EPA -660/2-74-029
April 1974
Environmental Protection Technology Series
Color Characterization Before
and
After Lime Treatment
Office of Research and Development
U.S. Environmental Protection Agency
Washington. DC 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and -non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
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EPA-660/2-74-029
April 1974
COLOR CHARACTERIZATION BEFORE AND
AFTER LIME TREATMENT
By
H. S. Dugal
R. M. Leekley
J. W. Swanson
Project S 800853
Program Element 1BB037
Project Officer
Ralph H. Scott
Chief, Paper and Forest Industries
U.S. Environmental Protection Agency
National Environmental Research Center
Corvallis, Oregon 97330
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
For tale by the Superintendent o( Documents, U.S. Government Printing Office
Washington, D.C. 20402 • PrlCO $2.15
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EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents neces-
sarily reflect the views and policies of the
Environmental Protection Agency, nor does mention
of trade names or commercial products constitute
endorsement or recommendation for use.
ii
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ABSTRACT
Four effluents from two different sources were studied before and after
lime treatment (massive and stoichiometric).
The massive lime treatment process was found to remove 73 percent color
and 53 percent total organic carbon (TOG) from kraft decker effluent, and
96 percent color and 80 percent TOG from kraft bleach caustic extract.
The analysis of the solids from the decker and caustic effluents showed
respective reductions of 73 and 50 percent phenolic hydroxyls, 63 and
26 percent sugars, and 51 and l6 percent methoxyls by lime treatment.
Color bodies not removed by lime from the decker effluent had weight
average molecular weight (M^) < 200, higher OH to C-H stretch ratio,
higher carboxylate to aromatic ring ratio and seemed to have more pro-
nounced carbonyl groups than the untreated color bodies. Similarly,
color bodies not removed from the bleach caustic extract had My. < HOO,
contained aliphatic acid-salt systems, pronounced carbonyl groups, lower
carboxylate to carbonyl ratio and chromophores which absorb more below
220 nm. In general, the massive lime treatment is more effective on
caustic extract than decker effluent.
The Btoichiometric lime treatment prowess was found to remove 79 percent
color and 50 percent TOC from kraft decker effluent, and 6k percent color
and 30 percent TOC from the NSSC effluent. The analysis of the solids
from the decker and NSSC effluents showed respective reductions of 76
and 25 percent phenolic hydroxyls, 31 and "negligible" percent sugars,
and 1*2 and 9.7 percent methoxyls by lime treatment. Color bodies not
removed by lime from the decker effluent had M^ < 500, higher OH to C-H
stretch ratio, higher carboxylate to aromatic ring ratio and seemed to
have more pronounced carbonyl groups than the untreated color bodies.
Color bodies not removed by lime from neutral sulfite semi chemical
(NSSC) effluent had M^ < 300, and showed no detectable differences in
character from the untreated color bodies. In general, stoichiometric
lime treatment is more effective on decker than NSSC effluents.
ill
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LIME TREATMENT WITH METAL IONS
Addition of 150 to 300 ppm FeCl3 with only 300-500 ppm lime removed
about 98 percent color from bleach caustic extract. Over 50 percent
of the color left by conventional lime treatment processes could also
be removed by incorporating polyvalent metal ions with lime. However,
below 1000 ppm of lime, the sludge obtained settled slowly. More color
could be removed when metal ions were used with lime than when each was
used individually indicating that a "synergistic" effect exists.
iv
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CONTENTS
Abstract iii
List of Figures vi
List of Tables x
Acknowledgments xiii
Sections
I Conclusions 1
II Recommendations 3
III Introduction 5
IV Massive Lime Treatment 11
V Stoichiometric Lime Treatment 77
VI Lime Treatment with Metal Ions 125
VII Experimental 151
VIII References 167
IX Appendices 169
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FIGURES
Ho..
1 Classification of Contents of the Report 7
2 Flow Diagram for Effluent Processing and Fractionation 9
3 Absorptivity Values at pH 1.6 of Untreated Wastes from
IPCO (Visible Region) 21
U Absorptivity Values of pH 1.6 of lime-Treated Wastes
from IPCO (Visible Region) 22
5 Absorptivity Values at pH 1.6 of Untreated Wastes from
IPCO (UV Region) 23
6 Absorptivity Values at pH 1.6 of Massive Lime-Treated
Wastes from IPCO (UV Region) 2U
7 Color and Total Organic Carbon Removal of Wastes from
IPCO by Lime Treatment 27
8 Decrease in Absorptivity of Wastes from IPCO by Lime
Treatment 28
9 Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Untreated Kraft Decker Waste from IPCO 33
10 Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Lime-Treated Kraft Decker Waste from IPCO 3U
11 Absorptivity Versus Wavelength (Visible Range) of
Indulin-C and Untreated Kraft Decker Waste from IPCO 35
12 Absorptivity Versus Wavelength (Visible Range) of
Indulin-C and Lime-Treated Kraft Decker Waste 36
13 Weight Average Molecular Weight (M^ Distribution of
Fractionated Color Bodies from Kraft Decker Effluent
from IPCO (My. Values at 0)2=0) 38
lU Weight Average Molecular Weight (M^) of Acid-Insoluble
Color Bodies from Decker Effluent Versus Percentage
of Removal by Massive Lime 39
15 Infrared Spectra of Untreated and Lime-Treated Color
Bodies from Kraft Decker Effluent from IPCO, Indulin-C
(Salt Form) and Indulin-A (Acid Form) U3
vi
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16 Infrared Spectra of Untreated and Lime-Treated Acid-
Insoluble Color Bodies from Kraft Decker Effluent
from IPCO 1»5
17 Infrared Spectra of Untreated and Lime-Treated Acid-
Soluble Color Bodies from Kraft Decker Effluent
from IPCO U8
18 Pyrolysis Gas Chromatograms of Untreated and Lime-
Treated Decker Effluent from IPCO Compared with
Indulin-C 50
19 Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Untreated Kraft Bleach Caustic Extract 55
20 Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and lime-Treated Kraft Bleach Caustic Extract 56
21 Absorptivity Versus Wavelength (Visible Region) of
Indulin-C and Untreated Kraft Bleach Caustic Extract 57
22 Absorptivity Versus Wavelength (Visible Region) of
Indulin-C and Lime-Treated Kraft Bleach Caustic Extract 58
23 Weight Average Molecular Weight (M^) Distribution of
Fractionated Color Bodies from Kraft Bleach Caustic
Extract from IPCO (M at u>2=0) 60
2k Weight Average Molecular Weight (l^) of Acid- Insoluble
Color Bodies from Caustic Extract Versus Percentage
of Removal by Massive Lime 6l
25 Infrared Spectra of Untreated and Lime-Treated Color
Bodies from Kraft Bleach Caustic Extract 65
26 Infrared Spectra of Untreated and Lime-Treated Acid-
Insoluble Color Bodies from Kraft Bleach Caustic 67
Extract
27 Infrared Spectra of Untreated and Lime-Treated Acid-
Soluble Color Bodies from Kraft Bleach Caustic Extract 69
28 Pyrolysis GLC of Untreated and Lime-Treated Kraft
Bleach Caustic Extract 71
29 Pyrolysis GLC of Untreated and Lime-Treated Acid-
Insoluble Fractions "A" from Kraft Bleach Caustic
Extract 72
30 Pyrolysis GLC of Untreated and Lime-Treated Acid-
Insoluble Fractions "C-H" from Kraft Bleach Caustic
Extract 73
vli
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31 Pyrolysis GLC of Untreated and Lime-Treated Acid-Soluble
Fractions "I" from Kraft Bleach Caustic Extract 7!*
32 Pyrolysis GLC of Untreated and Lime-Treated Acid-Soluble
Fractions "II+III+IV" from Kraft Bleach Caustic Extract 75
33 Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Untreated Kraft Decker Wastes from CONGO 89
3l* Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Lime-Treated Kraft Decker Wastes from
CONGO 90
35 Absorptivity Versus Wavelength (Visible Range) of
Indulin-C and Untreated Kraft Decker Wastes from
CONGO 91
36 Absorptivity Versus Wavelength (Visible Region) of
Indulin-C and Untreated Kraft Decker Wastes from
CONGO 92
37 Weight Average Molecular Weight (Mj Distribution of
Fractionated Color Bodies from Kraft Decker Effluent
from CONGO (t\j at U2=0) 91*
38 Weight Average Molecular Weight (\) of Acid-Insoluble
Color Bodies from Kraft Decker Effluent Versus
Percentage of Removal by Stoichiometric Lime 95
39 Infrared Spectra of Untreated and Lime-Treated Color
Bodies from Kraft Decker Effluent from CONGO 98
1*0 Infrared Spectra of Untreated and Lime-Treated Acid-
Insoluble Color Bodies from Kraft Decker Effluent
from CONGO 99
1*1 Infrared Spectra of Untreated and Lime-Treated Acid-
Soluble Color Bodies from Kraft Decker Effluent
from CONGO 101
1*2 Pyrolysis Gas Chromatograms of Untreated and Lime-
Treated Decker Effluents from CONGO 103
1*3 Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Untreated NSSC ;;aste from CONGO 107
1*1* Absorptivity Versus Wavelength (Ultraviolet Range) of
Indulin-C and Lime-Treated NSSC Waste from CONGO 108
1*5 Absorptivity Versus Wavelength (Visible Region) of
Indulin-C, and Untreated NSSC Waste from CONGO 109
viii
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U6 Absorptivity Versus Wavelength (Visible Region) of
Indulin-C and Lime-Treated NSSC Waste from CONGO 110
U7 Weight Average Molecular Weight (M^) Distribution of
Fractionated Color Bodies from NSSC Effluent from
CONGO (Mw at W2=0) 112
U8 Infrared Spectra of Untreated and Lime-Treated Color
Bodies from NSSC Effluent from CONGO Il6
U9 Infrared Spectra of Untreated and Lime-Treated Acid-
Insoluble Fractions from NSSC Effluent from CONGO 118
50 Infrared Spectra of Untreated and Lime-Treated Acid-
Soluble Color Bodies from NSSC Effluent from CONGO 120
51 Pyrolysis Gas Chromatograms of Untreated and Lime-
Treated NSSC Effluents from CONGO 123
52 Treatment of Kraft Decker Wastes from Bivalent Ions 129
53 Treatment of Kraft Caustic Extract with Bivalent Ions 130
5^ Treatment of Kraft Decker Waste vith Trivalent Ions 131
55 Treatment of Kraft Caustic Extract with Trivalent Ions 131
56 Effect of FeCls Concentration on. Color Removal.
Lime Concentration was Kept Constant. (Color Removal
Values at 150 ppm PeCl3 from Table UO Have Also Been
Plotted Here) 139
57 Effect of BaCl2 Concentration on Color Removal. Lime
Concentration was Kept Constant. (Color Removal
Values at 300 ppm BaCl2 from Table UO Have Also
Been Plotted Here)
58 Effect of Lime Concentration on Color Removal. Metal
Ion Concentration Kept Constant
59 Effect of Ferric Chloride and Lime on Sludge Volume
60 The Interactive Behavior of Lime and Metal Ions on
Color Removal
6l Percentage of Color Removal by Lime in the Presence of
Metal Ions
62 Diagram of Gel Permeation Chromatography Apparatus
ix
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TABLES
No. Page
1 Chemical Data on Effluents Before Shipment from IPCO 13
2 Sedimentation Coefficients of the Color Bodies lit
3 Chemical Data on Freeze-Dried Wastes from IPCO 16
1| Emission Spectroscopic Analysis of Freeze-Dried
Wastes from IPCO 17
5 Change in Metal/TOC Ratio During Lime Treatment of
Mill Wastes from IPCO 18
6 Absorptivity Values Obtained from Visible Spectrum
at pH 7.6 of Wastes from IPCO 19
7 Absorptivity Values Obtained from Ultraviolet Spectrum
at pH 7.6 df Wastes from IPCO 20
8 Effect of Lime Treatment on Wastes from IPCO 26
9 Change in Solids Isolated from IPCO Effluents Due to
Massive Lime Treatment 29
10 Fractionation of Decker Acid-Insoluble Color Bodies
by Column Chromatography 30
11 Fractionation of Decker Acid-Soluble Color Bodies
by Sorption on XAD-8 Resin 32
12 Analytical Data on Fractions of Decker Effluent
from IPCO l+i
13 Indulin-C Pyrolysis Products 1+9
lU Change in Solids Isolated from IPCO Effluents Due
to Massive Lime Treatment 52
15 Fractionation of Acid-Insoluble Color Bodies from
Bleach Caustic Extract by Column Chromatography 53
16 Fractionation of Acid-Soluble Color Bodies from
Bleach Caustic Extract by Sorption on XAD-8 Resin 5!*
17 Analytical Data on Fractions of Kraft Bleach Caustic
Extract from IPCO 62
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18 Chemical Data on Effluents Before Shipment from CONGO 79
19 Sedimentation Coefficients of NSSC Color Bodies 80
20 Chemical Data on Freeze-Dried Wastes from Continental
Can Company (CONGO) 82
21 Emission Spectrographic Analysis of Freeze-Dried
Wastes from CONGO 83
22 Change in Metal/TOC Ratio During Lime Treatment of
Mill Wastes from CONGO 8U
23 Effect of Lime Treatment on Wastes from CONGO 85
2k Change in Solids Isolated from CONGO Effluents Due
to Stoichiometric Lime Treatment 86
25 Fractionation of Decker Acid-Insoluble Color Bodies
by Column Chromatography 87
26 Fractionation of Decker Acid-Soluble Color Bodies
by Sorption on XAD-8 Resin 88
27 Analytical Data on Fractions of Decker Effluent
from CONGO 96
28 Change in Solids Isolated from CONGO Effluents Due
to Stoichiometric Lime Treatment ' 101*
29 Fractionation of NSSC Acid-Insoluble Color Bodies
"by Column Chromatography 105
30 Fractionation of NSSC Acid-Soluble Color Bodies by
Column Chromatography 106
31 Analytical Data on Fractions from NSSC Effluent
from CONCO
32 Treatment of Kraft Effluents with Bivalent Ions 127
33 Treatment of Kraft Effluents with Trivalent Ions 128
3U Percent Color Removal from Mill Wastes by the
Metal Ion-Lime System 134
35 Percent Color Removal from Mill Wastes by the
Metal Ion-Lime System 135
36 Effect of Ferric Chloride Concentration on Lime
Treatment of Kraft Bleach Effluents (Caustic Stage) 137
xi
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37 Effect of Barium Chloride Concentration on Lime Treatment
of Kraft Bleach Effluents (Caustic Stage) 138
38 Effect of Lime Concentration on Color Removal with
Constant Levels of Metal Ions 138
39 Lime Treatment of Kraft Bleach Caustic Extract in the
Presence of Metal Ion
^0 Percent Color Removal "by Lime in the Presence of
Metal Ions
^1 Effect of Varying Lime and Metal Ion Concentration
on Color Removal (Regression Equation)
U2 Comparison of Regression Coefficients
xii
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ACKNOWLEDGMENTS
The support of the President of The Institute of Paper Chemistry, Mr.
John G. Strange, is acknowledged with sincere thanks. Dr. John W.
Swanson, Director of the Division of Natural Materials and Systems of
the Institute, was the Project Director. Dr. Robert M. Leekley, Group
Coordinator, Division of Natural Materials and Systems of the Institute
was the coordinator. Dr. Hardev S. Dugal, Research Associate of the
Institute, was project leader and carried out the work himself and guided
the work for others on this project. Portions of the experimental work
were conducted by Messrs. Norman Colson, John Carlson, Lowell Sell,
Donald Gilbert, John Rademacher, LeRoy Borchardt, and Dr. Marion A.
Buchanan, each of whom contributed to the work in the area of his spec-
ialty. Dr. Dwight B. Easty and Mr. Edgar Dickey contributed through
valuable suggestion and consultation. Special thanks are given to Dr.
Donald C. Johnson who interpreted a huge number of IR spectra and to
Mr. John Church for statistical analysis.
Mr. J. E. Humphrey, Project Director, International Paper Company,
Springhill, La., and Mr. Edgar L. Spruill, Supervisor, Environmental
Control, Continental Can Company, Hodge, La. and their staff collected
the effluent samples and supplied the necessary information about their
lime treatment processes.
The partial support of the project by the Office of Research and Develop-
ment, Environmental Protection Agency and the help provided by ex-
project officers, Mr. George R. Webster and Dr. James D. Gallup, and
Mr. Ralph Scott, Project Officer, is acknowledged with sincere thanks.
xiii
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SECTION I
CONCLUSIONS
1. No appreciable changes occurred in the color bodies during ship-
ment of mill effluents from their sources to Appleton, Wisconsin.
2. A correlation exists between the absorbance and the color with
concentration of color bodies.
3. Color bodies could be stored in the freeze-dried form for longer
periods without any appreciable changes.
k. Color bodies of all effluents could be acidified to give acid-
insoluble and acid-soluble components.
5. When the "untreated" effluents are acidified, more of the kraft
waste color is found in the acid-insoluble rather than the acid-
soluble component. However, in the case of NSSC effluent the
opposite is demonstrated.
6. When the "lime-treated" effluents are acidified, the kraft Decker
and NSSC effluents give more color in the acid-insoluble component
whereas caustic extract gives more in the acid-soluble component.
7. All acid-insoluble components are of higher molecular weight (My)
than acid-solubles.
8. Generally, acid-solubles contain higher carboxylate content than
acid-insolubles and are more open in structure,
9- Color-to-carbon ratio is generally higher in acid-insolubles than
acid solubles.
10. In the case of kraft Decker and caustic extract more of the acid-
insoluble color bodies are removed by lime, where in the case of
NSSC effluent more acid-solubles are removed.
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11. Kraft Decker effluents contain higher methoxyl, and phenolic-
hydroxyl content than the caustic extract. However, the NSSC
effluents contain the highest concentration of these groups.
12. Color bodies which are not removed by massive or stoichiometric
lime treatment seem to have the same characteristics.
13. Color bodies which are not removed by lime generally have low M^
less ligninlike character, higher carboxylate to aromatic ring
ratio and lower color to TOG ratio.
Ik. The upper removal limit of M^ changes from effluent to effluent.
15. Color bodies not removed by lime have an upper M^ limit from
200-500.
16. Addition of certain polyvalent metal ions with lime seems to
greatly improve the effectiveness of the lime treatment process.
These metal ions should be added to untreated or lime-treated
effluents before lime addition.
17• The metal ions and lime together are more effective color remov-
ing agents than either of these alone.
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SECTION II
RECOMMENDATIONS
1. Further work is needed to determine the structural differences of
the color bodies in order to explain differences in response to
lime treatment of different effluents. This would lead to a bet-
ter understanding of the advantages and weaknesses of the existing
lime-treatment process and could point the way to improved means
of removing color bodies.
2. Pilot-scale study of a metal ion-lime system should "be carried out
on mill effluents in order to confirm the laboratory findings, and
to establish the cost of the treatment involved,
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SECTION III
INTRODUCTION
Approximately 90 percent of the United States' chemical wood pulp is
produced by the kraft pulping process. In the kraft or sulfate process,
"black liquor (the spent cooking liquor) is evaporated and the strong
liquor is burned to recover cooking chemicals. However, evaporation
of dilute wash liquors is uneconomical, and these traditionally have
been discharged to streams. It is a common practice to keep wastes
in the holding ponds to reduce stream pollution. In spite of various
measures taken to reduce pollution, kraft mill effluents discharged into
streams are objectionable in color, and further improvements are
needed to reduce the color of these effluents.
The nature of color bodies in kraft mill effluents apparently has not
been fully investigated. Presumably, two wastes are believed to be the
main sources of color in the effluents; weak black liquor and effluent
from the caustic extraction stages in the bleach plant. In addition,
some color may form in the holding ponds. The black liquor contains
degraded thiolignins, degraded carbohydrates, and small amounts of
fatty and resin acids and other extraneous materials. The degraded thio-
lignins are highly colored and may be an important factor in the color
of mill effluents. The bleach plant effluents contain lignins, which
have been degraded further by chlorination and oxidation, and smaller
amounts of other materials. These lignins also are highly colored.
Since lignin is highly resistant to microbiological degradation, the
color passes through the biological treatment processes. The colored
effluents make the receiving waters brownish in color and reduce the
light penetration in water. This reduction in light intensity affects
aquatic plants by reducing photosynthesis and thereby adversely affects
the dissolved oxygen content of water.
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LIME TREATMENT PROCESS IN GENERAL
The lime-treatment process, developed by the National Council of the
Pulp and Paper Industry for Mr and Stream Improvement (NCASl) is re-
ported to be capable of removing 85-95 percent of the color from both
bleaching and pulping effluents1 **. This process has gone through the
pilot-plant stage and at present is being used by several mills
5-7
Three demonstration grants were approved by EPA (formerly FWPCA) to
determine the feasibility of lime precipitation of color bodies from
mill effluents on larger scales. One of the grants, made to the Inter-
national Paper Company at Springhill, Louisiana, involved massive lime
treatment of bleach plant effluent and brown stock washer effluent
(decker) both separately and in combination. The other two grants in-
volved stoichiometric lime treatment of total mill effluents at the
Interstate Paper Corporation, Riceboro, Georgia, and at the Continental
Can Company at Hodge, Louisiana.
Although the technology of lime treatment was well developed, conflict-
ing results had been reported with respect to the underlying chemistry
of the process. However, recent studies by Dence et_ al_. 8 have shown
that the removal of colored material from spent caustic extraction liquor
with' lime is a chemical rather than a physical process and that color
removal is dependent on (a) 'the presence of enolic and phenolic hydroxyl
groups and (b) on the molecular weight of solids contained in the liquor.
No data on molecular weight distribution were reported.
More recent studies done by Dugal et_ al.9 on kraft Decker effluents from
the Interstate Paper Corporation have shown that the color bodies which
are not removed by lime treatment have an apparent weight average molec-
ular weight of less than UOO. These color bodies were shown to contain
conjugated carboxyl groups, some ligninlike character and were associated
with colorless carbon compounds.
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THE PROJECT AND REPORT
The present project has teen divided into two parts. The first part (or
Phase l) of the project has been concerned with the chemical and physical
characterization of the color bodies in the mill effluents both before
and after lime treatment. Effluents from two different mills were
studied.
Section IV of this report deals vith the study of effluents from the
International Paper Company (IPCO) mill at Springhill, Louisiana which
used the massive lime-treatment process. Section V describes the study
of the effluent from the Continental Can Company (CONGO) mill at Hodge,
Louisiana, which uses the stoichiometric lime-treatment process.
The second part (or Phase II) of the project has been concerned with
the lime treatment of mill effluents in the presence of multivalent
ions. The objective of Phase II was to establish conditions for an
improved lime-treatment process using small amounts of multi-valent ions
of other metals in addition to lime. This part of the project is de-
scribed in Section VI. The manner in which the report is organized
is shown in Figure 1.
Lime Treatment
Processes
I
I
Massive
(international Paper Co.)
Section IV
I
Kraft Decker
Effluent
I
Untreated
Lime
Treated
1
Kraft Bleach
Caustic Extract
I
Untreated
I
Lime
Treated
Lime Treatment
With Metal Ions
Section VI
Stoichiometric
(Continental Can Co.)
Section V
I
1
Kraft Decker
Effluent
i
reated Lime
Treated
NSSC-
Effluent
1
l i
Untreated Lime
Treated
Figure 1. Classification of contents of the report
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SAMPLING AND HANDLING OF SAMPLES
Composite samples of untreated and lime-treated effluents (containing
color bodies that are not removed by lime) were shipped by air from
their respective mills to Appleton, Wisconsin. The samples were ship-
ped in five-gallon polyethylene jugs enclosed in especially designed
wooden crates provided by The Institute of Paper Chemistry. The usual
transit time was two to three days. Previous work9 had indicated that
the color changed upon storage in liquid form, therefore, samples in
transit longer than three days were discarded.
A number of samples (including the duplicate ones) were obtained from
the mills. Only eight were processed and fractionated according to
the program shown in Figure 2 and the rest were investigated in a pre-
liminary way. These eight samples included the decker and caustic
extract effluents before and after massive lime treatment, and decker
and NSSC effluents before and after stoichiometric lime treatment. The
lime-treated effluents which were investigated in detail were obtained
from the clarifier before the carbonation stage. Carbonation of these
samples was carried out under controlled laboratory conditions. The
reason for selecting the lime-treated samples "before" carbonation was
that samples carbonated by the mill's stack gases showed an increase in
color' and TOG values and, therefore, for fear of contamination these
were not used for the study. Depending upon the color to TOG ratios
and their place in the eluate series of a fractionation run, some
fractions were combined to give larger fractions before analysis.
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Dilute Effluent
Acid-Insoluble
4
Alkalization
I
Fracti onati on
(Bio-Gel P-2, P-60)
I
Freeze-Dry
Concentrate
I
Carbonation
I
Centrifugation
J/
Freeze-Dry
V
Acidification
I
Acid-Soluble
i
Fractionation
(XAD-8 Resin)
i
Alkalization
I
Freeze-Dry
Figure 2. Flow diagram for effluent processing and fractionation
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SECTION IV
MASSIVE LIME TREATMENT
(international Paper Company, Springhill, La.)
COLLECTION AND PROCESSING OF EFFLUENT SAMPLES
Source £f Effluent
International Paper Company's (IPCO) plant at Springhill, Louisiana is
a 1600 ton per day sulfate bleached pulp and paper mill. The mill uses
debarked softwood and hardwood chips for pulping. A small percentage
of sawdust is also used.
Mill wastes for the massive lime treatment included effluents from the
caustic and the unbleached decker stages or a combination of the two.
Only a portion of the total effluent (about 25 percent) was treated.
This company uses Houghton's antifoaming agent, De Airex 557» for con-
trolling foam problems.
Massive Lime Process at. IPCO
The lime treatment system handled 530 gpm of waste and 63 tons of lime
(CaO) per day. Lime dosage ranged from 18,000 to 20,000 ppm. The
waste and slaked lime were mixed in a 8 x 7 ft reaction tank. The de-
veloped floe was allowed to settle in a 26 x 27 ft effluent clarifier.
The sludge, containing color bodies, hydrated lime, and fiber, was
pumped at 20 percent solids to a 10 x 15 ft lime mud storage tank and
after causticizing was burned in a kiln to obtain lime.
The decolorized and clarified effluent that overflowed from the clari-
fier was treated with 650 cfm carbon dioxide to a pH of 10.5-11.0 in a
30 x 2U ft carbonator. The sludge containing 30 percent solids was
sent to the lime kiln and the clear effluent was sent to the impounding
basin.
11
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Color bodies removed from the massive lime process with the sludge are
to a large extent soluble in sodium hydroxide. Most of the color com-
pounds dissolve in the white liquor as it is produced in the causti-
izing process. "White" liquor thus produced with this process is dark
in color. Color compounds which remain with lime and are not dissolved
in "white" liquor end up in the lime kiln and are burned. Color bodies
dissolved in "white" liquor eventually are burned in the mill's chemical
recovery furnace.
Variations in the effluent composition did occur because of the fluc-
tuations in the ratios of different kinds of wood used for pulping.
Color of the ef'luent from the caustic stage ranged from IT»000 to
30,000 APHA units. Details of the Massive Lime Treatment Pilot Plant
can be obtained from the EPA report10 based on work done at the IPCO's
plant at Springhill, Louisiana.
Effect of Shipment
Four batches of samples, each batch containing the untreated, lime-
treated before carbonation and lime-treated after carbonation wastes
were received from Springhill, La. over a period of three months.
The batches of samples contained effluents from the decker washing
stage (referred to as decker), the caustic extraction stage (referred
to as caustic), and mixtures containing 75 percent decker-25 percent
caustic and 50 percent decker-50 percent caustic.
Chemical analyses on these effluents (before shipment) was supplied by
IPCO and are given in Table 1. (Please note the sample code employed as
shown in Table 1 footnotes.) Upon receipt at the Institute, representa-
tive aliquots of some of the liquid wastes were chemically analyzed and
compared with the data of Table 1. The results showed a decrease in
color and TOC during shipment. The data fluctuated so much that no
definite numbers could be assigned. However, the percentage of color
removed, based on data obtained before and after shipment, was almost
the same, indicating that the change in color values during shipment is
constant and whether this change is real or experimental could not be
established.
12
-------
Table 1. CHEMICAL DATA OH EFFLUENTS BEFORE SHIPMENT FROM IPCO
U>
ICO? Decker
ppm UD3 LTBC8 LTAC8
pH value 10.1 12.1 11.7
Total solids 2250 3070 1330
Asha 1260 1700 690
Volatile solids* 990 1370 61*0
Calcium as Ga 15 50^ 67
Chlorides as Cl 50 Uo 35
Color units0 890 2UO 270
Total carbon 260 190 230
Inorganic carbon 20 10 10
TOC 2«*0 113d 156d
COD 65U U22 U62
BOD 192 276 252
75? Decker, 25%
UDC7
10.5
2598
1352
12U5
27
339
5100
1*75
50
U25
1U37
2»*6
LTBC7
13.2
3232
2U95
737
k66
339
215
150
20
130
«U
165
Caustic
LTAC7
12.6
31*95
2595
900
K>1*
339
350
160
20
lUO
371
201
50? Decker, 50?
UDC9
9-8
3950
2170
1780
36
835
10,500
1200
100
1100
2002
252
LTBC9
12.3
i*oUo
2760
1280
536
7U5
700
280
50
230
1*78
138
Caustic
LTAC9
10.7
27l»0
1710
1030
252
72»»
1000
U60
1*0
U20
516
130
UC10
9-3
5350
2960
2390
38
986
17 ,000
1^75
150
1325
1527
192
100? Caustic
LTBC10
12.0
1*1*90
3200
1290
552
956
675
270
10
260
563
168
LTAC10
10.5
1*350
2770
1580
21*0
986
780
1*30
150
280
572
132
*Ashed at 600°C for 1 hour.
Calculated by difference.
jIAPHA-color, Pt-Co units.
Calculated figures based on information from IPCO.
UD = Untreated decker effluent.
UC = Untreated caustic effluent.
UDC = Untreated effluent containing UD and
LTBC = Lime-treated before carbonation.
LTAC = Line-treated after carbonation.
UC.
TOC = Total Organic £arbon.
COD = Chemical Ojcygen Demand.
BOD = Biochemical Oxygen Demand.
IPCO = International Paper Company, Springhill, Louisiana.
7,8,9,10 = Batch numbers of the respective effluent samples.
-------
Table 1 shows that parameters generally increase with increasing amounts
of caustic waste. BOD values appear to be an exception in that they
fluctuate but show a downward trend. The results show that caustic ex-
tract is about 20 times more colored than the decker effluent. The data
further indicate that the color and TOG of lime-treated samples increase
after carbonation.
Effect of Freeze Drying and Storage
The liquid samples were first concentrated to one-tenth their volume,
carbonated to a pH of 10.2, centrifuged until clear and freeze-dried
(see Figure 2). Freeze-dried material was readily soluble in water.
Freeze drying of the colored wastes was found to prevent appreciable
changes in color bodies during storage.
The effect of freeze drying on color bodies was determined by observing
changes in the sedimentation coefficient values of the color bodies be-
fore and after freeze drying. The sedimentation coefficient is defined
as the velocity of sedimenting molecule per unit field and is a function
of the anhydrous molecular weight of the sedimenting substance and the
partial specific volume of the solute. It decreases with the decrease
in molecular weight and increase in the hydration of the sedimenting
molecule.
The sedimentation coefficients were determined according to the method
described by Schachman11 using the ultracentrifuge. The lapse time
between the measurements of samples before and after freeze drying was
U-5 days. Results are given in Table 2.
Table 2. SEDIMENTATION COEFFICIENTS OF THE COLOR BODIES
3.
Sedimentation coefficients, S
Before After
Effluent freeze-drying freeze-drying
Untreated decker 1.2 1.2
Untreated caustic 2.0 2>1*
aS = Svedberg = 1 * 10~13.
-------
Table 3. CHEMICAL DATA ON FEEEZE-DRIED WASTES FROM IPCO
1002 Decker
Yield, o.d. g/100 ml
Asha, %
>,
Volatile , %
Sul fated asha, %
Sodium, %
Calcium, %
Chloride, %
Sulfate, %
Sulfide, %
TOC, %
UD8
0.12
81.5
18.5
93.8
26.8
<0.10
6.3
3U. 6
-------
Table 1». EMISSION SPECTROSCOPIC AHALYSIS OF FREEZE-DRIED WASTES FROM IPCO
(All values on o.d. ash)
Metals, %
Aluminum
Boron
Calcium
Copper
Magnesium
Manganese
Silicon
Sodium
Total*
100% Decker
UD8
O.li30
0.016
0.066
0.0016
0.027
0.0032
0.070
31.0
0.61U
LTBC8
0.071*
0.0081*
0.093
0.0005
<0.020
<0.001
<0.050
31*. o
0.21*7
LTAC8
0.200
0.0085
0.098
0.0005
<0.020
<0.001
<0.050
33-2
0.378
75* Decker. 25* Caustic
UDC7
0.2l»0
0.0068
0.800
0.0008
0.050
0.0081*
0.052
36.7
1.158
LTBC7
0.053
0.0038
0.038
0.0005
<0.020
<0.001
<0.050
33.6
0.166
LTAC7
0.200
0.0058
O.OU6
o.oooU
<0.020
<0.001
<0.050
32.6
0.323
50 f Decker, 50? Caustic
UDC9
0.110
-------
Because no significant changes were noticed in the sedimentation coef-
ficients of color bodies on freeze drying and no appreciable color change
was noticed on storage in the freeze-dried state, all color bodies were,
therefore, freeze-dried and stored until used for further study.
INITIAL CHARACTERIZATION OF COLOR BODIES FROM THE KRAFT
DECKER AND KRAFT BLEACH CAUSTIC EXTRACT EFFLUENTS FROM IPCO
Chemical Characterization
Chemical analysis of the freeze dried wastes is given in Table 3. The
results are tabulated according to the increasing amount of caustic ex-
tract in the effluent and not according to the batch number. A compar-
ison of all untreated samples shows that as the amount of caustic extract
increases the volatile and chloride contents increase whereas ash and
sulfate decrease. No particular trend is noticeable in the case of
sodium and calcium (calcium was removed by carbonation of mill effluents
in our laboratory during processing). The sulfate and chloride removal
by lime decreases with increasing amounts of caustic extract.
The ash was analyzed by emission spectroscopy and the results are given
in Table k. The reason for this analysis was to determine whether or
not enough metals are present in the system which could form colored
complexes with the color bodies. The total amounts of metals in these
wastes were very small. Sodium values by the emission spectroscopy
method are not as accurate as by the flame photometry method (Table 3)
and are not included in the total. Surprisingly enough, no determinable
amounts of iron were found in these wastes. The data in Table U show
that with the increasing amounts of caustic extract in mill effluent,
silicon and magnesium increase whereas aluminum and boron decrease.
Copper content does not show any definite trend. The data further show
that more than 50 percent of the total metals are removed during the
lime treatment. However, the ratio of metal content to TOC does not
change much indicating that these may be associated with the organic
carbon in the effluents (Table 5).
17
-------
Table 5. CHANGE IN METAL/TOG RATIO DURING LIME TREATMENT
OF MILL WASTES FROM IPCO
Ratio, metal content/TOC
Effluent Untreated Lime treated8-
100% Decker O.OU 0.05
15% Decker, 25% caustic 0.05 O.Olt
50# Decker, 50$ caustic 0.02 0.03
100# Caustic 0.02 0.03
All values "based on o.d. total solids.
aLime treated before carbonation effluent.
(Carbonation was carried out in laboratory under
controlled conditions.)
Spectrophotometric Examination
The freeze-dried untreated and lime-treated decker, caustic extract and
mixed effluents vere dissolved in distilled water to give desired con-
centrations. Visible and ultraviolet spectra of these aqueous solutions
were determined at two pH levels. In one case the pH was "unadjusted"
and ranged from 9-10.5. In the other case it was adjusted with a buffer
solution to 7.6. Distilled water was used as a reference for all of
the samples. Absorbance values of all samples at pH 7«6 were lower than
their respective unadjusted samples.
In order to have a reasonable comparative picture, absorptivities at pH
7.6 were calculated from these spectra at different wavelengths by di-
viding the absorbance values with the volatile solid concentration in
g/1. The results are given in Tables 6 and 7 and are plotted in
Figures 3, !*, 5, and 6, and compared with those for Indulin-C. Values
for LTBC wastes are used. LTAC values fluctuated, probably because of
the contaminated stack carbon dioxide which was used for carbonation
at the mill site.
18
-------
Table 6. ABSORPTIVITY* VALUES OBTAMED FROM VISIBLE SPECTRUC AT pH 7.6 OF HASTES FRCM IPCO
VO
100* Decker
Total solid*, g/1
Volatile solids*. %
Volatile solids, g/1
Wavelength, tm
600
580
570
560
550
5kO
530
520
510
500
1*90
1.80
1.70
1.65
160
k55
150
k20
liOO
380
UD8
0.1.
18.5
0.071.
0.16
0.17
0.19
0.22
0.2k
0.27
0.28
0.30
0.35
O.kl
O.k3
0.50
0.50
0.61
0.62
0.66
0.72
1.10
1.5k
2.1.8
LTBC8
1.0
8.5
0.085
0.09
0.11
0.11
0.13
0.15
0.16
0.16
0.18
0.20
0.20
0.23
0.25
0.28
0.29
0.29
0.31
0.3k
0.53
0.85
1.86
L7AC8
1.0
10.5
0.105
0.10
0.10
0.10
O.Ik
0.15
0.16
0.16
0.16
O.I?
0.23
0.2k
0.25
0.28
0.29
0.29
0.32
0.35
0.5k
0.8k
1.7k
75? Decker, 25* Caustic
UDC7
O.k
27.2
0.1088
0.35
0.1.3
0.1.8
0.5k
0.59
0.68
0.75
0.8k
O.?k
1.03
1.16
1.30
1.1.6
1.5k
1.6k
1.73
1.63
2.70
3.k9
k.75
LT3C7
1.0
8.1
0.081
0.0k
0.05
O.O5
0.06
0.07
0.09
0.09
0.09
O.Ik
0.15
0.16
0.16
0.17
0.20
0.22
0.23
0.25
O.k5
0.66
1.32
LTACT
1.0
9-7
0.097
O.03
0.05
0.05
0.06
0.08
0.09
0.09
0.09
0.12
0.13
0.15
0.15
0.18
0.18
0.20
0.22
0.2k
O.38
0.56
1.08
50? Decker. 5Ot Caustic
UDC9
O.k
30.9
0.1236
0.1.2
0.53
0.59
0.68
0.75
0.85
0.9k
1.07
1.13
1.35
1.50
1.69
1.90
2.02
2.13
2.27
2.39
3.kl
k.38
5.78
-LTBC9
1.0
10.2
0.102
0.11
0.11
O.Ik
0.16
0.18
0.18
0.20
0.22
O.25
0.30
0.3k
0.37
0.1.1
O.k3
O.k6
O.k9
0.50
0-.75
1.05
1.66
LTAC9
1.0
9-1
0.091
0.13
0.15
0.16
0.17
0.18
0.20
0.20
0.20
0.23
0.28
0.29
0.33
0.35
0.38
0.39
0.39
O.kk
. 0.65
1.01
2.03
UC10
O.k
37.8
0.1512
0.53
0.68
0.76
0.85
0.9k
1.06
1.17
1.30
l.k6
l.kk
1.80
2.00
2.25
2.37
2.V8
2.6k
2.78
3.87
k.90
6.30
100* Caustic
LTBC10
1.0
8.2
O.O62
0.15
0.15
0.15
0.17
0.19
0.21
0.22
0.23
0.27
0.32
0.35
O.kl
O.k5
O.k9
0.50
0.53
0.55
0.79
1.08
1.73
LTAC10
1.0
9.5
0.095
0.07
0.09
O.09
0.11
0.12
0.15
0.17
0.18
0.22
0.27
0.31
0.36
O.k2
O.k5
O.VT
0.52
0.56
0.89
1.2k
1.92
Indulia-C
0.175
k6.2
0.061
O.6l
0.65
O.70
0.75
0.82
0.91
1.01
1.10
1.19
1.27
I.k3
1.60
1.79
1-90
2.00
2.11
2.25
3-39
k.68
6.9k
*l/(g)Cas), obtained b/ dividing absorbance values with volatile solids In g/1.
Bued on total solids.
For ssaple code see Table 1.
-------
Table 7. ABSORPTIVITY VALUES OBTAINED FROM ULTRAVIOLET SPECTRUM AT pH 7.6 OF WASTES FROM IPCO
100? Decker
Total solids, g/1
Volatile solids*. J!
Volatile solids, g/1
Wavelength, run
3ltO
320
300
295
290
265
282
280
276
275
270
265
260
255
250
2UO
235
230
225
220
215
205
202
200
UD8
0.2
18.2
0.037
5.57
6.98
8.65
9.1*9
10. u5
11.92
12.U7
12.70
12.89
13.19
13.1*9
13.67
1U.22
15.13
16. 1*3
21.38
2U.1.6
27.00
29-90
33.38
38.69
55. i1*
—
LTBC8
0.5
6.5
0.01*25
U. 77
U.82
5.00
5.1*8
5.95
6.60
7.22
7.3k
7.1*8
7.83
8.11
6.33
8.73
9-55
10.16
12.09
13.68
15.55
17.81
20.78
2U.17
37-16
—
LTAC8
0.5
10.5
0.0525
I(.U2
it.Uli
It. 71
5-09
5-70
6.50
6.Q7
7.11
7.19
7.58
7-78
7.96
8.29
8. 92
9."*7
11.53
13.26
15.07
17.28
19.81
23.3li
35-37
—
TT'S De
UUC7
0.02
27-2
0.005U
7. Pit
9.U
13.15
13.69
11*. 99
16.66
17. Ul
17.59
17.77
18.33
10. U
19-63
20.00
20.18
21.66
26.U8
30.37
33.33
38.38
l»1.6T
1*6.66
58.13
—
cker, ?5£
LT3J7
0.5
8.1
0.01*05
2.89
3.W
1*.20
U.69
5.36
6.17
6.6Q
6.86
7.11
7.><3
7.78
7.87
7.98
8.07
8.32
9.26
10.20
11.31
12. 91*
15.16
16.00
26.1*2
_ _
—
Caustic
LTAC7
0.5
9-7
0.0<*85
2.6U
3-09
3-73
lt.01
It.fiO
5-32
5-75
5.98
6.01*
6.3"
6.61*
6.76
6.66
7-01
7-21
8.ll»
9-03
10.02
11.U9
13. U6
15-98
23.62
_
—
so£ Decker, 50«
UDDJ
0.02
30.9
0.0062
10.17
12.26
15.50
16.62
18.23
19.68
20.33
20.81
21.1U
21.78
23-07
23.56
21*. OU
2!*. 36
25- «»9
29-36
32.1*2
37-92
39-52
1*3.39
U7.60
SU.86
.w
—
LTDC9
o.u
10.2
o.o'ioa
3.51
It. 66
6.05
6.86
7-72
8.87
9.1*1
9-78
10.07
10.1*9
10.93
11.08
11.10
11.10
11.12
11.89
12.99
lit. 22
16.08
18,58
21.61
28.06
30.«*7
32.08
Caustic
LVAC9
0.5
9.1
0.0lt55
It. 66
6.20
8.00
8.90
10. 01*
11.1*3
12.28
12.55
12.95
13.58
lit. 13
1"*.33
lfc.35
lit. 06
lit. 19
15. lit
16.36
17.89
20.16
22.90
26.79
35-06
37.32
39.9U
100' Caustic
UC10
0.02
37.8
0.0076
10.26
11.97
15.26
16.32
17-63
18.82
19- ^7
20.00
20.13
?0.76
21.98
22.52
23.03
23.55
2>*.35
28.16
30.79
33.82
37.37
lil. 19
U5-00
U8.U2
U8.69
U8.69
LTBC10
0.5
8.2
O.O1*!
3.76
5.10
7-13
7.93
9-20
10.59
11.1*5
11.76
12.16
12.72
13.26
13-ltO
13.25
12.93
12.78
13-Ult
11*. 56
16.13
18.51
18. 1.6
25."»5
31.50
33-10
3U.5"4
LTAC10
0.5
9.5
0.01*75
1*.OU
5.66
7.6U
8.59
9.77
11.16
11.96
12.36
12. 71*
13.35
lii.no
lit. 19
it*. 08
13.77
13.68
lit. 37
IS-'tg
17.03
19.30
22-Uo
26.29
33-03
35-15
36.69
Indulin-C
0.018
1*6.2
0.008
16.6
2i:6
27.6
30.6
33-5
37.0
38.0
38. U
38.8
38.8
36.6
38. U
39.0
U0.9
Ul*.6
60.5
71.1
80.3
88.9
98.6
llU.l
161.1
169.0
169.6
*l/(g) (CB). obtained by dividing absorbance values with volatile solids in g/1.
bBased on total solids.
For sample code see Table 1.
-------
o
a)
.0
7-0
6.0 _
380
Untreated Wastes
O 1002 decker
D 75% decker, 25? caustic
A 50? decker, 50% caustic
X 100? caustic
kko
520
560
580
kQQ 500
Wavelength, nm
Figure 3. Absorptivity values at pH 7.6 of untreated wastes from IPCO (visible region)
600
-------
6.0
ro
o
0)
5.0
i*.o
3-0
2.0
I >
(1
1.0
X
O
D
Indulin-C
8
I
I I
Lime-Treated Wastes
O 100 Jg decker
D 75 £ decker, 253? caustic
A 50# decker, 50JS caustic
X 100% caustic
§6l6ftaflft«
400
U20
UUO
520
560
580
1*60 1+80 500
Wavelength, nm
Figure 1*. Absorptivity values of pH 1.6 of lime-treated wastes from IPCO (visible region)
600
-------
170
160
150
130
120
g 110
bO
H" 100
•H
•H
•P
o
CO
90
80
70
60
50
1*0
30
20
10
8
Untreated Wastes
O 100$ decker
D 75# decker, 25# caustic
A 502 decker, 50$ caustic
caustic
200 220 240 260 280 300
Wavelength, nm
320
Figure $• Absorptivity valxies at pH J.6 of untreated wastes from IPCO (UV region)
23
-------
•H
-P
O
(0
Indulin-C
Lime-Treated Wastes
O 100JK decker
Q 75# decker, 25$ caustic
^ 50% decker, 5Q% caustic
X 100JS caustic
» t I
» . t
200
220
260 2~BO300320
Wavelength, na
Figure 6. Absorptivity values at pH 1.6 of nassiye lime-treated
wastes from IPCO (UV region)
21*
-------
The following is observed:
Visible Region (Figures 3 and U) —
a. All samples exhibit increased absoptivity as the wave-
length decreases.
b. None of the samples contain a maximum in this region.
c. Untreated samples containing higher percentages of
caustic extract give higher absorptivity values, with
100 percent caustic having the highest, even higher than
Indulin-C (Figure 3).
d. Lime-treated samples exhibit similar but lover absorp-
tivities than their respective untreated samples (Figure h).
The visible spectra demonstrated that no single color is present in the
waste samples, rather they are mixtures of different colors as character-
ized by the increase in absorptivity as the wavelength decreases. In
addition, it was demonstrated that lime treatment decreases the amount
of color-giving materials.
Ultraviolet Region (Figures 5 and 6) —
a. The samples exhibit increased absorptivities as the
wavelength decreases.
b. Untreated samples from the decker stage have lowest
absorptivity values compared to others (Figure 5)•
c. Lime-treated samples exhibit similar but lower absorptivities
than their respective untreated samples (Figure 6).
d. All samples show a "shoulder" at about 280 nm. A similar
"shoulder" was noticed at 205 nm in some cases. These
absorptivity curves are quite similar to the one exhibited
by Indulin-C.
e. Generally, samples containing higher percentages of untreated
caustic extract gave higher absorptivity values with a shift
in the absorptivity "shoulder" from 280 nm to 265 nm. The
reason for this shift is not understood. Chlorinated lignins
may have something to do with this. Hardwood lignins are
25
-------
known to have maxima (shoulder) at shorter wavelengths
than softwood lignins, about 275 instead of 280 run12.
Goring13 has cited 272 nm as the position for the maximum
for birch lignin.
The ultraviolet spectra indicated that the mill wastes contain materials
similar to those present in lignin and that the amount of these materials
is decreased by lime treatment.
Effect of Lime Treatment
The percentage of color and TOC removal and percentage decrease in absorp-
tivity were calculated from data in Tables 1,6, and 7 and the results
are given in Table 8 and plotted in Figures 7 and 8.
Table 8. EFFECT OF LIME TBEATMENT ON WASTES FROM IPCO
Composition of
mill effluent
Caustic,
%
0
25
50
100
Decker,
%
100
75
50
0
Color
removal ,
%
73.0
95.8
93.3
96.2
TOC
removal a,
%
53.0
69.14
79. U
80.3
Decrease in
absorptivity , %
at 1*20 nm at
5fc.6
83.3
78.0
79.6
280 nm
1*2.2
6l.O
53.0
U2.5
et
"Based on values for effluent samples.
Decrease in absorptivity caused by lime treatment based on volatile
solids content of solids isolated from effluents.
The data show that 7U to 96 percent of color and 53 to 80 percent of TOC
are removed during lime treatment. The effectiveness of lime generally
increases with increasing amounts of caustic extract in mill effluent
(Figure 7) • The decrease in absorptivity ranged from 51* to 83 percent
at 1*20 nm and 42-61 percent at 280 nm (Figure 8).
In order to understand the changes due to lime treatment and to avoid
the problems of mixed systems, only decker and caustic extract effluents
26
-------
as such were used for further study. Mixed effluents containing 50-50
or 75-25 percent decker and caustic effluents were not investigated in
detail.
Color
0
100
25 50
75 50
Effluent Composition
100$ caustic
I decker
Figure 7. Color and total organic carbon removal of
wastes from IPCO by lime treatment
FURTHER CHARACTERIZATION OF COLOR BODIES FROM KRAFT
DECKER EFFLUENT FROM IPCO
Fractionation of_ Color Bodies.
Acidification -
From previous experience9 it was known that most of the colored material
could be precipitated by acidification of the strong aqueous solutions
of the color bodies from kraft decker wastes. Thus, when 15 percent
solutions of the freeze-dried untreated and lime-treated decker wastes
were adjusted to a pH of 1.0 with approximately 3N hydrochloric acid,
27
-------
100 _
nm
nm
0 25 50 100# caustic
100 75 50 o% decker
Effluent Composition
Figure 8. Decrease in absorptivity of wastes from
IPCO by lime treatment
much gaseous material vas evolved, and a dark colored precipitate was
obtained. During acidification an odor similar to that of hydrogen
sulfide was also detected. However, the major part of gases is believed
to be due to the presence of carbonates in the parent sample. Thus, acid-
ification was used to isolate the acid-insoluble and acid-soluble color
bodies. The results of this fractionation are given in Table 9.
The data in Table 9 show that upon acidification of untreated wastes,
82.5 percent color and 51.0 percent TOC were recovered in the acid-
insoluble fraction. The acid-soluble fraction contained 17-5 percent
color and 1+9.0 percent of the TOC. However, when lime treated wastes
were acidified, the acid-insoluble fraction contained only 51.0 percent
color (13.8 out of 27.0) and 7.0 percent TOC (3.3 out of 1*7-0), The
acid-soluble fraction of the lime treated waste contained 1*9-0 percent
28
-------
color (13.2 out of 27.0) and 93.0 percent TOO (U3.7 out of U7.0). Table
9 further shows that the lime treatment removed 83.3 percent color and
93.5 percent TOO from the acid-insoluble color bodies and only 2k.5 per-
cent color and 10.8 percent TOC from the acid-soluble color bodies.
These values were calculated from the yield data of the untreated and
lime-treated color bodies.
Table 9. CHANGE IK SOLIDS ISOLATED FROM IPCO EFFLUENTS
DUE TO MASSIVE LIME TREATMENT
Untreated
decker waste
Fractions
Decker waste
Acid-insoluble
Acid-soluble
Colora
yield,
%
100
82.5
17-5
.
TOC
yield,
%
100
51.0
1*9-0
Lime-treated
decker waste
Color
yield,
%
27-0
13.8
13.2
TOC
yield,
*
1*7.0
3.3
1*3.7
Reduction
due
to limec
Color,
*
73.0
83.3
21*. 5
TOC,
%
53.0
93.5
10.8
Yield values basis untreated decker solids.
*APHA units, Pt-Co color.
Total organic carbon.
Column Chromat ography —
The acid-insoluble color bodies were dissolved in distilled water and
fractionated on Bio Gel P-2 column (200-cm long and 2.5 cm in diameter)
having an exclusion limit of molecular weight 2600. The first fraction
"A" from each run was further fractionated on Bio Gel P-60 column (100
cm long, 2.5 cm diameter) having an exclusion limit of molecular weight
60,000. The details of fractionation are given in the experimental part
of this report. All fractions obtained from the gel columns were ana-
lyzed for color, TOC, and absorbance at U20 nm and 280 nm. The data
were used for calculating percentages of yield and percentage of removal
by lime in each fraction. Only data on color and TOC are given in Table
10. (For details see Appendix I.)
29
-------
Table 10. FRACTIONATION OF DECKER ACID-INSOLUBLE COLOR
BODIES BY COLUMN CHROMATOGRAPHY
Untreated
acid-insoluble
color "bodies
Color TOC
yield, yield,
Fractions % %
Lime- treated
acid-insoluble
color "bodies
Color TOC
yield, yield,
% %
Re ducti on due
to lime0
Color, TOC,
% %
Fraction "A" from
P-2 through P-60
column
A2 through A6a
Acid-insoluble color
bodies through P-2
column
A
B
C
D through R
Un fractionated
acid-insoluble
color bodies
12.9
te.l
6.2
15.7
3.6
1.0
0.1*1
0.11
72.1
97-6
93.1*
99-3
55-0
2.U
2.1
23-0
82.5
21.9
1.7
2.1
25-3
51-0
U.6
1.0
1.1
6.1
13.8
0.52
0.18
0.2U
2.U
3.3
91.6
58.3
U7-5
73.5
97-6
89.1*
88.6
90.5
83.3 93.5
Percentages of yield are calculated on the basis of untreated original
waste.
Calculated by difference so that values for A =
+ A2 through
Calculated by difference so that values for un fractionated acid-insol-
uble color bodies =(A+B+C+D through R).
Values calculated from "yield" data of the solids isolated from untreated
and lime-treated effluents.
The results show that in the case of untreated acid-insolubles approxi-
mately 67 percent of the color (55.0 out of 82.5) and U3 percent TOC
(21.9 out of 51.0) were obtained in fraction "A," whereas in the case
of lime-treated acid-insolubles this fraction contained only 33 percent
of the color and 15*7 percent of TOC. Average color and TOC removed by
lime were 83-3 and 93.5 percent, respectively.
The untreated and lime-treated acid-soluble color bodies were isolated
into four fractions by first sorbing on Rohm & Haas Company's Amberlite
30
-------
XAD-8 resin (polystyrene cross-linked with divinyl benzene) and then
deserting with aqueous ethanol (1:1 mixture of water and 95 percent
t
ethanol). It should be kept in mind that the fractionation was not
sharp, and thus each fraction could contain some material similar to
that found in the previous fraction. The ethanol was removed under re-
duced pressure and each fraction was made alkaline with sodium hydroxide
to pH about 9-0,
The first fraction contained material which passed unadsorbed through
the column.
The second fraction contained material which was held on the column
initially, but was readily eluted from the column with water. Upon
alkalization this fraction deepened in color and was more highly colored
than the first fraction.
The third fraction was an intermediate fraction and was collected until
the eluate was neutral to Congo red.
The fourth fraction contained material eluted with aqueous ethanol.
All fractions obtained from the XAD-8 column were analyzed as before and
the results are given in Table 11. The results show that in that case
of untreated acid-solubles approximately 62 percent color (10.9 out of
17.5) and 33 percent TOG (l6 out of U9-0) were obtained in fraction IV.
(Some color and TOG is unaccounted for), whereas in the case of lime-
treated acid-solubles this fraction contained TO percent color and 30
percent TOG. The average color and TOG removed by lime were 2^.5 and
10.8 percent, respectively. The table further shows that practically
no color and TOG are removed by lime from acid-soluble Fractions III
and IV (when calculated on the combined basis).
Characterization of Decker Effluent Fractions
Fractions of acid-insoluble and acid-soluble color bodies of the untreat-
ed wastes were obtained by column chromatography. Several of these
fractions were very small, especially after allowing for amounts required
for molecular weight determinations.
31
-------
Table 11. FRACTIONATION OF DECKER ACID-SOLUBLE COLOR BODIES
BY SORPTION ON XAD-8 RESIN
Untreated
acid-soluble
color bodies
Lime-treated
acid-soluble
color bodies
Reduction due
Fractions
(Combined III + IV)
IV
III
II
I
Unfractionated acid-
soluble color bodies
Color
yield,
%
(12.1)
10.9
1.2
2,5
0.9
17-5
TOG
yield,
%
(19-0)
16.0
3.0
16.2
7.6
Up.O
Color
yield,
%
(12.0)
9.2
2.8
1.3
0.5
13.2
TOC
yield,
%
(20.1)
12.9
7.2
ll*.7
fc.9
^3.7
to limea
Color,
%
(1.0)
15.5
+
W.O
1*1*.5
21*. 5
TOC,
%
(+5.0)
19-5
+
9.2
35.5
10.8
Percentages of yield are calculated on the basis of untreated organic
waste. "+" Values showed an increase.
Values calculated from "yield" data of the solids isolated from un-
treated and lime-treated effluents.
To provide sufficient material for chemical analysis some adjacent frac-
tions were combined to give bullcy fractions. Thus, Fractions "Ai"
through "A6" were combined (referred to as "A"), "C" through "B" were
combined, and out of the four acid-soluble fractions the adjacent frac-
tions which were similar with respect to their ratios of color to organic
carbon were combined to give two larger fractions.
Visible and Ultraviolet Spectra —
Visible and ultraviolet spectra of Indulin-C, acid-insoluble fractions,
and acid-soluble fractions of the untreated and lime-treated wastes were
determined at pH 7.6.
Absorptivity values from these spectra were calculated at definite wave-
lengths and the results are plotted in Figures 9. 10, 11, and 12.
32
-------
Untreated Waste Fractions
O A
D C-R
A I+II 1
X in+iv/
V
Acid-
insoluble
Acid-
soluble
200
220
320
260 280 300
Wavelength, am
Figure 9« Absorptivity versus wavelength (ultraviolet range) of Indulin-C
and untreated kraft decker waste from IPCO
33
-------
200
Line-Treated Waste
Fractions
O A
D C-R
X IIX+ZV
220
21*0
300
320
340
260 280
Wavelength, no
Figure 10. Absorptivity versus wavelength (ultraviolet range) of Indulin-C
and lime-treated kraft decker waste from IPCO
31*
-------
a
o
to
•rl
-P
O
01
Untreated Waste
Fractions
Acid-
insoluble
U80
500
520
51*0
560
580
600
Tigare 11.
Wavelength, nm
Absorpti-rity versus vavelength (visible range) of Indulin-C and
untreated kraft decker waste from IPCO
-------
7-qir
Lime-Treated
Waste Fractions
U80 500
Wavelength, nm
Figure 12. Absorptivity versus wavelength (visible region) of Indulin-C and
line-treated kraft decker waste
600
-------
Ultraviolet region (Figures 9 and 10) - All samples exhibited an increase
in absorptivity as the wavelength decreased. Indulin-C, untreated "A"
fraction, untreated III and IV fraction and lime-treated III and IV
fractions showed an Indulinlike characteristic absorption band at 280 nm
indicating the presence of more ligninlike materials. The lime-treated
color bodies of the acid-insolubles (Fractions "A" and C-R) showed lower
absorptivity values than their respective untreated fractions. However,
the acid-soluble color bodies (Fractions I + II and III + IV) showed an
increase in absorptivity after lime-treatment (compare Figures 9 and 10).
Visible region (Figures 11 and 12) — All samples gave simple absorption
curves and exhibited an increase in absorptivity as the wavelength de-
creased.
Acid-insoluble color bodies (Fractions A and C-R) showed lower absorp-
tivities after lime-treatment while the absorptivities of acid-soluble
color bodies (Fractions I -t- II and III + IV) increased or remained un-
changed after lime treatment.
At this stage it can be said that almost all fractions contain lignin-
like color bodies. The differences in absorptivity may be due to
different levels of degradation of color bodies.
Molecular Weight Distribution —
Molecular weights of some selected fractions of acid-insoluble and all
acid-soluble components of the untreated and lime-treated color bodies
were determined by the sedimentation equilibrium method using the
analytical ultracentrifuge11*. In the present work the "short column
sedimentation equilibrium method" was used. Details of this method are
given in the Experimental part. The apparent "Weight Average" molecular
weights (My) for each fraction were calculated at zero angular velocity
(to2 = 0) because the My were changing with change in w2. The results
are plotted in Figures 13a and b. .
Figure 13a shows that untreated acid-insoluble components are much higher
in My than those of lime-treated acid-insolubles. The My values drop
37
-------
o
H
36
32
28
2k-
20
16
12
Acid-insolubles
Untreated
Lime Treated
?-.<-r>
Acid-solubles
-Untreated
-Lime Treated
IV III II I
Eluate Fractions
(XAD-8 Fractionation)
A3 A5 B D F
i A* .Ac C E
t i
H KM P
J L N
tluate Fractions
(Gel permeation chromatography)
Figure 13. Weight average molecular weight (My) distribution of
fractionated color bodies from kraft decker effluent
from IPCO (MV values at t,)2=0)
38
-------
sharply from 33,000 to about 300 and then rise slightly near Fraction
"J." The increase, however, is not very significant and may be due to
different ash contents of the fractions. The noticeable point of inter-
est is that most of the higher M material has been removed by lime.
My of untreated and lime-treated acid-soluble color bodies are quite
similar to each other (Figure 13b). Lime-treated materials (M^ range
< 350) have, however, lower M^ than untreated materials (range < 950).
Figure lU shows that acid- insoluble color bodies having an apparent M^
of less than 200 are not removed by the massive lime treatment. The
intermediate range of My. 200 to 2000 apparently undergoes partial removal
and over 2000 are completely removed. However, over 80 percent removal
occurs above a M^ of 200-500. The average color and TOG removal of the
acid- in soluble fraction was found to be 83-3 and 93.5 percent, respec-
tively (Table 10 ).
100
80
60
1*0
w
20
g
tsi
1-8
Partial
Removal
Zone
Complete
Removal
Zone
0
500 1000 1500 2000
M, acid-insoluble color bodies
2500
Figure lU. Weight average molecular weight (M^) of
acid-insoluble color bodies from decker effluent
versus percentage of removal by massive lime
39
-------
The acid soluble color bodies behave differently. In this case color
bodies which were sorbed on XAD-8 resin and later desorbed by aqueous
ethanol (Fractions III + IV) were practically untouched by lime, while
21 percent removal occurred in the case of color bodies which could not
be sorbed on XAD-8 resin. The average color and TOO removal of the acid-
soluble fractions was only 2U.5 and 10.8 percent, respectively.
Ghemi cal_ _Charact eri z at ion —
The results of the chemical analysis are given in Table 12. Fractions
were analyzed for ash, phenolic hydroxyl, total sugars, and methoxyl
content. Absorptivities (absorbance/volatile solids in g/liter) at U20
nm (Ei»2o), as a measure of original color, and at 280 nm (E^eo) as a
measure of lignin content have also been tabulated. Actually two values
may be used as approximate measure of lignin content, namely E2eo and
methoxyl. Calculated ratios of Ei^o/E^o, E^SS/ESOO, Ei^o/MeO, and
E2eo/MeO have also been included in Table 12.
The data in Table 12 suggest:
a. The untreated decker waste contains 0.25 meq phenolic
hydroxyl per gram of volatile solids, whereas the lime-
treated waste contains 0.07 meq./g volatile solids, about
73 percent reduction.
b. Total sugar content is reduced from l6.Ul g/100 g volatile
solids to 6.0 g by lime-treatment. A reduction of 63. U per-
cent. (For individual sugars see Appendix II.)
c. Msthoxyl content of decker waste is reduced from 6.hk to
3.18 percent by lime treatment (50.5 percent). Acid-
soluble fractions "l + II" contain the lowest amount of
MeO indicating least ligninlike character.
d. Ratios, Ei»20/MeO, E2eo/MeO, and Ei^o/Eaao indicate that
except for some greater loss in methoxyl, lignins in the
untreated waste are very similar to the lignins in Indulin-
C. The lignins in the lime-treated waste appear to be more
degraded.
-------
Table 12.
ANALYTICAL DATA OH FRACTIONS OF DiiCKER EFFLUENT FROM IPCO
(Basis o.d. volatile solids)
Untreated decker
Mol . vt . ran^e
Ash", %
Volatile solidsb, f
Phenolic hydroxyl,
neq/g
d
Total sugars , %
KeU-.cxyl (MeO) , %
En 20
E? 80
En 20 /MeO ratio
E; 10 /MeO ratio
Ei.2o/E2»o ratio
E*65/E600 ratio
Indulin-
C
—
53.80C
146.20
1.32
—
21.05
3-39
38.U
0.16
1.82
0.008
3-11*
Acid-insoluble
Original
100-33,000
81.5
18.5
0.25
16. in
6.14).
1.10
13.05
O.IT
2.03
O.OSlt
3.76
A
3,000-33,000
66 7
38. 5U
6l.li6
—
—
13. 51*
2.95
87. 7»»
0.22
2.0U
0.108
3.18
C-R
170-500
on L
63.86
36.1U
—
—
It.Uo
1.20
10.79
0.27
2.05
0.111
3.11
Acid-soluble
III+IV
600-930
6o.2
31-58
68.1.2
—
—
U.81*
0.92
10.86
0.19
2.2U
0.085
3.00
1+11
100-150
19.1*
90.9li
9.06
—
—
0.89
0.21
2.53
0.2)4
2.8U
0.083
3.6V
Original
150-1 .300
91-5
8.5
0.07
6.00
3.18
0.53
7.86
0.17
2.l»7
0.067
3-13
Lime- treated decker
Acid-insoluble
A
800-1 ,800
33. li
ND
—
—
—
ND
1.U3
6.63
—
—
0.216
2.U»
C-P
150-680
52.2
70.75
29-25
—
—
3.1t2
0.70
7.00
0.20
2.05
0.100
3.5b
Acid-soluble
III+IV
250-330
91.0
38.89
61.11
—
—
U.87
0.85
17.15
0.17
3.52
0.050
3.09
I+II
<170
13.6
79.21*
20.76
—
—
0.58
O.liU
U.19
0.76
7.22
0.105
3.36
aAshed at 600°C for 1 hour. Ash calculated on o.d. material.
tVolatile solids = 100 minus 5 ash.
"llndulin ash values higher than expected.
for individual sugars see Appendex II.
E2io, E»2o, E<.«s, Esoo are absorptivities at 280, U20, U65 and 600 nm wavelengths.
-------
e. Ratios of Ei^es/Eeoo were calculated on the baa is of
observations by Ortiz De Serra et_ al..15. The authors
have used ratios of Ei^es/Eees as an indication of condensed
(lower ratios) or open (higher ratios) structures of humic
(acid-insoluble) and fulvic (acid-soluble) acids. Our
use of E6oo was mainly due to the reason that Eees values
were not available and also that over 580 nm not much
change in absorptivity was noticed (see Figures 11 and 12).
The data suggest that except lime-treated acid-insoluble
fraction "A," all other color bodies had structures either
similar to or more open than Indulin-C.
Infrared Spectra —
The effect of lime treatment on the organic material is difficult to dis-
cern. A new band appears at 1722 in the lime-treated sample, but spectra
of the fractions from the original lime-treated sample do not contain
such a band nor even a distinct shoulder. Fractionation concentrates
the lignin-related systems primarily into untreated acid-insoluble "A"
fraction (and its lime-treated analog). In this fraction lignin bands
are very prominent compared with carboxylate bands. There is also lignin-
related material in the acid-soluble fraction of lower ash content, but
the carboaylate absorption is much more intense than the absorption of
the aromatic units.
Comparison of the spectra of untreated and lime-treated acid-insoluble
fractions "A" suggested that the lime-treated fraction has a signifi-
cantly higher ratio of carboxylate groups to lignin systems.
(Lime-treated Fraction C-R may be largely composed of an artifact since
the spectrum contains many unusual features.)
The IR-spectra were run on samples with ash, whereas references are
made to chemical analysis calculated on ash-free basis.
Untreated decker (Figure 15) - Tnis original sample (decker effluent)
has very prominent bands at 625 and llto cm"1, indicating that appreci-
able sulfate is present. The presence of carbonate is also suggested
1*2
-------
1»000 3500 3000 2500
2000 1800 1600
Wave Humber
ll»00 1200 1000 800 600 1*00 200
Figure 15- Infrared spectra of untreated and lime-treated color bodies
from kraft decker effluent from IPCO, Indulin-C (salt form)
and Indulin-A (acid form)
-------
by absorption bands at ihhO and 875 cm"1. The bands at 1600 and the
shoulder near lUOO are consistent with bands expected for carboxylate
salts.
Lignin-related aromatic systems are undoubtedly present to a small ex-
tent. This view is supported by methoxyl analysis (6.hh percent) and
a weak band at 10^5- A shoulder at 1505 provides further support for
lignin. The carboxylate and carbonate bands in this region (ll*00-l650
cm"1) are far more dominant than the aromatic-related band at 1505.
Lime-treated decker (Figure 15) ~~ The lime-treated sample spectrum, al-
though similar in general appearance to untreated, differs in several
ways: l) the OH/CH ratio is higher (judging from absorbances at 3UOO
and 2920), 2) a new band is evident at 1722, 3) more intense bands are
present at lUUO and 875 probably signifying higher carbonate content,
and U) a new band is seen at 670 cm"'1.
Higher inorganic content is supported by a higher ash content and lower
methoxyl content (3.18 percent) for the lime-treated sample.
The new band at 1722 may be the result of oxidation occurring during
lime-treatment creating carbonyl groups. The interpretation of this
band and its significance is uncertain since the band does not appear
in any of the subsequent lime-treated fractions.
Untreated acid-insoluble Fraction "A" (Figure 16) — The main differ-
ences resulting from the separation of the acid-soluble material are
that the sulfate and carbonate contents are markedly reduced and the
lignin bands are much more evident. The strong bands at 1582 and
about lUOO probably reflect carboxylate salts. Prominent bands at 1505
and lU60 are evidently due to lignin (aromatic skeletal vibrations), and
this agrees nicely with the high methoxyl content (13.51* percent). A
band at 1030 is also apparent, which is thought to arise in part from
in-plane aromatic C-H bonding in lignin. In fact, the bands at 1030,
1135, 1215, and 126U are probably all lignin-related.
-------
§
V/l
UOOO 3500 3000
2500 2000 1800 1600 lUOO 1200 1000 800
Wave Number, cm 1
600
200
Figure 16. Infrared spectra of untreated and lime-treated acid-insoluble
color bodies from kraft decker effluent from IPCO
-------
Lime-treated acid-insoluble Fraction "A" (Figure 16) — The lime-treated
decker waste yielded this acid-insoluble fraction which has an IR some-
what similar to that of the untreated Traction "A." However, this
sample seems to have much more sulfate and considerably less lignin.
Carboxylate salt is again apparent (1590 and ikkO cm"1) and a weak "band
at 1505 is probably due to lignin. Comparison of relative intensities
of the 1590 band with the band at 1505 suggests that the ratio of carbox-
ylate to aromatic rings is higher in the lime-treated than in the un-
treated acid-insoluble "A"-fraction.
Untreated acid-insoluble Fractions "C-R" (Figure 16) — This fraction
contains substantial sulfate in contrast to the higher molecular weight
acid-insoluble Fraction "A." The ash content is markedly higher (6h
percent vs_. 39 percent), and the methoxyl content is lower (-U.U percent
vs. 13.5^ percent). The ratio of carboxylate to aromatic rings is appre-
ciably higher in this sample than it is in untreated "A"-fraction (dis-
cussed earlier).
Lime-treated acid-insoluble Fractions "C-R" (Figure 16) — The spectrum
of this acid-insoluble fraction of the lime-treated material has several
distinctive bands which are not apparent in any of the other samples in
the series. These occur at 1160 (strongest band), 1075 (strong), and
medium bands at 950, 858, 5^5, and 52U cm"1. Nearly all of these bands
have a well-resolved appearance in contrast to the broad, multicomponent
bands which dominate the other spectra.
Above 1200 cm"1 the spectrum is somewhat more similar to the spectra of
other samples. There is only a very weak shoulder at 1510, possibly
suggesting low lignin content (3.^ percent methoxyl), but the other
lignin band near lO^tO is not visible at all. Again, carboxylate salt
is likely since broad absorption is seen at 1565 and 1380 cm"1. The
sulfate content is thought to be low due to the'limited intensity of
the band at 625.
The differences between this fraction and its untreated counterpart are
so substantial that it is quite probable that this particular fraction
is an artifact. Differences of this magnitude are not evident in any
1*6
-------
of the other comparisons (in all four series examined under this proj-
ect) between untreated and lime-treated samples.
Various possibilities were considered to account for this suspected ar-
tifact but none are very satisfactory. The spectrum is thought not to
be the result of column breakdown (the column is a polyacrylamide) nor
does it seem to reflect the presence of silicates.
Untreated and lime-treated acid-soluble Fractions "I + II" (Figure If.) —
These acid-soluble fractions show almost identical IR spectra, which are
dominated by sulfate peaks. The untreated and lime-treated samples have
ash contents of 91 and 79 percent, respectively. The only indications
of lignin-related substances are the methoxyl content (0.89 and- 0.58 per-
cent ) and the shoulder at 1050 cm 1.
Untreated and lime-treated acid-soluble Fractions "ill + IV" (Figure
IT) ~~ These spectra are also quite closely related. Sulfate content
appears to be quite low in both samples. Lignin content appears to be
comparable judging from methoxyl contents (U.81* and U.87 percent) and
from the bands at 1570 (shoulder), 1U60 (shoulder), 1265, 1215, and
10U5. The region between 11*00 and 1650 is dominated by the carboxylate
bands, with the aromatic ring bands at 1510 and lU60 visible only as
shoulders. This contrasts sharply with the lignin-rich untreated and
lime-treated Fractions "A" where the ratio of carboxylate bands to aro-
matic ring bands was much lower.
The only possible effect of lime treatment on the organic systems pres-
ent may be the inversion of intensities of the lignin-related bands at
101*5, 1265, and 1215. In the lime-treated sample the band at 10U5 is
of lower intensity than the other two bands (at 1265 and 1215).
Pyrolys is gas liquid chromatography — The details of the procedure
and conditions are given in the experimental part of this report.
In order to learn more from the small amounts of color bodies available,
pyrolysis gas liquid chromatography (GLC) was carried out. Initially
-------
Oo
lime-Treated 'I+II'
1*000 3500 3000 2500 2000 1800 1600 lUOO 1200 1000 800 600 UOO 200
Wave Number, cm
Figure 17. Infrared spectra of untreated and lime-treated acid-soluble
color bodies from kraft decker effluent from IPCO
-------
the mass spectrographic identification of the compounds was planned but
was not carried out because of lack of time and funds.
Although quantitative analysis of the vapor can be conducted by accu-
rately measuring the area under a GLC peak, only qualitative analysis
was carried out in the present work. The chromatograms are given in
Figure 18.
The peaks of Indulin-C were identified against known samples16 and then
compared with the decker effluent color bodies. Results are given in
Table 13.
Table 13. INDULIN-C PYROLYSIS PRODUCTS
Pyrolysis product
peak no. Identified compound
21 Guaiacol
23 U-Methyl guaiacol (creosol)
28 U-Ethyl guaiacol
29 U-Propyl guaiacol
31 Eugenol guaiacol
31a It-Vinyl guaiacol
32 cis-isoeugenol
3k~} trans-isoeugenol
f Probably
38) Vanillin
Peaks 10, 12, IT, 21 (guaiacol), and 35 which are quite prominent in
the untreated decker effluent are missing in the lime-treated one. The
relative ratios of peak heights also seems to have changed during lime-
treatment. Peaks 3^ and 38 in the untreated and lime-treated chromato-
grams had retention times similar to that of trans-isoeugenol, and
vanillin, respectively.
-------
Indulin-C
Lime-treated decker
38 .. 32 28
I
I
Tide, minW
Temp. , °C <-
36 32 28 21* 20 16 12 8 If 0
200 > 187 171 155 139 123 107 91 75
Figure 18. Fyrolysis gas chromatograas of untreated and lime-treated
decker effluent from IPCO compared vith Indulin-C
50
-------
Ferulic and vanillic acids upon pyrolysis had the same retention timca
as eugenol and guaiacol, respectively,
Figure 18 shows that the untreated and lime-treated decker effluents
gave somewhat similar chromatograras. A study of such chromatograms
as compared to that of Indulin-C suggest that the color bodies in
the effluent are degraded lignin fragments.
FURTHER CHARACTERIZATION OF COLOR BODIES FROM
KRAFT BLEACH CAUSTIC EXTRACT FROM IPCO
If the pulp is bleached, additional color bodies are solubilized and
removed from the pulp. Bleaching at IPCO was accomplished in multi-
stages with most of the color removed in the "Caustic Extraction Stage."
Effluent from the caustic extraction stage referred to as "caustic
extract" is almost black.
Fractionation o_f Color Bodies
Acidification -
Acidification was carried out by the same method that was used for the
decker effluent and is described in detail in the Experimental part of
this report. The results are given in Table lU. The data show that
when untreated caustic extract waste was acidified approximately 93 per-
cent color and 79 percent TOO were recovered in acid-insoluble fraction.
The acid-soluble fraction contained only 7 percent color and 20 percent
TOG. However, when lime-treated waste was acidified the acid-insoluble
fraction contained only 37 percent color (1.5 out of ^.0) and lU percent
TOG (2.7 out of 19.6).
The acid-soluble fraction of the lime-treated waste contained about
62.5 percent color and 86 percent TOG. Table lU further shows that
lime treatment removed 98. U percent color and 96-6 percent TOG of the
acid-insoluble fraction and only 66.7 percent color and 16.8 percent
TOG of the acid-soluble color bodies.
-------
Table lU. CHANGE IN SOLIDS ISOLATED FROM IPCO
EFFLUENTS DUE TO MASSIVE LIME TREATMENT
Untreated
caustic waste
Fractions
Caustic extract
Acid-insoluble
Acid-soluble
Colora
yield,
%
100
92.8
7-2
•u
TOC
yield,
%
100
79-3
20.3
Lime-treated
caustic waste
Color
yield,
%
U.O
1.5
2.5
TOC
yield,
%
19.6
2.7
16.9
Reduction due
to
Color
%
96.0
98.lt
66.7
lime
TOC,
%
80.1*
96.6
16.8
Yield values "basis untreated caustic extract solids.
fAPHA units, Pt-Co color.
Total organic carbon.
Column chromat ography —
Fractionations of acid-insoluble and acid-soluble color bodies of the un-
treated and lime-treated caustic extract were carried out on Bio Gel P-2,
P-60 columns and XAD-8 resin, respectively. The results are given in
Tables 15 and 16 (for details see Appendix III).
The results in Table 15 show that in the case of untreated acid-insolu-
bles approximately 77 percent of color (71.6 out of 92.8) and 70 percent
TOC (55-7 out of 79-3) were obtained in Fraction "A," whereas after
lime-treatment this fraction contained only 16 percent (0.2l* out of 1.5)
of the lime-treated color and 15 percent TOC. The average color and
TOC removed from acid-insolubles by lime were 98,1* and 96.6 percent,
respectively (over 99 percent of Fractions "A" and MB" were removed).
Table 16 shows that in the case of untreated acid-solubles approximately
96 percent color and 6k percent TOC were obtained in Fraction IV,
whereas lime-treated samples had 76 percent color and 1+1 percent TOC
in Fraction IV. The average color and TOC removed from acid-solubles
by lime were 67 percent and 17 percent, respectively.
-------
Table 15. FRACTIONATION OF ACID-INSOLUBLE COLOR BODIES FROM
BLEACH CAUSTIC EXTRACT BY COLUMN CHROMATOGRAPHY
Fractions
Untreated
acid-insoluble
color bodies
Color
yield,
TOC
yield,
Lime-treated
acid-insoluble
color bodies
Color
yield,
TOC
yield,
Reduction due
to lime
Color, TOC,
Fraction "A" from P-2
through P-60 column
Aa through Ae
Acid-insoluble color
bodies through P-2
column
A
B
C
D through H
Unfractionated acid-
insoluble color bodies
2.2
69.1*
2.6
53.7
0.08
0.16
0.15
0.26
96. U
99-8
9U.2
99.5
71.6
13.7
O.UO
7-1
92.8
55-7
0.
3.8(
79.3
0.21+
0.12
0.06
1.08
O.Ul
0.33
0.15n
1.1»3C
99.7
99.1
85.0
8U.8
99-3
98.7
82.7
62. U
1.5
2.7
96.6
Percent yields are calculated on the basis of untreated original vaste.
^Calculated by difference so that A = (Ai + Aa through Ae).
Calculated by difference so that values for unfractionated acid-insolu-
ble color bodies = (A + B+C+D through H).
°Total by actual determination.
'Values calculated from "yield" data of the solids isolated from untreated
and lime-treated effluents.
Characterization of Caustic Extract Fractions from IPCO
To provide sufficient material for chemical analysis some adjacent frac-
tions vere combined to give bulky fractions. Thus, Fractions "A" through
"A6" were combined giving "A," "C" through "H" were combined, and out of
acid-solubles, Fraction I was used as such and II, III, and IV were com-
bined.
53
-------
Table l6. FRACTIONATION OF ACID-SOLUBLE COLOR BODIES FROM BLEACH
CAUSTIC EXTRACT BY SORPTION ON XAD-8 RESIN
Untreated
acid-soluble
color "bodies
Fractions
(Combined II+III+IV)
IV
III
II
I
Unfractionated acid-
soluble color bodies
Color
yield,
%
(7.58)
6.9
0.36
0.32
0.27
7.2
TOG
yield,
%
(15-6)
13.2
1.0
l.U
6.6
20.7
Lime- treated
acid-soluble
color bodies'
Color
yield,
%
(2.21)
1.9
0.15
O.l6
O.ll*
2.5
TOG
yield,
%
(9.W)
7.0
0.76
1.7
7.0
16.9
Reduction
to lime
Color,
%
(70.8) (
72.2
58.3
50.0
W.I
66.7
due
a
TOG,
%
39.1*)
1+7-0
2U.O
+
+
16.8
Percent yield are calculated on untreated original waste. "+" Values
shoved an increase.
Values calculated from "yield" data of the solids isolated from un-
treated and lime-treated effluents.
Visible and UV Spectra —
Visible and UV spectra of all fractions were determined at pH 7-6. Ab-
sorptivity values were calculated by dividing absorbance with volatile
solids concentration in g/1 and the results are plotted in Figures 19,
20, 21, and 22.
Ultraviolet region (Figures 19 and20) — All samples exhibited an in-
crease in absorptivity as the wavelength decreased and were lower than
Indulin-C. Almost all untreated and lime-treated samples showed absorp-
tion bands at 280 and 205-210 nm indicating the presence of aromatic
compounds (ligninlike). The absorptivity values (in UV region) of acid-
insoluble Fractions "A" was reduced, "C-H" was increased and of acid-
soluble fractions (l and II + III + IV) remained almost unchanged by
lime treatment. Only at wavelengths less than 220 nm, the lime-treated
acid-soluble color bodies had noticeably higher absorptivity values than
-------
Untreated Yaste
Fractions
O A
D C-H
A i
X ii+in+iv
I
*t**A§ S8BBBB
9
i
i
200
220
2l»0
300
320
31*0
260 280
Wavelength, nm
Figure 19. Absorptivity versus vavelength (ultraviolet range) of Indulin-C
and untreated kraft bleach caustic extract
55
-------
Lime-Treated
Waste Fractions
200
220
260 280
Wavelength, na
300
320
3UO
Figure 20. Absorptivity versus vavelength (ultraviolet range) of Indulin-C
and lime-treated kraft bleach caustic extract
-------
Untreated Waste
Fractions
9 @ d fi fi
1*80 500
Wavelength, nm
Absorptivity versus wavelength (visible region) of Indulin-C
untreated kraft bleach caustic extract
580
600
and
-------
VJI
0>
Lime-Treated
Waste Fractions
O A
D C-H
A I
X ii+iu+iv
500
Wavelength, run
Figxore 22. Absorptivity versus wavelength (visible region) of Indulin-C and
lime-treated kraft bleach caustic extract
580
600
-------
their respective untreated color bodies. This suggests that chromophores
which absorb at lower wavelengths, especially below 220 nm, are removed
to a lesser degree by lime treatment.
Visible region (Figures 21 and 22) — All samples gave simple absorption
curves and exhibited an increase in absorptivity as the wavelength de-
creased. Fraction "A" of the untreated acid-insoluble color bodies had
absorptivity equal to or higher than Indulin-C. Except Fraction C-H all
other fractions showed a decrease in absorptivity after lime treatment.
A comparison of visible and UV spectra suggests that, although acid-
soluble fractions showed no loss in absorptivity in the UV region after
lime treatment (in fact an increase in absorptivity was noticed below
220 nm), a definite loss of absorptivity in the visible region occurs,
indicating that some color is in fact removed by lime from the acid-
soluble fractions.
Molecular Weight Distribution —
Molecular weights of selected fractions of acid-insoluble and all acid-
soluble components of the untreated and lime-treated color bodies were
determined in a manner similar to that used for the decker effluents.
The results are plotted in Figure 23a and b.
Figure 23a suggests that most of the higher molecular weight material
is removed by lime. The untreated acid-insoluble color bodies range
from My 100 to 125,000, whereas the acid-solubles range from M^ 100 to
1100. After lime treatment, however, these values range between < 250
to 9^00 and 100 to U50, respectively. Acid-soluble color bodies, Frac-
tion I, had the lowest M^ and acid-insoluble color bodies Fraction "A"
the highest. The individual My values of acid-insoluble fractions fluc-
tuated somewhat but still a general decrease is noticeable from AI to
H. These fluctuations could be due to different ash contents of the
fractions.
Figure 2k shows that acid-insoluble color bodies having an apparent M^
of less than UOO are not removed by lime treatment. The intermediate
range of M^ 1+00-9500 apparently undergoes partial removal. Over 9500
59
-------
M 2
Acid-insolubles
Untreated
o
H
X
Acid-solubles
• Untreated
Lime Treated
IV III II I
Eluate Fractions
(XAD-8 Fractionation)
A! A3 As B D
A2 Aj, A6 C E
Eluate Fractions
(Gel permeation chromatography)
Figure 23. Weight average molecular veight (My) distribution of
fractionated color bodies from kraft bleach caustic
extract fron IPCO (My at ^=0)
-------
complete removal occurred. Over 98 percent removal occurs above a M^
of 1000. The average color and TOG removal of the acid-insoluble
fraction was found to be 98. U and 96.6 percent, respectively (see Table
15).
.Nonremoval Zone
lOOi
80
60
1*0
20
Pkrtial
Removal
Zone
Complete
Removal
Zone
2000 1*000 6000 8000 10,000
Mw, .acid-insoluble color bodies
Figure 2l*. Weight average molecular weight (Mj of acid-insoluble
color bodies from caustic extract versus percentage
of removal by massive lime
The acid-soluble color bodies having a M^ of over 500 are removed by
lime. The average color and TOG removal of the acid-soluble frac-
tions was found to be 66.7 and 16.8 percent, respectively.
Chemical Characterizations —
The results of the chemical analysis are given in Table 1?. The data
suggest:
a. The untreated caustic extract contains 0.32 meq. .phenolic
hydroxyls per gram of volatile solids, whereas this
61
-------
Table 17- ANALYTICAL DATA ON FRACTIONS OF KRAFT BLEACH CAUSTIC EXTRACT FROM IPCO
(Basis o.d. Volatile Solids)
Untreated caustic extract
Mol. wt. range
Color recovery
Ash8, %
Volatile solids, %
Phenolic hydroxyl
meq/g
Total sugars0, %
to Methoxyl (MeO) , %
El. 20
E260
En 20 /MeO ratio
£2 ig /MeO ratio
E»j»/E2«o ratio
E»«s/E»o« ratio
Indulin-
C
—
—
53.8
1(6.2
1.32
21.05
3.39
38. U
0.16
1.82
0.088
3.1U
Ac id- insoluble
Original
100-125,000
—
62.2
37.8
0.32
1|.60
2. Oil
3.88
19-00
1.90
9-31
0.201*
I*.l*l4
A
2,000-125.000
71.6
23.2
76.8
„
1.90
3-69
20.61
1.914
io.au
0.179
li.lS
C-H
100-1.000
28.lt
86.6U
13. -36
..
0.62
0.91
5-71
1.1»7
6.27
0.159
3.U6
Acid-soluble
II+III+IV
800-1 ,100
96.5
28.69
71.31
1.61
2.23
15-90
1.39
9.88
O.lUO
U.6I*
I
100
3.5
83.65
16.35
0.7U
0.1*0
U.16
0.5l»
5.62
0.096
3.51
Original
100-9 .500
—
91.80
8.20
0.13
3.1*2
1.71
0.79
12.05
0.1.6
7.0U
0.067
3.3U
Lime-treated
caustic extract
Acid-insoluble
A
1.000-9.500
16.0
26.77
73.23
3.06
2.11
13.00
0.69
li.25
0.162
3.87
C-H
100-800
81*. 0
67.97
32.03
3.22
1.92
15.29
0.60
U.75
0.126
3.85
Acid-soluble
II+III+IV
1*00-500
88.5
38.82
61.18
2.71
1.21*
16.1*8
0.1*6
6.08
0.075
3.39
I
100
11.5
88.35
11.65
1.29
0.27
I*. 7U
0.21
3.67
0.057
3-33
.Ashed at 600°C. 1 hour. Ash calculated on o.d. material.
Volatile solids - 100* ash.
for individual sugars see Appendix II.
EJ««, E*2«i £*«$> and Esoo &re absorptivities at 260, 1*20, 1*65 and 600 nm wavelengths.
-------
value drops to 0.13 after lime treatment (59-3 percent
reduction).
b. Total sugar content is reduced from U.6 to 3-^2 g/100 g
volatile solids (25-5 percent reduction).
c. Methoxyl content of unfractionated color bodies (original)
decreases from 2.0U to 1.71 by lime treatment (l6.2 per-
cent reduction). However, the fractionated color bodies
(Fractions A, C-H, II + III + IV and l) of the lime-
treated waste have higher methoxyl per 100 gram volatile
solids than the untreated waste indicating a more lignin-
like character. Fractionation probably has eliminated
some carbon not associated with MeO.
d. Ratios of E^o/MeO, E280/MeO and Ei»2o/E280 suggest
that the untreated caustic extract color bodies con-
tain more chromophores which absorb in the visible
region than the lime-treated color bodies.
e. Ratios of E465/E6oo suggest that the untreated caustic
extract and its Fractions "A" (acid-insoluble), and
II + III + IV (acid-soluble) are more open in structure.
In fact, all color bodies have more open structure
than Indulin-C.
One noticeable difference between caustic extract and decker wastes is
that the lime-treated color fractions of caustic extract contain higher
MeO than their untreated counterparts.
'Infrared Spectra —
Caustic extract has the lowest lignin content (judged by MeO content
and certain IR-bands) compared to decker or NSSC wastes. lime treat-
ment seems to produce a band at 1723 (or else markedly changes the car-
boxylate content) which may also be present as a shoulder in spectra of
subsequent fractions.
One of the fractions of the untreated caustic extract was found to be
composed of ammonium chloride and sodium chloride. Carboxylate bands
63
-------
in the samples which have higher lignin contents are so strong that the
aromatic vibrations at 1510 cannot be detected.
Untreated caustic extract (Figure 25) — Strong bands are evident in the
OH region (ca. 3^00) and in the region where carboxylate salts commonly
absorb (l600 and 1380, broad). The presence of lignin is suggested by
a weak band at 10^0, but the usual obvious lignin band at 1500 is not
apparent. That lignin is a very minor component of the sample is further
indicated by the methoxyl content of only 2.04 percent.
There are distinct bands at 830, 765, and TOO cm~: which could be partly
due to lignin, but this is doubtful since they do not appear in the
spectra of subsequent fractions. These bands do appear to show again
in the lime-treated sample, but there again they are not evident in any
of the fractions resulting from this material. It is interesting to
note that the bands at 830 and 700 are also quite evident in the spectra
of the untreated and lime-treated decker wastes (Figure 15), but again
no sign of these bands is seen in the spectra of either acid-soluble or
acid-insoluble fractions.
Lime-treated caustic extract (Figure 25) — The higher ash content (91.8
vs. 62.2 percent) of the lime-treated sample is undoubtedly due to greater
carbonate content and somewhat greater sulfate content. The carbonate
bands at about lU50 and 890 are quite prominent, although it should
be recognized that the former band is broad and contains a component
due to carboxylate groups. The other carboxylate band is seen at about
1600. Carbonate bands are not evident in the spectrum of the untreated
caustic extract so their appearance is a direct result of the lime treat-
ment. The previously cited bands at 81+0, 780, and 700 are clearly seen
in the lime-treated caustic extract. These latter bands are consider-
ably more intense here relative to the untreated which parallels the
increase in ash and decrease in methoxyl contents (1.71 compared to
2.0*0. This argues against these bands having their origin in lignin.
A broad band at llUO and another band at 625 implicate sulfate as a
probable minor component of the sample.
-------
ON
O
§
•P
-P
•a
co
1*000
1 1
3500 3000
i
2500
i
2000
i
1800
Wave
i
1600
Number,
i
lUOO
cm l
i
1200
I
1000
Figure 25-
800
Infrared spectra of untreated and lime-treated color bodies
from kraft bleach caustic extract
1*00
200
-------
Lime treatment has apparently produced a carbonyl group in this fraction
judging from the new band which appears at 1723. The fractions which
result from this lime-treated sample do not contain such a band, al-
though a shoulder in this region is apparent in spectra of lime-treated
acid-insoluble fraction "C-H" and acid-soluble fraction II + III + IV;
however, such shoulders are also present in spectra of untreated samples.
An alternative interpretation is that the carboxylate absorption masks
the carbonyl band at 1723 in the untreated sample, but lime treatment
causes precipitation of calcium salts rich in carboxylate content. This
results in a change in the proportions of carboxylate and carbonyl groups,
thus accounting for the different appearance of the spectral region 1550-
1750 cm'1.
Neither of the alternative hypotheses can account, however, for the
absence of a distinct carbonyl band (rather than a shoulder) in all of
the spectra of fractions resulting from the lime-treated caustic extract.
Since there is a definite carbonyl band in the original lime-treated
sample spectrum, why isn't there a carbonyl band in at least one of the
four fractions analyzed?
Untreated acid-insoluble Fraction "A" (Figure 26) - The spectrum of this
acid-insoluble fraction is very similar to that of untreated caustic
extract. Dominant OH and carboxylate peaks are seen. The band at about
1380 is less broad than is the case in the untreated caustic extract,
and peaks at 830, 760, and 700 are not seen. The presence of lignin
is indicated by the methoxyl content (1.9 percent) and a band at about
10UO overlapping an adjacent band.
Lime-treated acid-insoluble Fraction "A" (Figure 26) — Again dominant
hydroxyl (3^20) and carboxylate bands (1570 and 1^*30) are seen, although
the latter are shifted significantly from the corresponding bands in
untreated acid-insoluble Fraction "A" and lime-treated caustic extract.
Carbonate, which was implicated as a component of the original lime-
treated sample, is also seen here (bands at lU30 and 880 cm** ).
66
-------
o
s
•p
•H
§
s
1*000 3500 3000 2500
2000 18OO 16OO ll»00 1200 1000 800 600
Wave Number, cm"1
200
Figure 26. Infrared spectra of untreated and lime-treated acid-insoluble
color bodies from kraft bleach caustic extract
-------
One interesting feature of this spectrum is the sharp resolution of the
OH stretching bands. The band components are at 2850, 2925 and a
shoulder at 2950. The appearance of this C-H region is like that of
the spectra of pure hydrocarbon systems with substantial methyl and
methylene content. It is thought that an aliphatic acid salt system (or
a mixture of such salts) would best explain the observed C-H stretch-
ing bands. In contrast, the C-H band at 2920 for untreated acid-insol-
uble Fraction "A" is very broad and ill-defined.
A component of the broad band at 10^0 is probably due to lignin.
Untreated acid-insoluble Fraction C-H (Figure 26) — This sample is anom-
alous . The spectrum shows its main bands to be due to ammonium ion:
1^00, 2800, 20^0, and 3130. X-ray diffraction analysis revealed that
this sample is primarily sodium chloride and also contains ammonium
chloride. Ammonia may have been generated during a localized degradation
(microorganisms?) of the polyacrylamide column; the ammonia in turn could
have been neutralized by acid groups to form the ammonium salt. The
position of the major bands (listed above) coincides with those observed
for known ammonium chloride. Thus, the infared data very strongly sup-
port the conclusion that ammonium salts are present.
Lime-treated acid-insoluble Fraction "C-H" (Figure 26) — This spectrum
is very similar to that of the lime-treated Fraction "A" except that
there is no sign of a carbonate band at 880, and that the maximum at
1U35 has shifted in this spectrum to lUOO. The latter shift probably
also reflects reduced carbonate content. The higher frequency carboxyl-
ate band is again near 1575 and the C-H stretching region is well-
resolved. The broad absorption centered at 10^0 in the lime-treated
Fraction "A" now is centered at about 1100, probably indicating higher
sulfate content.
Untreated and lime-treated acid-soluble Fractions "I" (Figure 27) -
These samples give very similar IR spectra. They are both over 80 per-
cent in ash content. The carboxylate bands show at 1600 and IkOO in
both. Both samples apparently contain sulfate (bands at 1130 and 620
68
-------
ON
3500 3000 2500
2000 1800 1600
Wave.Huraber, cn~1
1200 1000 800
200
Figure 27. Infrared spectra of untreated and line-treated acid-soluole color
bodies from kraft bleach caustic extract
-------
cm'1). Hie lime-treated contains bands at 1350 and 1190 not clearly
seen in the spectrum of untreated acid-soluble Fraction I. Their origin
is uncertain.
Untreated and lime-treated acid-soluble Fractions "II + III + IV"
(Figure 27) — These spectra are nearly identical in their appearance.
Broad carboxylate bands appear at 1580 and 1390 for the untreated and
at 1575 and 1395 for the lime-treated sample. No sulfate or carbonate
bands are clearly apparent. The contribution of aromatic rings is only
indicated by broad, weak absorption at 10^0 cm l.
FyrolyBis Gas Liquid Chromatography —
Qualitative pyrolysis-GLC vas run on all acid-insoluble ("A" and "C-H")
and acid-soluble (I and II + III + IV) fractions of the untreated and
lime-treated caustic extract. The chromatograms are given in Figures
2&-32. Similar peak numbers were allotted to a fraction before and
after lime treatment. Therefore, chromatograms in one figure can be
compared with one another with respect to their peak members. Chro-
matograms of the fractions from the same series (i.e. , untreated or
lime treated) from different figures can only be compared with respect
to their retention times and not by peak numbers.
Chromatograms of the untreated fractions in Figures 28, 29, and 30 are
almost similar to their lime-treated counterparts but are not identical,
indicating that most of the changes occur in these fractions (acid-in-
solubles) by lime treatment.
Chromatograms of the untreated and lime-treated acid-solubles (Figures
31 and 32) are almost identical, indicating a negligible change due to
lime treatment.
70
-------
(I
Lime-treated caustic extract
Untreated caustic extract
Tine, min
Temp., °C
IF
36
1
200 —-
Figure 28.
32 26
> 187
21*
171
20
155
16
139
JL
JL
12
123
8
107
k
91
Pyrolysis GLC of untreated and lime-treated
kraft bleach caustic extract
0
75
71
-------
Lime-treated caustic "A1
Untreated caustic "A1
Time, min
frvawm OT
1
1*1*
/. ,
1 J^
1*0 36
onn
I
32
•~~*r~~*^
I
28
TR7
— V-^
1
21*
1 71
r
20
1 c;=;
16
1 7O
1
12
197
1
8
1O7
1
14
01
J
0
•7
Figure 29. Pyrolysis GLC of untreated and lime-treated acid-insoluble
Fractions "A" from^ltraft bleach caustic extract
72
-------
Lime-treated caustic "G-H
Untreated caustic "C-H
2k 20 16
171 155 139
8 1» 0
107 91 75
Figure 30. Pyrolysis OLC of untreated and lime-treated acid-insoluble
Fractions "C-H" from kraft tleach caustic extract
73
-------
Lime-treated caustic "I"
(tatreated caustic "I"
Time,
fH» >•>•">
•
1 1 I
min Uk kQ 36
On / ^ftA
31*
1
32
_i
£
1
•TJS \J V
30
1 I
28 2k
At 1 Tl
^y\
2?*
1
20
ICC
iy
i
16
TSO
1
12
10-S
1
8
inv
1
k
m
|
0
TC
Figure 31. Pyrolysis GLC of untreated and lime-treated acid-soluble
Fractions "I" from kraft bleach caustic extract
-------
Lime-treated caustic II+III+IV
Untreated caustic II+III+IV
I
Time, min
Temp., °C
32
28
187
21*
171
20
155
16
139
12
123
8
107
91
0
75
Figure 32. Pyrolysis GLC of untreated and lime-treated acid-soluble Fractions
"in-IirHV" frori'iiraft tleach caustic extract
75
-------
SECTION V
STOICHIOMETRIC LIME TREATMENT
(Continental Can Company, Hodge, Louisiana)
COLLECTION AND PROCESSING OF EFFLUENT SAMPLES
Source of Effluent
Continental Can Company (CONGO) at Hodge, Louisiana is a kraft and neu-
tral sulfite semichemical (NSSC) pulp and paper mill using 88 percent
softwood and 12 percent hardwood (total capacity 700 t/day). No multi-
stage "bleaching is used. About 300 tons of pulp is bleached "by single-
stage hypochlorite every two weeks. This is expected to have very
little effect on the quality of total effluent17. The mill uses well
water of low hardness (12-20 ppm).
Mill wastes for the stoichiometric lime treatment included two effluents
from pulping and papermaking stages of kraft and NSSC mill. Effluent
containing major amounts of wastes from NSSC mill are referred to as
NSSC effluent and the other as decker effluent. The total mill effluent
volume was 16.5 MOD. Only a portion of this effluent (about 62 percent)
was treated. The total mill effluent had a BOD load of 3^,000 Ib per
day and a color of less than 1200 APHA units.
Stoichiometric Lime Process at_ CONGO
The lime-treatment system initially handled about 10 MGD of mill efflu-
ent. Lime concentration ranged from 1300-1500 ppm.
Lime slurry at about 10 percent consistency is injected in the pipe main
through which raw effluent is pumped to the color clarifier (135 ft diam-
eter) ; no mixing device is employed. The clarifier overflow is dis-
charged through submerged orifices into an external collecting channel.
Sludge discharge is through 8-inch draw-off piping.
From the color clarifier the effluent passes to a 30 x 12 ft carbonation
tank, where lime kiln stack gas is bubbled through the primary color
77
-------
clarifier waste. The calcium carbonate formed by carbon dioxide reac-
tion with the remaining calcium hydroxide is settled in a second clari-
fier substantially identical to the first one. Sludge is withdrawn
through a 6-inch pipe.
Fiber losses through the existing mill are 20-25 lb per ton pulp. These
fines are allowed to go through the system and seem to help in the set-
tling of lime-color bodies precipitate in the primary clarifier thickener
of the lime-treatment system . .
Combined sludge, withdrawn from the color clarifier, is pumped to a
storage tank. Dewatering of the sludge is carried out in a Sharpies
P-5*100 solid-bowl centrifuge operated at 2300 rpm. The cake is dis-
charged to the same kiln feed conveyor which receives the kraft lime
and filter cake. The concentrate liquor is returned to the color clari-
fier to recover residual solids.
The lime kiln is a gas fired unit 12 ft in diameter and 290 ft long.
Recovered lime and new lime use are shared impartially between causti-
cizing and effluent treatment.
Effect of_ Shipment
Two batches each of decker and NSSC effluents were received from Hodge,
Louisiana over a period of about five months. Each batch contained
separate samples of untreated, lime-treated before carbonation and lime-
treated after carbonation stages of the lime treatment plant. All
samples were characterized as follows:
Chemical analyses on these effluents (before shipment) were supplied by
CONGO and are given in Table 18 (please note the sample code employed as
shown in Table 18 footnotes). Aliquots of liquid wastes were also ana-
lyzed at the Institute upon receipt and the data were compared with
those of CONGO. The results showed that "after shipment" results gen-
erally were higher for color and lower for TOC. No definite conclu-
sion could be drawn from the results mainly because this trend was not
consistent and differed from sample to sample of the same waste. The
78
-------
Table 18. CHEMICAL DATA ON EFFLUENTS BEFORE SHIPMENT FROM COHCO
Batch 1
ppn CCUPP-1 CCLTBC-1
pH value 9.0 12.3
Tot|l solids 975 1103
Ash U91 908
Volatile solids 1.81. 195
Sodium 163 18U
Sulfate 22 't 230
Chloride
Color units0 685 70
70C 202 69
BOD 19!* 135
*Ashed at 600°C for 1 hour.
Calculated by di f f erence.
APHA color, Pt-Co units.
CONGO = Continental Can Company, Hodge,
Decker
CCLTAC-1
10.1.
671*
557
117
193
231
17
76
75
132
La.
Effluent
CCUPP-3
9-1
11*11
557
851*
21.2
325
980
298
CCUPP = Untreated decker effluent including paper machine and
CCU3 = Untreated N3SC including kraft decker, paper machine
CCLTBC = Line- treated before carbonation from CONGO.
CCLTAC = Lim<_— treated after carbonation
TOC = Total Organic Carbon.
BOD . = Biochemical Oxygen Demand.
from COHCO.
Batch 2
CCLTBC- 3
12.1
2033
661.
1369
380
220
179
CCLTAC-3
10.5
1723
1109
1.15
370
17
300
l!*l
282
CCUS-2
8.1
2068
806
1262
299
310
'2000
521
628
Bat ch 1
CCLTBC-2
12.1
2393
1137
1256
331*
301*
820
1.1*7
637
NSSC Effluent
CCLTAC-2
9.8
1797
802
995
322
293
11*
91*0
1*59
633
ccus-4
7.8
1833
867
966
310
180
1750
672
51*5
Batch 2
CCLTBC-1.
12.2
21*0!*
1268
1136
3U5
185
12
390
398
163
CCLTAC— 1*
9.5
1690
6^0
1C 50
160
500
1*16
i*as
pulping area vastes from CONGO.
and pulping wastes from CONGO.
-------
data obtained at the Institute vere consistent and could be checked with-
in reason at different times. It was, therefore, concluded that no
major change occurred during the shipping (transit) time.
Table 18 shows that the NSSC wastes contain higher color, TOG, BOD, vola-
tile solids, ash, and total solids but lower sulfate content than-kraft
decker effluent. The data further show that carbonation of lime-treated
wastes increased color by 11-llj percent and TOC by 10 percent (only in
one case TOC dropped by 20 percent). Similar increase in color and TOC
was noticed after carbonation in the case of lime-treated effluents from
IPCO (see Table l).
This increase could be due to the release of chromophores during car-
bonation which were previously "shielded" by the presence of lime.
Effect of Freeze-Drying and Storage
Changes in sedimentation coefficients before and after freeze-drying of
mill effluents were followed for NSSC wastes only. It was expected that
kraft decker effluents would behave similar to the ones studied earlier
(see Table 2). Results are given in Table 19 which show that the sedi-
mentation coefficient values slightly increase after freeze-drying of
NSSC wastes. These increases, however, are not very significant and so
it can be said that no appreciable change is occurring in color bodies
during freeze-drying.
Table 19. SEDIMENTATION COEFFICIENTS OF NSSC COLOE BODIES
Sedimentation coefficients, Sa
Before After
Effluent freeze-drying freeze-drying
Untreated NSSC
Lime treated
before carbonation
after carbonation
0.61;
0.7^
0.66
0.8U
0.75
0.70
aS = Svedberg = 1 x 10~13.
80
-------
INITIAL CHARACTERIZATION OF COLOR BODIES FROM THE KRAFT DECKER
AND NSSC EFFLUENTS
Chemical Characterization
The results of this analysis are given in Table 20. The data show that
freeze-dried NSSC effluents have higher volatile solids, TOC, and much
higher amounts of sugars than the decker effluents. Major difference
in sugars is due to very high amounts of xylose in NSSC effluents (see
Appendix II). Higher sugar content may be the reason for higher BOD
values of the NSSC waste.
The ash was analyzed by emission spectroscopy and the metal analysis is
given in Table 21. Except calcium and silicon, the amounts of other
metals in most of the samples are the same. Substantial differences
occur in the amounts of calcium and silicon in similar samples (e.g.,
Batches 1 and 2 of NSSC or decker effluents). The amounts of silicon
and calcium were, therefore, excluded from the total. The data in Table
21 further show that on an average about 65 percent of total metals are
removed by lime. However, metal/TOC ratios (see Table 22) of the freeze-
dried color bodies from untreated and lime-treated wastes did not change
much, suggesting a correlation between the metals and organic carbon and
their removal by lime.
Spectrophotometric Examination
Visible and ultraviolet spectra of aqueous solutions of the freeze-dried
decker and NSSC wastes (before and after lime treatment) were determined
at pH 7.6. Absorptivity values were calculated from these spectra by
dividing the absorbance values with the volatile solids in grams per
liter. The plots obtained are not shown here. The results showed that:
111 the Case of_ Decker Effluent —
All samples showed simple absorption curves in the visible region; the
absorptivity increased as the wavelength decreased. In the ultraviolet
region all samples gave absorptivity maxima between 270-280 nm, indicating
the presence of ligninlike materials.
81
-------
Table 20. CHEMICAL DATA OH FREEZE-DRIEB WASTES FROM COHTIHHITAL CM COMPAHT (COHCO)
(Basis o.d. Material)
Decker effluent
Yield, g/100 ml
Ash. %
Volatile*, %
Sulfated ash. %
Sodium, %
Calcium, %
Sulfate. %
TOC, %
Total sugars , %
CCUPP-1
0.06
69.1
30.9
79-5
22.U
0.39
35.2
16.3
5-30
Batch 1
CCLTBC-1
0.06
8li.8
15.2
96.0
27. k
<0.10
37-2
8.1
1.18
CCLTAC-l
0.06
85.3
Ik. 7
96.9
29.8
<0.10
36.8
7.6
1.39
CCUPP-3
0.11
71.8
28.2
79.0
20.3
O.U8
33.3
18.5
2.23
Batch 2
CCLTBC-3
0.12
88.9
11.1
102.6
28.0
<0.1
30.1
7-1
1.07
CCLTAC-3
0.13
85.9
Ik.i
99-6
26.1
<0.1
28.2
3.7
0.53
CCUS-2
0.18
50.k
1.9-6
56.2
1U.1
0.70
17.6
30.6
8.13
Batch 1
CCLTBC-2
0.15
70.7
29-3
65-9
17.1
<0.1
20.6
2k. 3
9-13
HSSC effluent
CCLTAC-2
O.lU
71.1
28.9
65-k
17.3
<0.1
20.3
25.8
6.66
CCUS-k
0.16
56.6
fc3-k
63.2
19.8
0.36
2k.5
27. 5
6.6k
Batch 2
CCLTBC-k
0.12
59.6
30.k
76.8
20.6
<0.1
21.. 1.
19.5
5-05
CCLTAC-k
0.13
76.2
23.8
7k. 0
20.6
<0.1
2k.O
19.3
k.ko
^Calculated by difference.
For individual sugars see Appendix IV.
For ivaple code see Table 18.
-------
Table 21. 5UISSIOH SPECTROGRAPHIC AHALYSIS OF FREEZB-DRIED WASTES FROM COMCO
(Basis o.d. Ash)
Metals,
•••••••
Aluminum
Barium
Boron
Calcium
Copper
Iron
Magnesium
Manganese
Silicon
Total*
—'••i i —^— ••— ^^j,
"Total does
For aaaple
-~~—
0.370
0.013
0.018
O.kjo
0.008
0.036
0.200
0.05)1
5.k
0.75
^^•••^••^
not include
code see Tal
Batch 1
CCLTBC-1
0.150
<0.002
0.016
0.098
0.003
0.068
<0.022
0.00k
1.3
0.26
calcium and
)le 18.
Decker effluent
CCLTAC-1.
— _
0.180
<0.002
0.01k
0.089
0.002
0.062
<0.022
0.00k
0.88
0.29
CCUPP-3
0.170
0.007
0.02k.
1.00
0.003
0.076
0.160
0.031
1.10
O.k7
— ^^— — — .^.^
Batch 2
CCLTBC-3
0.079
<0.002
0.018
O.C50
0.002
0.032
0.023
0.003
0.360
0.16
^— •• .—
CCLTAC-3
~
<0.036
<0.002
0.020
0.052
0.002
0.038
0.033
0.002
0.620
O.Ik
CCUS-2
0.2k
0.012
0.017
2.10
O.OOk
O.OQ2
0.180
0.07k
2.20
0.62
CCLTBC-2
O.O6
0.016
0.086
0.003
0.037
0.050
O.OOk
0.90
0.17
HSSC effluent
CCLTAC-2
O.Ik
0.01k
0.080
0.002
0.068
0.056
0.011
1.20
0.29
CCUS-k
0.22
0.008
0.010
0.039
O.OOk
0.060
0.160
0.038
0.50
Batch 2
CCLTBC-k
<0.07U
<0.003
0.010
0.06k
0.003
<0.036
<0.033
<0.002
0.20
0.17
CCLTAC-k
0.083
<0.003
0.010
0.070
0.003
0.038
0.037
0.003
0.38
0.18
silicon rallies. " ~ —
-------
Table 22. CHANGE IN METAL/TOG RATIO DURING LIME TREATMENT
OF MILL WASTES FROM CONGO
Lime-treated
Effluent
Untreated
before
carbonation
after
carbonation
Decker effluent
Batch 1
Batch 2
NSSC-effluent
Batch 1
Batch 2
0.032
0.018
0.010
0.010
0.027
0.020
0.005
0.005
0.033
0.032
0.008
0.007
All values based on o.d. total solids.
In the Case of NSSC Effluent -
Also single absorption curves vere obtained in the visible region. The
absorptivity increased as the wavelength decreased.
In the ultraviolet region the absorptivity values of all samples first
increased slowly, and then rapidly as the wavelength decreased from 3^*0
to 280 run. There was little change between 255-280 nm, thus giving a
characteristic "shoulder," referred to as maxima. Below 250 nm the
absorptivity values increase drastically. Absorptivity values of lime-
treated samples were lower than the untreated ones but the nature of the
absorptivity curves remained almost the same. This indicated again that
the effluents contain materials which show a ligninlike character.
Effect of_ Lime Treatment
The percentage of color and TOG removal and percentage decrease in ab-
sorptivity during lime treatment of the effluents were calculated and
the results are given in Table 23.
The results show that generally effluents containing NSSC effluents are
not readily decolorized by lime. Lower TOC removal in this case (com-
pared to decrease in absorptivity at 280 nm) may be due to the fact that
-------
these effluents contain higher amounts of sugars which resist removal
by lime.
Table 23. EFFECT OF LIME TREATMENT ON WASTES FROM CONGO
Color removal8", %
TOC removal01, %
Decrease in absorptivity , %
at 1*20 nm
at 280 nm
Decker
effluent
79-0
50.0
52.3
33.0
NSSC
effluent
6U.O
28.0
62.8
35-5
Note: Average values from 2 or more samples.
^Based on values of effluent samples.
Decrease in absorptivity caused by lime treatment based
on volatile solids content isolated from effluents.
Because of lack of material the untreated decker wastes (Batch 1 and 2)
were mixed in a ratio of 1:3 and lime-treated decker waste "before car-
bonation" (Batch 1 and 2) were mixed in a ratio of 1:1. These larger
mixed amounts were then used for further fractionation.
FURTHER CHARACTERIZATION OF COLOR BODIES FROM
KRAFT DECKER EFFLUENT FROM CONGO
Fractiojiation of_ Color Bodies
Acidification -
Concentrated solutions of color bodies were acidified as before and the
results are given in Table 2k.
The data show that, upon acidification of untreated wastes, 86.5 percent
color and 65.8 percent TOC were recovered in the acid-insoluble fraction.
The acid-soluble fraction contained only 13.5 percent color and 3U.2 per-
cent TOC, The lime-treated wastes upon acidification yielded 61 percent
color (12.8 out of 21.0) and 37 percent TOC in the acid-insoluble fraction,
and 39 percent color and 63 percent TOC in the acid-soluble.
85
-------
Table 2k. CHANGE IN SOLIDS ISOLATED FROM CONGO EFFLUENTS
DUE TO STOICHIOMETRIC LIME TREATMENT
(Basis untreated decker solids)
Untreated
decker waste
Fractions
Decker waste
Aci d-ins oluble
Acid-soluble
Co lor a
yield,
%
100
86.5
13.5
TOCD
yield,
%
100
65.8
3*. 2
Lime- treated
decker waste
Color
yield,
%
21
12.8
8.2
TOC
yield,
%
50
18.5
31.5
Reduction due
to
Color,
%
79
85.2
39-3
lime
TOC,
%
50
71.9
8.6
bAPHA color, Pt-Co units.
Total organic carbon.
Lime treatment removed 85.2 percent color and 71-9 percent TOC from the
acid-insoluble fraction and only 39«3 percent color and 8.6 percent TOC
from the acid-soluble fraction. In other words color bodies which are
not precipitated by acidification to pH 1.0 are removed to a lesser
degree by lime than those color bodies which are precipitated by acidifi-
cation. A comparison of "massive" lime treatment of kraft decker wastes
from IPCO (Table 9) and "stoichiometric" lime treatment of kraft decker
wastes from CONGO (Table 2*0 confirms that massive lime treatment has no
advantage over the stoichiometric system with respect to the percentage
color removal. Slight variations in data are, however, expected as the
wastes are from different mills.
Column Chromat ography
The acid-insoluble and acid-soluble color bodies were fractionated on
Bio Gel columns and XAD-2 resin, respectively. The results are given in
Table 25 (for details see Appendix IV). Fraction "A" of the untreated
waste contains 6H percent color (55. ^ out of 86.5) and 69«5 percent TOC
(U5.7 our of 65.8) of the acid-insolubles. Whereas this fraction in the
lime-treated waste contains only k3 percent color and 16 percent TOC in-
dicating the change in composition taking place during lime-treatment.
-------
The percentage color and TOG removal decreases from Fraction AI to J (Ai
has the highest M^ as it is excluded from the P-60 column). The average
color and TOC removed by lime were 85.2 and 71.9 percent, respectively.
Table 25. FRACTIONATION OF DECKER ACID-INSOLUBLE COLOR
BODIES BY COLUMN CHROMA.TOGRAPHY
Fractions
Fraction "A" from P-2
column through P-60
Al a
A 2 through Ai»
Untreated
acid-insoluble
color bodies
Color TOC
yield, yield,
% %
22. U 27. U
33.0 18.3
Lime- treated
acid-insoluble
color bodies
Color TOC
yield, yield,
% %
1.9 1.2
3.6 1.8
Reduction due
to lime
Color, TOC,
% %
91.5 95.6
89.1 90.2
Acid-in soluble color
bodies through P-2
column
B through E,
F through J
Unfractionated acid-
insoluble color bodies
55A
llt.O
7.1
1*5-7
i^.l
6.0
5.5
7.6
—
86.5
65.8 12.8
3.0
8.0
7.5
18.5
90.1
1*5-7
93. U
1*1*. 1*
85.2 71.9
Percentages of yield are calculated on the basis of untreated original
vaste.
^Calculated by difference so that values for A = (Ai + Aj through Ai»).
Calculated by difference so that values for unfractionated acid-insolu-
ble color bodies = (A + B through J).
cValues calculated from "yield" data of the solids isolated from un-
treated and lime-treated effluents.
The acid-solubles were fractionated on XAD-8 resin and results are given
in Table 26. The data show that the untreated fraction "ill + IV" con-
tained 59 percent color (8 out of 13.5) and 31 percent TOC of the acid-
soluble color bodies. The same fraction after lime-treatment contained
5U percent color and 31 percent TOC of the lime-treated acid-solubles,
indicating that lime-treatment does not appreciably change the color and
TOC composition of the acid-soluble color bodies. The table further
87
-------
shows that average color and TOG removed by lime from these color bodjcj;
were 39 percent and 9 percent, respectively.
Table 26. FRACTIONATION OF DECKER ACID-SOLUBLE COLOR
BODIES BY SORPTION ON XAD-8 RESIN
Untreated
acid-soluble
Fractions
III + IV
I + II
Unfractionated acid-
soluble color bodies
color
Color
yield,
%
8.0
4,2
13-5
bodies
TOC
yield,
%
10.7
17.1
34.2
Lime-treated
acid- soluble
color
Color
yield,
%
4.4
2.4
8.2
"bodies
TOC
yield,
%
9.9
17-9
31.5
Reduction due
to limea
Color, TOC,
% %
45.0 7-5
42.8
39.3 8.6
Percentages of yield are calculated on the basis of untreated original
vaste.
Values calculated from "yield" data of the solids isolated from un-
treated and lime-treated effluents.
Characterization of Decker Effluent Fractions
Individual fractions were combined, as before, to give larger acid-in-
soluble fractions "A," C-J, and acid-soluble fractions I + II and III +
IV.
Visible and UV Spectra —
Visible and UV spectra of all fractions were determined at pH 1.6. Ab-
sorptivity values were calculated by dividing absorbance with volatile
solids concentration in g/1 and the results are plotted in Figures 33-36,
Ultraviolet region (FJLgure 33, and 34) — All samples exhibited an increase
in absorptivity as the wavelength decreased, A "hump" is also noticed
at 280 nm, Except for acid-soluble fractions of both untreated and
lime-treated color bodies, all other samples showed a tremendous increase
in absorptivity below 250 nm. A comparison of Figures 33 and 34 suggests
88
-------
Untreated Waste
Fractions
O A > Acid-
Q C-^T / insoluble
A I+II ") Acid-
X ni+ivj soluble
200
Figure 33,
220 2^0 260 280
Wavelength, nm
Absorptivity versus wavelength (ultraviolet range) of Indulin-C
and untreated kraft decker wastes from CONGO
89
-------
•
*
Lime-Treated
Waste Fractions
O A
D c-j
A rui
X III+IV
260 280 300
Wavelength, run
Figure 31*. Absorptivity versus wavelength (ultraviolet range) of Indulin-C
and lime-treated kraft decker wastes from CONGO
90
-------
Untreated Waste
Fractions
O A / Acid-
0 C-J J insoluble
A I+II \ Acid-
X III+IV/ solu:ble
1*80 500 520 5^0 560
Wavelength, nm
Figiire 35.» Absorptivity versus wavelength (visible range) of Indulin-C and
untreated kraft decker wastes froia CONGO
580
600
-------
Lime-Treated
Waste Fractions
O A
d C-J
A i-m
X in-nv
1*80 500
Wavelength, mn
Figure 36. Absorptivity versus wavelength (visible region) of Indulin-C and
•untreated kraft decker wastes from CONGO
-------
that generally the acid-insoluble color bodies (A and C-J) show lower,
and acid-insoluble color bodies (I + II and III + IV) show the same or
higher absorptivity values after lime treatment, indicating that most
of the acid-solubles containing UV-chromophores are not removed by lime.
Visible region (Figures 35 an.d 36) — All samples gave simple absorption
curves. Only acid-soluble color bodies, III + IV showed higher absorp-
tivities after lime treatment than the untreated fraction indicating
that less color giving carbon is removed from this fraction by lime.
Molecular Weight Distribution —
Molecular weights of the selected fractions of acid-insoluble and all of
acid-soluble components of the untreated and lime-treated color bodies
were determined as before. The results are plotted in Figures 37a and b.
The data show that acid-insoluble components of the untreated waste are
much higher in My than those of lime-treated acid-insolubles. The My. of
untreated acid-insoluble color bodies range between approximately 200 to
167,000 whereas after lime-treatment these values drop to < 500 to U2,000
(see Figure 37a).
The My of untreated and lime-treated acid-soluble color bodies are quite
similar to each other (Figure 37b).
Figure 38 shows that acid-insoluble color bodies having an apparent My
of less than 500 are not removed by lime-treatment. The intermediate
range of My 500 to 1*2,000 apparently undergoes partial removal, and over
1*2,000 are completely removed. However, about 90 percent removal occurs
above a My of 2500. It should be mentioned here that My of these kraft
decker wastes is much higher than kraft decker wastes from another
mill (compare Figures 13 and lU with 37 and 38). As a matter of fact
My 1*2,000 for a lime-treated waste is the highest found so far. Not
much change is found in My of the acid-soluble color bodies after lime-
treatment. My ranged between 100-550. Maximum removal in these color
bodies was about 8.0 percent.
93
-------
Acid-insolubles
Untreated
Lime Treated
m
O
X
a?
Acid-solubles
Untreated
Lime Treated
IV III II I
Eluate Fractions
(XAD-8 Fractionation)
AI A3 B D F H
A2 Ai» C EG J
Eluate Fractions
(Gel permeation chromatography)
Figure 37- Weight average molecular weight (V^) distribution of
fractionated color bodies from kraft decker effluent
from CONGO (M at w2=0)
-------
100
Nonremoval Zone
Complete
Removal
Zone
Partial
Removal
Zone
500 10,000 20,000 30,000 1*0,000 50,000
M^, acid-insoluble color bodies
Figure 3d Weight average molecular weight (M^) of acid-
insoluble color bodies from kraft decker effluent
versus percentage of removal by stoichiometric lime
Charact eri zat ion —
results of the chemical analysis are given in Table 27. The data
suggest:
*• The untreated decker waste contains 0.38 meq phenolic
hydroxyls per gram of volatile solids. This value drops
to 0.09 after lime treatment, roughly about 76 percent
reduction and compares well with the 73 percent reduction
observed under the massive lime treatment.
b. Total sugars are reduced from 8.98 to 5.22 g/100 g volatile
solids, by lime, a drop of 30.7 percent.
c. Methoxyl content of decker waste is reduced from 5.99 to
3.149 percent (a drop of 1*1.7 percent). Acid-soluble fraction
95
-------
Table 27- ANALYTICAL DATA ON FRACTIOUS OF DECKER EFFLUEHT FROM COHCO
(Basis o.d. Volatile Solids)
Untreated decker
Mol. vrt. range
Color recovery, %
A
Ash8, %
Volatile solidsb, %
Phenolic hydroxyls,
men/g
Total sugars0, *
Methoxyl (MeO), %
E»?o
E2..
E-io/MeO ratio
E2*»/MeO ratio
E* 28/Ezto ratio
Ei,tj/E«oo ratio
Indulin-
C
—
—
53.80
1*6.20
1.32
—
21.05
3.9
38.1.
0.16
1.82
0.088
3.ll<
Original
100-167,000
—
71.11
28.89
0.38
8.98
5.99
1.19
12.36
0.20
2.06
0.096
3.01
Acid-insoluble
A
2,000-167,000
6U.O
22. lit
77.86
—
_
10.8o
2.02
19.9U
0.19
1.85
0.101
3.68
C-J
180-<2,000
21.. 6
70.03
29-97
~
__
6.38
1-57
15-70
0.25
2.1.6
0.100
3-86
Acid-soluble
III + IV
300-550
59-3
38.53
61.1*7
—
__
5.51
0.820
11.89
0.15
2.16
0.069
1..51
I + II
<100
31.1
86.97
13.03
__
__
1.1.6
O.UoS
"*.73
0.28
3.21.
0.086
3.86
Original
lOO-Ua.OOO
—
86.83
13.17
0.09
6.22
3-U9
O.568
8.17
0.16
2.3«*
0.070
3.01
Lime-treat
ed decker
Acid-insoluble
A
1,500-1.2,000
1.3. 0
32.71
67-29
__
8.65
1.90
18.1.2
0.22
2.13
0.103
3.38
C-J
500-<2,000
69-5
1.9-72
50.28
— —
3.1.2
0-805
9.61.
0.21.
2.82
0.081.
3.55
Acid-soluble
III + IV
500-550
53.7
35-90
61.. 10
_—
__
6.72
0.985
1I..25
0.15
2.12
0.069
1..20
I + II
<120
29-2
91.21*
8.76
__
1.26
0.1.00
»t. 53
0.32
3.60
0.088
2.1.8
b Ashed at 600° C, 1 hour. Ash calculated on Q. d. aaterlal.
cVolatile solids - 100 - % ash.
For individual sugars see Appendix II.
EI.J,, Etts, and Ettt are absorptiTitles at indicated wavelengths.
-------
'I + II" contain the lowest amounts of MeO indicating a ieu.;l.
ligninlike character.
d. Ratios, Ei^o/MeO, E280/MeO, and E^o/^eo indicate that
except for some greater loss in MeO, the color bodies are
quite similar to the lignins in Indulin-C.
e. Higher ratios of E^es/Eeoo indicate that acid-soluble
fractions III + IV have more open structures than Indulin-C
or color bodies of other fractions. In fact Indulin-C
contains material with the least open structure.
Infrared Spectra —
The spectra of this series are very similar to the spectra (of comparable
fractions) which were discussed for the decker wastes from IPCO (Figures
15-17). Lime treatment seems to produce a carbonyl band at 1722, but
this cannot be detected in the spectra of any of the subsequent fractions.
The fractions richest in lignin are acid-insoluble; acid-soluble frac-
tions have lower lignin contents and much greater carboxylate content
relative to aromatic rings.
The interpretation of the spectrum of one particular fraction, lime-
treated acid-insoluble fraction "C-J," is uncertain because it contains
so many new bands, including bands in the conjugated carbonyl region.
Untreated and lime-treated decker wastes (Figure 39) — These samples
give spectra that are very comparable to the two samples in the other
decker effluent series (Figure 15). The only obvious change is that
the untreated material gives a carboxylate band at 1595 which is more
intense than the band at 1^25. This is the reverse of the relative in-
tensities of these bands for the other (Figure 15) series. Once again
the lime-treated sample shows a weak band in the carbonyl region at 1722.
Untreated and lime-treated acid-insoluble Fractions "A" (Figure Up) —
Sulfate and carbonate are more apparent in the lime-treated sample, and
the ash content is higher for this sample as well (32.71 percent vs.
22.l^t percent). The lime-treated sample shows spectral bands at 700
and 830 which are not seen in the spectrum of the untreated sample.
97
-------
«l
o
§
•p
•H
9
3
OO
*000
1
3500
1
3000
t
2500
1 I I
2000 1800 1600
Wave Number,
1
11*00
cm~
i
1200
1
1000
1
800
1
600
1
Uoo
1
200
Figure 39* Infrared spectra of untreated and lime-treated color "bodies
from kraft decker effluent from CONGO
-------
NO
o
9
+»
-p
n
a
2
H
1»000 3500 3000 2500 2000 1800 1600 lUOO 1200 1000 800 600 1»00 200
Wave number» cm
Figure liO. Infrared spectra of untreated and lime-treated acid-insoluble color
bodies from kraft decker effluent from CONGO
-------
The "bands at 700 and 830 are not seen in the spectrum of the correspond-
ing fraction of the other decker system (Figure 16), although weak bands
at this frequency were evident in the original untreated and lime-
treated samples.
The lime-treated sample appears to have a somewhat larger carboxylate
to aromatic ring ratio than the untreated sample. This parallels the
situation found previously (Figure 16).
Untreated__and lime-treated acid- insoluble Fractions "C-J" (Figure
The untreated sample spectrum is very similar to the corresponding
fraction in the previous series (Figure 16) . This lime-treated fraction
gives an unusual IR spectrum. The spectrum of lime-treated acid-
insoluble fraction "C-R" (Figure 16) vas also atypical, but it differs
considerably from that of the lime treated acid-insoluble fraction
(Figure
In the lime-treated fraction, there are again bands at TOO and 832, as
was the case for the lime-treated fraction "A" (Figure kO) just discus-
sed in the previous section. There appears to be a small sulfate content
even though ash content is quite high (^9-72 percent). The region from
1550-1700 is very unusual; bands are present at 1562, 1615, 166U and a
shoulder at 1690. The latter two frequencies reside in the conjugated
carbonyl region. Lignin bands are either very weak or nonexistent. The
C-H and 0-H absorptions are comparable to those of the other fractions,
however.
Untreated and lime-treated acid-soluble Fractions "I + II" (Figure *tl) —
These spectra are nearly identical and very rich in sulfate (ash contents
are 87 and 91 percent). The corresponding fractions in the other decker
effluent (Figure 17), gave spectra that are nearly identical with these
spectra.
Untreated and lime-treated acid-soluble Fractions III + IV (Figure
These spectra are almost identical. There may be a slightly higher con-
centration of lignin-related aromatic rings in the lime-treated system;
100
-------
o
H
•p
-p
s
S-,
Lime-Treated
•• III-HV
Lime-Treated
"I+II"
Untreated
"I+II"
1*000 3500 3000 2500 2000 1000 1600 lUOO 1200 1000 800 600 UOO 200
Wave Number, r-m-1
Figure Ul. Infrared spectra of untreated and lime-treated acid-soluble
color bodies from kraft decker effluent frctn CONGO
-------
this is based on the higher methoxyl content (6.72 percent vs. 5-51 per-
cent) and the greater prominence of lignin bands at 1510, 1270, and 10^5
cm"].
The region between lUOO and 1650 cm"1 is dominated by carboxylate bands.
The ratio of carboxylate to aromatic ring absorption is much greater
than is the case with the acid-insoluble fractions which also had high
lignin content.
Pyrolysis Gas Liquid Chromatography —
Qualitative pyrolysis-GLC was run on untreated and lime treated decker
effluent from CONGO. The chromatograms are given in Figure k2. The
peak numbers are comparable to those in Figure 18. A comparison of
Figure *+2 and 18 shows that the color bodies in decker waste from CONGO
is more like Indulin-C. Note that peaks 21, 23, 28, 29, 31, 31a, and
32 which have been identified in Indulin-C (Figure 18, Table 13) are
also present in CONGO'S decker effluent. Lime-treated waste also gives
these materials but in lesser relative concentrations. It seems that
more degraded and modified color bodies are present in decker effluent
from IPCO discussed earlier. Unidentified peaks 36, 38, 39, and hQ are
present in both effluents.
FURTHER CHARACTERIZATION OF COLOR BODIES FROM NEUTRAL
SULFITE SEMICHEMICAL (NSSC) EFFLUENT FROM CONGO
As has been mentioned earlier, the effluent containing major amounts of
wastes from NSSC mills are named as "NSSC-effluent." The minor compo-
nents of this effluent are other wastes from the pulping and papermaking
stage. This is the effluent which is being treated by lime at CONGO'S
treatment facility at Hodge, Louisiana.
Fractionation of_ Color Bodies
Acidification —
Acidification of concentrated aqueous solutions was carried out similar
to other effluents. The results are given in Table 28. The data show
102
-------
Lime-treated decker
Time, mi
Temp,, °
,. .. 1. 1
n 1»U 1*0
C < 200
3b
1
32
4
i
28
187
--J
2k
171
I
20
155
i
16
139
i
12
123
I
8
107
i
Ji
91
j
0
75
Figure te. Pyrolysis gas chromatograas of untreated and lime-treated
decker effluents from CONGO
103
-------
that upon acidificatiori 1*8.2 percent color and 36.0 percent TOO were
recovered in the acid-insoluble fractions. The acid-soluble fraction
contained more color (51.8 percent) and more TOG (6k percent) than the
acid-insoluble. The lime-treated wastes on the other hand yielded 57.8
percent color (20.8 out of 36) and 51 percent TOG in the acid-insoluble
fraction compared to 1*2 percent color (15-2 out of 36) and 1*9 percent
TOG in the acid-soluble. This is different than the situation found in
decker effluents vhere major portions of color in the untreated waste
was found in the acid-insoluble component. Table 28 further shows that
lime-treatment removes more color and TOG from the acid-soluble color
bodies (70.6 and 1*6.1* percent).
Table 28. CHANGE IN SOLIDS ISOLATED FROM CONGO EFFLUENTS
DUE TO STOICHIOMETEIC LIME TREATMENT
Untreated
NSSC waste
Fractions
NSSC waste
Acid- insoluble
Acid-soluble
Colora
yield,
%
100
1*8.2
51.8
TOCD
yield,
%
100
36.0
61*. o
Lime- treated
NSSC waste
Color
yield,
%
36
20.8
15.2
TOG
yield,
%
70
35.7
3U. 3
Reduction due
to
Color
%
61*
56.8
70.6
lime
, TOG,
*
30
<1.0
1*6.1*
APHA color, Pt-Co units.
Total organic carbon.
Column Chromatography —
The acid-insoluble and acid-soluble color bodies were fractionated as
before on Bio-Gel and XAD-8 columns, respectively. The results are
given in Table 29 (for details see Appendix V).
The data show that Fraction "A" of the untreated acid-insoluble color
bodies contains 32.1+ percent color (15.6 out of 1*8.2) and 1*5 percent
TOG. The lime-treated Fraction A contains 30.3 percent color (6.3
out of 20.8) and 27.0 percent TOC.
10 U
-------
Table 29. FRACTIONATION OF NSSC ACID-INSOLUBLE COLOR
BODIES BY COLUMN CHROMATOGRAPHY
Fractions
Fraction "A" from P-2
column through P-60
AI
A2
A3 + AH&
Untreated
aci d- in soluble
color bodies
Color TOG
yield, yield,
% %
7.U 9.6
5.5 6.3
2.7 0.3
Lime-treated
acid-insoluble
color bodi.es
Color TOC
yield, yield,
% %
l*.l U.3
1.9 ^.2
0.3 0.8
Reduction due
to lime
Color, TOC,
% %
UU.6 55-2
65. U 33. U
88.9
Acid-insoluble color
bodies through P-2
column
A
B through J
Unfractionated acid-
insoluble color bodies
15.6
32.6
H8.2
16.2
19.8
36
6.3
1*.5
20.8
9.3
26.U
35.7
59.6
55-5
56.8
U2.6
Percentages of yield are calculated on the basis of untreated original
waste.
^Calculated by difference so that values for A = (Ai + Aa + Aa + A«»).
Calculated by difference so that values for unfractionated acid-insolu-
ble color bodies = (A + B through J).
°Values calculated from "yield" data of the solids isolated from un-
treated and lime-treated effluents.
The average color and TOC removed from acid-insoluble color bodies
were 56.8 percent and < 1.0 percent, respectively (TOC removal fig-
ures are much lower than expected).
The acid-soluble color bodies were fractionated on XAD-8 resin and the
data are given in Table 30. The results show that on the basis of un-
treated acid-soluble material Fractions III + IV combined contain 52.1
percent color (27 out of 51.8) and U?.5 percent TOC (30.2 out of 6U),
whereas on the basis of lime-treated material this combined fraction
had 57.2 percent color and 29.5 percent TOC. The data further show
that average color and TOC removed from acid-soluble color bodies were
70.6 and k6.h percent, respectively. (These are based on actual deter-
minations and not on mathematical averages from the data on fractions.)
105
-------
Table 30. FRACTIONATION OF NESC ACID-SOLUULE COLOK
BODIES BY COLUMH CHROMATOGHAPHY
Untreated
acid-soluble
color bodies
Fractions
IV
III
II
I
Unfractionated acid-
soluble color bodies
Color
yield,
15.1
11.9
15-9
5-2
51.8
TOC
yield,
19.2
11.0
23.6
10.3
61*
Li me- treated
acid-soluble
color bodies
Color
yield,
6.0
2.7
1*.5
1.6
15.2
TOC
yield,
6.3
3.8
11.3
5-5
3l+. 3
Reduction due
, , . a
to lime
Color,
60.3
77-3
71.7
69-2
70.6
TOC,
67-2
65.5
52.1
1*6.5
1*6. U
Percentages of yield are calculated on the basis of untreated NSSC waste.
Values calculated from "yield" data of the solids isolated from un-
treated and lime-treated effluents.
It can be concluded that in the case of untreated color bodies most of
the color and TOC are obtained in the acid-soluble fractions, whereas
in lime-treated samples it is the opposite. Lime removes more color
and TOC from the acid-soluble color bodies.
Characterization of Effluent Fractions —
Individual fractions from chromatography columns were later combined
to give larger acid-insoluble fractions "A" and C-J, and acid-soluble
fractions I + II and III + IV.
Visible and UV-Spectra -
Absorptivity values from the spectra at pH 7-6 were calculated as before
and plotted in Figures 1*3-1*6. As no "lignin" such as "indulin-C" for
kraft, was available for NSSC effluent, the absorptivity values of
Indulin-C vere, therefore, used for comparison.
106
-------
Untreated Waste
Fractions
Acid-
insoluble
Acid-
soluble
200
220
260 280
Wavelength, nm
Figure 1*3. Absorptivity versus wavelength (ultraviolet range) of Indulin-C
and untreated NSSC vaste from COM CO
10?
-------
Lime-Treated
Waste Fractions
200
Figure
220
300
320
260 280
Wavelength, nm
Absorptivity versus wavelength (ultraviolet range) of Indulin-C
and lime-treated NSSC waste from CONGO
108
-------
o
vo
380
Untreated Waste
Fractions
O A ~) Acid-
D C-J > insoluble
A i+n
Acid-
X m+ivj soluble
1*00
U20
Figure
U60
520
560
U80 500
Wavelength, nm
- Absorptivity versus wavelength (visible region) of Indulin-C and
untreated NSSC waste from CONGO
580
600
-------
7-00-
H
H
O
Lime-Treated
Fractions
O A
a c-
A i+n
X in+iv
UOO 1>20
Figure
UO
1*60
520
5^0
560
U80 500
Wavelength, ma
Absorptivity versus wavelength (visible region) of Indulin-C and
line-treated NSSC waste from CONGO
580
600
-------
Ultraviolet region (Figures ^3 and kk) — All samples exhibited an increase
in absorptivity as the wavelength de-creased. The spectra also show
"shoulders" at 280 and 205 nm. Generally, the untreated acid-soluble
color bodies have lower absorptivity values than untreated acid-insoluble
color bodies. This trend changes after lime treatment. Except acid-
soluble Fractions III and IV, all other fractions showed a decrease in
absorptivity after lime treatment. The values for Fraction III + IV
did not change much after lime treatment. Indicating that either the
color bodies from this fraction are not removed at all or, if they are,
they are removed in the same ratio so that the absorptivity does not
register any change. From previous data (Table 30) it is seen that about
1*6 percent TOC is in fact removed by lime.
Visible region (Figures 1*5 and U6) — All samples gave simple absorption
curves and the absorptivities of all lime-treated fractions were lower
than the untreated ones, indicating the removal of more color bodies.
Surprisingly, the untreated acid-insoluble Fraction C-J and acid-soluble
Fraction III + IV had higher absorptivity in the visible region than the
untreated Fraction "A."
Molecular Weight Distribution —
Molecular weight ranges are plotted in Figures ^7a and b. The results
show that the weight average molecular weights of untreated acid-insol-
ubles range from 600 to ^0,000 and that of lime-treated acid-insolubles
from 300-25,000. The acid-soluble color bodies before lime treatment
range from UOO-1200 and after lime treatment from 200-800.
The percentage removal data fluctuated so that definite relationships
between percent removal and M^ could not be drawn. However, it was
established that acid-insoluble color bodies having My. of 300 were not
removed by lime. There was a partial removal in M^ range of 300-25,000
and over 25,000 complete removal occurred. Data further showed that
only a very small amount of material fell in the high My. range.
Ill
-------
35
30
25
H 20
15
10
-D
I I I I
Acid-solubles
Untreated
e Treated
IV III II I
Eluate Fractions
(XAD-8 Fractionation)
Acid-insolubles
Untreated
Lime treated
A3
H
B D F
A2 Ai» C E a J
Eluate Fractions
(Gel permeation chromatography)
Figure ^7. Weight average molecular weight (My) distribution of
fractionated color bodies from NSSC effluent
from CONGO (M at u?-0)
112
-------
The acid-soluble color bodies behaved differently in NSSC effluent. In
these color "bodies, those above MW of 770 were completely removed, be-
low My. 230 were not removed and partial removal occurred in the inter-
mediate range of 230-770. Maximum My. found in untreated acid-soluble
color bodies was 1150. About 65 percent removal occurred at M^ of 720,
so that between M^ 720 and 770 the percentage removal jumped from 65 to
100 percent.
Chemical Characterization —
The results of the chemical analysis are given in Table 31. The results
show:
a. The meq phenolic hydroxyls per gram of volatile solids
do not change appreciably during lime treatment. In
all other effluents it was reduced.
b. The amount of total sugars per gram of volatile solids
increases by about 62 percent after lime treatment,
indicating that more of the non-sugar volatile solids
compared to the sugars are removed.
c. Average methoxyl content in the unfractionated (original)
waste decreases from 7.72 to 6.97 percent (9-7 percent
reduction), indicating that the ratio of MeO to volatile
solids remains ajbipst unchanged by lime treatment. This,
however, does not agree with the fact that sugars are
not removed. Appreciable reduction in MeO occurs in
Fraction "C-J" during lime treatment. It cannot be
established whether this reduction is real or caused
by preferential carbon fractionation in Bio-Gel columns.
d. Higher £1,20/MeO ratio of untreated acid-soluble
Fraction "I + II" indicates loss of MeO in this fraction.
It is also substantiated by higher Eaao/MeO, and E^o/Eaeo
ratios indicating higher color compared to the aromatic
nature.
e. Ei»65/E6oo ratios indicate that all fractions have more
open structures than Indulin-C.
113
-------
Table 31.
AHALYTICAL DATA OH FRACTIOUS FROM HSSC EfTLUHTT FROM COBCO
(Basis o.d. Solids)
Untreated HSSC
Mol. wt. ranpe
Color recovery, I
Asha, %
Volatile solidsb, *
Phenolic hydroxyls, neq/g
Total sugars0, %
Methoxyl (MeO), %
E»20
Ej.D
En 20 /MeO ratio
E2t«/MeO ratio
EHIO/EZIO ratio
E»ss/Etoo ratio
Indulin-
C
—
53.8
1.6.20
1.32
21.05
3.9
38.1.
0.16
1.82
0.086
3.14
Acid— insoluble
Original
56.6
I.3-4
0.39
10.79
7.72
1.37
11.66
0.177
1.51
0.117
3.02
A
16.79
83.21
~~
14.60
1.47
15.69
0.101
1.07
0.094
3.61
C-J
59-29
40.71
I
11.22
2.14
17.89
0.191
1-59
0.120
4.44
Aci d-soluble
III + IV
39-90
"60.10
—
8.88
1.68
13.45
0.189
1.51
0.125
4.43
I + II
60.00
40.00
—
4.13
1.32
8.7
0.320
2.11
0.152
H.15
Original
76.2
23-8
0.38
17.25
6.97
0.51
7.54
0.073
1.08
0.067
4.0
Lime-treated HSSC
Acid-insoluble
A C-J
19.26
80.74
—
15.33
0.901
11.92
0.059
0.778
0.076
3.58
71.32
28.68
—
7.71
1.08
11.46
0.14
1.49
0.094
3.89
Acid-soluble
III + IV
37.58
62.42
—
9-01
1.03
12.84
0.114
1.43
0.080
4.66
I + II
60.51
39-49
—
3.24
0.476
5.98
0.1U7
1.85
0.080
3.62
.Ashed at 600°C, 1 hour and calculated on o.d. material.
^Volatile »olids " 100-Jl ash.
for individual sugars see Appendix IV.
Ej»e,
, Ei,«s. and £«•• are absorptirities at indicated ware length*.
-------
Infrared Spectra —
The IR spectra for this series do not reveal significant differences in
the organic material that could be attributed to lime treatment. Sul-
fate and, in the case of lime-treated samples, carbonate are the most
obvious inorganic components present. Sulfite does not seem to be pres-
ent, but it is not possible to rule out small amounts of thiosulfate.
This series is distinguished from the others by bands suggesting the
presence of lignosulfonates in small amounts.
The region 1 1*00-1650 cm"1 is particularly interesting in distinguishing
differences between acid- insoluble and acid-soluble material. The ratio
of intensities of carboxylate bands to aromatic ring bands in this re-
gion is much higher for the acid-soluble materials than for the acid-
insoluble materials. The acid-soluble fractions thus seem to have a
much higher carboxylate content and this increased polarity is undoubt-
edly a major factor in determining solubility.
Untreated NSSC vaste (Figure ^8) — The intensity of the broad band at
3UOO cm""1 agrees vith the high water content of this sample. Sulfate
is evident as a major component of the ash, giving bands at 11 Uo and
620. There is no sign of sodium sulfite in this spectrum or in any
of the spectra of fractions. A weak band at 995 may be indicative of
thiosulfate. The carboxylate bands are quite intense at 1575 and lUlO.
Lignin is probably responsible for the band at 10^0 and shoulders at
1U60 and 1510.
The region between lUOO and 1600 is quite interesting in this series.
The appearance of absorption is thought to reflect the relative amounts
of carboxylate salt groups and aromatic nuclei present. In this sample
the carboxylate salt groups are quite dominant, and their broad bands
overlap the aromatic bands of the lignin so that the latter appear only
as shoulders. The relative amounts of these groups change dramatically
during fractionation as will be pointed out in the ensuing discussion.
One other distinctive feature of the spectrum is the shoulder at 655
and weak broad band at 530. This is attributed to lignosulf onate , which
is a reasonable component for this particular effluent.
115
-------
0\
Lime-Treated NSSC
Uooo
3500 3000 2500 2000 1800 1600 1^00
Wave Number, cm 1
1200
1000
800 600
Uoo
200
Figure 1*8. Infrared spectra of untreated and lime-treated color bodies
from NSSC effluent from CONGO
-------
Lime-treated NSSC waste (Figure H8) — The general appearance of the spec-
trum is very similar to that of the untreated sample. The lignin bands
are less evident in the lime-treated sample at 1500 and 10UO cm"1.
The sulfate bands are comparable to those in the spectrum of the un-
treated sample. The presence of carbonate is suggested by the broaden-
ing of the band at lUlO in the untreated sample to a wide maximum (lUlO-
11+50) in the lime-treated sample. Further evidence for carbonate is
the sharp peak at 8?5 cm'1, which is also noted in other lime-treated
samples in other series. Evidence for a small amount of lignosulfonate
is also present in this spectrum.
The disappearance of the lignin band at 1510 cm'1 does not necessarily
signify a marked structural change in the lignin systems resulting from
action of lime. This lignin band could have been simply obscured by the
combined influence of neighboring carboxylate and carbonate bands.
Untreated acid-insoluble Fraction "A" (Figure 1*9) - This fraction is
comparatively low in ash and the sulfate content is clearly much lower
than is the case for the original effluent sample (judging from the ab-
sorption at 1130 and lack of absorption at 620). The lignin-related
bands at 1030 and 1500 are quite intense as would be expected from the
high methoxyl content of lU.6 percent. A band at lii60 is also quite
prominent and this, too, may be largely representative of the aromatic
systems in lignin.
Careful comparison of the 1^00-1650 for this fraction (Figure U9) and
for untreated NSSC waste (Figure U8) suggests that the relative amounts
of lignin (aromatic systems) and carboxylate salts are very different in
the two samples. Although it is not possible to make even semiquantita-
tive statements, it appears that this region is dominated by lignin-
related bands for the acid-insoluble fractions (though to a lesser ex-
tent for untreated acid-insoluble Fraction "C-J," whereas it is dominated
by carboxylate salt bands for the acid-soluble fractions and the un-
treated NSSC waste.
117
-------
OO
Lime-Treated
C-J"
Untreated "C-J"
1*000 3500 3000 2500 2000 1800 1600 ll+OO 1200 1000 800 600 UOO 200
Wave Number, cm 1
Figure k9. Infrared spectra of untreated and lime-treated acid-insoluble
fractions from NSSC effluent from CONGO
-------
Thus, the distinctive feature of the acid-insoluble fractions seems to
be the relatively high ratio of lignin (or aromatic rings) to carboxyl-
ate systems. The lower polarity implied by this analysis would be
expected to result in lover water (or acid) solubility, as is indeed
the case.
Lime-treated acid-insoluble Fraction "A" (Figure kg) ~~ This sample appears
extremely similar to its untreated counterpart. The ash content, methoxyl
content, and the IR spectra show few differences. The ratio of lignin
bands to carboxylate bands in the 1UOO-1650 region is almost identical
in the two spectra. There are no differences significant enough to be
interpreted as results of the lime treatment.
Untreated acid-insoluble Fraction "C-J" (Figure t>9) — There is a high
ash content (59.29 percent) and a substantial part of it is sulfate,
since there is a broad maximum at 1120 and related absorption at 620.
This is a distinct difference relative to the untreated Fraction "A."
Although bands at 1505 and 1030 and a methoxyl content of 11.22 percent
suggest a considerable amount of lignin, this fraction is much richer .
in carboxylate salt content than untreated "A." This is deduced from
the relative band intensities in the 1^00-1650 region.
Lime-treated acid-insoluble Fraction "C-J" (Figure U£) — In comparing
the spectrum of this fraction with its untreated counterpart, again
there is little difference that could be attributed to the lime treat-
ment. In the region 2900-3200 there are new bands apparent, and the
band at ikOO is sharper and more intense than it usually is. This, how-
ever, is thought to be due to production of an artifact-ammonium ion
during the column fractionation. This is even more clearly revealed in
the untreated "C-H" (see Figure 26), which was obtained at the same
fractionation stage but came from a caustic extract effluent.
Acid-Soluble Material -
Untreated acid-soluble Fraction "I+ II" (Figure 50) — This sample is
characterized by high ash (60.00 percent) and the lowest methoxyl content
119
-------
o
§
•p
•p
ft
e
01
§
EH
Lime-Treated
"III+IV"
1800 1600 lUOO 1200 1000 800
JtOOO 3500 3000 2500
Wove Number, cm
Figure 50- Infrared spectra of untreated and lime-treated acid-soluble
color bodies from NSSC effluent from CONGO
-------
(It. 13 percent) of any of the five untreated NSSC waste fractions (the
original NSSC effluent sample and the four fractions derived from it).
A substantial component of the inorganic material appears to be sulfate,
as seen by strong bands at 11*40 and 625. A probable lignin-related band
is quite prominent at 10^0. The region betveen l^tOO and 1650 is domi-
nated by the carboxylate salt bands at 1^10 and 1605. The lignin-related
bands at 1500 and about 1^60 are seen in this spectrum only as shoulders.
The general appearance of this region, and even the entire spectrum, is
very similar to that seen for the untreated NSSC vaste sample. The
primary difference between the organic material in this fraction and
the organic material present in the acid-insoluble fractions is that
the ratio of carboxylate groups to lignin-related ring systems is much
greater for the acid-soluble sample. The suspected lignosulfonate band
at 530 is most prominent in the spectrum of this acid-soluble material.
Lime-treated acid-soluble Fraction "I + II" (Figure 50) — This lime-
treated fraction has ash (60.51 percent) and methoxyl content (3«2l* per-
cent) comparable with its untreated counterpart discussed above. The IR
spectra of these fractions are virtually identical and the effect of
lime treatment is not at all apparent from the IR spectra.
Untreated acid-soluble Fraction "III + IV" (Figure 50) — This sample con-
tains lower ash (39.90 percent) and higher methoxyl (8.88 percent) than
the other acid-soluble fraction just discussed. The spectrum suggests
that lignin content is indeed higher since prominent bands are present
at 10U5 and 1210. Sulfate may be contributing to the absorption at 1120
and 625. Weak bands whose origin is uncertain, are seen at 925 and 650.
The 925 band is also evident in the untreated NSSC sample,, but the 650
band would be masked by sulf ate absorption.
The region between lUoo and 1650 is quite similar to that of the other
acid-soluble fraction ("I + II"), suggesting that both acid-soluble
fractions contain organic material that has a relatively high ratio of
carboxylate to lignin-related ring systems. This ratio appears similar
121
-------
to that of the original untreated sample Taut is clearly much higher than
is the case for the acid-insoluble fractions.
The primary difference between the two acid-soluble fractions seems to
be that of inorganic content. Molecular weight differences may also
exist but could not be detected from the IR spectra.
Lime-treated acid-soluble Fraction "III + IV" (Figure 50) — Again there
is no significant difference in ash content, methoxyl content, or IR
spectra between this fraction and its untreated counterpart.
Fyrolysis Gas Liquid Chromatography —
Qualitative pyrolysis GLC was run on untreated and lime-treated NSSC
effluent from CONGO. The chromatograms are given in Figure 51. Both
chromatograma are quite similar. The color bodies in NSSC waste con-
tain some of the compounds obtained by pyrolyzing Indulin-C. Note the
peaks marked 21 to 32, These have been previously identified (see
Figure 18 and Table 13).
122
-------
Time, Bin
Temp.
Figure 51. Pyrolysis gas chromatograms of untreated and lime-treated
NSSC effluents from COHCO
123
-------
SECTION VI
LIME TREATMENT WITH METAL IONS
It was mentioned in the Introduction of this report that the objective
of this phase of our study was to establish an improved lime treatment
system for the removal of color from kraft decker effluents, kraft
bleach caustic extract and NSSC effluents.
BACKGROUND INFORMATION
James, in his book entitled "Water Treatment" (Technical Press Ltd.,
1965, p. 110-14), mentions that sufficient lime is added to water to
combine with the free carbon dioxide and then to convert the bicarbo-
nates of calcium and magnesium into carbonate and hydroxide, respec-
tively. He further indicates the use of iron salts in clarification
and subsequent addition of alkali to precipitate the iron. Small
amounts of lime have also been used to produce "ferric floes."
Although the use of lime as a water softener is quite old, its use as
a color fiocculant in kraft industry is fairly recent. Lime precipita-
tion has been shown to remove certain solid constituents and 85 to 90
percent of color from the kraft pulping waste. Excessive amounts of
lime (over the minimum required) have no apparent effect on percentage
of color removal. Preliminary studies at the Institute have shown that,
by the addition of certain multivalent ions with lime, practically all
of the color is removed.
The objective of this work was to establish conditions for such an "im-
proved lime-treatment system." This study was divided into 3 major
steps:
1. Treatment of mill wastes with metal ions.
2. Treatment of mill wastes with varying metal ion
concentration and constant lime concentration.
3. Treatment of mill wastes with varying lime
concentration and constant metal ion concentration.
125
-------
TREATMENT OF MILL WASTES WITH METAL IONS
Preliminary color removal studies were performed on untreated kraft
wastes from the decker and the caustic extraction stages using salts
such as alum, "barium chloride, ferric chloride, magnesium hydroxide
and zinc chloride.
Concentrated salt solutions (6000 ppm) were individually prepared and
stored for future use. Freeze-dried color bodies from decker and caus-
tic extraction stages were dissolved in distilled water to give 0.1 per-
cent solutions which, eventually, were used for this study.
The desired amount of salt solution to give 100-1000 ppm salt per 50 ml
total volume was measured into graduated cylinders and filled to the
50-ml mark with the waste to be evaluated. Mixing was accomplished by
inverting the graduates five times. The treated effluent was then al-
lowed to stand undisturbed for a minimum of 15 minutes prior to centri-
fuging to remove flocculated material. Each treated sample was centri-
fuged for 15 minutes at 9000 rpm. The clear supernatant was carefully
poured off and stored until tested for pH, color, absorbance, and total
organic carbon (TOG). Only the ferric chloride treatment was run in two
series. In one the pH was not adjusted and in the other pH was adjusted
to about 9.0 with NaOH to produce "ferric floe" and then centrifuged.
The sediment was discarded.
The percentage of removal of color and TOG were calculated from the data
obtained (absorbance values at 280 nm were not very reliable because of
interference by ferric ion) and the results are given in Tables 32 and
33. Only the color removal values are plotted against salt concentra-
tion in moles/liter in Figures 52 through 55.
A comparison of Figures 52 and 53 shows that BaCl2 is a better color
removing agent for decker effluent than for caustic extract. At the
concentrations studied Mg(OH)2 was the least effective.
Figures 5U and 55 show that alum is more effective in the case of decker
effluent than caustic extract, whereas FeCl3 is more effective on caustic
126
-------
Table 32. TREATMENT OF KRAFT EFFLUENTS WITH BIVALENT IONS
Decker effluent
Salt
ppm
Mg(OH)2
0
100
200
250
300
350
1*00
600
ZnCla
0
100
200
250
300
350
1*00
600
BaCla
0
100
200
250
300
350
1*00
600
800
1000
Ca(OH)?
0
100
200
250
300
350
1*00
600
concentration
10"1* moles /I
— —
17.15
3>*. 3
1*2.9
51.5
60.0
68.6
103.0
M
7.3U
11*. 68
18.33
22.0
25.7
29.33
Wt.O
— —
U.8
9.6
12.0
11*. I*
16.8
19.2
28.8
38.1*
1*8.0
__
13.5
27.0
33.8
1*0.5
1*7.3
51*. o
81.0
Final
pH
7.2
7.1*
7-5
7.8
8.0
8.0
8.1
8.0
7.2
6.9
6.5
6.5
6.1*
6.3
6.2
6.0
7.2
7-3
7.2
7.1
7.0
6.9
6.7
6.1*
6.2
5-7
__
-_
_—
*~
__
— —
—
Color
removal ,
%
....
0
2.5
2.5
5.0
2.5
7.5
7.5
__
2.5
5.0
7-5
12.5
17.'5a
22.5
1*5.1*
^ m
5.0
16.7
21.7
23.3
26.7
28.3
1*1.2
1*2.5
61.2
M.
*.
«
VM
— —
H
TOC
removal ,
%
— _
3.3
3.5
6.2
3.9
5.9
11.3
15.1*
__
5.3
8.9
13.3
13.6
13.9
17.7
1*0.8
— ^
6.5
8.3
9-5
10.1
13.3
13.6
21*. 3
31.1*
1*0.8
__
~
—
__
—
m
__
~
Caustic extract
Final
pH
8.2
8.1*
8.7
8.9
9.0
9-0
9.1
9.2
8.1
6.9
6.7
6.7
6.7
6.7
6.7
6.7
7.1
6.9
6.5
6.5
6.6
6.8
6.9
7.0
7.1
7.1
8.6
10.3
11.3
11.6
11.7
11.8
11.9
12.1
Color
removal ,
%
— —
0
6.8
11.1*
11.1*
11.1*
12.0
22.8
«.
0
3.9
3-9
13.6
13.1*
22.9
1*1*. 0
__
0
0
0
+1.3
U.I
1.1
23.7
35-9
1*5.2
~—
20.0
22.5
22.5
25.0
32.5
62.5
72.5
TOC
removal ,
%
__
1.6
>».5
5.7
8.0
l*. 5
7.1*
13.2
«
2.8
7.1*
8.1*
11.1
11*. 3
21.3
1*6.5
__
6.0
U.3
6.3
6.6
9-8
9-8
20.0
33.1
1*2.9
—
—
—
—
—
__
__
—
Calculated value.
127
-------
Table 33'. TREATMENT OF KRAFT EFFLUENTS WITH TRIVALEHT IONS
Decker effluent
Salt concentration
ppm
Alum
0
100
200
250
300
350
1(00
600
FeClj
0
100
200
250
300
350
1(00
600
PeCli
0
100
200
250
300
350
1(00
600
10~" moles/1
(Ali(SOjs«l8H20)
1.1(2
2.81*
3.55
U.26
U.97
5.68
8.51
— gH_ unadjusted
wv
6.2
12. 1*
15.1(5
18.5
21.6
2U.7
37.0
— pH adjusted
••••
6.2
12. 1*
15A5
18.5
21.6
2U.7
37.0
Final
PH
7.2
7.3
5.1
k.T
I*. 6
"*.5
1».5
"i.5
7-2
5.8
5.0
l*.l
3.8
3.7
3.U
3.1
7.2
8.2
8.7
fl.3
8.5
8.9
8.9
8.8
Color
removal ,
%
59.1
87.1
90.9
88.1
88.2
88.2
86.8
••_
27-3
75-5
76.1*
77.3
77.3
75.5
76.1»
__
0
21.1
12.6
38.9
58.3
50.9
72.5
TOC
removal ,
*
23.9
—
__
—
58.0
52.8
514.2
«•
22.0
5U.8
66.6
66.9
59.8
65.3
68.1
_ _
19.3
58.9
67.1
70.3
65.6
69-9
71.2
Caustic extract
Final
PH
7.9
6.5
U.8
U.l»
U.3
U.2
1*.3
U.I
6.7
6.1
5.6
5.1
U.8
U.I.
U.l
3.8
6.7
8.1*
8.9
8.7
9.1
8.6
8.1
7.8
Color
removal ,
%
7.7
63.1
85.2
8U.6
85.2
8U.6
86.5
— —
0
2U.U
26.9
51.3
7U.8
91.7
90.7
__
0.6
67.1»
83.1
97.2
97.3
97-3
97.1*
TOC
removal ,
%
22.1
6U.5
7U.1
71.9
72.1
75.8
75.7
— ^
5.8
22.6
27.5
U6.8
6U.6
80.1
82.9
__
17.2
73.6
86.1
86.3
88.0
76.6
81.3
128
-------
lOOr-
VO
10
20
30 fcO 50 60 70
Salt Concentration, 10"1* moles per liter
Figure 52. Treatment or kraft decker wastes with bivalent ions
90
100
110
-------
lOOi
90
8G
70
8 50
&
20
10
X Ca(OH);
10
30
to 50 _ 60 70
Salt Concentration, 10~* moles per liter
80
90
Figure 53. Treatment of kraft caustic extract with bivalent ions
100
110
-------
FeCl3-pH unadjusted
100 _
5
10 15 20 _ 25 30
Salt Concentration, 10~" moles per liter
35
Figure 51* . Treatment of kraft decker waste with trivalent ions
FeCl3-pH adjusted
FeClj-pH unadjusted
5 ~ 10 15 20 _ 25 30 35
Salt Concentration, 10~" moles per liter
Figure 55, Treatment of kraft caustic extract with trivalent ions
1*0
131
-------
extract. An interesting observation is that FeCls removes more color
from decker when the pH is not adjusted and is on the acid side. This
situation reverses itself in the case of caustic extract. It seems
that some decker color is precipitated because of lower pH and is re-
moved with color-Fe complex. In the case of caustic, however, because
of higher carboxyl content (see IR investigation, this report) less
color is precipitated at lower pH but is taken out with the "ferric
floe" under alkaline conditions.
The results, in general, show that trivalent ions are more effective
color removing agents than the bivalent ions and that higher percentage
of color is removed from caustic extract with FeCla under alkaline con-
ditions.
From the above results "optimum" levels of salt concentrations were
found or in some cases projected over which no significant increase
in color removal was achieved or expected.
Further experiments with metal ions and lime were planned in which metal
compounds were varied below the established "optimum" addition levels.
TREATMENT OF MILL WASTES WITH VARYING METAL-ION CONCENTRATION
AND CONSTANT LIME CONCENTRATION
Barium chloride and ferric chloride were the two salts used (in conjunc-
tion with lime) in the lime treatment of untreated and lime-treated
caustic extract and NSSC effluents. Lime-treated effluents contained
color bodies not removed by the conventional one-step lime-treatment
process. The effluents were used in this study to find out whether or
not more color can be removed by the metal ion-lime system. Lime con-
centrations for these runs were kept at 850-1000 ppm and the metal ions
(as salts) were varied between 25-1500 ppm (ppm unit was used for easy
understanding, conversion units are given for moles/liter wherever neces-
sary). Freeze-dried color bodies from the effluents were dissolved in
distilled water to give 0.2 percent solutions, which were then used for
this study.
132
-------
Forty milliliters of the above solution were measured into a 100-ml
graduated cylinder, the desired amount of salt solution was added and
the volume brought to the 80-ml mark with distilled water. Lime slurry
was then added to the above mixture giving a final lime concentration
of 850-1000 ppm. Mixing was accomplished by inverting the graduates
five times. The treated effluent was then allowed to stand undisturbed
for a minimum of 15 minutes and the volume of sludge was centrifuging
at 9000 rpm for 15 minutes. The clear supernatant was carefully poured
off and stored until tested for color. The percentage of removal of
color was calculated from the data and the results are given in Table
3k. The results show that at 850 ppm lime, 300 ppm BaCl2 , and 150 ppm
FeCls are reasonably optimum quantities for color removal from the un-
treated caustic extract , whereas in the case of lime-treated caustic
extract only £ 50 ppm BaCla and £ 25 ppm FeCls are sufficient to give
maximum color removal. (Metal ions should be added before lime addi-
tion. )
In the case of NSSC effluents, however, at 1000 ppm lime the percentage
of color removal generally increases with increasing amounts of salt
concentrations. It seems that "optimum" concentration was not reached
in the range studied.
TREATMENT OF MILL WASTES WITH VARYING LIME CONCENTRATION
AND CONSTANT METAL ION CONCENTRATION
In this set of experiments lime concentration was varied from 300 to
1500 ppm and ferric- and barium chloride were kept constant at concen-
trations set by previous experiment.
Forty milliliters of 0.2 percent effluent was mixed with the required
amounts of salt solution and lime, the volume was made-up to 80 ml in a
100-ml measuring cylinder and the mixture processed and analyzed as be-
fore. The results are given in Table 35-
The data show that FeCla is more effective than BaCla in the case of all
effluents tried. For example, with untreated caustic extract over 96
percent color was removed with 150 ppm FeCl3 and only 300 ppm lime,
133
-------
whereas in the case of BaCl2 > 96 percent removal could be reached at
300 ppm BaClz and 1500 ppm lime.
Table 3!*. PERCENT COLOR REMOVAL FROM MILL WASTES BY THE
METAL ION-LIME SYSTEM
(Lime Concentration Kept Constant)
Salt
concentration,
ppm
Caustic extract
(850 ppm lime)
NSSC effluent
(1000 ppm lime)
Untreated
Li me- treated
Untreated
Lime-treated
FeCl3
86.0
91.1
93.0
91-7
9»*.8
93.9
91*.9
9U.8
67.2
>85.
>85.
>85.
>85.
>85-
>85.
>85-
>85.
>85.7
53.3
5 8; 5
56.7
63.5
60.
60,
62,
61*.
67.2
31.9
37-5
1*2.8
1+0.0
l*o! 8
53.1*
59.0
58.0
0
25
50
75
100
125
150
200
300
86.0
9^.3
95.2
92.5
91*. 9
91*. 5
96.6
96.8
97.8
67.2
>85.7
>85.7
>85.7
>85.7
>85.7
>85.7
>85.7
>85,7
53.5
61*. 1
68.1*
73.0
7!+. 1
73.7
7l*. 3
79.9
80.7
31-9
1*1.3
1*5-9
1*9.2
1*9.2
51.1*
51+.1
5U.5
61.8
BaCl2, 100 ppm = H.8 x 10""1* moles/I.
FeCl3, 100 ppm = 6.2 x 10"" moles/I.
The low figure of 300 ppm lime in combination with 150 ppm FeCl3 is much
lower than the stoichiometric lime requirement of 1000-1500 ppm in the
absence of metal ions. At this concentration (300 ppm) of lime, how-
ever, the sludge obtained was very light and hard to settle. Further
exploration showed that good settling sludges were obtained, especially
when FeCla was present, at a minimum lime concentration of about 1000
ppm. The Table 35 further shows that over 50 percent of the color left
13U
-------
by conventional lime treatment can be removed by using a FeCl3-lime
system.
Table 35. PERCENT COLOR REMOVAL FROM MILL WASTES BY
THE METAL ION-LIME SYSTEM
(Metal Ion Concentration Kept Constant)
Lime
concentration,
Caustic extract
NSSC effluent
ppm
0
300
1*00
500
600
700
800
900
1000
1500
0
300
1*00
500
600
700
800
900
1000
1500
Uh treated
BaCl2 300 ppm
0
91-7
92.6
92.7
93.3
9l*. 1
91*. 6
95-0
9l*. 9
95-9
Fed 3 150 ppm
•^20.00
96.5
97.5
97.8
97.9
98.1
98.3
98.3
98.3
98.3
Lime-treated
100 ppm
1*5.6
1*5.6
1*9.1
52.6
52.6
52.6
1*9. 1
52.6
51*. k
25 ppm
51*. 1*
5U.1*
57-9
5l*.l*
52.6
52.6
50.9
5U.1*
59-7
Untreated
300 ppm
18.6
25-7
27.1*
51.9
53.1
55.7
56.8
62.2
6l.l
200 ppm
1*1.7
58.9
67.0
-—
—
73.1*
71.0
73.3
73.9
Lime-treated
1000 ppm
28.0
29.6
31*. 5
2l*.i
37-9
39-1*
1*2.5
35-9
1*0.9
200 ppm
31.1*
1*7.1
1*0.9
52.7
50.3
57-3
58.8
57.9
1.8.9
BaCl2, 100 ppm = 1*.8 x
FeCl3, 100 ppm = 6.2 x
Lime, 100 ppm = 13. 5
lO"*1 moles/1.
lo"1* moles/1.
x 10~" moles/1.
In the case of NSSC effluent, conventional stoichiometric lime treatment
has been found to remove about 6U percent of the color (see Appendix V) ;
this percentage removal figure can be achieved using about half the stoi-
chiometric lime required with 200 ppm FeCl3. In this case also over 50
percent color can be removed from the lime-treated effluent.
135
-------
STATISTICAL ANALYSIS (REGRESSION ANALYSIS)
In any system in which variable quantities change, it is of interest to
examine the effects that some variables exert (or appear to exert) on
others. There may be in fact a simple functional relationship between
variables; but most often the functional relationship which is too com-
plicated to grasp or describe in simple terms. If this is the case, we
may vish to approximate this functional relationship by some simple
mathematical function, such as a polynomial, which contains the appro-
priate variables and which approximates the true function over some
•limited ranges of the variables involved. By examination of such a
function we may be able to learn more about the underlying true rela-
tionship and to appreciate the separate and Joint effects produced by
changes in certain important variables.
Even where no sensible physical relationship exists between variables,
Ve may wish to relate them by some mathematical equation. The equation
may foe physically meaningless, but it may nevertheless be extremely
valuable for predicting the values of some variables from knowledge of
others. The details of this analysis are given in the experimental part
of this report.
The data obtained by previous experiments (Tables 3^ end 35) were ana-
lyzed using the standard regression analysis techniques. The results of
the analysis relate the change in percentage of color removed to the
amount of lime and metal ion present. The three regression equations
obtained are given in their respective tables, 36, 37» and 38. The
theoretical values of color removal obtained by regression analysis are
plotted against experimental values in Figures 56, 57, and 58-
The data from Table 3^, where metal ion concentration was varied and
lime concentration kept constant, were analyzed to obtain constants
shown in Tables 36 and 37. Analysis showed that both iron and barium
contribute significantly to the removal of effluent color. The presence
of the b2 term in both equations indicates slight deviation from a
linear effect. Lime has a "constant" effect on color removal when iron
136
-------
is present and a "nonconstant" effect vhen barium is present (because
of the presence of the b3 slope). In other words, vhen barium is used
vith lime, both barium and lime can be added to significantly change the
color removal effect.
Table 36. EFFECT OF FERRIC CHLORIDE CONCENTRATION ON LIME
TREATMENT OF KRAFT BLEACH EFFLUENTS (CAUSTIC STAGE)
Model: Percent = b0 -
b .» [lime]2
Regression
terms
bo, %
bi
b2
f bi[FeC!3] + b2[FeC!3]2
Regression
coefficient
92.17
0.0^8388
-0.000097
+ b 3 [lime] +
Standard
error
—
0.005700
0.000052
bi,
r
r
2
,
5U.O
Note: The regression coefficients bi, ba» b3, b^, give the
response per unit change in the variable. In the
above table terms b3 and bij are not significant.
bo = Average percentage color removal by FeCl3 over the
range studied.
r2 = Percentage total variability of color removal ex-
plained by the above equation.
The values labeled r2 indicate the percentages of total variation of
color removal which have been explained by the regression equations
shown. The lower percentage values ($b and 60 percent, Tables 36 and
37, respectively) are not very good and indicate the existence of
potentially sizable deviations between predicted and experimental color
removal values. The 96 percent value for the model in Table 38 is much
better.
The data from Table 35, where metal ion concentration was kept constant
and lime concentration varied, were used to obtain the constants shown
in Table 38. A dummy variable was introduced in the calculations to
indicate the different metal ions present. Results showed that lime has
a significant effect on color removal and that this effect is nonlinear.
137
-------
Table 37. EFFECT OF BARIUM CHLORIDE CONCENTRATION ON LIME
TREATMENT OF KRAFT BLEACH EFFLUENTS (CAUSTIC STAGE)
Model: Percent = b0 + bi[BaC!2] + b2[Bad2]2 + b3[lime] +
b i» [lime]2
Regression
terms
bo, %
bi
b2
bs
Refression
coefficient
89.11
0.007683
-o.oooooi*
0.003208
Standard
error
—
0.003579
0.000002
0.0009M
:, % 60.0
Note: The regression coefficients bi, b2, b3, bi,, give the
response per unit change in the variable. In the
above table term bi» is not significant.
bj = Average color removal by BaCl2 over the range studied.
r2 * Percentage total variability of color removal explained
by the above equation.
Table 38. EFFECT OF LIME CONCENTRATION ON COLOR REMOVAL
WITH CONSTANT LEVELS OF METAL IONS
Model: Percent • b0 + bi[lime] + b2[lime]2 + b3[X]
where X = 0 when FeClj is present, and
• 1 when Bad2 is present.
Regression
terns
b0
bi
ba
bs
r2
Regression
coefficient
9^.21
0.007599
-0.000003
-U.03
96,0
Standard
error
—
0,000^16
0.000001
0.23
Note: The regression coefficients bi, ba, bs, give the
change in response per unit change in the variable.
bo « Average percentage color removal by lime over the
range studied.
r2 • Percentage total variability of color removal ex-
plained by the above equation.
138
-------
9.9r-
9-8
9-7
£ 9.6
w
O
O
9.5
9-If
9-3
9.2
X: Experimental values
Curve: Theoretical values by
regression analysis
I
10
15 20
Iron, ppm (x 10')
25
30
35
Figure 56.
Effect of FeClj concentration on color removal. Line concentration was
kept constant. (Color removal values at 150 ppm FeClj
from Table kO have also been plotted here)
139
-------
9.6
9.52
2
£ 9.36
I
<* 9.28
9.2
9.12
* Experimental values
Curve: Theoretical values by
regression analysis
9.0lt
I
I
8 12 16
Barium, ppm (x 102)
20
28
Figure 57.
Effect of BaCl2 concentration on color removal. Lime concentration vas
kept constant. (Color removal values at 300 ppm BaClz from
Table ^0 have also been plotted here)
li*0
-------
9.8
x
o
Q
5? x x
Ferric chloride, 150 ppm
9-7
9-6
3
^
**
-------
The presence of bs constant indicates that the use of barium in place of
iron will result in a loss of h percentage units of color removal.
The analysis of the data suggested that iron is a more effective color-
removing agent than barium in the lime treatment of mill effluents (Fig-
ure 58)- The analysis shows that when the amount of iron is held con-
stant and lime varied, a good estimate of the effect of lime can be made.
Figures 56 and 57 show large deviation from the regression curve (theo-
retical curve) and suggest that when discussing the expected percentage
color removal due to either metal ions, a range would be more useful
than a definite prediction.
To provide information about the independence of the effect of the two
additives (lime and iron) it was thought that a series be run in which
the amounts of both iron and lime be varied.
TREATMENT OF MILL EFFLUENT WITH VARYING LIME AND FeCl3
Designed experiments were performed to study the effect of lime treat-
ment on kraft bleach effluent in the presence of metal ions (FeCla).
The purpose of this study was to determine the effect of these additives
on the amount of color removed from the effluent samples, and also to
determine whether or not the effects of the two additives are indepen-
dent of each other. The following levels of additives were studied.
Lime, ppm: 1000, 2000, 18,000
FeCl3, ppm: 0, 25, 50, 100, 200, 300, 500, 800
The levels of each variable were run once with all levels of the other,
giving a total of twenty four experiments. The results obtained are
given in Table 39.
The effect of FeCl3 on sludge volume at different levels of lime is
depicted in Figure 59- Lime concentrations of 1000 and 18,000 ppm and
FeCla concentration of more than 100 ppm give denser sludges than those
at 2000 ppm. In fact, sludge obtained at 18,000 ppm lime is the most
dense indicating better settling properties.
-------
Table 39. LIME TREATMENT OF KRAFT BLEACH CAUSTIC EXTRACT IN THE PRESENCE OF METAL ION
Experiment
no.
FeCl3,
ppm
Lime,
ppm
Sludge vol. , Final
ml pH
Untreated caustic extract
1
2
3
U
5
6
7
8
1
2
3
1*
5
6
7
8
1
2
3
U
5
6
7
8
0
25
50
100
200
300
500
800
0
25
50
100
200
300
500
800
0
25
50
100
200
300
500
800
1,000
1,000
1,000
1,000
1,000
1,000
1,000
1,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
2,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
6.2
8.2
8.2
8.5
13.3
11*. 1*
22.0
30.1
6.2
7.0
7-3
9-7
ll*.l
19-1
33.5
62.0
8.9
8.7
9.0
9.1*
11.2
12.2
U*. 3
16.8
8.83
11.58
11.50
11.1*2
11. U2
11.1*9
11.50
11.1*0
11.32
11.79
11.70
11.70
11.70
11.70
11.71
11.78
11.73
11.98
11.99
11.98
12.00
12.01
12.01
12.01
12.00
Color
units
1*»397
820
806
627
1*1*0
377
370
186
196
561
528
U62
361
291*
209
11*1
111
292
226
220
180
162
119
80
58
Ah sorb an ce ,
280 run U80 nm
9.1*5
2.53
2.57
2.20
1.60
1.1*2
1.1*1*
0.81
0.8U
2.00
1.83
1.7U
1.1*2
1.10
0.97
0.70
0.50
1.01
0.97
0.87
0.82
0.68
0.51
0.1*0
0.31*
2.12
0.38
0.36
0.32
0.19
0.19
0.21
0.09
0.09
0.29
0.23
0.25
0.20
0.13
0.12
0.10
0.05
0.15
O.lU
0.11
0.09
0.06
O.Ol*
o.oU
0.02
TOC,
mg/1
220
73.5
7l+. 5
63.8
1*8.3
52.0
56.5
1*2.0
37.8
69.0
51*. o
59.5
51*. 5
UU.S
1*0.5
30.8
28.0
U3.0
1*5.0
1*9.3
1*0.3
35.0
Uo.8
27.0
2U. 8
BOD,
mg/1
1^*7
UU
1*5
1*7
1*1
36
31*
30
28
36
36
35
33
31
30
26
23
32
32
29
30
30
25
25
23
-------
I
r-l
CO
,D
Lime '
/2.000 ppm
A
18,000
606
700
100 200 300Voo 500
Fed 3, ppm
Figure 59. Effect of ferric chloride and lime on sludge volume
-------
The percentage color removal based on results in Table 39 are given as
"actual" data in Table UO. The data in Table Uo were analyzed using
standard regression analysis techniques similar to the one used earlier.
The regression equation which was obtained from the data in Table Uo
is given in Table Ul. The last term (bs) in the regression equation in-
dicates a lack of independence between lime and the metal ions and their
effect upon the color removal. In other words, it cannot be predicted
how much color one may remove by adding 500 ppm FeCl3 without knowing
how much lime will be added also. This fact has also been demonstrated
by Figure 60. Had the effect of these two variables been independent,
all curves would have shown similar trends and slopes.
Table 1*0. PERCENT COLOR REMOVAL By LIME iw THE
PRESENCE OF METAL IONS
FeCl3
concentration
ppm
0
25
50
100
200
300
500
800
"Experimental
Limp concentration , ppm
1000
actual a
81. U
81.T
85-7
90.0
91. U
91.6
95-8
95-5
values.
calb
83.8
8U.7
85.5
87.1
89.8
92.0
9U.8
95. ^
LC- c" -i r\n a
2000
actual8-
87-2
88.0
89.5
91.8
93.6
95-2
96.8
97.5
nnl VST s .
cal
87.3
88.1
88.9
90.5
93.1
95.2
98.0
98. U
16,000
actual
93. 1+
9U.9
95.0
95-9
96,3
97.3
98.2
98.7
cal
93.3
93-9
9U.5
95-5
97.3
98.5
99.5
97.2
Using the regression equation (Table Ul) and the actual levels of addi-
tives, the "calculated" percentage color removal values are obtained
(see Table Uo). The agreement between the actual and the calculated
data is extremely good for all levels (Figure 6l). The correlation for
1U5
-------
this equation, i.e., the percentage variation, r2, in color removal ex-
plained by the regression is 93$ (Table 1*1).
Table 1*1. EFFECT OF VARYING LIME AND METAL ION CONCENTRATION
ON COLOR REMOVAL (REGRESSION EQUATION)
Model: Percent =
bjlime]2
Regression
terms
bo
bi
- b2
U 3
D li
bs
r2
bo + bj[FeCl3] = b2[FeC!3]2 + b3[lime] +
+ bs[FeCl3][lime]
Regression Standard
coefficient error
80.05
35.03
-0.025
3.99
-0.0001809
-0.0005991*
93.0
x 10" 3
x 10" 3
x 10" 3
x 10" 3
x 10~3
—
U.239
0.0051^
0.882U
O.OOOOU5
0.000150
x 10" 3
x 10- 3
x 10" 3
x 10~3
0
x 10
Note: The regression coefficients bi, b2, b3, bi», bs, give
the change in the response per unit changes in variable.
bo = Average percentage color removal over the range studied.
r2 = Percentage total variability of color removal explained
by the above equation.
A comparison of regression coefficients obtained earlier (Tables 36 and
37) and now (Table Ul) is made in Table U2. This table shows that with
the exception of the constant for the quadratic effects, the regression
coefficients of the present work are in line with those obtained in the
earlier work. The linear terms for both lime and FeCl3 are within the
statistical limits of acceptability. The changes in the quadratic terms,
however, would seem to be due to the presence of_ the interaction of FeCl3
and lime.
Similar experiments run on the lime-treated caustic extract as run on
the untreated caustic extract (see Table 39) indicated that over 80 per-
cent of the color, which was left by conventional lime treatment process,
can be removed using 500 ppm FeCl3 and 1000 ppm lime. At lower FeCl3
concentrations (less than 150 ppm) and 1000 ppm lime only, 65-70 percent
color was removed.
-------
10.8 r~
8.0
6 8 10
Iron Concentration, ppo (x 102)
Figure 60. The interactive behavior of line and metal ions on color removal
-------
90
80
8 8 i 8
Q9 ™ Lime « 18,000 ppm
ll
O
s
I
KnL.
I!*
1001-
O Actual
D Calculated
ioor
a
g 2,000
go L • Actual
D Calculated
90
I
1
80
8
!• i i
3 100 200
8
i i
300 UO
fi
1,000
1 1
0 500 600
1 1
700 800
Fed 3, ppm
Figure 61 Percentage of color removal by lime in the presence of metal ions
-------
Table U2. COMPARISON OF REGRESSION COEFFICIENTS
Regression coefficients
From Tables 35, 36 From Table
Linear FeCl3, ppm 1+8.39 x 10~3 35-03 x 10~3
Linear lime, ppm 7.60 x 10~3 3.99 x 10~3
Quadratic FeCl3, ppm -0,097 x 10~3 -0.025 x 10~3
Quadratic lime, ppm -0.003 x 10~3 -O.OOOlSl x 10~3
Interaction8", ppm -NA- -0.00056 x 10~3
NA = not available.
ft.
Interaction of Fed3 and lime.
The statistical analysis suggested that iron is a more effective color-
removing agent than barium in the lime treatment of mill effluent.
This study further suggests that some interaction between lime and
FeCls is present resulting in better color removal then when either
of the two is used separately. In other words a "synergistic" effect
exists.
11*9
-------
SECTION VII
EXPERIMENTAL
PROCESSING AND FREEZE-DRYIWG OF WASTES
Untreated and lime-treated colored samples were concentrated under re-
duced pressure to one-tenth of their original volume. (Untreated
samples, if concentrated further, were very difficult to freeze-dry.)
Most of the calcium, especially in the lime-treated samples, was pre-
cipitated by carbonating the samples to a pH of 10.2. The carbonated
samples were then centrifuged in the beta-centrifuge at 9000 rpm for 15
minutes. This speed and time was sufficient to give clear solutions.
If, in some cases, slight turbidity was still present, these samples
were filtered through a Millipore filter paper. The pH of the solution
was checked at every stage. The colored but clear solutions were frozen
in strong glass containers (centrifuge bottles) and dried, under high
vacuum. This freeze-dried material formed a low density powder and was
readily soluble in water. The dried samples could be kept in airtight
bottles for longer periods without any significant change.
ISOLATION OF ACID-INSOLUBLE COLOR BODIES
Freeze-dried solids of the untreated waste (lU.3 g od basis) were dis-
solved under mechanical stirring in 60 ml of water and approximately 17
g of clean cellulose powder (Whatman standard grade) was suspended in
the solution. The stirring was continued and the pH was adjusted to
1.0 with strong hydrochloric acid (l vol. concentrated acid to 2 vol. of
distilled water). The acidified mixture was filtered through a precoat
of about h g of cellulose powder on a Buchner funnel and the filter cake
was washed with a total of 50 ml of water in small portions. When the
filtrate was just acid to Congo Red paper, some of the precipitate pep-
tized and formed a cloudy filtrate. The cloudy filtrate was mixed with
about 3 g of acid-washed Fibra-Flo 11C (Johns-Manvilie filter aid), the
mixture was filtered on a thin precoat of Fibra-Flo on a small Buchner
funnel, and the filter cake was washed with water.
151
-------
Both the cellulose powder and the Fibra-Flo filter cakes vere separately
extracted with 50 percent aqueous ethanol. The alcohol was evaporated
from the combined solution at reduced pressure whereupon a finely divid-
ed precipitate formed; the slurry containing this precipitate was subse-
quently freeze-dried, and designated as "acid-insolubles," The aqueous
filtrate contained the "acid-soluble" material.
ISOLATION OF ACID-SOLUBLE COLOR BODIES
The acid-soluble fractions obtained during acidification of mill wastes
were recovered and fractionated using Rohm & Haas Co.'s Amberlite XAD-8
resin (polystyrene cross-linked with divinyl benzene).
The acid-soluble solutions were first passed through a 2*K) ml bed of
Amberlite XAD-8 resin. The column was eluted first with water and then
with aqueous ethanol (l:l water — 95 percent ethanol mixture). The
eluate was actually collected in seven fractions but the last four
fractions (eluted with aqueous ethanol) were combined to give four final
fractions. Each fraction was made alkaline with sodium hydroxide to pH
about 9^0 (ethanol was removed under reduced pressure).
The first fraction contained material which passed through the column
(unadsorbed) with the original solution. A floe similar to that of fer-
ric hydroxide was noticed when this fraction was made alkaline, and the
floe was separated by filtration.
The second fraction contained material which was held on the column
initially, but was readily eluted from the column with water. Upon
alkalization this fraction deepened in color and was more highly colored
than the first fraction.
The third fraction was an intermediate fraction and was collected until
the eluate was neutral to Congo Red.
The fourth and the final fraction contained material eluted with aqueous
ethanol.
152
-------
It should "be kept in mind that the fractionation was not sharp, and thus
each fraction could contain some material similar to that found in the
previous fraction.
FRACTIONATION OF COLOR BODIES
Two types of Bio-Gels (Bio Had Co.) were used for this purpose. Bio-
Gel P-2 (exclusion limit 2600) and P-60 (exclusion limit 60,000) were
hydrated in distilled water and separately packed in 2.5 x 200 cm and
2.5 x 100 cm glass columns, respectively. The complete apparatus used
for fractionation is shown in Figure 62.
The volume of the solutions used for fractionation was less than 3 per-
cent of the void volume of the column (void volume, Vo, = total bed
volume x 0.38). A measured quantity of the solution was added to the
top of the column. A glass fiber filter was used on the gel so that
upon addition of the solution, the gel surface was not disturbed. The
eluate was allowed to flow into an automatic collecting device and the
collector timer and the UV-cord recorder were started. When the solu-
tion dropped to just below the surface of the gel, one milliliter of
distilled water was added to the column and elution continued. When
the level was again slightly below the gel, more distilled water was
added and the column was then connected to the constant head water
reservoir through a filter and a flowmeter. The elution rate (0.2-0.3
ml/min) was controlled by a teflon stopcock with a needle adjust. Frac-
tions were collected every 30 minutes. At the end of fractionation,
which took three to four days, the collected fractions were combined
according to the number of peaks on the UV recorded chart. The combined
fractions were freeze-dried and used for study. (Aliquots of the
fractions were taken for color, TOC, and absorbance before freeze dry-
ing. )
COLOR MEASUREMENT
Color was measured according to the platinum cobalt standard method of
the American Public Health Associaliion (APHA)18. The only modification
of the method was the use of a norvcarbonate buffer for pH adjustment to
153
-------
30 cm Head
50
Approx. Scale! I mm1 I cm
i- Water Reservoir
50 cm
100 cm
Filter
Flowmeter
•Bio-Gel Chromatographic Columns
Coupling w/Teflon Solv-Seal
— 2.5 cm I.D.
Teflon
Needle
Valve
UVI-Cortl Monitor
UVI-Cord Recorder
Automatic Collector
Teflon Stopcock
w/Needle Adjust
Figure 62. Diagram of Gel Permeation Chromatography Apparatus
-------
7.6. It was necessary to have color values at a constant pH of 7.6,
because color was found to be pH dependent. Most natural waters have a
pH range close to 7«6.
It should be noted that the color unit is a measure of color intensity.
When it has been necessary to refer to the total amount of colored mate-
rial in a solution this has been called "total color" and is the product
of the color units and the volume of the solution.
ABSORBANCE MEASUREMENT
The samples used for color measurement were also used for absorbance
measurement at desired wavelengths on the Beckman DU Spectrophotometer.
The values obtained were multiplied by the dilution factor to give
absorbance of the concentrated solutions. Absorptivity was calculated
by dividing the absorbance values by concentration in grams per liter.
DETERMINATION OF SOLIDS
Total solids were determined by evaporation of a measured volume of waste
at 105°C overnight. The resultant weight of solids was expressed in mil-
ligrams per liter (mg/l) of waste.
Fixed and volatile solids were determined by igniting the total solids
at 600°C in an electric muffle furnace to constant weight, usually re-
quiring one hour. The loss on ignition is reported as mg/l volatile
and the residue as mg/l fixed solids.
METHOXJfL CONTENT
Methoxyl content was determined by TAPPI Method T 2 m-60.
PHENOLIC HYDROXTL CONTENT
Phenolic hydroxyls content was determined by the Goldschmid method19
using ultraviolet spectrophotometry.
155
-------
TOTAL ORGANIC CARBON (TOG)
The Process Carbonaceous Analyzer (Bechman and Co.) was used for this
purpose. Because this instrument gives only total carbon, it was modi-
fied to give TOG by the indirect method.
Based on new TOC analyzers, one combustion tube was filled with Quartz
beads saturated with concentrated phosphoric acid. Total inorganic car-
bon was first estimated by injecting samples in the HsPO^-combustion
tube at 175°C. This tube was then replaced by the regular combustion
tube containing the catalyst and total carbon was estimated by injecting
samples in catalyst-tube at 950°C. The difference between total carbon
and total inorganic carbon gave TOC.
Twenty-three microliters of the specimens were injected at 3 to 5-
minute intervals and an average reading was thus obtained from which
the "blank" reading was subtracted to give the TOC value in mg/1.
The "blank" consisted of all the ingredients listed above minus the
sample and was handled in the same manner as the sample.
In addition to the precautions listed in the operating manual, the fol-
lowing precautions are recommended for accurate results.
a. The injection syringe should be checked often for burrs,
cracks, etc. , which cause particles from the rubber cap
to drop into the combustion tube thus giving high readings.
b. A constant slow needle insertion and retraction is essen-
tial to prevent "popping" of the combustion chamber rubber
cap.
c. Combustion chamber rubber cap should be replaced often.
d. Tygon tubing close to the condenser, filters, and glass
combustion chamber dome should be cleaned often.
DETERMINATION OF MOLECULAR WEIGHTS
Due to large number of samples to be analyzed, the "conventional sedimen-
tation equilibrium method"11* was considered impractical and the "short
156
-------
column sedimentation equilibrium method" was used. An effective way to
reduce operating times is to shorten the fluid column in the centrifuge
cell. In the "short column method" samples columns are 1 mm or less
compared to 3 mm of the "conventional method." The time for equilibrium
was reduced from 2^ hours to 3 hours by using the 1-mm column.
Although providing the time advantage as well as simplified computations5
"short columns" result in only single value for molecular weight and
thus little information concerning the polydispersity or nonideality
is available. The values obtained are apparent weight average molecular
weights for polydisperse solutes. Normally this procedure has a pre-
cision of about 3 percent; hpwever, for most of this work especially due
to low molecular weights of most samples, the precision is probably much
lower.
For calculation of molecular weights the quantity required from the
equilibrium run is the concentration gradient at the midpoint of the
solution column usually obtained directly from schlieren patterns. How-
ever, at the higher concentrations required for schlieren optics, the
colored solutions resulted in photos which were not measurable. The
more sensitive interference optical system allowed use of less concen-
trated solutions with less color and provided reasonably clear fringe
patterns. In this case, the slope of the interference fringes at the
midpoint of the solution column is the concentration gradient. It is
assumed, in this method, that the solute concentration at the midpoint
is equal to the initial concentration. The initial concentration must
also be determined. This is done in a separate centrifuge run measuring
the total fringe shift (fringe number) across a synthetically formed
boundary. Sample concentrations were normally 0.2 percent (in h^O) al-
though a few were run at 0.1 percent due to color problems. Solutions
prepared from freeze-dried samples were adjusted to pH 9.0-9.5. Equil-
ibrium runs were made in a 6-channel cell which accommodates three
samples per run.
The densities of the solutions were measured according to the method de-
scribed by Bauer20 and plotted against their respective concentrations
157
-------
in g/ml. A straight-line plot was developed and the partial specific
volume, V, was calculated from the straight-line relationship using the
Equation
V = ^- - [(-)] (d " d° )
V do LVJ l do '
where
x = concentration, g/ml
do = density of solvent
d = density of solution.
The calculations were made by the following equations and a computer
program (SHOCOL) was written to handle the raw data.
(l-vp)w2 mid o mid
m = molecular weight
R = 8.31^ x 10 7 (Universal gas constant)
T_ =303 (temperature)
v = partial specific volume
p = solution density
r . , = radial distance to solution midpoint, cm
c = initial solution concentration
dc
( — ) = concentration gradient at solution midpoint
dr mid
0) = angular velocity, radians per second.
The initial rotor speed in all runs was 1*2,01*0 rpm which is near the
recommended maximum speed for the 6 channel cell. After equilibrium
was achieved (usually less than 3 hours) a photograph was taken and the
rotot speed was reduced to 3 lower speeds allowing time for equilibrium
to be reached at each rpm. The analysis then results in apparent molec-
ular weights (Mw) at each of k rotor speeds for each sample.
Plots were then made of 1/M^ versus angular velocity with linear extrap-
olation to w2 = 0. Comparisons in molecular weights could then be made
with the effect of rotor speed eliminated.
In most cases the plots had only a slight slope. However, for some
fractions, especially AI, M^ were highly dependent on to2, apparentlj
due to solute polydispersity. The much higher M^ (at u>2 = 0) for A;
158
-------
fractions in general were confirmed by analysis of the photographs by
the conventional equilibrium method. An extension of this procedure
would be to run each sample as described at several concentrations and
plot I/My, at w2 = 0 versus concentration to eliminate concentration
effects also.
REGRESSION ANALYSIS21
The analysis was performed to study the effect of one variable on other
as per example given below:
»
Linear Regression, Case Problem
Let us assume that the regression line (the mathematical equation) of
a variable Y on a variable X has the form 30 + 61 X. Then we can write
the linear, first order model
Y = g + BiX + e (1)
That is, for a given X, a corresponding observation Y consists of the
value B0 + 3iX plus an amount e, the increment by which an individual
Y may fall off the regression line.
Equation (l) is the model of what we believe. We begin by assuming
that it holds; we will inquire later if it does hold. $0 and Bi are
called the parameters of the model. When we say that a model is linear
or nonlinear, we are referring to the linearity or nonlinearity in the
parameters. The value of the highest power of an independent variable
in the model is called the order of the model. For example
Y = B0 + B:X + Bi^X2 + e (2)
is a second-order (in X) linear (in the B's) regression model.
The values Bo> Bi» and e are unknown in Equation (l) and in fact e would
be difficult to discover since it changes for each observation Y. (30
and Bi however remain fixed. Although we cannot find them exactly with-
out examining all possible occurrences of Y and X, we can use informa-
tion from an experiment in which we measure a subset of the values, and
159
-------
obtain estimates, bQ and bi of 3O and 81 • We then can vrite
Y1 = b0 + biX (3)
where Y1 denotes the predicted value of Y for a given X. Equation (3)
is then used as a predictive equation; substitution for a value of X
would provide an estimate of the true mean value of Y for that X.
Linear Regression, Solution
Suppose we have available n sets of observations (Xi, YI), (Xa, Y2), •••»
, Yn). Then we can write [from Equation (l)]
The sum of squares of the deviations from the true line is
S - Z6i2 = ZfYj - B0 - Bi^)2 (5)
We will choose our estimates bQ and bi to be values which when substi-
tuted for $0 and 3i in Equation (5) produce a minimum value of S. We
determine bQ and bi by differentiating Equation (5) first with respect
to 30 and then with respect to 3i and setting the result equal to zero.
We have then
o
3S _. _,„ _ e B } (?)
0
Substitution of bo and bi for 3O and 3i then gives the following equa-
tions to solve
- b0 - b^) * 0 (8)
- b0 - b^JXi = 0 (9)
Rearranging the terms and collecting them into a computable form gives
the following as solutions for bQ and bj
, nZXY - (£X)(ZY)
bl " nZX' -
b0 = (EY - bi ZX)/n (ll)
160
-------
(The subscripts have been eliminated since all n observations are -used
in the summations.) Substitution of Equation (ll) into Equation (3)
and rearranging terms gives
Y' = Y + bj (X - X) (12)
If we subtract each side of Equation (12) from the observation (Y) it-
self we have
Y - Y1 = Y - Y - bi (X - X) (13)
Summation over all of the n observations yields
E(Y - Y1) = Z(Y - Y) - b! £(X - X) (lU)
Since both terms of the right-hand side equal zero, we have that the sum
of the residuals (observation minus prediction) is equal to zero, i.e.,
the deviations are minimum.
Linear Regression, Precision
The precision of the regression line (and the validity of our original
assumption) is determined from the identity:
Yi - V = ^ - Y - (Y./ - Y)
If we square both sides of the identity and sum over all observations it
can be shown that
1^ - Y)2 = E(Yi - Y^)2 + Z(Yi' - Y)2 (15)
and note that the left-hand side of Equation (15) is the sums of squares
of deviations of the observations from the mean. The first term on the
right-hand side is the sum of squares of the deviations of the observa-
tions from their predictions; and the second term is the sum of squares
of the deviations of the predictions from the mean we can write Equation
(15) in words as follows:
Sum of squares _ Sum of squares + Sum of squares
about the mean about regression due to regression
This shows that some of the variation can be ascribed to the regression
line and some to the fact that the actual values do not all lie on the
161
-------
regression line. We assess the usefulness of the regression line or; u
predictor by comparing how much of the SS about the mean fulls into tho
SS due to regression against the amount that falls into the CS about
the regression. The ratio r2 is computed as
2 _ SS due to regression
r ~ SS about the mean
and we note that when r2 = 1, we have no deviations of predictions from
their observations; when r2 = 0, we have that the regression equation
is useless in its present form.
Multiple Linear Regression —
The usual situation encountered is not that of a response and one inde-
pendent variable. In many cases it is known beforehand that a response
is dependent upon several variables. We require information about the
type of relationship (positive, inverse, curvilinear, etc.)s the magni-
tude of the dependence, and the interactions of the independent variables
with the response.
Let us assume that we have three independent variables, Xi, Xa , and Xa
and the response Y, and we have data from an experiment designed to in-
sure independent estimates of the parameters . If we assume the model
Y = 60 + BiXi + 02X2 + 63X3 + 3i,2XiX2 + $1,3X1X3
+ 62,3X2X3 + Bi.iXi2 + 02,2X22 + 63,3X3* + e
and obtain estimates b^ of the 3^ as described previously. The solution
is obtained by solving simultaneous linear equations which result from
differentiating the Function S [Equation (5)3 under our present assump-
tions. A statistical test is made for each of the parameters to deter-
mine whether the parameter is equal to zero (i.e., no effect) or not
equal to zero.
The interpretation of the bA and bj^ parameters is straightforward. The
"interaction" parameters , bij , is testing the independence of the effect
of the variables "i" and "j" upon the response. If it is found that a
162
-------
Injector:
Column:
parameter b^ j is not equal to zero, it implies the effect is dependent
upon the levels of the two variables.
PYROLYSIS-GAS LIQUID CHROMATOGRAPHY
The Varian Aerographs lUOO series gas chromatograph vas used for this
purpose. Selected samples of freeze-dried color bodies from dilute
waste liquors were subjected to pyrolysis-gas liquid chromatography
(GLC). The conditions were as follows:
Pyrolysis: Hamilton Multi-Purpose Sampling System
Furnace temp, UOO°C
Oven zone temp, 2l*0-2U5°C
Heated line temp, 2UO-260°C
190-200°C
10 percent Carbowax 20M; 5 ft x 1/8 inch
Initial temp, 75°C
Final temp, 200°C
Rate, Wmin
Hydrogen flame ionization
Temp, 275-285°C
Gas sources: Carrier gas: He at 75 ml/min
Hydrogen: Varian Aerograph Model 9652 Hydrogen Generator
Air: Cylinder
Sample size: Sample weights could not be kept constant due to differ-
ences in ash contents. Most of the samples were not
weighed for this qualitative study.
Modular Construction
The Hamilton Multi-Purpose Sampling System consists of temperature con-
trol unit, a gas control unit, a furnace assembly, a heated line and
miscellaneous parts and supply.
The temperature control unit supplies adjustable power to the Furnace
Assembly and Heated line. It also provides thermocouple meter read-out
Detector!
163
-------
of temperature at two points in the Furnace Assembly and at one point
in the Heated Line.
The gas control unit provides means for diverting carrier gas through
the Furnace Assembly to flush sample vapors into the inlet of the gas
chromatograph by way of the Heated Line and its terminal needle.
The Furnace Assembly includes a tubular Vycor chamber in which the
sample is processed. This processing tube passes through three zones
of Furnace Assembly:
(l) A room temperature zone, where the sample may be
held while purging air from the system,
(2) a furnace zone, capable of 800°C, into which the
sample is dropped for heating,
(3) an oven zone, which heats to 300°C for vapor
holding. After passing through the oven, the
processing tube connects directly with the
heated line.
The Heated Line operates at temperatures up to 300°C and has only stain-
less steel in contact with the sample. It is quite flexible, to allow
insertion of its terminal needle into the chromatograph inlet. Accord-
ing to the Hamilton manual the insulation on Heated lane should permit
safe handling at high temperatures. Our experience showed, however,
that the Line could not be handled with bare hands.
Sample Handling
Samples are usually contained in thin-wall quartz sample tubes during
processing. One purpose of the sample tube is to facilitate determi-
nation of initial sample weight and weight of residuals after pyrolysis.
Another purpose is to insure that all forms of sample —powders, liquids,
etc. — drop into the furnace in an identical manner, to the same spot,
and are exposed to identical conditions. The sample also protects the
processing tube from direct contact with other than sample vapors, thus
lengthening the time between cleanings,
-------
The best method of retaining samples is to use small plugs of woven
quartz fiber yarn or quartz wool.
Quartz tubes and loosely "wadded" quartz wool were fired in a muffle
oven at 800°C until clean (usually 15 minutes were enough) and cooled
in a desiccator. Sample tubes and quartz wool were handled with tweez-
ers to avoid contamination by body oils. Samples were loaded in the
tubes as follows:
(l) Sample tube was plugged on one side with the wadded
quartz wool.
(2) The tube was held with clean tweezers and the solid
sample was loaded through a small funnel made out of
aluminum foil, solvent cleaned on the side that
contacts the sample. The open end of the filled
tube was then plugged with quartz wool as before.
The pltigs were dense enough to prevent the sample
grains from falling.
(3) In case of low density powders, the open end of the
sample tube was inverted on the sample and pushed,
turned upright and tapped on the plugged end for the
sample to fall in the tube. In some cases, clean
needles were used to push the sample to the middle
of the tube before plugging the open end.
(k) Care was taken to ensure that no grains were left
on the outside of the sample tube.
(5) The liquid samples were injected with a microliter
syringe onto the quartz packing, allowing capillary
action to retain the sample.
Sample tubes (filled) were inserted into the processing tube through the
sample port and the cap was screwed in (sample introduction knob was on
"on" position and the gas flow had "been adjusted to 75 ml/min with the
help of flow balance adjust). The furnace assembly was tipped to drop
the sample tube onto the quartz wool plug in the furnace zone, lowered
back to horizontal position, latched in place and the GLC column oven
linear temperature program and recorder chart were started.
165
-------
SECTION VIII
REFERENCES
1. National Council of the Pulp & Paper Industry for Mr and Stream
Improvement (NCASl). Tech. Bull. No. 157, Dec. 1962.
2. Le Compte, A. R. Tappi. 1*9(12) :121A, 1966.
3. Berger, H. F. and R. I. Brown. Tappi. U2(3):2l+5, March 1959.
U. Smith, D. R. and H. F. Berger. Tappi. 5l(lO):37A, Oct. 1968.
5. Davis, C. L. , Jr. Tappi. 52(ll):2132, Nov. 1969.
6. Spruill, E. L. Water and Sewage Works. Industrial Waste Supple-
ment. 118:15, 1971.
7. Information from Humphrey, J. E. Project Director, International
Paper Company, Springhill, La.
8. Dence, C. , et_ al. NCASI Tech. Bull. 239, 1970.
9. Dugal, H. S., et_ al. EPA Report No. EPA-R2-73-11*!, February 1973.
10. Swanson, J, W., H. S. Dugal, M. A. Buchanan, and E. E. Dickey.
Effluent Color Characterization Before and After Stoichiometric
Lime Treatment. Environ. Protection Agency, Washington, D.C.
Publication No. EPA-R2-73-086. February 1973- 75 p.
11. Schachman, H. K. Reprint from Methods in Enzymology. Vol IV.
Academic Press Inc., New York, N.Y., 1957-
12. Goldschmid, L. 0. In_ Sarkanen and Ludvig's Lignins Occurrence,
Formation, Structure and Reactions. New York, Wiley Interscience,
1971. p. 256-258.
13. Goring, D. A. I. Chromophore Seminar, Raleigh, N.C., April 1972.
Ik. Chervenka, C. H. A manual of Methods for the Ultracentrifuge.
Beckman Instruments Inc., 1969. P- ^2-55.
15. Ortiz, De Serra, and Schnitzen's Soil. Biol. BioChem. 5(3):28l-
286, 1973.
16. Supplied by Fleck, J. PhD Student. The Institute of Paper
Chemistry, 1973.
17. Personal communication. Spruill, E. L., Supervisor, Environmental
Control, Continental Can Co., Hodge, La.
167
-------
18. Standard Methods. American Public Health Association (APHA).
12th ed., 1965. p. 129.
19. Goldschmid, 0. Anal. Chem, 26(9):ltel, 195^.
20. Bauer, N. Determination of Density. In_ Weissberger's Tech-
nique of Organic Chemistry. Physical Methods. 2nd ed. Vol.
1. Part 1. Interscience, New York, 19^9. p. 25U-296.
21. Draper, N. R., and Smith, H., Applied Regression Analysis, John
Wiley & Sons, New York, 1966.
168
-------
SECTION IX
APPENDICES
Page
I. Fractionation of Color Bodies from IPCO's Kraft Decker Effluent:
Massive Lime Treatment ' 170
II. Sugar Analysis of Decker, Caustic Extract, and NSSC Wastes from
Massive and Stoichiometric Lime Treatment 171
III. Fractionation of Color Bodies from IPCO's Kraft Bleach Caustic
Extract: Massive Lime Treatment 172
IV. Fractionation of Color Bodies from CONGO'S Kraft Decker Effluent:
Stoichiometric Lime Treatment 173
V. Fractionation of Color Bodies from CONGO'S NSSC Effluent: Stoi-
chiometric Lime Treatment 17**
169
-------
APPENDIX I
FRACTIONATION OF COLOR BODIES FROM IPCO'S KRAFT DECKER EFFLUENT
(Material Balance of Color and TOC)
Untreated
Decker Waste
Color (100)
TOC (100J
Removal by "Massive"
Line Treatment
(-73) [-53.0]
Lime-Treated
Waste Contains
(27) [VT.O]
Acid
Treatment
Acid-
Insoluble
< 33,000 »
Acid-
Soluble
t < 1000
Acid
Treatment
Acid-
Insoluble
M < 2000
Acid-
Soluble
K.. < 500
(85.5)
[51.0]*
(17.5)
(13.8)
[3.3]
(13.2)
[1*3.7]
Fractionation
Fractionation
On
P-60
On
XAD
Bio-Gel + Res
On
P-20
Bio-Gel
Ai(l2.9)[6.2]
Aa (9-W3.9]
Aj (7.l)[2.7l
Ai,(ll.l)[3.8]
A5 (2.6)[0.7l
A, (0.6)[0.15l
A(55.0)[21.9]
B (2.1*) [1.7]
C (2.1) [2.1]
D (2.5) [2.5]
E (0.6) [1.7)
F (O.U) [0.7]
0 (1.7) [1.8]
H (1.6) [1.2]
J (!».!*) (3.1»1
K (0.1*) [1.0]
L (1.2) [1.3]
M(0.25) [0.2]
N(0.25) [0.2]
P(0.25)[0.15l
Q(0.17)[0.15]
R(0.33) [O.UJ
IV(10.9)[16.0]
III (1.2) [3-0]
I (2.5)[l6.2]
I (0.9) [7.6]
On
P-60
Bio-Gel
On
XAD-8
Resin
Ai(3.6)[O.Ul]
IV(9.2)[12.9]
111(2.8) [7-2]
I(0.50)[U.9l
A (1*.6)[0.52]
B (1.0)[0.18]
C (l.l)[0.2l»]
D+E(0.77)[0.21]
F (0.8)[0.2l»]
G (1.0) [0.21*]
H (l.0)[0.22]
J (3.1*) [0.58]
K(0.58)[0.52]
L(0.1*0) [0.08]
M(0.1*6)[0.0l*]
N(0.1»0)[0.06]
P — [0.02]
Q(0.09)[0.02]
R(0.l8)[0.0l»]
apparent weight average molecular weight. Color values are shown in parentheses and
TOC in brackets. Fraction 'A' from Bio-Gel P-2 was further fractionated on Bio-Gel
P-6o column.
170
-------
Appendix II. SUGAR ANALYSIS OF FEEEZE-DRIED WASTES
(Basis o.d. Volatile Solids)
Massive lime treatment
Sugars, %
Arabinose
Galactose
Glucose
Mannose
Xylose
Total
Indulin
-C
0.37
1.69
0.02
_—
0.52
2.60
Decker
Untreated
0.0k
0.60
2.37
2.U3
10.20
16. Ul
waste
Lime
treated
-------
APPENDIX III
FRACTIONATION OF COLOR BODIES FROM IPCO'S KRAFT BLEACH CAUSTIC EXTRACT
(Material Balance of Color and TOC)
Untreated
Caustic Extract
Color (100)
TOC [100J
Acid I Treatment
Acid-
Insoluble
MW < 125,000
(92.8).I
[T9.3] !
Removal by "Massive"
Lime Treatment
(-96.0) [-80.1*]
Lime-Treated
Waste Contains
(fc.O) [19.6]
Acid Treatment
Acid-
Soluble
< 1100
(7.2) I
[20.7] j
Fractionation
On
P-60 I
Bio-Gel I
Ai(2.2)[2.
A2(l.8)[2.
A,(2.8)[3.
6]
3]
3]
Ag(3.8)[3.3]
AS(2.5)[1.6]
On
P-2
Bio-Gel
A(71.6)t55.7]
B(13.7)[2I*.6]
C(0. 1*0) [0.87]
D(0. 16) [0.148]
E(0.17)[0.3'»]
On
XAD-8
Resin t
IV (6.9)[13.2]
111(0.36) [1.0]
11(0.32) [1.1»]
1(0.27) [6.6]
Acid- Acid-
Insoluble Soluble
M^ < 10,000 MW <
(1.5) 1 (2.5)
[2.7] J [16.9] .
Fractionation
On 1 On
P-60 XAD-8
Bio-Gel 1 Resin •
Ai(0.08)[0.15] IV
A2(0.12)[0.17] IH(
500
i
•
(1.9) [7.0]
0.15H0.76]
I(O.lU) [7.0]
0(0. 87) [0.83]
H(0.21)[0.36]
A(0.2l»)[0.1H]
B(0.12)[0.33]
C(0.06)[0.15]
D(0.09)[0.ll4]
E(0.1»3)[0.68]
F(0.18)[0.30]
G(O.U)[0.22]
H(0.0l»)[0.09]
Mw = apparent weight average iralecular weight. Color values are shown in parentheses
and TOC in brackets. Fraction "A" from Bio-Gel P-2 was further fractionated on
Bio-Gel P-60 column.
172
-------
APPENDIX IV
FRACTIONATION OF COIOR BODIES FROM CONGO'S KRAFT DECKER EFFLUEIJT
(Material Balance of Color and TOC)
Untreated
Decker Waste
Color (100)
TOC [100]
I
Acid Treatment
Removed by "Stoichiometric"
Lime Treatment
(-79) [-50]
Line-Treated
Waste Contains
(21) [50]
Acid I Treatment
Acid-
Insoluble
< 167,000
Acid-
Soluble
i < 550
Acid-
Insoluble
< 1*1,000
Acid-
Soluble
< 550
(86.5)
[65.8]
(17.5)
[U9.0]
(12.8)
[18.5]
(8.2)
[31.5]
Fractionation
Fractionation
On
P-60
Bio-Gel 4
Ai(22.U)[27.J»]
Aj(13.10 [10.9]
As (7.U) [U.8]
A% (2.8) [2.2]
On
P-2
Bio-Gel
On
XAD-8
Resin
IV .
III (1.6)[2.5]
11(0.75)17.3]
I (3.UH9.8]
I
B
C
D
E
r
0
H
J
(1.
(1.
(2.
(9.
(1.
(2.
(U.
(0.
3)
0)
3)
U)
9)
3)
0)
1»)
[1
(1
tl
(9
[3
•
,
5
k'
• 9]
.3]
•
(3.
[U
[0
7]
8]
• 9]
• 5]
On !
P-60
BiorOel
Ai(l.9) [1.2]
A2(0.8)[0.63]
A|(l.8)[0.92]
A*(0.3)[0.22]
A(5.5)[3.0
On
XAD-8 I
Resin 4
IV (U.I.
111(0.27)
I+II (;
[8.8]
[1.1]
.0]
.9]
C(2.9)[3.5]
D(l.8)(2.5]
F(0.8)[1.3]
0(2.U)[3.7]
• apparent weight average molecular weight. Color values are shewn in parentheses
and TOC in brackets. Fraction "A" from Bio-Gel P-2 was further fractionated on
Bio-Gel P-60 column.
173
-------
APPENDIX V
FRACTIOBATION OF COLOR BODIES FROM CONGO'S NSSC EFFLUENT
(Material Balance of Color and TOC)
Untreated
NSSC Waste
Color (100)
TOC [100}
Acid Treatment
Removed by "Stoichiometric"
Lime Treatment
(-61*) [-30]
I
Acid-
Insoluble
1 < 1*0,000
(1*8,2)
[36.0] .,
1
Acid-
Soluble
M < 1200
(51.8) |
[61*.0] |
Lime-Treated
Waste Contains
(36) [70]
Acid Treatment
On
P-60
Bio-Gel
Fractionation
A2(5.5)[6.3j
A,(0.5)[0.5]
Ai,(0.5)[0.6]
On
P-2
Bio-Gel
A(15.6)[16.2]
B (1.10 [1.7]
C (0.5) [0.7]
D (0.9) [1.2]
E <0.8) [1.1]
P (0.7) [1-3]
0 (1.0) [0.7]
H (2.3) [1.3]
J (3-M [2.0]
Acid-
Insoluble
L < 25,000
t
Acid-
Soluble
M < 800
On
XAI>-8
Resin •*•
(20.8) j (15-2)
[35.7] | [31*.3)
Fractionation
On . On
P-60 XAD-8
Bio-Gel I Resin
111(11.9)[11-0]
11(15.9)123.6]
I (5.2)[10.3]
IV(6.0)
111(2.7)
[6.3]
[3.8]
A3(0.2)[0.5l
II(1».5)111.6]
1(1.6) [5.5]
A(6.3)
8(1.2)
C(0.8)
D(0.6)
P(-0.6)
G(7-3)
H(l.l)
J(2.3)
[9.3]
[2.1*]
[1.9]
[2.J*]
[1.5]
[2.7]
[11.91
[2.5]
[2.9]
M * Apparent weight average molecular veight. Color values are shown in parentheses
V and TOC in brackets. Fraction "A" from Bio-Gel P-2 was further fractionated on
Bio-Gel P-60 column.
PB.NT.NG OFFICE »74 546-3,9/4,8 ,-3
171*
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No.
2.
3. Accession No,
4. Title
COI0R CHARACTERIZATION BEFORE AND AFTER T.TMR TREATMENT
7. Author(s)
Dugal, Hardev S., Leekley, Robert M., Swanson, John W.
9. Organization
The Institute of Paper Chemistry
5. Report Daie
6.
8. 1- ttorm.. /;
Report No.
10. Project No.
11. Contract/ Grant No.
_s 800853
13 Type i Repci^ , and
Period Covered
12. Sr 'Tjsori'r Organ' it/on
15. Supplementary Notes
Environmental Protection Agency report
number,'EPA-660/2-74-029, April 197U
16. Abstract in general, the lime treatment removed maximum color from the caustic extract
and minimum from the neutral sulfite semichemical (NSSC) effluent.
The massive lime treatment was found to remove 73 percent color and 53 percent total
organic carbon (TOC) from kraft decker effluent, and 96 percent color and 80 percent TOG
from kraft bleach caustic extract. The analysis of the solids from the decker and caustic
effluents showed respective reductions of 73 and 59 percent phenolic hydroxyls, 63 and
26 percent sugars, and 51 and l6 percent methoxyls by lime treatment.
The stoichiometric lime treatment was found to remove 79 percent color and 50 percent TOC
from kraft decker effluent,.and 6U percent color and 30 percent TOC from NSSC effluent.
The analysis of the solids, from the decker and NSSC effluents showed respective reduc-
tions of 76 and 25 percent'phenolic hydroxyls, 31 and "negligible" percent sugars, and
U2 and 9.7 percent methoxyls by lime treatment.
In the metal ion-lime system the addition of 150-300 ppm FeCl3 with only 300-500 ppm lime
removed about 98 percent-color from bleach caustic extract. Over 50 percent of the color
left by conventional lime treatment process could also be removed by incorporating poly-
valent metal ions with. lime. However, below 1000 ppm of lime, the sludge obtained
settled slowly. More color could be removed by metal ion-lime system than when each was
used individually indicating that a "synergistic" effect, exists.
I7a. Descriptors *Effluents, *Waste water treatment, *Colored effluents, *Color isolation,
Chemical analysis, Water pollution, Effluent treatment, Out plant treatment,
Secondary treatment, Tertiary treatment, Advanced treatment.
nb. Identifiers *iime treatment, *Massive lime treatment, ^Stoichiometric lime treatment,
*Kraft color, *Neutral sulfite semichemical color, *Color, *Decker effluent, *Kraft
decker effluent, *Caustic extract, *Bleach effluent, *Kraft bleach effluent, *Kraft
caustic extract, "Molecular weights, *Color characterization, "Color isolation.
lie. COWRR Field & Group
18. A vailability
19.
Security Class.
Repot }
'0. Sc: rityC.' S.
(Page)
21.
No. of
Pages
Pt: .'J
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. O. C. 20240
Abstractor H. S. Dugal
| institution The Institute of Paper Chemistry
WRSIC 102 (REV. JUNE 1971)
------- |