIMATE OF ADSORBED LITHIUM AS DETERMINED BY

TVO METHODS FOR THE DESORPTION OF LITHIUM FROM A PROV PASS

SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 2000 fig Li mL"1 AND A SOLID-TO- LiqUID RATIO OF 1:20

Targeted

Initial

Solution

Concentration

(/*g Li mL'1)

1

5

10

50

100

250

500

750

1000

2000

Lithium

Solid Phase

Before

Desorption

teg"1)

2.78

18.7

21.9

50.0

126

153

367

423

494

605

Lithium

Gained in

Solution

(/*eq)

0.725

4.82

4.02

16.1

22.6

-10.2

-45.9

0.80

-7.53

-8.58

Cations

Loss From

Solution

(/«eq)

5.47

4.59

10.5

13.9

20.1

38.5

45.0

54.3

-11.2

54.6

Best

Estimate

(/*eq)

0.725

4.82

4.02

16.1

21.3

38.5

45.0

54.3

—

54.6

Lithium

in Solid Phase

after Desorption

(Z^gg"1)

0.264

2.00

7.95

2.00

52.0

19.0

211

235

—

415

Excluding lithium.

93
TABLE B-VIII

THE BEST ESTIMATE OF ADSORBED LITHIUM AS DETERMINED BY

TVO METHODS FOR THE DESORPTION OF LITHIUM FROM A PROV PASS

SUSPENSION IN J-13 VELL VATER AT 38°C FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 150 fig Li ml"1 AND A SOLID-TO-LiqUID RATIO OF 1:10

Targeted

Initial

Solution

Concentration

(fig Li mL'1)

1

5

10

20

50

100

150

Lithium in

Solid Phase

Before

Desorption

1.90

4.41

21.2

33.7

83.1

92.9

94.7

Lithium

Gained in

Solution

(/teq)

0.625

2.78

5.02

11.0

20.4

24.9

27.7

Cations

Loss From

Solution

(/<eq)

-2.42

1.26

2.74

7.54

20.3

24.8

27.9

Best

Estimate

Ueq)

0.625

2.78

5.02

11.0

20.3

24.9

27.8

Lithium in

Solid Phase

After Desorption

(/*g g'1)

0.45

1.50

9.59

12.3

36.1

35.3

30.5

Excluding lithium.
Appendix C

EqUILIBlIUl CONCENTRATIONS AND MODELING VARIABLES

95
Appendix C compiles all the data sets from the adsorption and desorption

equilibrium batch experiments that are referred to in this report. The tables

correspond to experiments conducted at 25°C, 38°C, and 45°C for two ranges of

initial concentrations of lithium in solution, that is, 1 to 2000 and 1 to 150

fig mil . Columns labeled S« through S, and CQ through C. are transformations

of equilibrium concentrations C and S used to calculate the linear

regressional parameters of the Langmuir, Freundlich, and Modified Freundlich

isotherms. The regression of the Linear isotherm uses the C and S values

directly. All these variables are inputs to a code based on SAS routines (52)

that generates the parameters and the regressional statistics for each

isotherm. The various columns are defined as follows:

C = initial concentration

CEC = cation exchange capacity of Prow Pass material, fig Li g solid

S = equilibrium concentration on the solid, fig Li g" solid

C = equilibrium concentration in solution, fig Li mL" 1L0

Sg = C S , dependent variable used in the regression for the Langmuir

isotherm

Cg = C, independent variable used in the regression for the Langmuir

isotherm

S, = log S, dependent variable used in the regression for the

Freundlich isotherm

Cg = log C, independent variable used in the regression for the

Freundlich isotherm

S4 = log [S(CEC-S)" ] , dependent variable used in the regression for

the Modified Freundlich isotherm.

96
C, = log C, independent variable used in the regression for the

Modified Freundlich isotherm

Data sets are organized in accordance with the following sequence:

1. Adsorption equilibrium data for the 1- to- 2000- fig ml" range of

initial concentrations at a solid-to-liquid ratio of 1:20.

1.1 Temperature = 25°C

Data set based on measured lithium.

Data set based on measured lithium and other cations (best

estimate).

1.2 Temperature = 38°C

Data set based on measured lithium.

Data set based on measured lithium and other cations (best

estimate).

1.3 Temperature = 45°C

Data set based on measured lithium.

Data set based on measured lithium and other cations (best

estimate).

2. Adsorption equilibrium data for the l-to-150-/ig ml" range of

initial concentrations at a solid-to-liquid ratio of 1:10.

2.1 Temperature = 25°C

Data set based on measured lithium.

Data set based on measured lithium and other cations (best

estimate).

2.2 Temperature = 38°C

Data set based on measured lithium.

97
Data set based on measured lithium and other cations (best

estimate).

2.3 Temperature = 45°C

Data set based on measured lithium.

Data set based on measured lithium and other cations (best

estimate).

3. Desorption equilibrium data at 38 C and a solid-to-liquid ratio of

1:10.

3.1 Data set based on measured lithium and other cations for 1 to

2000 fig rnL'1.

3.2 Data set based on measured lithium and other cations for 1 to

150 ftg ml'1.

98
TABLE C-I

ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig nt'1 RANGE OF INITIAL LITHIUM CONCENTRATIONS IN

SOLUTION AT 25°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-L1QUID RATIO = 1:20.

CEC

1.00

1.00

4.86

4.86

10.20

10.20

53.S0

53.50

112.00

112.00

200.00

200.00

446.00

'446.00

682.00

682.00

895.00

895.00

1844.00

1844.00

0.87

0.87

4.08

4.27

9.03

9.07

47.70

50.70

103.00

105.00

162.00

153.00

444.00

461.00

676.00

666.00

861.00

870.00

1751.00

1882.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

2.S2

2.58

15.60

11.80

23.40

22.60

116.00

56.00

180.00

140.00

760.00

940.00

40.00

-300.00

120.00

320.00

680.00

500.00

1860.00

-760.00

0.87

0.87

4.08

4.27

9.03

9.07

47.70

50.70

103.00

105.00

162.00

153.00

444.00

461.00

676.00

666.00

861.00

870.00

1751.00

1882.00

0.3468

0.3376

0.2615

0.3619

0.3859

0.4013

0.4112

0.9054

0.5722

0.7500

0.2132

0.1628

11.1000

-1.5367

5.6333

2.0813

1.2662

1.7400

0.9414

-2.4763

-0.05849

-0.05998

0.61066

0.63043

0.95569

0.95761

1.67852

1.70501

2.01284

2.02119

2.20952

2.18469

2.64738

2.66370

2.82995

2.82347

2.93500

2.93952

3.24329

3.27462

0.40140

0.41162

1.19312

1.07188

1.36922

1.35411

2.06446

1.74819

2.25527

2.14613

2.88081

2.97313

1.60206

•

2.07918

2.50515

2.B3Z51

2.69897

3.26951

•

-0.05849

-0.05998

0.61066

0.63043

0.95569

0.95761

1.67852

1.70501

2.01284

2.02119

2.20952

2.18469

2.64738

2.66370

2.82995

2.82347

2.93500

2.93952

3.24329

3.27462

-2.6406

-2.6303

-1.8437

-1.9664

-1.6644

-1.6799

-0.9303

-1.2722

•0.7104

-0.8379

0.3443

0.7583

-1.4249

•

-0.9138

-0.3892

0.2051

-0.0821

•

99
TABLE C-II

ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL"1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 25°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20.

CEC

0.87

4.18

9.05

49.20

104.00

158.00

452.00

671.00

895.00

1844.00

3.47

13.88

10.41

83.30

163.10

281.00

319.00

392.00

590.00

604.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

0.87

4.18

9.05

49.20

104.00

158.00

452.00

671.00

895.00

1844.00

0.25072

0.30115

0.86936

0.59064

0.63765

0.56228

1.41693

1.71173

1.51695

3.05298

•0.06048

0.62118

0.95665

1.69197

2.01703

2.19866

2.65514

2.82672

2.95182

3.26576

0.54033

1.14239

1.01745

1.92065

2.21245

2.44871

2.50379

2.59329

2.77085

2.78104

-0.06048

0.62118

0.95665

1.69197

2.01703

2.19866

2.65514

2.82672

2.95182

3.26576

-2.5013

-1.8951

•2.0214

-1.0883

-0.7611

•0.4667

-0.3911

-0.2592

0.0599

0.0821

100
TABLE C-MI

ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 /ig ml"1 RANGE OF INITIAL LITHIUM CONCENTRATIONS IN

SOLUTION AT 38°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID RATIO = 1:20.

CEC

0.98

0.98

4.91

4.91

10.10

10.10

53.90

53.90

111.00

111.00

230.00

230.00

470.00

470.00

690.00

690.00

959.00

959.00

1915.00

1915.00

0.81

0.83

3.80

4.14

8.63

9.39

48.50

49.20

98.90

101.00

224.0!)

229.00

460.00

479.00

704.00

656.00

973.00

907.00

1910.00

1680.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

3.40

3.00

22.20

15.40

29.40

14.20

108.00

94.00

242.00

200.00

120.00

20.00

200.00

-180.00

-280.00

680.00

-280.00

1040.00

100.00

4700.00

0.81

0.33

3.80

4.14

8.63

9.39

48.50

49.20

98.90

101.00

224.00

229.00

460.00

479.00

704.00

656.00

973.00

907.00

1910.00

1680.00

0.2382

0.2767

0.1712

0.2688

0.2935

0.6613

0.4491

0.5234

0.4087

0.5050

1.8667

11.4500

2.3000

-2.6611

-2.5143

0.9647

-3.4750

0.8721

19.1000

0.3574

-0.09151

-0.08092

0.57978

0.61700

0.93601

0.97267

1.68574

1.69197

1.99520

2.00432

2.35025

2.35984

2.66276

2.68034

2.84757

2.81690

2.98811

2.95761

3.28103

3.22531

0.53148

0.47712

1.34635

1.18752

1.46835

1.15229

2.03342

1.97313

2.38382

2.30103

2.07918

1.30103

2.30103

2.83251

3.01703

2.00000

3.67210

-0.09151

-0.08092

0.57978

0.61700

0.93601

0.97267

1.68574

1.69197

1.99520

2.00432

2.35025

2.35984

2.66276

2.68034

2.84757

2.81690

2.98811

2.95761

3.28103

3.22531

-2.5102

-2.5647

-1.6878

-1.8493

-1.5629

-1.8851

-0.9648

-1.0312

-0.5517

-0.6551

-0.9138

-1.7340

-0.6551

•

«

0.2051

•

1.2109

-1.0017

101
TABLE C-IV

ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 fig mL~1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 38°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20.

CEC

0.82

3.97

9.00

48.90

100.00

226.00

470.00

680.00

940.00

1795.00

2.78

18.70

21.90

50.00

126.00

153.00

367.00

423.00

494.00

605.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

0.82

3.97

9.00

48.90

100.00

226.00

470.00

680.00

940.00

1795.00

0.29496

0.21230

0.41096

0.97800

0.79365

1.47712

1.28065

1.60757

1.90283

2.96694

-0.08619

0.59879

0.93424

1.68931

2.00000

2.35411

2.67210

2.83251

2.97313

3.25406

0.44404

1.27184

1.34044

1.69897

2.10037

2.18469

2.56467

2.62634

2.69373

2.78176

-0.08619

0.59879

0.95424

1.68931

2.00000

2.35411

2.67210

2.83251

2.97313

3.25406

-2.5978

-1.7637

-1.6938

-1.3239

-0.8900

-0.7935

-0.3028

-0.2068

-0.0916

0.0837

102
TABLE C-V

-1

ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 /Jg mL RANGE OF fHITtAL LITHIUM CONCENTRATIONS IN

SOLUTION AT 45°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID RATIO = 1:20.

.C CEC

1.03

1.03

4.89

4.89

10.80

10.80

53.40

53.40

115.00

115.00

162.00

162.00

468.60

468.60

655.90

655.90

941.40

941.40

2044.00

2044.00

0.88

0.88

4.21

4.19

9.21

9.18

49.00

48.80

101.00

104.00

126.00

147.00

445.70

460.10

699.00

685.00

908.30

916.20

1974.00

2004.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

2.96

3.00

13.60

14.00

31.80

32.40

88.00

92.00

280.00

220.00

720.00

300.00

458.00

170.00

-862.00

-582.00

662.00

504.00

1430.00

800.00

0.88

0.88

4.21

4.19

9.21

9.18

49.00

48.80

101.00

104.00

126.00

147.00

445.70

460.10

699.00

685.00

908.30

916.20

1974.00

2004.00

0.2977

0.2931

0.3096

0.2993

0.2896

0.2833

0.5568

0.5304

0.3607

0.4727

0.1750

0.4900

0.9731

2.7065

-0.8109

-1.1770

1.3721

1.8179

1.4100

2.5050

•0.05458

-0.05557

0.62428

0.62221

0.96426

0.96284

1.69020

1.68842

2.00432

2.01703

2.10037

2.16732

2.64904

2.66285

2.84448

2.83569

2.95823

2.96199

3.29535

3.30190

0.47159

0.47741

1.13354

1.14613

1.50243

1.51055

1.94448

1.96379

2.44716

2.34242

2.85733

2.47712

2.66087

2.23045

2.82086

2.70243

3.14613

2.90309

-0.05458

-0.05557

0.62428

0.62221

0.96426

0.96284

1.69020

1.68842

2.00432

2.01703

2.10037

2.16732

2.64904

2.66285

2.84448

2.83569

2.95823

2.96199

3.29535

3.30190

-2.5702

-2.5644

-1.9040

-1.8913

-1.5278

-1.5195

-1.0624

-1.0414

-0.4688

-0.6040

0.2730

-0.4281

-0.1494

-0.7399

0.1754

-0.0757

.

0.4202

103
TABLE C-VI

ADSORPTION EQUILIBRIUM DATA FOR THE 1-2000 M9 ml-"1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 4S°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:20.

CEC h

0.88

4.20

9.20

48.90

102.50

136.50

453.00

692.00

912.00

1989.00

3.47

6.94

13.90

111.00

132.00

90.20

208.00

219.00

243.00

500.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

0.88

4.20

9.20

48.90

102.50

136.50

453.00

692.00

912.00

1989.00

0.25360

0.60519

0.66187

0.44054

0.77652

1.51330

2.17788

3.15982

3.75309

3.97800

-0.05552

0.62325

0.96379

1.68931

2.01072

2.13513

2.65610

2.84011

2.95999

3.29863

0.54033

0.84136

1.14301

2.04532

2.12057

1.95521

2.31806

2.34044

2.38561

2.69897

-0.05552

0.62325

0.96379

1.68931

2.01072

2.13513

2.65610

2.84011

2.95999

3.29863

-2.5013

-2.1989

-1.8945

-0.9516

-0.8671

-1.0507

•0.6342

•0.6065

-0.5494

-0.0821

104
TABLE C-VII

1

ADSORPTION EOUILIBRIUH DATA FOR THE 1-150 fig mL RANGE OF INITIAL LITHIUM CONCENTRATIONS IN

SOLUTION AT 25°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID RATIO = 1:10.

CEC

0.744

0.744

3.970

3.970

8.370

8.370

21.200

21.200

60.700

60.700

89.600

89.600

138.000

138.000

0.549

0.575

3.560

3.470

7.210

7.310

19.400

19.400

62.900

62.900

81.000

85.300

135.000

140.000

1104

•1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1.95

1.69

4.10

5.00

11.60

10.60

18.00

18.00

-22.00

-22.00

86.00

43.00

30.00

-20.00

0.549

0.575

3.560

3.470

7.210

7.310

19.400

19.400

62.900

62.900

81.000

65.300

135.000

143.000

0.2815

0.3402

0.8683

0.6940

0.6216

0.6896

1.0778

1.0778

•2.8591

-2.8591

0.9419

1.9837

4.5000

-7.0000

-0.26043

-0.24033

0.55145

0.54033

0.85794

0.86392

1.28780

1.28780

1.79865

1.79865

1.90849

1.93095

2.13033

2.14613

0.29003

0.22789

0.61278

0.69897

1.06446

1.02531

1.25527

1.25527

•

•

1.93450

1.63347

1.47712

#

-0.26043

-0.24033

0.55145

0.54033

0.85794

0.86392

1.28780

1.28780

1.79865

1.79865

1.90849

1.93095

2.13033

2.14613

-2.7522

-2.8144

-2.4286

•2.3420

-1.9739

-2.0135

-1.7806

-1.7806

•

-1.0732

-1.3922

-1.5539

105
TABLE C-VI1I

ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig nrt."1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 25°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:10.

CEC

0.562

3.520

7.260

19.400

62.900

83.200

138.000

1.82

5.60

15.50

29,10

74.90

66.90

.1104

1104

1104

1104

1104

1104

0.562

3.520

7.260

19.400

62.900

83.200

0.30879

0.62857

0.46839

0.66667

0.83979

1.24365

-0.25026

0.54654

0.86094

1.28780

1.79865

1.92012

0.26007

0.74819

1.19033

1.46389

1.87448

1.82543

-0.25026

0.54654

0.86094

1.28780

1.7'5865

1.92012

-2.7822

-2.2926

-1.8465

-1.5675

-1.1380

-1.1904

111.00 1104 138.000 1.24324 2.13988 2.04532 2.13988 -0.9516

106
TABLE C-IX

ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL*1 RANGE OF INITIAL LITHIUM CONCENTRATIONS IN

SOLUTION AT 38°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUM; SOLID-TO-LIQUID RATIO = 1:1(1.

CEC

1.00

1.00

4.90

4.90

9.80

9.80

24.00

?4.00

75.00

75.00

93.20

93.20

143.00

143.00

0.83

0.79

3.60

3.70

7.70

7.70

19.00

19.00

64.00

64.00

80.60

80.40

130.00

117.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1.7

2.1

13.0

12.0

21.0

21.0

50.0

50.0

110.0

110.0

126.0

128.0

130.0

260.0

0.83

0.79

3.60

3.70

7.70

7.70

19.00

19.00

64.00

64.00

80.60

80.40

130.00

117.00

0.48824

0.37619

0.27692

0.30833

0.36667

0.36667

0.38000

0.38000

0.58182

0.58182

0.63968

0.62812

1.00000

0.45000

-0.08092

-0.10237

0.55630

0.56820

0.88649

0.88649

1.27875

1.27875

1.80618

1.80618

1.90634

1.90526

2.11394

2.06819

0.23045

0.32222

1.11394

1.07918

1.32222

1.32222

1.69897

1.69897

2.04139

2.04139

2.10037

2.10721

2.11394

2.41497

-0.08092

-0.10237

0.55630

0.56820

0.88649

0.88649

1.27S75

1.27875

1.60618

1.80618

1.90634

1.90526

2.11394

2.06819

-2.8119

-2.7199

-1.9239

-1.9590

-1.7124

-1.7124

-1.3239

-1.3239

-0.9560

-0.9560

-0.8900

-0.8822

-0.8746

-0.5114

107
TABLE C-X

ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig trl'1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 38°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:10.

CEC

0.81

3.65

7.70

19.00

64.00

80.50

124.00

1.90

4.40

21.20

33.70

83.10

92.90

94.60

1104

1104

1104

1104

1104

1104

1104

0.810

3.650

7.700

19.000

64.000

80.500

124.000

0.42632

0.82955

0.36321

0.56380

0.77016

0.86652

1.31078

-0.09151

0.56229

0.88649

1.27875

1.80613

1.90580

2.09342

0.27875

0.64345

1.32634

1.52763

1.91960

1.96802

1.97589

-0.09151

0.56229

0.88649

1.27875

1.80618

1.90580

2.09342

-2.7635

-2.3978

-1.7032

-1.5019

-1.0894

-1.0368

•1.0282

108
TABLE C-XI

ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig ml*1 RANGE OF INITIAL LITHIUM CONCENTRATIONS IN

SOLUTION AT 45°C. CONCENTRATIONS CORRESPOND TO MEASURED LITHIUH; SOLID-TO-LIQUID RATIO = 1:10.

CEC

0.77

0.77

4.40

4.40

9.10

9.10

23.50

23.50

101.00

101.00

159.00

159.00

0.52

0.50

3.40

3.40

7.30

7.10

17.50

18.30

80.00

86.00

140.00

140.00

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

1104

2.5

2.7

10.0

10.0

18.0

20.0

60.0

52.0

210.0

150.0

190.0

190.0

0.52

0.50

3.40

3.40

7.30

7.10

17.50

18.30

80.00

86.00

140.00

140.00

0.20800

0.18519

0.34000

0.34000

0.40556

O.3S500

0.29167

0.35192

0.38095

0.57333

0.73684

0.73684

-0.28400

-0.30103

0.53148

0.53148

0.86332

0.85126

1.24304

1.26245

1.90309

1.93450

2.14613

2.14613

0.39794

0.43136

1.00000

1.00000

1.25527

1.30103

1.77815

1.71600

2.32222

2.17609

2.27875

2.27875

•0.28400

-0.30103

0.53143

0.53148

0.86332

0.85126

1.24304

1.26245

1.90309

1.93450

2.14613

2.14613

-2.6440

-2.6105

•2.0390

-2.0390

-1.7806

-1.7340

-1.2405

-1.3060

-0.6291

-0.8035

-0.6822

T0.6822

109
TABLE C-XII

ADSORPTION EQUILIBRIUM DATA FOR THE 1-150 fig mL*1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 45°C. CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM ANO OTHER

CATIONS; SOLID-TO-LIQUID RATIO = 1:10.

CEC

0.511

3.400

7.160

17.900

63.550

83.550

140.000

2.6 1104 0.511 0.19654 -0.29158 0.41497 -0.29158 -2.6270

10.6 1104 3.400 0.32075 O.5314S 1.02531 0.53K8 -2.0135

19.7 1104 7.160 0.36345 0.85491 1.29447 0.85491 -1.7407

21.6 1104 17.900 0.82870 1.25285 1.33445 1.25285 -1.6999

103.0 1104 63.550 0.61699 1.80312 2.01284 1.80312 -0.9876

100.0 1104 83.550 0.83550 1.92195 2.00000 1.92195 -1.0017

129.0 1104 140.000 1.08527 2.14613 2.11059 2.14613 -0.8784

110
TABLE C-XIII

OESORPTION EQUILIBRIUM DATA FOR THE 1-200 0 /l g nt" 1 RANGE OF INITIAL LITHIUM CONCENTRATIONS

IN SOLUTION AT 38°C . CONCENTRATIONS ARE BEST ESTIMATES FROM MEASURED LITHIUM AND OTHER

CATIONS; SOLID-TO-LIOUID RATIO = 1:20 .

CEC

0.23

1.10

1.39

5.48

8.66

14.50

35.80

34.70

104.00

0.264

2.000

7.950

2.000

52.100

19.300

210.800

234.720

415.000

.1104

1104

1104

1104

1104

1104

1104

1104

1104

0.23

1.10

1.39

5.48

8.66

14.50

35.80

34.70

104.00

0.87121

0.55000

0.17484

2.74000

0.16622

0.75130

0.16983

0.147E4

0.25060

-0.63827

0.04139

0.14301

0.73878

0.93752

1.16137

1.55388

1.54033

2.01703

-0.57840

0.30103

0.90037

0.30103

1.71684

1.28556

2.32387

2.37055

2.61805

-0.63827

0.04139

0.14301

0.73878

0.93752

1.16137

1.55388

1.54033

2.01703

-3.6213

-2.7412

-2.1395

-2.7412

-1.3051

-1.7498

-0.6271

-0.5686

-0.2202
Appendix D

STATISTICAL AND IODEL PAIAKTEI ESTIMATES FOl ISOTIEIIS

113
TABLE D-I

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE LINEAR ISOTHERM FOR THE ADSORPTION OF

LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN INITIAL CONCENTRATION

RANGE OF 1 TO 2000 jxg Id Mi"1 AND A SOLIEHFO-LIQUID RATIO OF 1:20

R

2

CV

Slope

(Kd)

Li

Data

0.18

224

0.35±0.

25°C

17

Best Estimate Data

0.845

55

0.43±O.06

Li

Data

0.354

264

0.94+O.29

38°C

Best Estimate Data

0.905

45

0.425±0.046

Li

Data

0.407

188

0.45-t0.12

45°C

Best Estimate Data

0.924

40

0.27+0.03

Equation: S = K.C

Regression: Svs C

Units: S = fig Li g~ solid

C - ng Li ml"1 H2O

Kd = mL H2O g"*1 solid
TABLE D-II

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE IANQflJIR ISOTHERM FOR THE ADSORPTION

OF LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN INITIAL LITHIUM

CONCENTRATION RANGE OF 1 TO 2000 jug Li mL*1 AND A SOLID-TO-LIQUID RATIO OF 1:20

R

2

CV

Slope

(1/b)

Intercept

(1/kb)

b

k

Equation:

Regression:

25C

Li

Data

0.0004

240

-0.00009

±0.001

1.23+0.80

l.lxio" 4

7.3X10*"5

S -^ g

C/S VS C

>c

Best Estimate Data

0.92?

22

0.001

±0.0001

0.50410.096

714

2.8X10"3

38°C

Li

Data

0.175

299

0.004

±0.002

O.O13±1.33

2.5X102

3.1X10"*1

Units: S = ng

Best Estimate Data

0.888

25

0.0014

±0.0002

0.60±0.12

714

2.3X10"3

Li g"1 solid

Li mL"1 H2O

Li

Data

0.252

127

0.0008

±0.0003

0.32*0.23

1.3X103

2.5X10"3

b =

k =

45°C

Best Estimate Data

0.792

40

0.0020

±0.0004

0.85±0.27

500

2.4X10"3

pg JA g~ solid

•• mL H2O jig*"1 Li
TABLE D-III

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE FREUNDLICH ISOTHERM FOR THE

ADSORPTION OF LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN INITIAL

OONCENTRATION RANGE OF 1 TO 2000 pq Li mL"1 AND A SOLID-TO-LIQUID RATIO OF 1:20

R

2

CV

Slope

(N)

Intercept

(logK)

Li

Data

0.794

21

0.72±0

0.6510

25°C

Best

Estimate

0.963

8.3

.09 0.72±0.09

.19 0.61+0.11

Li

Data

0.736

24

0.67±0.

0.71±0.

38°C

10

21

Best

Estimate

0.979

5.9

0.68±0.03

0.66±0.08

Li

Data

0.926

11

0.73±0

0.71+0

45°C

.05

.11

Best

Estimate

0.

9.

0.

0

,952

.3

,65±0.05

.60±0.11

Equation: S = KCr

Regression: log S vs log C

Units: S - nq Li g"1 solid

N = dimensionless

K - (mL fig""1 Li)N (pg Li g"1 solid)
TABLE D-IV

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE MODIFIED FREUNDLICH ISOTHERM

FOR THE ADSORPTION OF LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN

INITIAL CONCENTRATION RANGE OF 1 TO 2000 fig Li mL*1 AND A SOUD-TO-LIQUID RATIO OF 1:20

R

2

CV

Slope

(0)

Intercept

(01og KJ

«D

25°.

Li

Data

0.675

56

0.80t0.14.

-2.410.28

l.oxio"3

r%

Best

Estimate

0.973

17

0.8210.05

-2.50ttO.10

8.9xlO~4

38°C

Li

Data

0.642

53

0.72+.0.15

-2.3+0.28

6.7X10"4

Best

Estimate

0.981

13

0.77+.0.04

-2.45±0.08

6.6xlO~4

45°C

Li

Data

0.909

32

0.86±(L07

-2.4tO.14

1.2X10"3

Best

Estimate

0.958

15

0.70+0.05

-2.49+0.11

2.8X10"4

Equation: S^,^ - S)

Regression: log

-1

Units: S = jtg Ii g" solid

- S)~x] vs log C Smax

 = u g soli d

Li mL*1

C = H2O

0= dimensionless

» mL H2O Li
TABLE D-V

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE LINEAR

ISOTHERM FOR THE ADSORPTION OF LITHIUM ON A PROV PASS SUSPENSION IN

J- 13 WELL VATER FOR AN INITIAL CONCENTRATION RANGE OF

1 TO 150 /ig raL"1 AND A SOLID-TO-LIQUID RATIO OF 1:10

R

2

CV

Li

Data

0.664

92

25°C

Best

Estimate

0.968

26

Li

Data

0.970

26

38°C

Best

Estimate

0.933

36

Li

Data

0.925

41

45°C

Best

Estimate

0.957

31

Slope 0.47±0.11 0.87±0.06 1.87*0.09 0.96±0.10 1.58*0.14 1.24*0.11

Equation: S = K.C Units: S = fig Li g solid

Regression: S vs C C = /*g Li ml" H20

Kd = mL H20 g'1 solid

118
TABLE D-VI

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE IANOKJIR ISOTHERM FOR THE ADSORPTION OF

LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN INITIAL CONCENTRATION

RANGE OF 1 to 150 jig Li mL*1 AND A SOLID-TO-LIQUID RATIO OF 1:10

R

2

CV

Slope

Li

Data

0.773

50

0.02310

25°C

.004

Best

Estimate

0.843

20

0.00610.001

38°C

U

Data

0.515

21

0.002010.0007

Best

Estimate

0.737

25

0.005810.0016

45°C

Li

Data

0.839

19

0.003010.0004

Best

Estimate

0.587

40

0.0047+0.0017

Intercept 0.44±0.23 0.4810.08 0.3710.04

(1/kb)

b

k

43.5 167

5.2x10

-2 1.3x10

-2

500

0.48+0.10

172

5.4X10

-3 1.2X10

-2

0.280+0.028 0.3510.12

333 213

1.1x10

-2 1.3x10

-2

kbC

Equation: S - j^jg

Regression: C/S vs C

Units: S • t>q Li g"1 solid b = jig Li g solid

C - jug Li mL"1 H2O k = mL H2O pq~l Li-
to

O

TABLE D-VII

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE FREUNDLICH ISOTHERM FOR THE

ADSORPTION OF LITHIUM ON A PROW PASS SUSPENSION IN J-1 3 WELL WATER FOR AN INITIAL

CONCENTRATION RANGE OF 1 t o 150 pq Li UlL"1 AND A SOLID-TO-LIQCJID RATIO OF 1:1 0

R

2

CV

Slope

(N)

25°C

Li

Data

0.924

15

0.638±0.061

Best

Estimate

0.987

6.1

0.759±0.039

38°C

Li

Data

0.981

6.6

0.90010.038

Best

Estimate

0.958

11

0.833+0.077

Li

Data

0.986

5.9

0.807+0

45°C

.031

Best

Estimate

0.981

6.5

0.722±0.045

Intercept 0.413±0.077 0.444+0.055 0.477±0.051 0.37±0.11 0.632±0.042 0.643±0.064

(K)

Equation: S = KCr

Regression: log S vs log C

Units: S = /ig Li g~ solid

C - fig Li mL"1 H20

N = dimensionless

K - (mL /tg"1 Li) N Qig Li g"1 solid)
I

i

TABLE D-VIII

STATISTICAL AND MODEL PARAMETER ESTIMATES OF THE MODIFIED FREUNDLICH ISOTHERM FOR

THE ADSORPTION OF LITHIUM ON A PROW PASS SUSPENSION IN J-13 WELL WATER FOR AN

INITIAL OONCENTRATTON RANGE OF 1 to 150 (iq Li JtiL"1 AND A SOLID-TO-LIQUID RATIO OF 1:10

Li

Data

25°C

Best

Estimate

Li

Data

38°C

Best

Estimate

Li

Data

45°C

Best

Estimate

R 0.921 0.988 0.982 0.961 0.985 0.979

CV 8.2 4.8 6.6 9.2 6.1 6.9

Slope 0.647±0.063 0.777+0.039 0.936±0.038 0.852*0.077 0.844*0.033 0.7481:0.049

Intercept -2.63±0.079 2.60±0.06 -2.58±0.051 -2.67±0.11 -2.42±0.04 -2.41t0.07

8.6X10

.-5

4.5x10 1.75x10 7.3X10

-4 1.35xlO~

3

6.0X10"

4

Equation:

Regression: log =) vs log C

Units: S = nq Li g~~ solid

Smax

i g^solid

C = nq Li H2O

0= dimensionless

Kp = mL F fig"1

 Li
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