STATIC COAL STORAGEBIOLOGICAL AND CHEMICAL
EFFECTS ON THE AQUATIC ENVIRONMENT
by
x-*
Nathan A. Coward, Joseph W. Horton
Center for Lake Superior Environmental Studies
and Department of Chemistry
and
Rudy G. Koch, Robert D. Morden
Center for Lake Superior Environmental Studies
and Department of Biology
NERC-R-803937-02-0
Project Officer
Frank Puglisi
Environmental Research Laboratory
U.S. Environmental Protection Agency
6201 Congdon Boulevard
Duluth, Minnesota 55804
Prepared For
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PERSONNEL
Biological - Fauna
Principal Investigator
Staff Assistant
Assistant
Robert Morden, Ph.D.
- Annette Morden
- Mary Ann Carter
Biological - Flora
Principal Investigator
Staff Ass i stant
- Rudy Koch, Ph.D.
- Lorra i ne Koch
Chemistry
Principal Investigators - Nathan Coward, Ph.D., Project Director
- Joseph Horton, Ph.D.
- Will iam Cook
- Thomas Markee
Graduate Student Robert Stephenson
Undergraduate Assistant - Charles Kpea
Undergraduate Student - Harvey Johnson
Staff
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ABSTRACT
A.
1.
BIOLOGICAL STUDIES
Vascular Macrophytes
A survey was made and representative samples of vascular macrophytes.
from the Superior, Wisconsin-Duluth, Minnesota Harbor were collected in
August 1975 and stored in a frozen condition until processed. The processed
samples were analyzed for environmentally sensitive metal concentrations by
flameless atomic absorption spectrophotometry.
The effects of the presence of Western coal upon the growth patterns of
Lemna minor L. was investigated. Lemna minor L. was grown in Lake Superior
water in the presence of additional amounts of particulate coal. Temperatur~
humidity and light were controlled by the use of environmental growth cham-
bers. Growth rates were determined by plant frond counts, and samples of
Lemna were collected for metal uptake analyses.
Evidence was found to indicate that coal particulates, at certain con-
centrations, may diminish the growth of this aquatic plant. There also ap-
peared to be increased metal uptake by the organism in the presence of coal
particulates.
2.
Benthos
A method using a recirculating water system is presented for rearing
benthic organisms. A species of Chironomus was maintained in this system
for seven generations. Heavy metals especially copper and lead were se-
questered by Helobdella stagnalis. The benthic community in the region of
the study changed little over the summer and the area of greatest community
stability was located where higher levels of coal were found. The waters in
the region of the ORBA coal dock facility were found to be mildly polluted as
determined by the presence or absence of benthic indicator organisms as a
measure of water quality and by using the diversity index of species found
in the area as a measure of biologic stability.
B.
CHEMICAL STUDIES
The aqueous leaching of heavy metals from soft coal has been examined
under a variety of conditions. Variables examined were pH, particle size,
rate of flow, time of contact and oxygen or nitrogen atmosphere. Simple
leaching of coal from Western mines with pure water does not remove large
amounts of metal. Extended, successive releaches and mildly acid leaches
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tend to remove greater amounts of metal from the coal. Leaching with a
strong complexing agent removes relatively large amounts of metal from the
coal. When placed in contact with water previously spiked with metal ions,
the coal can actually act as an absorber and reduce the concentration of
metal ions in solution. Hydrogen ion concentration has a marked effect on
the release of certain metals.
Continuous flow and simple shaker leaching experiments correlate qual-
itatively with each other.
Considerable variation was found between Eastern and Western coal and
also between different samples of Western coal.
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CONTENTS
Personnel
Foreward
Abstract
Acknowledgment
General Introduction 1
Broad General Conclusions
A. Biological 2
1. Vascular Macrophytes . 2
2. Benthos 2
B. Chemical 3
Future Research Possibilities
A. Biological 5
1. Vascular Macrophytes 5
2. Benthos 5
B. Chemical 5
Biological Research
A. Vascular Macrophytes 7
1. Background Levels of Heavy Metals in 7
Harbor Aquatic Macrophytes
2. Effects of Particulate Coal on Lemna minor Growth 8
3. Literature Cited 16
B. Benthos 17
1. Introduction 17
2. Methods 17
3. Results 20
4. Discussion 22
5. Literature Cited 23
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Chemical
A.
B.
C.
Research
Basic Experimental Design. . . . . . . . . . . . . . . . . . . 39
Experimental Design and Description of Supporting. . . . . . . 40
Equipment and Supplies
1. Coa 1 Samp 1 es . . . . . . . . . . . . . . . . . . . . . . . 40
2. Coal Grinding. . . . . . . . . . . . . . . . . . . . . . . 41
3. Stainless Steel Sieves. . . . . . . . . . . . . . . . . . 41
4. Sieving Techniques. . . . . . . . . . . . . . . . . . . . 41
5. Deionized Water. . . . . . . . . . . . . . . . . . . . . . 42
6. Continuous Flow Leaching Apparatus. . . . . . . . . . . . 42
7. Chemical Analysis of Biological Samples. . . . . . . . . . 44
Exploratory Experiments. . . . . . . . . . . . . . . . . . . . 48
1. Coal Titration. . . . . . . . . . . . . . . . . . . . . . 48
2~ Design of Buffer System for Low pH Runs. . . . . . . . . . 49
3. Filter Uptake Study. . . . . . . . . . . . . . . . . . . . 49
4. Extremum Runs. . . . . . . . . . . . . . . . . . . . . . . 50
Major Leaching Experiments. . . . . . . . . . . . . . . . . . 56
1. First Factorial Run. . . . . . . . . . . . . . . . . . .. 56
2. Continuous Flow Re1eaching Runs. . . . . . . . . . . . . . 71
3. Re1eaching Shaker Runs. . . . . . . . . . . . . . . . . . 94
4. Re1eaching Factorial Study. . . . . . . . . . . . . . . . 113
5. Spiked System Uptake Study. . . . . . . . . . . . . . . . 133
6. EDTA Shaker Study. . . . . . . . . . . . . . . . . . . . . 150
7. Short Term Shaker Study. . . . . . . . . . . . . . . . . . 153
D.
. . . . . . . . . . .
. . 162
Error Statistics of Analytical Data
. . . . .
. . . . 168
Chemistry References. . . . .
. . . . . . .
. . . . . .
. . . .
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ACKNOWLEDGMENTS
We wish to acknowledge the assistance and advice received from the fol-
lowing organizations and persons:
The Duluth Environmental Research Laboratory: Especially helpful were:
Herbert Kopperman and John Teasley who obtained coal samples for us; Gayle
Olson and John Poldoski who gave us considerable advice on trace metal anal-
ysis.
We received much useful advice and guidance from Rodney Skogerboe of
Colorado State University and Robert Thurston and Rosemarie Russo of Montana
State University.
Walter Mahlig of W. S. Tyler Company was especially helpful in fabricat-
ing the special stainless steel sieves used in this research.
We thank Paul Eisele of the Detroit Edison Company for providing us with
a sample of "Eastern" coal.
Glen Bowman and John Ethen of the ORBA Coal Facility were most helpful
in providing on-site coal samples.
Julie Lien and Denese Odermann of the Center for Lake Superior Environ-
mental Studies deserve special appreciation for all their work connected with
this project.
And finally, Albert Dickas, Director of
Environmental Studies and Frank Puglisi (our
Duluth Environmental Research Laboratory are
direction and guidance.
the Center for Lake Superior
project officer) from the
especially thanked for their
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1.
GENERAL INTRODUCTION
The use of low-sulfur western coal, as an acceptable energy source has
been on the increase for several years. A transshipment facility, located at
Superior, Wisconsin has been established to service coal shipped from western
mines. The coal is transported by rail to Superior, transferred to an open
air holding pile, and then from the holding pile to freighters (modified iron
ore carriers) which carry the coal by water to its final destination where it
is used as fuel for a steam-driven electrical power plant. Approximately
three quarter of a million tons of coal per year pass through the transship-
ment fac i1 ity.
The Center for Lake Superior Environmental Studies (CLSES), under con-
tract with the Environmental Protection Agency, undertook a three phase study
of the coal, and its possible effects on the immediate environs of the coal
transshipment facility, the Superior, Wisconsin - Duluth, Minnesota Harbor and
Lake Superior. The three phases of the study involved the following:
1. A survey of the vascular macrophytes of the area contiguous with the coal
shipment facility, and a study of the uptake of metals, leached from the
coal, by these macrophytes. Macrophytes, as an integral part of the local
food chain, could serve as an entry point for high concentrations of en-
vironmentally sensitive metals which were derived from the coal.
2. A survey of the benthic organisms of the immediate area, and a rearing
study of certain of these organisms, where the aquatic portions of the
life cycles would be carried out in the presence of coal. Since benthic
organisms are also an integral part of the food web of the area, the in-
corporation of deleterious metals, which were possibly derived from the
transshipment coal, could be a serious problem.
3. A chemical study was undertaken to determine the levels of EPA sensitive
metals in the western coals, and to investigate the factors which deter-
mine the mobilization of the metals from the coal matrix. Determination
of these parameters would give an index as to the probable effects of the
transshipment of millions of tons of coal upon the water quality and upon
the aquatic flora and fauna of the immediate area.
The chemistry study was performed to develop a reiiab1e system and meth-
odology for the determination of the leaching properties of coals, with
respect to the mobilization and release of the environmentally sensitive
metal content.
Another portion of the duties of the chemistry research group was to pro-
vide routine chemical analyses for the two biological studies.
1
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II.
BROAD GENERAL CONCLUSIONS
A.
1.
BIOLOGICAL
Vascular Macrophytes
The survey of background levels of metal concentration in aquatic vascular
macrophytes collected from the Duluth-Superior Harbor reveals considerable
variation in different plants (see Table IV-A-2). Thi~ variation is particu-
larly noteworthy for barium, lead and manganese. One species, an aquatic moss
(F~~~de~ g4an~6~o~, Brid.) appears to have the capacity to sequester man-
ganese, lead and barium in quantities in excess of those of other aquatic
macrophytes which were sampled.
The rearing study indicates that the addition of ground coal to lake wa-
ter appears to initially augment Lemna growth. After 20 days, unfortified
and low fortified (5.00 g of added coal) cultures of Lemna exhibit a decline
in frond number, perhaps reflecting depletion of nutrients. Cultures with
greater amounts of coal present (10.00 and 25.00 g of added coal) do not ex-
hibit such declines of frond production, perhaps because the larger amount of
coal present in the growth medium supplies larger amounts of nutrients. Ex-
amination of the growth rate constants suggests that there is a general de-
cline in the growth rate of Lemna with time, irrespective of the presence or
absence of added coal. Further work is needed to determine if this apparent
effect is due to increased amount of deleterious materials leached from the
coal, or merely due to other variables such as nutrient depletion, or simply
crowding of individual organisms.
Within the limitations of this preliminary study, there is no overwhelm-
ing evidence to suggest that the presence of ground coal in the growth medium
has a detrimental effect on the growth of Lemna m~no~ L.
2.
Benthos
The presence of coal appears to playa part in the stability of the ben-
thic community. The increased stability is reflected in a greater number of
organisms inhibiting a region. With more organisms there is a greater utili-
zation of resources such as minerals in the area. Heavy metals appear to be
sequestered by these organisms and thus a greater level is present in the
food webs than before. If man is the highest level consumer in some of these
food webs, caution should be used and conditions monitored to assure that
these metals do not reach levels which are or will be detrimental to man.
2
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B.
1.
CHEMICAL
Simple, slow percolation of relatively pure water (rain water or regular
city water) does not leach heavy metals from western coal to any consider-
able extent.
2.
Heavy metal leaching would be enhanced by:
a. very acid leachant: The coal is naturally self-buffered, and leach-
ant in contact with the coal approaches a pH of greater than 7 pH
units (slightly alkaline). Additional acid, of the order of magni-
tude of approximately 4 liters of concentrated sulfuric acid per ton
of coal would be needed to overcome the self-buffering capacity of t~
system and allow the mobilization of dangerous amounts of heavy metal
ions. Of the metals studied, leaching of barium and manganese are
most enhanced by high acid levels.
b. strong complexing agents: Complexing agents such as EOTA (ethylene-
diaminetetraacetic acid) are capable of removing relatively large
amounts of heavy metals from the coal. This implies that leach wa-
ters, heavily loaded with organic materials, might extract more heavy
metals than pure water.
c. successive releaching with pure water: The leaching of heavy metals
from coal appears to be an equilibrium process. Continuous applica-
tion of fresh, relatively metal-free water, will eventually remove
rather large amounts of heavy metal from the coal. This is not pos-
tulated here as any real environmental hazard. Assuming that long
term releaching could remove about 5 x 10-6 g of manganese from 1 gram
of western coal (based on the EOTA extraction work), a disaster which
deposited about 50,000 metric tons of coal into the lake could con-
tribute only about 0.3 ppb of Mn to 1 cubic kilometer of water. Dur-
ing EOTA extraction of western coals, manganese was extracted to the
greatest extent. vOther metals should give smaller effects.
There is excellent qualitative agreement between the results obtained
from simple shaker extractions and those obtained from the more complex
(and time consuming) continuous flow extractions. This would appear to
be one of the most valuable results of this work as it establishes a
reasonably firm basis for using shaker studies to survey the leaching
properties of a variety of coal samples.
3.
4.
Western coal actually is an excellent sequesterer of metal ions at its
naturally buffered pH of about 7.3. The spiked system uptake study shows
that when the system is spiked with large concentrations of metal ions,
the coal absorbs much more metal ion than it would release in equilibrium
with distilled water. This suggests that if eastern (high sulfur) coal
and western coal were to be used conjointly, storage of the western coal
"downstream" from the eastern coal might be beneficial environmentally.
5.
There appears to be significant differences in the leaching properties of
different samples of western coal. This observation is in agreement with
the work of Chadwick et al.6 who did trace metal analyses on cores taken
--
3
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from a typical western coal seam. This implies that future leaching work
should probably be based on a rather extensive and statistically signifi-
cant sampling scheme.
4
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III.
FUTURE RESEARCH POSSIBILITIES
BIOLOGICAL
A.
1.
Vascular Macrophytes
F~~lden6 g~~ndi6~on6 Brid., apparently has the ability to sequester
large quantities of certain heavy metals. It would seem most useful to test
other samples of this moss, as well as to examine other aquatic mosses to de-
termine if mosses have greater potential than other aquatic vascular macro-
phytes to serve as sequestering agents, and thus serve as bioassay organisms
for heavy metals.
Also, the problem of growth of Lem~ sp. should be investigated more com-
pletely to determine whether a very simply handled and cultured aquatic mac-
rophyte could serve as a bioassay organism for these purposes.
Additional monitoring of plants which can absorb these environmentally
sensitive materials and insert them in the food chain which can ultimately
lead to man remains a necessity.
2.
Ben thos
Future research should concentrate on studies conducted in the laborato-
ry. This study has shown that benthic organisms are able to be reared under
laboratory controlled conditions for generations. By exposing these orga-
nisms to known levels of introduced material, their effect can be assumed by
monitoring the level of time of the various growth stages of the organism and
the mortality of the colony.
B.
CHEMICAL
The most obvious extension of this work would appear to be the develop-
ment of a coal field survey technique. This would involve; (1) field geolog-
ical sampling from the coal field, (2) trace metal leaching tests in the lab-
oratory and (3) analysis of other coal parameters of interest.
The lion site" sampling would be a major project in itself. It would re-
quire a trained field geologist who would obtain proper "in situ" samples
from the coal field. It is assumed that samples would be taken from selected
test holes along the entire coal seam.
5
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The laboratory leaching studies would involve deionized water leaching
and EDTA (ethylenediaminetetraacetic acid) leaching of the samples. Shaker
tests using 200 grams of ground and sieved coal for each liter of leachant
would be used. Samples would be analyzed using flameless atomic absorption
with a roulette type automatic sample feeder. The atomic absorption output
could be interfaced with a digital computer for ease in data reduction.
The laboratory leaching work should be standardized as much as possible
so that the method would give reliable comparisons between different coal
seams.
The problem of filter absorption of trace metals during sample prepara-
tion has not been solved. Research on this problem should definitely be con-
tinued.
6
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IV.
BIOLOGICAL RESEARCH
A.
1.
VASCULAR MACROPHYTES
Background Levels of Heavy Metals in Harbor Aquatic Macrophytes
a. Introduction--
Heavy metals are frequently sequestered by plants, and if these plants
are important in the food chains of an area, they may serve as a source for
the introduction of the same heavy metals into higher level consumers. In
examining the effect of the coal transshipment facility on the addition and
dispersion of heavy metals throughout the Superior-Duluth Harbor, it was nec-
essary to obtain some preliminary estimates of background levels of the met-
als under study in the aquatic vascular macrophytes which were present in the
harbor.
b. Experimental Procedure--
Samples of the aquatic macrophytes were collected in August 1975 from
areas in the Superior-Duluth Harbor near the coal transshipment facility con-
struction site. The samples were rinsed with distilled water to remove sur-
face contaminants and then placed in acid-washed polypropylene bottles. The
specimens were then frozen and stored in a frozen condition until processed
for metal analyses.
Representative portions of the stored specimens were oven dried to con-
stant weight, digested in an ignition bomb by means of ultrapure nitric acid,
and then metal concentrations were determined by f1ame1ess atomic absorption
spectrophotometry. Sample preparation was as described in Section V-B-7 of
this report.
c. Results and Oiscussion--
. Results of the preliminary population survey are shown in Tables IV-A-1
and IV-A-2. Table IV-A-1 is a record of the species collected, and the por-
tion of the plant which comprises the analytical sample. Table IV-A-2 gives
the results of the various analyses for the metals under consideration.
Results demonstrated that the different species concentrated the differ-
ent metals not only in differing amounts, but also that the various parts of
the plant had differing levels of metals present. Perhaps most unusual were
the levels of lead and manganese sequestered by the aquatic moss, F~~idelu
g~ndi6~o~ Brid; These high levels are worthy of further study, particular-
ly to determine if the concentration of these metals is a result of the sub-
strate from which they were collected, or if the species under consideration
has an unusual facility for sequestering these metals (lead and manganese).
Also noteworthy are the relatively low levels of metals in wild rice (Zizania
7
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aquatiQa L.), which is one of the few aquatic macrophytes in the area now di-
rectly eaten by man.
Many of the other species investigated may be eaten by ducks or fish,
and in turn consumed by man (Fassett, 1960). Thus, the levels of environmen-
tally sensitive metals in these aquatic vascular macrophytes may eventually
be a matter of concern to the region.
d. Recommendations--
A continual monitoring program of selected plant species in the harbor
would be a useful tool in judging the role of plants in heavy metal uptake
within the Superior-Duluth Harbor ecosystem. The high levels present in the
aquatic moss F~~~den6 g~ndin~On6 needs further study.
2.
Effects of Particulate Coal on Lemna mino~ Growth
a. Introduction--
Many metal ions have been found to be essential for normal plant growth
and function. Manganese was found by early workers (Epstein, 1972) to be re-
quired. The role of many such elements has been shown in enzyme activation,
regulation or stimulation. Epstein has reported (1972) that, in addition to
its primary function, manganese served as an activator of some enzymes by sub-
stituting for magnesium in certain phosphate transferring enzymes. The same
author also reported that manganese, if present in high concentration, in-
duced iron deficiency in some plants. Treshow (1970) demonstrated that cer-
tain trace elements and/or alien metal ions could induce metal deficiencies
or be directly toxic to plants.
In .view of the relatively low levels of nutrients and dissolved ions in
the waters of Lake Superior, addition of even small amounts of coal, from
which a variety of materials can leach, is potentially disruptive. The ad-
dition of coal particles to the aquatic environment would presumably have an
effect on the aquatic vascular macrophytes, depending on the amount. of coal
present. The presence of coal could result in increased growth (through the
addition of nutrients) or increased environmentally sensitive metal uptake
from the coal-enriched surroundings (which could result in growth inhibition
at excessive metal levels).
The second phase of this aspect of the study was to investigate the
feasibility of studying heavy metal uptake in vascular aquatic plants. Ini-
tial efforts were directed toward selecting a study species and determining a
potentially useful procedure. Within the limitations of the budget and time
allocation of the first year (and in anticipation of further work in subse-
quent years), it was possible to make only preliminary attempts to answer the
major questions of this year. Initial efforts were focused upon a study of
the effect of coal upon Lemna ~no~ L. This study was to serve the dual pur-
poses of: (1) determining laboratory techniques for the rearing of Lemna
m~no~ L. in the presence of coal, (2) providing a first approximation of the
relationship between the presence of coal particles and Lemna growth.
Lemna mino~ L. was selected as the plant for these initial studies be-
cause of its small size, relatively rapid growth and structural simplicity. .
8
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TABLE IV-A-l. SPECIES AND HABITATS MONITORED FOR BACKGROUND LEVELS OF HEAVY
METALS IN THE DULUTH-SUPERIOR HARBOR AREA.
Sample Portion
Number Taxon Analyzed Habit
Lemnar minor L. Whole Plant Free-Floating
2 Fissidens grandifrons Brid. Attached to
(a moss) Wood Piling
4A Bidens cernua Stem Emergent
4B Leaves
Flower
5 Ceratophyllum demersum L. Submerged
7 Scirpus validus Vahl. Rhizome Emergent
8 Root
9 Leaf
10 Nuphar variegatum Engelm Whole Plant Floating Leaved
11 Zizania aquatica L. Sead Emergent
12 Root
13A Stem
13B Leaf
14 Bidens beckii Torr. Leaf Submerged
15 Root
16 Sparganium chlorocarpum Rydb. Root Emergent
17 Flower
18 Leaf
19 Sagittaria latifolia Willd. Root Emergent
20 Leaf
21A Stem
218 Flower
9
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TABLE IV-A-2. CONCENTRATION OF METALS (ppm) IN CERTAIN DULUTH-SUPERIOR HARBOR PLANTS (BY DRY WEIGHT)
Sample As Ba Cd Cr Co Cu Pb Mn Mo Ni Se V Zn
1 1 237 0.4 4.9 6.5 15 29.4 5000 1.5 23 0.8 5 16
2 11 528 0.8 14.8 15.0 32 198.8 15400 <1.5 11 <0.1 8 9
4A <1 25 0.2 0.9 0.7 12 4.7 653 -~ 39 10
4B <1 95 0.1 1.8 4.6 17 2.2 2080 3 8
4C <1 23 0.1 0.9 1.0 13 2.0 1170 3 5
5 5 604 0.8 4.1 5.7 106 30.5 746 11 11
7 4 <0.1 2 0.4 102 2 3
8 12 20 0.5 1.9 6.9 7 11 .5 2040 6 <0.1 10
9 <1 78 0.1 0.5 1.9 2 3.3 962 1.2 4 0.3 <4 3
...... 10 <1 367 0.3 1.7 5.0 28 78.8 618 <2.1 79 1.2 <5 23
o
11 <1 <7 0.1 0.4 8.8 11 2.4 250 4 1.6 <5 8
12 5 50 0.1 2.5 5.4 9 8.8 573 14 9
13A 8 176 0.5 11.7 9.0 208 23.5 781 59 22
13B <1 87 0.3 3.2 5.5 31 13.3 353 12 18
14 <1 112 0.2 1.3 2.3 8 3.8 1250 2 4
15 6 95 0.2 2.5 3.5 24 10.4 1570 2 6
16 6 64 0.1 1.8 5.8 10 11 .8 1520 35 7
17 <1 <3 0.1 0.3 2.4 3 1.4 90 1 7
18 <1 50 0.1 0.8 2.8 18 23.1 254 29 <0.2 8
19 10 479 0.4 5.5 1.0 18 15.9 479 5 21
20
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Lemna m~o~ L. produces new daughter fronds from pockets at the base of the
parent plant and these new plants may, in turn, produce daughter fronds even
before they are detached from the original parent. Growth may be followed by
counting these fronds, a procedure which has proven to be quite reliable
(Hillman, 1961).
Another factor which lead to the adoption of Lemna mino~ L. as the test
organism was the extensive experimental literature on Lemna sp. (see Hillman,
1961, for a y'eview of the description and use of the Lemnacae in experimental
procedures).
b. Experimental Procedures--
Field collection of Lemna mino~ L. were made from indigenous populations,
rinsed with deionized water to remove any gross contamination, and reared in
acid-washed aquaria using Lake Superior water as a culture medium. From the
above culture, groups of twenty-five (25) unattached Lemna mino~ L. fronds
(without daughter fronds) were removed, rinsed three times with deionized
water and placed in 600 ml acid-washed polypropylene beakers which contained
300 ml of Lake Superior water.
A portion of Western Coal No.1 (see Section V-B-l) was ground in the
Wiley@ mill and then added to the beakers of Lemna m~o~ L. culture. The
amount of coal added to each beaker was 5.00 g, 10.00 g or 25.00 g. Tripli-
cate sets of Lemna mino~ L. culture samples were prepared with each size of
coal adduct.
The beakers were covered with acid-washed glass plates and placed in an
environmental chamber in which temperature was held constant at 25°C. A six-
teen-hour light period at an intensity of 1200 foot-candles (12,900 lumens/
square meter) alternated with eight hours of darkness. Growth was allowed to
proceed for 21 days. Water lost through evaporation was replaced with deion-
ized water.
The lake water culture medium was sampled prior to the start of the
growth chamber study, and all growth media which had been in contact with
coal were sampled at the end of the 21 day growth period. The samples were
acidified with ultrapure nitric acid and were stored in acid-washed polypro-
pylene bottles until analysis for metal content were performed. In addition,
samples of the Lemna mino~ were taken from the population for metal analyses
at the initiation of the run, as well as from each culture at the conclusion
of the test period.
At the end of the growth, the Lemna were harvested (after counting),
dried to constant weight, and the residue analyzed for its metal content (see
Section V-B-7 for sample preparation and analysis).
Individual counts of all plant fronds (as previously described) were
made at intervals, to determine growth rates and to observe the plant growth
response to the presence of coal derived materials in the Lake Superior water
growth medium.
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c. Results--
Initial efforts in the laboratory phase of this study were directed to-
ward establishing procedures for the"cu1turing of Lemna m~no~ L. in media
which was fortified by the addition of ground coal in various concentrations.
As a result, time was not available for the adequate retesting of the results
tabulated in this report. Inspection of these data showed no consistent pat-
terns. Because of the preliminary nature of the data (and the inherent vari-
ance), it was felt that no statistical tests were warranted.
A summary of the growth response of Lemna m~no~ to varying concentra-
tions of ground coal present in the lake water medium is presented in Table
IV-A-3. "
TABLE IV-A-3.
Growth of Lemna m~Ho~ L. in Coal Fortified Lake Water
(Average Frond Counts of Three Trials)
Number of Fronds by Day
Medium
3
7
10
13
16
20
22
23
Lake Water, No Coa 1 Added
Lake Water, 5.00 g Coal Added
Lake Water, 10.00 g Coa 1 Added
Lake Water, 25.00 g Coal Added
25 52 128 184 215 243 140 147 _h
25 61
25 71
146 182 191
218 169 193 h-
126 163 195 241
232 --- 267
25 61
148 188 200 235 228 --- 256
Table IV-A-4 presents the growth rate constants as determined from frond
counts (Hillman, 1961). The first three days are omitted on the assumption
that they represent more nearly the conditions existing in the original cul-
ture than that of the experimental media. Frond count data after 16 days are
also omitted from this table since frond counts for unfortified lake water
and water with 5.00 grams of added coal are dec1ining--perhaps due to lack of
nutrients.
TABLE IV-A-4.
Growth Rate Constants for Lemna m~no~ L. in Coal Fortified
Lake Water (Average of Three Replicates)
Interval (Days)
Medium 3-7 7-10 10-13 13- 16
Lake Water, No Coal Added .098 .053 .023 .018
Lake Water, 5.00 g Coal Added .095 .033 .007 .019
Lake Water, 10.00 g Coal Added .083 .037 .026 .031
Lake Water, 25.0_0 g Coal Added .096 .035 .009 .023
12
-------
Table IV-A-5 presents data for the average metal concentration in the
lake water culture media (with and without coal) at the beginning and end of
the 21 day growth test with Lemna m~no~. Table IV-A-6 contains data for the
average metal concentration in the Lemna grown in the above culture media.
Certain metals (such as barium) seem to be increasingly sequestered from the
media with increasingly higher amounts of added coal. Others (Zn, Pb) show
greater levels of accumulation at intermediate concentrations of coal addi-
tive. However, other metals (cobalt, copper, manganese) exhibit no marked
trends.
d. Recommendations--
Preliminary work suggests that Lemna m~no~ is a useful plant to study
uptake of heavy metals. It does not require elaborate culture techniques and
its small size allows smaller (and less expensive) culture facilities.
Although the work reported above reflects only a first approximation in
examining the role of plants in heavy metal uptake from coal particles, there
is evidence that coal particulates may, in certain concentrations, diminish.
the growth o( an aquatic plant. In addition, there appears to be increased
uptake in the presence of coal particles, but considerably more work remains
to be done in understanding the nature and extent of this uptake before as-
sessing its significance.
The use of unfortified lake water alone as the medium poses some dif-
ficulties since the 1 evels of available nutrients is low. However, within
the harbor ecosystem, uptake of these metals by aquatics is likely to be lim-
ited by similarly low nutrient levels. Further work to relate uptake with
the nutrient level of the growth media would be useful.
Another variable which needs to be examined is the effect of water cur-
rents and circulation on rate of metal from the coal. The above work in-
volved only static testing, simulating coal accumulation at the bottom of the
water column. Since water currents are present, much coal, especially fine
particles, could be held in suspension for periods of time, increasing the
likelihood of leaching. Related to this is the need to better understand the
effect of particle size upon leaching rate which should be reflected in up-
take rates.
The significance of metal concentrations reported in Table IV-A-6 must
be interpreted with extreme caution. It is hard to explain the variance
present without a much greater understanding of the behavior of each metal
tested. The possibility of error in metal determinations, particularly due
to the small amount of tissue available, must be considered.
13
-------
TABLE IV-A..;5. HEAVY METAL CONCENTRATION, ppb, IN THE WATER CULTURE MEDIUM BEFORE AND AFTER A 21 DAY
Lemna mi nor GROWTH PERIOD WITH VARYING CONCENTRATIONS OF COAL ADDITIVES (AVERAGE OF
THREE REPLICATES).
As Ba Cd Cr Co Cu Pb Mn Mo Ni Se V Zn
Initial Lake Water 0.0 3.3 0.00 0.0 0,0 1.30 0,70 0.4 0.00 0.7 0.20 0.0 0.4
Levels
Water Levels After
21 Days of Growth
No Coal Additive 0.0 0.0 0,08 0.1 0,0 1.80 0,00 0,1 0,00 20.5 0.30 0.0 1.4
5.00 9 Coal Added 0.0 1 .1 0.05 0.1 0.2 0.10 0.30 0,1 0,60 3,7 0.00 1.0 1.9
10.00 9 Coal Added 0.1 2.2 0.05 0.0 0.2 1,60 0.10 1.1 2.32 0.0 0.00 1.9 0.8
.j:::.
25.00 9 Coal Added 0.0 3.3 0.07 0.1 0.2 1.10 0.06 1.0 2.10 7.1 0.95 0.0 0.1
-------
TABLE IV-A-6. HEAVY METAL CONCENTRATION, ppm (~y DRY WEIGHT BASIS) IN Lemna minor L. GROWN IN DIF-
FERING LEVELS OF COAL-FORTIFIED MEDIA (AVERAGE OF THREE REPLICATES).
As
Cd
Ba
Cr
Co
Pb
Cu
Mn
Mo
Ni
Se
v
Zn
Initial.Concentrations 0 30
ln Lemna .
8.0
Final Concentrations
in Lemna
Lake Wa ter,
No Coal Added
Lake Water,
5.00 9 Coal Added
.....
(J1
Lake Water,
10.00 9 Coal Added
Lake Water,
25.00 9 Coal Added
10.0 1.9 0.5 0.30 40.0
0.8
8.0
4.0 50.0
33.0 1.6
0.70
11.0 0.4 0.4 0.70 14.0 41.2 257.0 3.4
9.0
0.5
8.0 17.0
0.80 161.0 0.7 0.7 2.20 20.2
4.1 117.0 4.3 10.0
0.6 11.0 28 . 0
0.7 11.0 42.0
1.33 114.0 1.6 0.8 1.30 21.0 16.0 143.0 6.7 46.0 13.9 17.0 62.0
0.80 210.0 0.8 2.9 1.05 81.0
7.7 268.0 4.2 19.0
-------
3.
Literature Cited
Epstein, E. 1972. Mineral Nutrition of Plants:
John Wiley and Sons.
Principles and Perspectives.
Fassett, Norman C.
sin Press.
1960.
A Manual of Aquatic Plants.
University of Wiscon-
Hi 11 ma n, W. S.
1961.
The Lemnaceae, or Duckweeds.
Bot. Rev., 27:221-287.
Treshow, M.
York.
1970.
Environment and Plant Response.
McGraw-Hill, Inc., New
16
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B.
BENTHOS
1.
Introduction
The study of benthos is concerned with substrate organisms, both plant
and animal, that live in or on the bottom of a body of water. In the St.
Louis River, these organisms are important in the ecosystem as sources of food
either directly or indirectly for higher organisms such as fish, birds and man
(Anderson and Smith, 1971). Thus the stability and the functioning of this
portion of the ecosystem has far ranging effects upon a variety of organisms.
Certain substances may accumulate either temporarily or permanently in these
organisms. These substances may be later found stored in higher members of
the food chain of the animal kingdom at an increased level because of the high
number of organisms consumed as food. The increased concentration of certain
substances, which can in some cases reach many thousand fold over the concen-
tration originally found in the waterway, may interfere with normal physio-
logical functions within the higher level consumers. Therefore, it is becom-
ing increasingly apparent that the chain of events leading from benthic orga-
nisms to the highest member of the food chain needs to be further investigated
in greater detail. This study identifies the benthic organisms which will be
exposed to material leached from coal to coal dust as a result of storage
close to a water system. It also shows concentrations of heavy metals found
in some of the benthic organisms and it describes how some benthic organisms
can be reared under laboratory conditions so that future laboratory controlled
experiments can be performed. Also described are various aspects of the nat-
ural history of benthic organisms which were kept in culture.
2.
Methods
Field Sampling Techniques--
The biological research group at the University of Wisconsin-Superior
sampled four areas in the region of the ORBA Coal Dock facility and two areas
of the existing Riess Coal Dock three times during 1975. The sampling dates
were July 9, August 9 and September 29, 1975. All benthic samples were col-
lected with a 23 cm x 23 cm Ponar dredge. Three samples were taken from each
of the six areas. The three replicate sites were generally within 50 yards
of each other and were visually selected to represent the general conditions
found within the area. All samples were placed in five quart plastic contain-
ers and frozen immediately upon return to the laboratory. These samples were
kept frozen until sieving and then the organisms were sieved with a 30 mesh
screen and preserved in 70% ethyl alcohol until they were identified using a
dissecting microscope. Identification of organisms to species, where possi-
ble, was accomplished using the following keys: Burch, 1972 and 1973; Mason,
1973; Edmondson, 1959; Pennak, 1953; Eddy and Hodson, 1961; Needham and Need-
ham, 1962; Williams, 1972; Klemm, 1972; Brown, 1972; and Holsinger, 1972.
Laboratory Rearing--
The initial stock organisms of Ch~onomu~ sp. were collected from the
substrate in the St. Louis River July 21, 1975. These organisms were trans-
ported to the laboratory in five quart containers and here the Chironomids
freed themselves from the substrate and entered the water column. These orga-
nisms were then transferred to the rearing chambers with a wide apparatus eye
17
-------
---.---'" ~ - ,...~
dropper.
Rearing Chambers--
The rearing chambers were 3" x 8" culture dishes in which a hole 20 mm
in diameter was drilled one inch from the to~ and was fitted with a #3 one-
hole neoprene stopper in which was inserted an 8" L-shaped glass tube (see
Figure IV-B-l). This tube formed an outlet to the rearing chamber. The end
of the tube which protruded into the rearing chamber was lightly fitted with
glass wool to prevent culture organisms from escaping. Recirculated water
passed through this outlet tube and into a five gallon aquarium which was lo-
cated directly beneath (Figure IV-B-l). This aquarium held the bulk of the
recirculated water used for the rearings.
. Water entered the rearing chamber by being elevated from the five gallon
aquarium mentioned above by a continuous stream of air bubbles passing through
a 10" culture dish inlet tube. The temperature of the incoming water could be
regulated by controlling the rate of air flow through the inlet tube byad-
justing the air valve. A temperature of 20.5 + 0.5°C (monitored by a contin-
uous recording thermometer) was maintained for-all chironomid colonies. Wa-
ter used for the rearings was Lake Superior water obtained from the Environ-
mental Research Laboratory, Duluth, Minnesota.
Temperature Control Tank--
To control the temperature of water in the five gallon aquarium which in-
fluenced the temperature in the culture dishes, the five gallon aquaria were
placed in a thirty gallon aquarium tank which had connections to hot and cold
water (not shown in Figure IV-B-l). By regulating the flow of water from each
tap a uniform (+ 1°C) temperature could be maintained both during the summer
and winter months.
ClUJz.onomulJ s p. --
Egg Stage--Eggs were deposited by the female at the surface of the water
in agelatlnous mass with a varied egg pattern. Some contained a single
strand of eggs evenly deposited in a spring-like coil and some had a more ran-
dom egg pattern. The number of eggs laid varied among the females but usually
the number was between 100-350. Based on ten colonies reared at 20.5 + 1°C,
it takes 5.1 days to hatch. -
Larva Stage--Soon after hatching the larvae began to build tubes which
were open at both ends and in which the larvae spent the majority of their
larval and pupal life. As the larvae grew material was added to this tube to
compensate for the increase in body size. In nature this tube is usually
built of algae, fine silt and small sand grains but in the laboratory without
extraneous material the tube was constructed mostly of fecal material.
Growth from the time of hatching to pupal formation based on ten colonies
took 21.9 days. The first day after hatching the larval length ranged from
1 mm to 1-1/2 mm; the third day from 3 to 6 mm; the seventh day 5 to 8 mm;
the ninth day 8 to 10 mm;the twelfth day 10 to 15 mm, the sixteenth day from
10 to 20 mm. Because much of the larval life is spent inside their tubes it
is difficult to predict with certainty the number of larval instars. However,
it may be predicted, by indirect means, to be approximately six. Because of
18
-------
the range in size throughout the growth period, the size difference appears to
be a result of dimorphic differences among the larvae. The size may be the
difference between future males and females. This accounted for the size dif-
ference among larvae of the evergreen bagworm, Thy~dopt~yx ephem~e6o~
(Morden, unpublished data) which also had a case which enclosed the larvae.
Laboratory stress factors can influence the rate of growth of the larvae.
One factor was stagnation. Several attempts were made to rear the larvae us-
ing two quart non-circulating rearing chambers. In all cases the chironomids
failed to complete one life cycle with most colonies failing to gro\'1 past the
fourth i nstar.
Another factor was diet. The food fed to the larvae influenced the
growth rate as well as their general vitality. Two kinds of food were fed to.
the larYR~' The chironomids were able to complete a life cycle using either
Red Sta~instant blend active dry yeast or Tetrami~staple food, a widely dis-
tributed tropical fish food. However, there w~s slower growth and higher mor-
tality when yeast was used instead of Tet.rpmi~ The data on life cycles were
based on colonies which were fed TetramiN„ This food was placed in the rear-
ing chamber each day. The amount fed was just what the colony would consume
in thirty minutes.
Larvae in the fourth instar were transferred to tap water.
became slower and the colony failed to survive beyond the fourth
tap water even though food was supplied. This may have resulted
found in tap water.
Activity soon
day in the
from ch 1 ori ne
Water from a well which was drilled on campus during the fall of 1975 was
used and the chironomids were able to complete a life cycle although mortality
was higher than when Lake Superior water was used. Mortality in this colony
approached 90% compared to the 10% reared under optional conditions. This
well water was later tested and found to be high in salts.
The hemaglobin pigment found in some Chironomids is red and the presence
in the insect can be observed by visual inspection. During the first instar
no red pigment can be seen. During the second instar the larvae change from
pink to red and by the third instar the larvae blood appears to be fully hema-
globinized.
The larvae swim by an interesting twisting motion of one part of its body
on another. Following a "S" shaped pattern, the posterior end of the larvae
curls up in a twisting motion and passes over the head. As this happens the
anterior half of the body flips quickly downward giving the "lift" necessary
for swimming.
When healthy larvae are not swimming they remain in their tubes with the
anterior half of the body extending from the tube and swaying back and forth.
This motion may aid the larvae in obtaining oxygen by permitting more water
to pass over the body surface. This motion in clearer water, however, may
attract fish and thus would not be as beneficial to the chironomid.
19
-------
Pupa Stage--The pupa stage, based on ten colonies at 20.5-10C, lasts for
2.1 days. When the larvae change to the pupa stage the head capsule become
larger and more defined and possess two small white tufts. The pupae are less
active then the larvae but retain some motility as they can tumble through the
water. The size of the head capsule in relation to the body becomes notice-
ably greater when the larvae change to the pupal stage.
Just before pupation the larvae closes the ends of its tube and then de-
velops to the pupa stage. However, it is not necessary to change within the
tube as some successfully completed the transformation in the laboratory out-
side the tube. Just before the adult emerges from the pupal case, the pupa
is found at the surface of the water.
Adult Stage--The adult emerges from the pupal skin by pulling itself out
through the split in the thoracic segment and then flies away. Based on ten
colonies, from the moment until the first eggs are deposited takes 5.4 days.
The females are easily distinguished from the males by the antennae.
The males' antennae are feathery or plumose while the females' antennae are
simple and stylate.
The total duration from egg stage through egg stage based on the ten col-
onies at 20.5 + 1°C was 32.4 days. The percent mortality of the colonies from
the egg stage to the adult stage was approximately 10%.
3.
Res u lts
Benthic Indicator Organisms--
Indicator organisms are used to provide a relatively fast and easy means
for attempting to classify the environmental quality of an area.
Benthic organisms which normally do not tolerate toxic pollution are:
Phy~a snails and one was found at site six (The C. Reiss Coal Company site)
in the spring sampling. Sphaerid clams were generally found in the shallow
sites during the entire collecting season. Red chironomids were generally
present in all areas sampled. Worms, leeches, ~ett~ and molluscs are very
susceptible to lead, zinc and copper and members of these taxa were found
within the collecting area (Thomas, Wilcox and Goldstein, 1976).
Diversity Index-- .
A more stable and predictive assessment of environmental stability and
water quality is the concept of species diversity. Its shortcoming is the in-
ability to reflect accurately the biomass and the individual species present.
Because of the uniform size of the samples taken from each collecting
site the following equation was used to calculate the diversity index (0.1.).
N2
0.1.
~n12 + n22 + n32 ... nx2
Ka ill and Frey, 1973
=
20
-------
The total number of organisms collected from a site is squared (N2) and
this number is divided by the sum of the squares of each species (n2). A
higher number reflects a greater diversity among the species and this usually
indicates a greater species interaction and greater ecological stability.
Using the above formula, values close to 10 indicate clean water and a
stable environment. Values close to 1 indicate that the number of species
interaction is generally reduced while intermediate values indicate a moderate
degree of interaction and stability.
All sites indicate little species interaction. However, one site is
clearly more stable than the others during all sampling periods. This was
site six, a shallow, coal-rich area found at C. Reiss Coal Company site (see
Tables IV-B-4 through IV-B-6).
Diversity Index Re1ationships--
t-Test--Because the data was symmetrically matched by site location dur-
ing the collecting period a t-test (McCall, 1975) was performed on the 0.1.
to see if any significant differences existed between the spring samples, the
summer samples and the fall samples. This analysis should show changing lev-
els of species interactions among the sites during the collecting period.
As seen from Table IV-B-1 the greatest difference observed was between
the summer .sampl ing and 'fall samp1 ing but the assumption that a change occur-
red can be made with only 29% certainty. There was no significant change
between spring and summer samples. Therefore, the change in the relative
stability of the environment among the sites during the seasonal period of
active growth for organisms is at most only extremely slight.
Correlation Analysis--
A correlation using the 0.1. was performed on the data
nity stability was different among the sites when comparing
ne1 depths and between coal and non-coal environments.
to see if commu-
shallow and chan-
From Table IV-B-2 the t values exceed the critical values at the .05
level with seven degrees (n-2) of freedom. Therefore, a significant differ-
ence does exist at the .05 level. There is a greater diversity found in coal
areas than non-coal areas and there is greater diversity in shallow areas c~
pared to channel depths.
Heavy Metal Concentrations--
The heavy metals examined in the laboratory were found in /-IuobdeLta.
~tag~ at all sites during the collecting period.
The test organisms were collected during 1975, identified in the labora-
tory and stored in 70% ethyl alcohol. Samples were later dried in a vacuum
oven for 5 hrs at 70°C. If not used immediately samples were stored in a .
desiccator. Sample weights were determined, then organisms were placed in
Parr bomb and digested. Approximately 2 m1 of ultrapure nitric acid was used
for each digestion. The digested samples were then diluted to a predetermin-
ed volume (m-1 through m-8 to 20 m1) and analyzed by atomic absorption meth-
ods. Results are found in Table IV-B-3. For methods refer to Section V-B-7.
21
-------
To obtain enough weight per sample to be analyzed, leeches from differ-
ent sites had to be combined. Thus heavy metal information about some in-
dividual sites was lost. However, some sites were not combined. Organisms
from different collecting times were never mixed.
Background levels of heavy metals found in the sediments where benthic
organisms were taken are not available as a result of a laboratory oversight.
However, concentrations of heavy metals present in Lake Superior water are
given in Table IV-B-3. For procedures refer to Section V-B-7.
Table IV-B-3 indicates that heavy metals are sequestered by benthic or-
ganisms. It appears that the affinity toward different metals varies as they
are found at different concentrations. Exceptionally high values of copper
and lead were found in organisms collected during July from the dredged chan-
nel at C. Reiss Coal Company dock. An analyzed environmental sample from
this area might help explain these high levels.
4.
Discussion
One species of Chrionomidae was successfully reared under laboratory con-
trolled conditions. This organism could be used as an invaluable aid for de-
termining environmental stress. Because of its noted sensitivity to changing
rearing conditions, it would be used to determine the precise effects of coal
material or other material on the life cycle and physiology. This is the di-
rection that future studies of environmental stress on aquatic organisms
should follow.
The kind of species of benthic organisms found in the study area suggest
that the water is moderately polluted yet contains low levels of toxic heavy
metals (Cairns and Dickson, 1973).
Heavy metals are apparently sequestered by the leech, Hetabdetta
~tag~. This organism is a member of the food chain leading through fish
to man. Heavy metals are sequestered by benthic organisms. If these orga-
nisms with concentrated levels of toxic material are consumed in large amounts
by higher level consumers and the metals further concentrated by top level
consumers than there is reason for concern especially if man is the highest
level consumer.
Although coal appears not to be harmful to the aquatic system and in fact
may be correlated with environmental stability we must not lose sight of the
fact that certain metals released either from coal or from other sources are
concentrated in organisms at every level in the food chain. Thus low level
concentrations of certain materials may be tolerated by organisms occupying a
low level in a food chain but these metals may be concentrated through the
food chain and may become so toxic in higher level consumers that pathological
conditions develop.
22
-------
5.
Literature Cited
Anderson, E. D. and L. Smith, Jr. 1971. A Synoptic Study of Food Habits of
30 Fish Species from Western Lake Superior. Tech. Bull. 279, Minn. Ag.
Expt. Station.
Brown, Harley P. 1972. Aquatic Dryopoid Beetles (Coieopt~) of the United
States. Environmental Protection Agency, Project No. 18050ELD, Contract
No. 14-12-894, 82 pp.
Burch, J. B. 1972. Freshwater Sphaeriacean Clams (Mollusca: Pelecypoda) of
Northern America. Environmental Protection Agency, Project No. 18050ELD,
Contract No. 14-12-894, 31 pp.
1973. The Freshwater Molluscs of the Canadian Interior Basin.
Malacologia, Vol. 13,509 pp.
Cairns, J. and K. L. Dickson. 1973. Biological Methods for the Assessment
of Water Quality. American Society for Testing and Materials,
Philadelphia, Pennsylvania, p. 256.
Eddy, S. and A. C. Hodson.
North Central States.
1961. Toxonomic Keys to the Common Animals of the
Burgess Publishing Company, Minneapolis, 162 pp.
Edmondson, W. T. 1959.
Jersey, 1248 pp.
Holsinger, John R. 1972. The Freshwater Amphipod Crustaceans (Gamm~dae)
of North America. Environmental Protection Agency, Project No. 18050ELD,
Contract No. 14-12-894, 89 pp.
Freshwater Biology.
John Wiley and Sons, Inc., New
Kaill, W. M. and J. K. Frey. 1973. Environments in Profile, an Aquatic Per-
spective. Canfield Press, pp. 206.
Klemm, Donald J. 1972. Freshwater Leeches (Annelida-Hirudinea) of North
America. Environmental Protection Agency, Project No. 18050ELD, Con-
tract No. 14-12-892, 53 pp.
Mason, William T. Jr. 1973. An Introduction to the Identification of Chiro-
nomid Larvae. Analytical Quality Control Laboratory National Environ-
mental Research Center, U.S. Environmental Protection Agency, Cincinnati,
Ohio, 90 pp.
McCall, Robert B. 1975. Fundamental Statistics for Psychology.
Brace and Jovanovich, Inc., pp. 406. I
Harcourt
Needham, J. G. and P. R. Needham. 1962. A Guide to the Study of Freshwater
Biology. Holden-Day, Inc., San Francisco, 108 pp.
Pennak, Robert W. 1953. Fresh-Water Invertebrates of the United States.
The Ronald Press Company, New York, 769 pp.
23
-------
Thomas, W. A., Wilcox, W. H. and G. Goldstein. 1976. Biological Indicators
of Environmental Quality. Ann Arbor Science Publishers Inc., Ann Arbor,
Michigan, pp. 254.
Williams, W. D. 1972. Freshwater Isopods (A6eltidae) of North America. En-
vironmental Protection Agency, Project No. 18050ELD, Contract No. 14-12-
894, 45 pp.
24
-------
fl:;>J
':II
6 rnm. culture diSh in let tube
/
6" culture
=It 3 neoprene stopper
./
/"
I
:0')
, '.0.'
1 I , I
..... I-t..
I 1 I~': I -
I I ~ I I
1
I ...:'
(~ol /"
I I I I
-- ,......, /'
I I I;~
, I~'
" , ,
\ \......',
'......
/
--
/
/
--
r
,
)---
;"
"
;'
"
"
"
"
-.-
--
~
-~-
./
-~~----------------
/'
. fir
inlet
FIG. IV-BI
-------
25
-------
TABLE IV-B-l
Significance of the Difference in the Diversity Indices
as Related to Seasonal Collecting Times
t Score*
Spring Sampling
vs.
Summer Sampling
0.009
Summer Sampling
vs.
Fall Sampl ing
0.29
Spring Sampling
vs.
Fall Sampling
0.24
a diff.
*Calculated from the equation:
amd =
IrlT
amd =
standard error of the mean difference
Xdiff.
= mean of the difference data
adiff.
= standard deviation of the difference data
Mc Ca 11, R . B., 1 97 5 .
26
-------
TABLE IV-B-2
Correlation and Significance of. Site Variations With Sampling Depth
and Between Coal Areas and Non-Coal Areas Using Diversity Indices
Coefficient of
Correlation*
rxy
Significance
of the
Correlation
Coefficient
t Value**
Sha 11 ow Site
vs.
Channel Site
-0.19
.512
Coal Areas
vs.
Non-Coal Areas
0.29
.802
* Values calculated from the equation:
r
xy
=
NEXy - (EX)(Ey)
I[NEX2 - (EX)2][NEy2 .. (Ey)2]
IN-2
**Values calculated from the equation:
t = robs
11 ..robs 2
with df = N-2
McCall, R. B. 1975.
27
-------
TABLE IV-B-3
Concentration of Metal in Organisms (ppm) Dry Weight
Sample As Ba Cd Cr Co Cu Pb Mn Mo Se V Zn
Helobde11a stagnalis
M-l 6.7 360 3.3 8.0 3.3 110 22 190 <0.7 <6.7 <3.3 1270
M-2 5.1 70 3.1 5.1 2.3 695 665 275 <0.3 <2.6 <1.3 1570
M-3 <2.1 60 2.1 1.7 1.7 . 45 3.4 145 <0.2 <2.1 <1.1 700
M-4 <4.2 225 0.9 4.7 1.3 45 3.5 195 <0.4 <4.2 <2.1 780
M-5 6.9 95 1.4 5.8 2.1 140 23 220 <0.3 <3.4 <1. 7 400
N M-6 3.7 129 1.1 3.3 1.9 180 7.0 110 <0.4 <3.7 <1.9 140
co M-7 <1.7 75 2.2 1.0 0.8 50 6.9 185 <0.2 <1.7. <0.8 400
M-8 2.9 135 8.7 6.7 1.4 180 27 145 <0.3 <2.9 <1.4 580
~1-A-9 1 abora tory <1. 9 190 0.6 1.7 0.6 40 0.8 40 0.2 <1. 9 <0.9 55
amphipods
M-I-l0 1 abora tory 4.1 75 2.1 2.9 1.0 265 2.9 110 0.2 <2.1 <1.0 90
isopods
Background concentration
of liquid preservation 0.0 0.0 0.2 0.4 0.0 1.1 0.7 0.7 0.0 1.0 0.0 0.7
70% ethyl a 1 cho 1
Concentration of Metal in Lake Water (ppb)
Sample As Ba Cd Cr Co Cu fib Mn Mo Se V Zn.
Lake Water 2 37 0.6 0.3 0.9 34 '1.9 4.9 1.1 <1 <1 5.5
-------
TABLE IV-B-4
Benthic Organisms of the St. Louis River, 9 July 1975
PHYLA GENUS SPECIES l~A 1 ~B l-C 2-A 2-B 2-C 3-A 3-B 3-C
Nemathelmenthes Nematoda 2 1 86 2 19 17
Annelida Marvi nmeyer lucida 1
Helobdella elongata 3 9 4 13 2 3
Helobdella stagnalis 3 2 1 4 8 4
r.1yzode 11 a moorei 1
Illinobdella alba
Mollusca Sphaerium transversum
Sphaerium s i mil e
Sphaerium lacustre 3
Sphaerium niti dum 22
Sphilerium securis 3 2
Sphaerium partumium
Sphaeri um rhomboideum
Sphaerium fabale
Sphaerium striatinum
N immature of Sphaerium occidentale
~ 3 2 2 2
damaged clams
Promentus exacuous megas
Gyraul us deflectus
Helisoma anceps anceps
Promentus unbi 1 i catell us
Marstonia decepta
Amnicola 1 imnosa 7
Valvata s i ncera 1
Valvata tricarinata 3
Pisidium fall ax
immature or
damaged s na i1 s
Eupera cubensis
Ferrissia rivularis 1
Planorbidae (immature) 4
Pisidium dubium
Pisidium ventrosum
Pisidium idahoensi
Physa jennessi
DIVERSITY INDICES (D.l.) 4.84 3.88 4.43 1.84 1.32 3.01 3.41 2.45 2.02
-------
TABLE IV-B-4, Continued
Benthic Organisms of the St. Louis River, 9 July 1975
PHYLA GENUS SPECIES 4.A 4-B 4-C 5-A 5-B 5-C 6-A 6-B 6-C
Nemathelmenthes Nematoda 4 13 8
Annelida Marvinmeyer lucida
Helobdella elongata 18 2
Helobdella stagnalis 10
Myzodella moorei
lllinobdella alba 10
Sphaer;um transversum 6 2
Sphaer;um s ; mil e 1 1
Sphaer;um lacustre 1 6 10 7 2
Sphaer;um n;t;dum 1 1
Sphaerium securi.s 6
Sphaer;um partumium
Sphaer; um rholllbo;deum
Sphaer;um faba 1 e
Sphaer;um striat;num
w Sphaer;um occidentale
a inunature or 4 2 4 5
damaged clams
Promentus exacuouS megas
Gyraulus deflectus
Hel;soma anceps anceps
Promentus ulllbil;catellus
Marstonia decepta
Allln;cola limnosa
Valvata s;ncera
Valvata tricar;nata 2
P;sid;um fa 11 ax 9
inunature. or 1
damaged snails
Eupera cubensis
Ferrissia rivular;s 2
Planorbidae (;mmature)
P;sid;um dubium
P;s;dium ventrosum
P;sid;um idahoens; 2
Physa jenness;
DIVERSITY INDICES (0.1.) 1.57 2.32 2.60 1.47 3.80 4.19 5.11 5.73 4.57
-------
PHYLA
TABLE IV-B-4, Continued
Benthic Organisms of the St. Louis River, 9 July 1975
GENUS
SPECIES
1-A
2-A
2-B
2-C
3-A
3-B
3-C
1-B
1-C
Arthropoda
w
--'
Insecta
Insecta
Tricoptera
Tricoptera
Tri coptera
Tricoptera
C1adocera
Gamma rus
Gammarus
Gammarus
Hyall ell a
Pontoporia
Ase11us
Asell us
Rheotanytarsus
Tribe1as
Cricoptopus
Lauterborn;ella
Proc1adius
Parachironornus
Cryptochironomus
Chironol1lus
Po1ypedilum
Coe1otanypus
Potthastia
Parac1adope1ma
Podonominae sp.
G1ossosoma sp.
Phy1ocentropus sp.
Neurec1ipis sp.
Mo1anna sp.
Leptoce11a sp.
Corixidae Nymph sp.
P1ecoptera Nymph sp.
Hexagenia sp.
Worl1la1dia sp.
Eurycercus sp.
Tanypus sp.
C1inotanypus sp.
Unidentified
fasciatus
1 acus tri s
pseudo1imnaeus
azteca
affinis
intermedius
racovitzai
sp.
sp.
sp.
sp.
sp.
sp.
sp.
sp.
sp.
sp.
sp.
1
4
1
27
1
2
6
3
(Crayfish) Astac1dae (family)
Bryozoa
Crys ta te 11 a
mucedo
23
33
3
24
1
1
34
3
52
4
24
2
-------
TABLE IV-B-4, Continued
Benthic Organisms of the St. Louis River, 9 .July 1975
PHYLA GENUS SPECIES 4-A 4-B 4-C 5.A 5-B 5-C 6-A 6-B 6-C
Arthropoda Gammarus fasciatus
Gammarus lacustris
Gammarus pseudolimnaeus 5
Hya 11 ell a azteca 1
Pontoporia affinis
Asellus intermedius 2 6 28 3
Ase11us racovitza i 1
Rheotanytarsus sp,
Tribelas sp.
Cri coptopus sp.
Lauterborni ell a sp.
Procladius sp. 24 15 19 5 5 9 5 2
Parachironomus sp.
Cryptochironomus sp. 2
w Chi ronomus sp.
N Polypedilum sp.
Coelotanypus sp.
Potthastia sp.
Paracladopelma
Podonominae sp.
Tricoptera Glossosoma sp.
Tricoptera Phylocentropus sp. 4
Tricoptera Neureclipis sp.
Tricoptera Molanna sp.
Leptocella sp.
Insecta Corixidae Nymph sp.
Insecta Plecoptera Nymph sp.
Hexagenia sp.
Wormaldia sp.
Cladocera Eurycercus sp.
Tanypus sp.
Cl inotanypus sp. 3
Uni dentified
(Crayfish) Astacidae (family)
Bryozoa Crystatella mucedo
-------
TABLE IV-B-5
Benthic Organisms of the St. Louis River, Summer 1975
PHYLA GENUS SPECIES 1-A 1-B 1-C 2-A 2-B 2-C 3-A 3-B 3-C
Bryozoa Grys ta te 11 a mucedo
Nemathe1menthes Nematoda 5 29 29 8 6
Annel ida He 1 obde 11 a e10ngata 2 2 1 1
He1obde11a stagnalis 6 18 5 5 5 7
Moll usca Sphaerium fabale
Sphaerium 1acustre
Sphaeri um partumeium 4
Sphaerium securis 4
Sphaerium transversum 1
damaged snails 1
Sphaerium (immature) 3 3 6 14
Pisidium fa11ax 1 2
Valvata tricarinata
He1isoma anceps anceps
Promentus exacuous mega
w Promentus umbi1icatel1us
w
Amnico1a 1 i mnosa
Ferrissia rivularis
Marstonia . decepta
Gyrau1us defl ectus
Arthropoda Ase 11 us forbesi
Ase 11 us racovitzai
Ase11us sp.
Ase11us ( i nUlla ture) 19 2 2
Ganllnarus fasciatus
Ganllnarus 1acustris 5
Gammarus pseudolimnaeus
Procladius sp. 5 4 2 14
Cryptochironomus sp. 2 2 .1
Paracladope1ma 3
Podonominae sp.
Coelotanypus sp.
GlossosOllla
Phylocentropus sp.
Neureclipsis sp. 7 3
damaged insect
Polypedilulll sp. 2
f) T VERS ITY INOICES ([), I.) 1.86 0.00 5.73 2.91 2.22 1.00 4.26 5.50 2.59
-------
TABL~ IV-B-5. Conti nued
Benthic Organisms of the St. Louis River. Summer 1975
PHYLA GENUS SPECIES 4-A 4-B 4-C 5-A 5-B 5-C 6-A 6-B 6-C
Bryozoa Grystatella mucedo
Nemathelmenthes Nematoda 14 22 13 6 1
Annelida Helobdel1a elongata 3 4 1 1
He 1 obde 11 a stagnalis 1 23
Mollusca Sphaerium fabale 2
Sphaerium 1 acus tre 2
Sphaerium partumeium 2
Sphaerium securis 2 3
Sphaerium transversum 1 1
damaged snails 5
Sphaerium (i mma ture) 22 2 7 2 41 5 16
Pisidium fa 11 ax 21 6
Valvata tricarinata 3 1
Helisoma anceps anceps 2
w Prolllentus exacuous mega 1
~ Promentus ulllbil icate11us 1
Amnicola 1 imnosa 2
Ferrissia rivularis
Marstonia decepta 3
Gyraulus defl ec tus 2
Arthropoda Asellus forbesi 6(?
Ase11us racovitzai
Ase 11 us sp.
Asellus (immature) 16
Galllmarus fasciatus 24
Gammarus 1 acus tri s 41
Gammarus pseudolimnaeus
Procladius sp. 14 5 14 3 3 3
Cryptochironomus sp. 1 2
Paracladopelma 1
Podonominae sp. 12
Coelotanypus sp. 3
Glossosoma 1
Phylocentropus sp. 10 5
Neureclipsis sp. 7
damaged insect
POlypedilum sp.
nTllrn("TTV Tr'rHrrc: In r I 1 r;r; 1\ 7!1 1 n? ? fiR 1 ?R 1 qq h?? h nf> 1.m
-------
TABLE IV-B-6
Benthic Organisms of the St. Louis Ri vert Fall 1975
PHYLA GENUS SPECIES l-A l-B l-C 2-A 2-B 2-C 3-A 3-B 3-C
Platyhelminthes
Turbellaria (class)
Bryozoa Crys ta te 11 a s ta tob 1 as t 1
Annelida Helobdella stagnalis 2 2 4
Helobdella elongata 10 8 2
unidentified but large unique sp.
Valvata tricari nata
Glossiphonia complanata
Moll usca Sphaerium simile
Sphaerium sp. 2
w Sphaerium striatinum 1
U'1 Sphaerium securis 3
Sphaerium fabale
Sphaerium transversum
Sphaerium occidentale
Sphaeri um lacustre
Sphaerium pa rtumei um
Sphaeri um (immature)
Valvata tricarinata
Amnicola lililnosa 2
Ferrissia rivularis 5
Pisidium fallax
damaged snails
Arthropoda Chironomus sp. 1 19
Asellus racovitzai 7
Asellus sp. (immature) 100 12
Ase 11 us sp.
Glyptotendipes 5
Gammarus fasciatus 19
Gamma I'U s lacustris 5
Gamma I'US pseudolimnaeus
Procladius sp. 5 4 3 7 8
-------
TABLE IV-B-6. Continued
Benthic Organisms of the St. Louis River. Fall 1975
PHYLA GENUS SPECIES 4-A 4-B 4-C 5-A 5-B 5-C 6-A 6-B 6-C
Platyhelminthes
Turbellaria (class) 5
Bryozoa Crystatella statoblast
Annelida He 1 obde 11 a stagnalis 3 20 2
He 1 obde 11 a elongata 2 4
unidentified but large unique sp. 1
Valvata tricarinata
Mollusca Glossiphonia complanata
Sphaerium simile
w Sphaerium sp.
~ Sphaerium striatinum
Sphaerium securis
Sphaerium fabale 4
Sphaerium transversum 1
Sphaerium occidentale 1
Sphaerium lacustre
Sphaerium partuOleiuOl 1
Sphaerium ( i Olma ture) 7 2 9
Va 1 va ta tricarinata
Arnnicola 1 i mnosa
Ferrissia rivularis 1
Pisidium fa 11 ax 1
damaged snails 1
Arthropoda Chrionomus sp. 17
Asellus racovitzai 5 21
Ase 11 us sp. (immature) 2 3 42
Ase 11 us sp.
Glyptotendipes 1
Gamlla rus fasciatus 6 5
GaillillarUS lacustris 5
Ganlllla ru s pseudolimnaeus 4
Procladius sp. 2 4 5 14
-------
PHYLA
Arthropoda (continued)
w
.......
Astacidae (family)
Insecta (class)
Trichoptera (order)
Insecta (class)
Plecoptera (order)
Nemathelmenthes Nematoda
TABLE IV-B-6, Continued
Benthic Organisms of the St. Louis River, Fall 1975
GENUS SPECIES l-A 1-B l-C 2-A 2-B 2-C 3-A 3-B 3-C
Cryptochironomus
Potthastia longimanus
Microtendipes
Dicrotendipes nervoses
Coelotanypus sp.
Einfeldia sp.
Hyalella azteca
Neureclipsis
Isoperia
13
3
3
2
sp. .
sp.
DIVERSITY INDICES (0.1.)
2.59 2.29 2.46 3.17 3.02 1.00 ~.52 2.20 3.00
-------
TABLE IV-B-6, Continued
Benthic Organisms of the St. Louis River, Fall 1975
PHYLA GENUS SPECIES 4-A 4-B 4-C 5-A 5-B 5-C 6-A 6-B 6-C
Arthropoda (continued) Cryptochironomus 1 3 5
Potthastia longimanus 2 1
Microtendipes 1
Dicrotendipes nurvoses 1
Coelotenypus sp. 1 6
Einfeldia sp. 1
Hyalella azteca 5
w Astacidae (family)
0:> Insecta (class)
Trichoptera (order) Neureclipsis sp. 2
Insecta (class) .
Plecoptera (order) Isoperia sp. 2
Nemathelmenthes Nematoda 2 13
DIVERSITY INDICES (0.1.) 3.17 1.00 3.60 4.09 2.00 4.11 1.00 7.37 6.97
-------
v.
CHEMICAL RESEARCH
A.BASIC EXPERIMENTAL DESIGN
The major thrust of the chemistry portion of this study was to determine
the factors which were instrumental in mobilizing environmentally hazardous
materials (heavy metal ions) from the static coal storage piles.8 In the con-
sideration of factors which could be effective in mobilization of heavy metals
from the coal, and allowing their subsequent release to the aquatic environ-
ment of the Duluth-Superior Harbor, the primary mode of mobilization was as-
sumed to be that of water. This water was found to be primarily of three
sou rces:
1. raifl falling on the coal and its subsequent leaching through the pile
2. snow falling on the coal, eventually melting and then leaching through
3. water drawn from the bay, and sprayed on the coal as a dust abatement
procedure
Therefore, additional parameters were deemed necessary to provide the
needed experimental control of the water leachant. These parameters were
chosen to provide the maximum amount of information as to the effects of aque-
ous leaching on the static coal pile. The following additional parameters
were:
1.
pH control: The solubility of many metal ions is dependent on the hydro-
gen ion concentration of the medium in contact with the ions. Elements
such as arsenic or chromium which occur as oxyanions, could be expected
to mobilize under different conditions from other elements such as copper,
or cobalt, which would occur as cationic species. In addition, if many
of the metals were bound by anionic sites on the coal, the pH of the
leachant could have a profound effect on solubility and mobilization.
Also, since the western coal is low in sulfur content and relatively high
in alkaline earths, it tends to give an alkaline leachant.
Rate of percolation through the coal (leachant-coal contact): It was nec-
essary to control the rate of percolation through the coal to investigate
the effect of contact between the coal and leachant. The concentration of
metal ions in the leachate could be influenced by the amount of additional
materia 1 removed from the coal, due to an "equil i bri um" set-up between the
leachate and the coal.
2.
Other factors were determined to have probable effects on heavy metals
leaching from the coal. These factors were chosen to explore the influence of
temperature, oxidizing versus non-oxidizing atmosphere, and size of the coal
particles. The rationale for the choice of the above factors may be summa-
rized in the following manner:
39
-------
Since there are wide temperature ranges to be found in the storage area
for the coal (air temperature above gO°F in summer and below -30°F in the
winter), the effects of changes in the temperature of the leachant on the
mobilization of heavy metals was necessary. Also, it was necessary to de-
termine the effects of elevated temperature, since spontaneous interior
heating of the coal pile occurred.
Conditions on and in the coal storage pile were found to range from oxi-
dizing at the surface (exposure to air, heat, light) to non-oxidizing in
the interior of the pile (removal of oxygen by reaction with the coal).
It was considered to be extremely important to determine whether the sol-
ubilization and mobilization of the heavy metals occurred more readily
under oxidizing or non-oxidizing conditions.
It had been noted that the western coal was of a "soft" character, and
relatively porous in nature. Thus it was necessary to determine if the
removal of the heavy metals from the coal by an aqueous leachant was a
function of the surface area of the coal in contact with the leachant, or
whether the coal was permeable to a sufficient extent to render the par-
ticle siz~ of the coal of no consequence.
As a result of the above considerations, the following factors were set
as the parameters to be controlled in the first major leaching study:
1. temperature
2. gas saturation of leachant (N2 or 02 atmosphere)
3. rate of leachant flow
4. particle size of coal
5. pH of leachant
1.
2.
3.
The above listed parameters were the factors chosen, and were the first
to be investigated. As the coal study progressed, additional avenues of in-
vestigation presented themselves and were made the subject of research.
B.
1.
EXPERIMENTAL DESIGN AND DESCRIPTION OF SUPPORTING EQUIPMENT AND SUPPLIES
Coal Samples
The leaching study was carried out in three different samples of coal.
Western C~al No. 16_- ..
This sample was obtained from one of the cars of a unit train which was
transporting the coal from the western mines to the coal transshipment facil-
ity in Superior, Wisconsin. The coal car was selectively sampled, and all
portions were combined and stored (as a single composite sample) in a polyeth-
ylene bag.
Western Coal No. 26_-
This sample was obtained from the coal pile at the Superior transship-
ment facility. A bulldozer was used to dig down approximately two meters in-
to the coal pile, s9 that a sample which had not been exposed for a long pe-
riod of time to the effects of air, or air-borne contaminants, could be ob-
tained. The sample was collected and stored in a pOlyethylene bag until
40
-------
processed for experimentation.
Eastern Coa14_-
The sample of eastern coal was furnished to the CLSES research group
through the assistance of the Detroit Edison Company, who sampled their stock-
pile at the Detroit power plant. The sample was shipped to the local labora-
tory in a polyethylene lined container.
2.
Coal Grinding
It should be noted that all coal samples were quite moist when obtained.
The polyethylene bags were kept sealed, and the high amount of moisture became
apparent as a condensate on the inner surface of the sample bags. It was nec-
essary to air-dry portions of the samples for at least ,24 hours before grind-
ing and sieving operations could be performed, otherwise the damp coal "gummed
Up" both the mill and the stainless steel sieves to the point that accurately
sized fractions could not be obtained.
The coal, as obtained from the various sources of supply, ranged from
fine dust up to lumps approximately five cm (two inches) across the largest
dimension.
A Thomas-Wiley@ Laboratory Mill-Model 4 was used in the grinding pro-
cess. The knives (both stationary and moving) were adjusted according to the
specified tolerances recommended by the manufacturer. A 2 mm exit screen was
used to set the maximum size for the ground coal. A single pass of the coal
through the mill was sufficient to reduce the coal to the desired ranges of
particle sizes. Further passes through the mill did not significantly reduce
the sizes of the larger particles or increase the amount of "fines."
3.
Stainless Steel Sieves
On examination of available sieves of standard mesh sizes, it was noted
that the usual sieve was fabricated from the brass wire cloth soldered to a
brass frame. Construction of this nature was deemed unacceptable due to pos-
sible contamination of the samples with heavy metals (copper, zinc, lead) by
abrasion of the screen or wall material during the sieving process.
It was found that the same type of sieve was available with stainless
steel construction throughout. Specimens of these sieves were obtained and
were found to be unacceptable since the stainless steel sieve cloths were
mounted to the rims by the use of a soft solder which could be abraded by the
sieving process and contaminate the sample.
Upon consultation with the fabricator, S.W. Tyler Co., it was found to be
possible to fabricate solder-free sieves of all stainless steel construction,
and the company prepared a set of screen to those specifications.
4. Sieving Technique
The ground coal sample obtained by passage of
through a Wiley@ Mill, was placed in a stainless
the crude coal sample
steel sieve stack consist-
41
-------
ing of 2 mrn, 1 mm, 0.5 mrn, 0.25 mm, 0.125 mm and 0.063 mm sieves. The stacked
sieves were covered with a stainless steel cover and a stainless steel pan to
collect the IIfinesll was placed on the bottom of the stacked sieves.
The sieve stack was placed in a Ro-Tap@ apparatus and the sample \'Jas
shaken with tapping for approximately 15 minutes. At the end of the shaking
period, the stacked sieves were separated, and the various fractions were
brushed from the sieves into polyethylene containers, using a plastic-bristle
brush. The containers were closed with pOlyethylene lids and the sized coal
samples were stored until needed.
5.
Deionized Water
Deionized water from the experimental work performed in this study was
prepared through the use of a Mill ipore @ system consisting of the following
components and sequence.
Water from the city mains was drawn into the purification train through
a plastic tube, then through a Milli-Q3@unit (prefiltration and reverse os-
mosis) and finally through a Mill i-Q2 @ system of cartridges containing ac-
tivated carbon and ion exchange resins. This treatment produced purified,
deionized water from sufficient purity to give zero readings for the metals
being determined by f1ame1ess atomic absorption spectrophotometric analysis.
6.
Continuous Flow Leaching Apparatus
This apparatus was used in the coal leaching studies which involved con-
tinuous flow of the 1eachant through the coal. Since the same system was
used in all recirculating (continuous flow) studies, a single description of
the apparatus will suffice. See Figures V-B-l through V-B-3 for details of
construction.
The leaching apparatus was fabricated entirely from pOlypropylene bot-
tles and tubing, po1~ropy1ene fittings and tubing connectors, po1ytetraf1u-
oroethy1ene (Tef1onUY) screening and flexible silicone rubber tubing. Thus,
the leaching fluid, as it circulated, came only in contact with coal and/or
plastic. In this manner, trace metal contamination from outside sources was
minimized, and the concentrations of metal ions in the leachate may be assum-
ed to be derived from the coal in contact with the circulating 1eachant.
The principal leaching study module consisted of a nominal 2-1iter (one-
half gallon) polypropylene bottle with a pOlypropylene screw cap. The bottle
cap was fitted with four polypropylene tubes which served as 1eachant inlet,
1eachant outlet, gas inlet and gas out1et--vo1ume makeup, respectively. The
polypropylene tubes were passed through the bottle cap by means of polypro-
pylene bulkhead fittings.
The leachate outlet tube was fitted with~ polypropylene thistle-tube
top, to which was attached at 74-micron Tef1on~ screen. The f1uoropo1ymer
screen was mounted on the thistle-tube top my means of a polyproPYlene fiber
which was used to tie the screen across the opening. The function of the
Teflon @ screen \'Jas to minimize the passage of fine particles of coal through
42
-------
the tubing and tubing pump, so that only solubilized materials were recircu-
lated through the system.
Polypropylene tubing (one-quarter inch size) lines were used to conduct
the leachant solution to and from the tubing roller pump heads. All changes
in direction of the polyolefin tubing were made with ninety degree (90°) el-
bow fittings which were fabricated from polypropylene. Unit fittings were
used to attach a length of flexible silicone rubber tubing to the inlet and
outlet polypropylene lines. The flexible silicone tubing was necessary to
give the necessary pumping action through the roller pump heads of the tubing
pump.
A change of ground and properly sized coal was placed in the bottom of
the leaching bottle. The amount of coal was such that the bottle was approxi-
mately one-quarter to one-third full of coal. Sufficient leaching solution
(leachant) was then added to completely cover the coal and have the bottle
approximately two-thirds full with the coal-leachant mixture. The volume of
leachant used was in the range of 800-1000 ml.
Leachant was drawn from the center fo the leaching bottle, and as near
the bottom of the bottle as was possible. This placement of the outlet tube
was to allow the maximum percolation of the leaching fluid through the pul-
verized coal-bed in the bottle. The leachant inlet tube was terminated above
the surface of the liquid in the leaching bottle, so that the continuous cy-
cle of fluid was broken. This termination was done for a two-fold purpose.
The passage of the return flow of the leachate through the gas space above
the leachant-coal served to keep the leachant saturated with the gas used as
atmosphere in the particular run, and in addition, the impact of the return-
ing leachant stream acted as a partial stirring aid in order to facilitate
mixing of the leachate and to minimize channeling effects through the coal-
bed.
The leachate inlet tube, on its return from the tubing pumphead, was
split and a IIT-jointll inserted. A dust-protected tube was attached to the
IIT-jointll and served as the sample withdrawal point. Sample makeup volume
was returned to the system through the gas outlet tube in the bottle cap.
Flexible silicone rubber tubing was used to conduct the cylinder gases
(which maintained the controlled gas space over the coal) from the storage
cylinders to the gas washing train. The individual parts of the gas washing
train were also connected by silicone tubing.
Commercial cylinder gases (nitrogen and oxygen) were purified through a
sealed, seven-bottle washing train. The gases passed serially from the tank
through (1) a ballast bottle, (2) 6 N sulfuric acid, (3) 6 N sulfuric acid,
(4) deionized water, (5) 6 N sodium hydroxide, (6) deionized water, and (7)
deionized water. With the exception of the initial ballast bottle and surge
tank which was of glass, the remaining six bottles of the train were poly-
propylene. The gas train was pressurized to approximately 10 psig to give
adequate control of gas flow to each leaching module through a gas splitting
manifold. The long distance run (approximately 2 meters) from the gas wash-
ing train to the gas splitting manifold was polypropylene tUbing. The gas
43
-------
splitting manifold was polypropylene valves and tubing.. The final connectioffi
to the leaching bottles was silicone rubber tubing.
The total continuous flow leaching system consisted of a 300 liter (80
gallon) rectangular constant temperature bath which was fitted with tempera-
ture controllers (thermostats, heaters and cooling coils) and stirrers. A
total of six leaching bottles, fitted with leachant circulating lines and gas
feeds (for controlled atmosphere) could be accommodated in the constant tem-
perature tank at one time. Thus, four runs and two IIcontrolll bottles could
be carried out as a simultaneous process.
7.
Chemical Analysis of Biological Samples
Oven-dried samples of vascular macrophytes and benthic organisms (as
provided by the biological research groups) were prepared for metal analysis
by the fOllowing procedure.
Samples, in the size range of 0.08-0.10 g, were accurately weighed on an
analytical balance. The weighed samples were then placed in Parr@ Teflon@
lined acid digestion bombs and 2.50 to 3.00 ml of ultrapure, concentrated
nitric acid were added.12 The acid digestion bombs were then assembled,
sealed and heated in an oven at 150aC for a period of two to three hours.
The digestion
room temperature.
tively transferred
deionized water.
bombs were removed from the oven and allowed to cool to
The bombs were then opened and the contents were quantita-
to volumetric flasks and diluted to a standard volume with
Samples, after digestion, were analyzed for metal content by the use of
flameless atomic absorption spectrophotometry.l, 2, 10, 11, 15,16
44
-------
BOTTLE CAP SCHEMATIC
. ~..
@
@J
@J £~@
FIGURE V-B-l
LEGEND FOR FIGURES V-B-l AND V-B-2
A. LEACHATE INLET TUBE
B. LEACHATE OUTLET TUBE
C. GAS INLET TUBE
D. GAS OUTLET AND LIQUID VOLUME MAKEUP TUBE
E. BULKHEAD FITTING
F. BOTTLE CAP
G. 2-LITER LEACHING BOTTLE
H, THISTLE TUBE END
I. 74-MICRON TEFLON SCREEN
NOTE: ALL PARTS OF SYSTEM ARE POLYOLEFIN PLASTIC OR. TEFLON.
45
-------
LEACHING BOTTLE
A
B
c
D
o
o
o
G
L £A CHATE
~ "" "" "
" "" "" "
COAL" "-
~' '
~
~~
~""
':
FIGURE V-B-2
46
-------
+::0
.......
GAS
WASHING
TR AIN
V)
q:
(!)
CONTINUOUS FLOW LEACHING SYSTEM
PUMP
SAMPLE
TAKE-OFF
TEMP
CON TROL
-------
c.
EXPLORATORY EXPERIMENTS
1. Coal Titration
a. Experimental--
This experiment was formulated to give an approximate "equivalent weight"
of the coal in terms of its ability to react with either acid or base.
Separate 2.00 gram samples of coal (Western Coal No.1) were placed in
pre-rinsed polyolefin bottles and covered with forty millimeters of deionized
water. Particle sizes of coal used in the separate samples were:
1. 0.500 - 1.00 mm
2. 0.250 - 0.500 mm
3. 0.125 - 0.250 mm
4. 0.063 - 0.125 mm
Successive five ml portions of standard acid or base were added to each
sample every 24 hours. The sample was then agitated and allowed to stand for
a period of 24 hours, after which time, the pH of the system was measured
with a pH meter.
The pH of each particle size of coal was then plotted versus milliliters
of titrant added (see Fig. V-C-l).
b. Results and Discussion--
A plot of pH versus ml of acid or base is shown in Fig. V-C-l. The
curve appears as a typical, multi-functional, weak acid or weak base titra-
tion curve. There is some effect due to particle size, with larger particle
sizes showing a smaller buffer effect, only at higher pH value.
The buffer effect appears to be more of a bulk effect rather than a sur-
face effect. With 35 ml of base added, the pH was about 9.5 for the largest
particles and about 8.5 for the smallest particles. If there was no coal
present, the pH should have be~n 11.7. Calculation will show that the 2.00 g
of coal reacted with 2.1 x 10- m moles of OH- ion for the large particles
and 4.2 x 10-3 m moles of OH- ion for the small particles. This is a 2 to 1
ratio. Assuming spherical particles and constant density, gives the small
particles 8 times the surface area of the large particle. Also, the curves
show the 35 ml, base addition point as about the largest surface effect ob-
tained. It would seem, therefore, that the reaction of the coal with acid or
base is primarily a bulk effect.
The actual runs using an acetic acid-sodium acetate buffer gave 0.142 m
mole H+ per gram of coal to reach a pH of 4.85. A similar calculation using
the data from this experiment gave a value of 0.170 m mole H+ per gram of
coal to reach pH = 4.85. The two values are in reasonably good agreement and
an average value of 0.16 m mole H+ per gram of coal to reach pH = 4.85 seems
to be fairly reliable.
Using 0.16 m mole H+ per gram of coal yields a value of 150 equivalents
of H+ to bring 1 ton of coal to pH = 4.85. This would be equivalent to about
4.0 liters of concentrated sulfuric acid per 1 ton of coal, or in pure metric
48
-------
c.
EXPLORATORY EXPERIMENTS
1.
Coal Titration
a. Experimental--
This experiment was formulated to give an approximate lIequiva1ent weightll
of the coal in terms of its ability to react with either acid or base.
Separate 2.00 gram samples of coal (Western Coal No.1) were placed in
pre-rinsed po1yo1efin bottles and covered with forty millimeters of deionized
water. Particle sizes of coal used in the separate samples were:
. 1. 0.500 - 1.00 mm
2. 0.250 - 0.500 mm
3. 0.125 - 0.250 mm
4. 0.063 - 0.125 mm
Successive five m1 portions of standard acid or base were added to each
sample every 24 hours. The sample was then agitated and allowed to stand for
a period of 24 hours, after which time, the pH of the system was measured
with a pH meter.
The pH of each particle size of coal was then plotted versus milliliters
of titrant added (see Fig. V-C-1).
b. Results and Discussion--
A plot of pH versus m1 of acid or base is shown in Fig. V-C-1. The
curve appears as a typical, multi-functional, weak acid or weak base titra-
tion curve. There is some effect due to particle size, with larger particle
sizes showing a smaller buffer effect, only at higher pH value.
The buffer effect appears to be more of a bulk effect rather than a sur-
face effect. With 35 m1 of base added, the pH was about 9.5 for the largest
particles and about 8.5 for the smallest particles. If there was no coal
present, the pH should have be~n 11.7. Calculation will show that the 2.00 g
of coal reacted with 2.1 x 10- m moles of OH- ion for the large particles
and 4.2 x 10-3 m moles of OH- ion for the small particles. This is a 2 to 1
ratio. Assuming spherical particles and constant density, gives the small
particles 8 times the surface area of the large particle. Also, the curves
show the 35 m1, base addition point as about the largest surface effect ob-
tained. It would seem, therefore, that the reaction of the coal with acid or
base is primarily a bulk effect.
The actual runs using an acetic acid-sodium acetate buffer gave 0.142 m
mole H+ per gram of coal to reach a pH of 4.85. A similar calculation using
the data from this experiment gave a value of 0.170 m mole H+ per gram of
coal to reach pH = 4.85. The two values are in reasonably good agreement and
an average value of 0.16 m mole H+ per gram of coal to reach pH = 4.85 seems
to be fairly reliable.
Using 0.16 m mole H+ per gram of coal yields a value of 150 equivalents
of H+ to bring 1 ton of coal to pH = 4.85. This would be equivalent to about
4.0 liters of concentrated sulfuric acid per 1 ton of coal, or in pure metric
48
-------
units, 4.4 liters of concentrated sulfuric acid per metric ton of coal.
2.
Design of Buffer System for Low pH Runs
Western Coal produced slightly alkaline solutions in distilled water,
and it was suspected that the buffer capacity of the coal was appreciable.
In order to make leaching runs at pH values other than the natural buffer
point of the coal, it became necessary to design buffer solutions.
Attempts were made to design:
1. an alkaline buffer near pH = 10 using C032-, HC03~ system
2. an acid buffer near pH = 5 and pH = 6 using a HC03-' H2C03
3. an acid buffer near pH = 5 using a C2H302-' HC2H302 system
Of the three systems, only system 3 was usable. The basic (near pH = 10)
system gave leachates which were very concentrated in interferring materials
(probably organic). These leachates actually blackened the quartz windows
of the atomic absorption furnace and were thus impossible to analyze using
the methods adopted for this work. The HC03-' H2C03 system would not hold
pH due to escape of C02 to the atmosphere.
system
The final buffer of choice was 0.072 M HC2H302 and 0.028 M (Na+, C2H302-)
in deionized water. Runs with this leachant are designated as Ia,cetate buffer"
runs. This system:
1. gave no background heavy metal contamination
2. gave no significant interferences in the atomic absorption analyses
3~ held the pH of the system at 4.85 plus or minus a few tenths of a
pH unit during the leaching runs. Final pH values for the first
factorial run gave a = 0.024 pH units. -
Assuming a pH of 4.74 for HC2H302 gives an initial pH of 4.33 for the
buffer. Using 1,000 ml of original leachate applied to 200 g of coal and a
final pH of 4.85 as data, routine calculations show that 28.3 m moles of
HC2H302 are neutralized by 200 g of coal. This yields 0.142 m moles H+ used
per gram of coal to reach a pH of 4.85.
In comparison, the HCl titration of coal gives 0.170 m moles H+ used per
gram of coal to reach pH = 4.85.
3.
Filter Uptake Study
It was suspected that lead ion was adsorbed on Millipore@ filters and
thus lost to the analysis. A series of experiments, here reported, seem to
show that the effect is real.
Samples of both deionized water and Lake Superior wate~ were spiked with
lead ion and the loss on filtering through 0.45~ MilliporeVY filters was
measured with the atomic absorption spectrophotometer. On the deionized wa-
ter samples, filtration time was ~3 min. Filtration time for the lake water.
runs was ~2 min. Results are shown in Figures V-C-2 and V-C-3. One set of
the filters from the deionized water runs were washed with 0.01 N ~Hl (ultra-
pure) and another set of the filters were washed with a 1.0 ppm Al + ion
49
-------
solution (lead free). Lead was measured in these filtrates and the results
combined with the original filtrates to give total lead recovery with wash
(see Fig. V-C-4). These results imply that, at least at the higher concen-
trations of lead ion, significant amounts of lead are retained on the filters.
Even though an acid or Lewis acid wash can recover this lead, the nature of
the coal leaching system may hot allow an acid wash or pretreatment of the
sample before filtration.
It should be noted that, at the 10 ppb level, there was consicerably
less loss of lead from the lake water sample than from the deionized water
sample. This protection of the lead ion, possibly by complexation, should
be considerably enhanced in media such as coal leachates and bottom lake sam-
ples. Nevertheless this filter adsorption is of serious concern in any lead
analysis of filtered water samples.
At this point in the research, it was decided (by definition) that a
metal was mobilized by the leachant if the metal passed a 0.45~ filter (a
:" fa i rly standardi zed parti cl e in thi s type of work). Any aci d treatment of
the leachate prior to filtration or acid wash of the filter would have dis-
turbed the system by changing the properties of residual colloids and other
particles in the system.
In this work, no lead was observed to leach from the coal with pure wa-
ter, however, these results must be held inconclusive at this time.
A future, detailed study of filter absorption from coal leachate would
certainly be in order.
4.
Extremum Runs
Preliminary to the large experimental designs, some coal was subjected
to the extreme conditions that might be expected in the coal handling facil-
ity.
a. Experimental--
Three samples of coal grindings were subjected to extreme conditions:
(1) One sample (50% coal - 50% water by weight was shaken on a fast shaker
at room temperature for 72 hours. The mud obtained was unfilterable.
No analysis was done.
(2) One sample (50% coal - 50% water) was subjected
and thawing for 1 week under still (not shaken)
results were Cu-4.0 ppb; Mn-2.1 ppb; Ba-70 ppb.
tection limits.
(3) One sample (50% coal - 50% water) was held near 100°C in a steam bath
for 6 days. Analytical results were Cu-10.7 ppb; Mn-6.8 ppb; Ba-160 ppb.
V and Mo were below detection limits.
to alternate freezing
conditions. Analytical
V and Mo were below de-
b. Discussion--
Experiment (1) shows that the coal is rather fragile.
was done, no further conclusions were drawn.
As no analysis
50
-------
Experiments (2) and (3) do show a 2 to 3 fold increase in metal extrac-
tion for sub-boiling conditions over the extractions obtained for freeze-
thaw conditions.
The temperature effect was studied in some detail in the later work.
The interesting point, however, is that alternate freezing and thawing did
not release large amounts of metal ions. Because many open storage piles
will be subjected to moist, freeze-thaw cycles, this fact is certainly of
environmental significance.
51
-------
:r .
a. U1
a
-
C B F\.L T'I.T' R.P\ T"I B'N
9l[!)
(!) X [!)
X [!]
++xx
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~
+
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*
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'tD
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an
InD
rr
m
.-
La
:r
m
N
-
aD
MI. E:~SE
'to 6D
MI. ~CIJJ
SD
FIGURE V-C-l:
WESTERN Ca~L Na. 1
S~MPLE SIZE :: ~.OO 9.
HCI : 0.0106 N
N2IBH : 0.0096 N
(!] : O.SO - 1.0C mm P~RTICLE: SIZE:
x : 0.2S - C.SC mm P~RTICLE SIZE
+ : 0.1~S - O.~S mm P~RTIC:LE: SIZE
~ = 0.063 - 0.1~S mm P~RTIC:LE SJ:ZE
52
-------
ci
U'I
FIL TER RETENTIBN STU:DV
('\
cOQ [!]
n.:r
n.
v
Il
W
...
.J
HQ
u.m HI
>-
cO ~ I!I
A
W
cOQ
Il",
~
U1
A
d:
R
([
we m
.J [!]
2D
~D 6D BD
C!lR:IG1:NPlL LE:PlJJ C:~NC:'N <:PP~:>
IDD
FIGURE V-C-2:
LE:PlJJ
JJE:1:3N1:ZEJJ LN'P\ T'E:R ME:JJ1:UM
M,1:L,L1:P(3'RE: 0.&+-5: ME:MI!iRPlNE: F"1:L TE:R
PlPR~X. :3 M1:NUTES' F"'1:L TRPlT'1:ClN T'1:ME:
PH RPlNG'E :' S'.C -.S'.5:'
53
-------
()
d]
lL
lL
V
c
n::~
w
I-
.J
H
l£.
>-c
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W
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EI
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AC
([:r
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([
W
.J
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Q
FIL TER RETENTI~N STUJJY
[!J
!
2D
~D 6D BD
eJRIGINP\L LEP\J] C~NC1N Cpp~:>
C
nJ
FI GURE V-C -3: LEP\J]
LP\KE WP\TER MEJ]IUM
MILLIPeRE c.'t-s: MEM~R~NE F"IL TER
P\PPR~X. ;a MINUTES F"IL TRP\TI~N TIME
54
ffi
[!J
100
-------
CI
CI
IU
FIL TER RETENTI~N STU:DY
f'lCi
ell!!
n.
Q..
v
R
d:
WCl
.J!!! X
1£.. X
~
)-
[t [!]
W
~CI
!g. [!]
U
W
[l
.J ~
d:
~ (!J
~CI [!]
~7
i!D
~D &0. U
13R:I:G:I:NPlL LE:f':D c:mNC:'N <:FlP~:>
100
FIGURE V-C-4:
LE:f'JJ
JJE::I:C:JN:I:ZE:JJ W~ TE:R ME:JJ:I:UM
M:I:LL:I:PC:JRE: cID C.'H~ Jl ME:M~Rf'NE: F":I:L TEFl
PlPPR13X. :3 M:I:NUTE: F":I:L TRPlT:I:13N T:I:ME:
. 13 = C.J. M ~LUH1:NUM J:C!lN WPl5H
. X = C.J. H HYJJR13C:HL13R:I:C: PlC::I:JJ W~5H
55
-------
D.
MAJOR LEACHING EXPERIMENTS
1.
First Factorial Run
a. Experimental--
The first factorial run consisted of a complete, single factorial exper-
iment on five factors at two levels each. Each portion of tge experimental
run was sampled at three different times, producing a pure 2 factorial de-
sign, overlain with a time parameter to give a pseudo 25 x 3 factorial de-
sign. The time of sampling cannot be taken as a pure factorial level, be-
cause samples which are withdrawn during the run cannot be considered truly
independent. .
The rationale for the choice of factors and their final experimental
levels are described elsewhere in this report (see Section V-A). Factors
and their experimental levels as used in this run were as shown in Table V-
0-1.
TABLE V-O-l.
VARIABLES FOR FACTORIAL RUN
Factor
Levell
Level 2
Temperature (T)
Gas Saturation (G)
Rate of Pumping (R)
Particle Size (S)
pH (P)
20°C
40°C
N2
20 ml/min
02
80 ml/min
0.125 to 0.250 mm
0.500 to 1.00 mm
Unbuffered deionized
water whose pH reached
7.3 in the leachate
Sodium acetate-acetic
acid buffer whose pH
was 4.8 in the leachate
Time of Sampling (H)
24 hours
48 hours
The factors, when placed in an operational grid, gave 32 separate runs.
These runs were set-up four at a time in the leaching system. Since the sys-
tem consisted of six leaching containers, it was capable of a run of four
variables, with two blanks at one servicing of the system. The two blanks
were for pure leachate and trace metal-spiked leachate, respectively. It
was found that two runs could be accomplished in a one week period, if sched-
uling of variables was arranged carefully. Thus, a minimum of four weeks'
was necessary to proceed through the entire set of 32 variables in the fac-
torial run. This, however, gave no opportunity for replication of runs,
therefore, certain of the runs were replicated for purposes of analytical
control.
The coal (Western Coal No.1) was obtained from a coal-car sampling
56
-------
performed by the Envi ronmenta 1 Resear.ch Laboi'atory,
visibly wet when obtained.
Sufficient coal for the entire first factorial study was air dried for
24 hours to remove surface moisture. The dried sample was then ground in one
pass through a Wiley@ Laboratory Mill-Model 4. The exit screen on the
Mill's grinding chamber was set to a size of one millimeter. These grindings
were then successively mixed by passing them through a stainless steel rif-
fler. The riffler was then used to separate the total sample into 16 repre-
sentative portions of approximately 10 liters each of ground coal of all
grain sizes from one millimeter on down to "fines." These samples were then
stored in sealed polyethylene containers. The composite coal samples were
sieved as necessary, through specially fabricated stainless steel sieves in
order to furnish the appropriate size range of coal granules.
r\..' ...&.1-
UU I UI",.
The sample was
Factorial Levels--
Temperature--The temperatures of 20°C or 40°C were maintained in a 300
liter water bath to +0.5°C.
Gas Saturation--The leaching system was maintained at two extremum con-
ditions: (a) anoxic, with the circulating leachate being saturated with
nitrogen gas, or (b) highly oxygenated, by the use of oxygen to saturate the
leachant. The gases were purified, and humidified to minimize evaporation
from the system, as described in the section on the structure of the leaching
system (Section V-B-6).
Rate of Pumping--A single Masterflex
-------
Early studies, as described elsewhere in this report, showed that one
gram of the western coal reacted with about 0.14 millimoles of acetic acid
in moving from a pH of 7.3 (unbuffered) to an acetate-acetic acid buffer at
a pH of 4.85. High concentrations of the acetate-acetic acid buffer gave
matrix problems in the metal ion analyses by atomic absorption spectrophotom-
etry, while low concentrations of buffer in the leachant gave fairly large
(and therefore unacceptable) fluctuations in pH over longer periods of time,
which made the pH levels in the analyses of variance an unacceptable factor
from a statistical standpoint. .
A buffer solution which was 0.072 M in acetic acid and 0.028 M in sodium
acetate was found to give reasonable pH control on the acidic side. This
buffer solution, in contact with western coal stabilized to within 0.1 pH
unit after six to twelve hours. This concentration of buffer did not give
serious matrix problems during analysis of the metals (see Section V-C-2).
Creation of a buffer of essentially the same capacity on the basic side
was not feasible.
Therefore two systems of pH control were adopted for the factorial
system:
1.
A sodium acetate-acetic acid buffer which stabili2ed the coal-
leachant system at approximately pH 4.7.
2. Unbuffered, deionized water (allowing the coal to serve as its
own buffer) which produced an alkaline leachate at a pH of ap-
proximately 7.4 in most cases.
The above conditions were within the limits of acceptability of experimental
control and for heavy metal analysis.
It should be mentioned that the two systems are not equivalent in ionic
strength and are probably not equivalent in absolute buffer capacity. Due
to the inherent difficulties in the coal-leachant system, it was felt that
pH control was the factor of paramount importance and that the above limits
were the best compromise.
Time of Sampling--Preliminary investigations and earlier work demon-
strated that there were considerable fluctuations of metal concentrations
in the leachate during the very early portions of a run, but that the system
stabilized somewhat in the vicinity of 6 hours of running time. Therefore
6, 24 and 48 hours were selected as the three points which would establish
any true time trends in metal concentrations in the leachate. These three
times established the three levels for the factorial analysis of variance.
b. Results--
Analysis was started on 13 ~eta~s for this run, and was completed for
the fall factorial set of 96 samples on 5 of these (As, Sa, Cr, Cu and Mn).
The remaining 8 metals showed values near or below detection limits in the
early analysis. It was therefore decided to analyze these metals (Cd, Co,
Pb, Mo, Ni, Se, V and Zn) on a reduced factorial basis. That is, holding
gas constant as N2' particle size constant at the 0.125 mm screen fraction
58
-------
and using only the 24 hour sample.
perature, rate of pumping and pH.
This gave a 2 x 2 x 2 factorial o~ tem-
The results of the reduced factorial are given in Table V-D-7. It can
be seen that the values for these metals over these conditions are near or
below detection limits. The only obvious trends are (a) Selenium seems to
extract better at high pH and (b) Molybdenum seems to extract better at low
pH.
Total release data for the complete factorial analyses for (As, Ba, Cr,
Cu and Mn) are given in Tables V-D-8 through V-D-12. The W31 runs (the 1st
half of the third week) showed totally wild results. These runs were re-
peated and the data for the repeat runs are shown in the table.
In addition some of the copper values for the Wll runs were obviously
out of line. The Wll runs were repeated for the copper and the values shown
in Table V-D-ll are the repeat values.
The original statistical analysis of these data were done using a 26
factorial method developed by Yates.7 The data were later refined using the
ANOVAR progrqm from the "Dartmouth Statistical Package." The ANOVAR program
allowed a 25.31 analysis (time at 3 levels). The ANOVAR results are dis-
cussed below:
Arsenic -
Using 3rd, 4th and 5th order interactions as -a pooled error-esti-
mate gives the following variables and interactions as significant:
Extremely Significant: oc«O.OOl T, P, HP
Highly Significant: oc <0.001 GRP, H
Very Significant: oc <0.01 TG, SH, SHP
Significant: oc <0.025 RP, GRS
These results imply a fairly complex mechanism for leaching. - The
significant primary variables T, P and H and the fir$t order inter-
action, HP are clearly shown in Figure V-D-l. The combined effects
T, P, Hand HP account for 76.7% of the total sum of squares in the
analysis.
Bari um -
It is immediately obvious from Table V-D-9 that pH has a very
large effect on barium leaching. The grand mean of the high pH
runs is 26.4 ppb of Ba while the grand mean at low pH is 1,580 ppb.
That is, an increase of approximately 60 fold is observed in Sa
leaching when the system is buffered to high H+ concentrations.
From a statistical viewpoint, these data must be treated as two
separate experiments. - Otherwise, the lack of a homogeniety of
variance would vitiate any analysis of variance treatment. There-
fore, the high and low pH runs were split and run on the ANOVAR
program as two separate 24 x 31 designs.
The high pH (low H+) runs: Using 3rd and 4th order -interactions
as a pooled error estimate gives the following variances and in-
teractions as significant:
59
-------
Highly Significant:
Very Significant:
Significant:
The main effects R,
~
-------
Tho T ,
111\.0. I, -',
D :> nrl
I' u.n...
1-1 o.f.fo,..t",
II \",0 I 1"'"""'\.0""
~rrnlln+
""''''''''''''''''''''1 ""
.fn~ h~ ho/ n.f tho tnt"l
'_I """",U/U VI ""'- "'"'''''''''I
cl'm n.f
""""'111 v I
squares.
Chromium -
As in the high pH runs, slower rate of pumping and shorter resi-
dence times give greater leaching. Temperature, which was not a
main effect in the high pH runs becomes the major variable at low
pH. The strange effect of increased leaching with larger particle
size is difficult to explain. Most probably it involves a lack of
readsorption on the larger particle sizes.
Using 3rd, 4th and 5th order interactions as a pooled error esti-
mate gives the following variables and interactions as significant:
Extremely Significant: ~«0.001 T, P
Highly Significant: ~ <0.001 S, TG, SP
Very Significant: ~ <0.01 T, TGR, TS, RS, GSP, HP, THP
Significant ~ <0.025 RSP, GP
The main effects T, R, Sand P are outlined in Table V-D-4.
TABLE V-D-4. MAIN EFFECTS: CHROMIUM
% of
Effect Value Mean
- - +0.1304 ppb +72.2
T2 - Tl
- - -0.0517 ppb -28.6
R2 - Rl
52 - 51 -0.0983 ppb -54.4
]J2 - Pl -0.1688 ppb -93.4
The leaching of chromium seems to be enhanced at higher tempera-
tures, slower pumping rate, smaller particle size and lower hydro-
gen ion concentration (higher pH).
Even with the large number of significant interactions, the four
main effects account for 36.6% of the total sum of squares.
The grand mean for total release chromium in this experiment was
0.181 ppb. The detection limit for chromium (for unpyrolized
tubes) is 0.52. This comparison obviously casts some doubt on the
above results. Even so, the main effects are probably real and the
large number of significant interactions probably indicates a fair-
ly complex leaching mechanism.
Copper -
The results for copper seem to vary on a random basis. The grand
mean for the data is 2.41 ppb with an overall standard deviation of
1.75. This yields a Cu value of 95% confidence limits of 2.41 +0.36
61
-------
Manganese
I"\l"\h
1-'1-''''''
The ANOVAR analysis showed a very confused picture. Using 3rd,
4th and 5th order interactions for an error estimate gives an
Serror = 1.42 (almost as large as the overall s value). Two in-
teractions: PG and GHP were the most significant at ~<0.025.
With 63 variables and interactions in the design, one would ex-
pect about 1.6 effects to show an ~ this small on a random basis.
Therefore, the statistical analysis of the Cu data was terminated
at this point.
- As in the barium results, manganese leaching is very strongly af-
fected by changes in pH. The grand mean for the high pH runs is
0.748 ppb while the grand mean for the low pH runs is 127 ppb.
Therefore, the manganese results were split into'two 24 x 31 fac-
torial designs for analysis.
The high pH (low H+) runs: Using 3rd and 4th order interactions
as a pooled error estimate gives the following varib1es and in-
teractions as significant:
Highly Significant: ~<0.001 T, S
Very Significant: ~<0.01 R, TS
The main effects T, Sand R are outlined in Table V-D-5.
TABLE V-D-5.
MAIN EFFECTS:
MANGANESE AT HIGH pH
Effect
Value
% of
Mean
+48.6
12 - 11
$2 - $1
R2 - R1
+0.438 ppb
-0.513 ppb
-68.6
-34.0
-0.254 ppb
T, Sand R account for 68.3% of the total sum of squares.
At high pH, manganese leaching is enhanced by high temperatures,
small particle size and slow pumping rate.
The low pH (high H+) ,runs: Using 3rd and 4th order interactions
as a pooled error estimate gives the following variables and in-
teractions as significant:
Extremely Significant: ~«O.OOl
Highly Significant: ~ <0.001
Very Significant: ~ <0.01
The main effects Hand S are given
H
S
GR, TR
in Tab1e,V-D-6.
62
-------
TABLE V-D-b.
MAIN EFFECTS:
MANGANESE AT LOW pH
Effect
Va 1 ue
% of
Mean
H3 - Hl
$2 - $1
+38.5 ppb
-12.5 ppb
+30.4
-9.87
The main effects Hand S account for 75.5% of the total sum of
squares.
At low pH, manganese leaching is enhanced by long leaching times
and small particle size.
c.
Overall Results--
The general picture which emerges here is:
(1) Most of the variables seem to be significant to some extent.
(2) pH has a striking effect on barium and manganese.
(3) The overall mechanism seems to be very complex with considerable
variation from metal to metal.
. -
This experiment was probably too complex to design to give much definite
information. It did, however, serve as an excellent springboard to the later
experiments in this study.
63
-------
TABLE V-D-7
RESULTS OF REDUCED FACTORIAL
Raw Data at 24 hr. Sample Time Metal Concentrations in ppb
Cd Co Pb Mo Ni Se V Zn
T 1 Rl P 1 0.00 0.7 0.9 0.3 5.0 3.5 0.0 1.9
T 2 Rl P 1 0.01 1.4 1.9 3.2 7.9 2.4 2.5 4.2
T 1 R2 P 1 0.18 0.5 1.2 0.6 1.6 2.7 0.0 0.7
T 2 R2 P 1 0.12 0.6 0.4 2.6 7.9 3.1 0.0 1.9
T 1 Rl P 2 0.02 1.0 0.1 . 10.0 5.5 1.2 2.5 5.0
T 2 Rl P 2 0.07 0.7 0.5 11.3 3.4 1.2 0.0 2.6
T 1 R2 P 2 0.16 0.3 0.0 10.7 21,1 1.2 0.0 0.0
T 2 R2 P 2 0.57 5.4 0.2 10.0 2.9 1.0 0.0 0.2
Detection 0.08 1.0 0.47 6.6 4.1 2.4 0.18
Limit
64
-------
TABLE V-D-8
FIRSf FACTORIAL ANALYSIS
TOTAL RE LE ASE ARSEN IC
Week & Bottle Factor Code 6 Hr Z4 Hr 48 Hr
W41-B4 T 1G1R1S1P 1 l,ZO 0,56 0,88
WU-B1 TZGIR1S1P1 Z,80 Z.44 Z. 35
WZ1-B4 T1GZR1S1P1 1.50 0.87 l,U
W31-B1R* T ZGll SIP 1 Z.30 0,91 1.45
WZZ-B1 T1G1RZS1Pl 1,00 0,55 0,57
W3Z-B4 TZG1RZS1Pl Z,OO 1,10 1, 15
W4Z-Bl TIGZRZS1P1 0.80 0,74 0.37
W1Z-B4 TzGlzS1P1 1,30 1,06 1.31
W41-B1 T 1G1R1Sli 1,10 1,85 0.64
WU-B4 TZG1R1Sll 1.50 Z.17 1.38
WZ1-Bl T1GZR1Sll 1,00 1,05 0,50
W3CB4R* TZGZR1Sll 1.50 1,37 1.24
WZZ-B4 T 1G1RZSll 0.80 0,64 0,67
W3Z-B1 TZG1RZSll 1.10 0.75 0.69
W4Z-B4 T 1GZRZSll 0,40 1.0Z 0.67
W1Z-B1 T zGlzSll Z.OO Z.50 1.OZ
W41-Bz T1Gl1S1PZ 1.50 1.87 1. 76
WU-B3 TZG1\SlPZ Z.30 Z.51 4.13
WZ1-BZ T1GZR1S1PZ Z.60 Z.13 3.33
W31-B3R* TzGl1S1PZ Z.90 3.04 4.49
WZZ-B3 T 1G1RZS1P Z Z.ZO 3.U Z.Z6
W3Z-BZ TZG1RZS1PZ 3.60 3.38 4.04
W4Z-B3 T1GlzSIPZ Z.OO Z.ZO 3.Z0
W1Z-BZ TzGlzS1PZ Z.OO Z ,80 Z,33
W41-B3 T 1G1R1Slz 1.10 1,55 Z.53
WU-BZ TZGIR1Slz Z.10 3.60 6.08
WZ1-B3 T 1Gz\Slz 1,80 Z.19 Z. 89
W31-BZR* TzGl1Slz Z.30 3.01 4.06
WZZ-BZ T1G'lRZSlz 1,70 Z. 38 3.40
W 3Z - B 3 TZG1RZSlz Z,90 3.34 4.10
W4Z-BZ T 1 GzRzSlz 1,80 1,89 Z,88
W1Z-B3 TZGZRZSlz Z,OO Z.50 4,5Z
*Va1ues from replicate run were used.
65
-------
TABLE V-D-9
FIRST FACTORIAL fu~ALYSIS
TOTAL RELEASE BAR IUM
Week & Bottle Factor Code 6 Hr 24 Hr 48 Hr
W41-B4 T1G1R1S1P1 45 Z7 29
W11-B1 T2G1R1S1P1 90 60 67
W21-B4 T 1Gl1S1P 1 65 48 36
W31-B1R* T2Gl1S1P1 30 32 33
WZZ-B1 T1G1RZS1P1 15 16 17
W3Z-B4 TZG1RZS1P1 Z5 Z6 Z8
W4Z-B1 T 1GlzS1P 1 15 6 11
W1Z-B4 T ZGlZSIP 1 """ 40 Z7 Z8
.p,
W41-B1 T 1G1R1Sl1 .c:: Z5 11 12
00
.~ 8
W 11-B 4 TZG1R1Sl1 ::I: 45 17
WZ1-B1 T 1Gl1Sl1 70 24 25
W31-B4R* T2Gl1Sl1 26 10 11
W22-B4 T 1G1RZSl1 30 17 7
W 3Z - B 1 T 2G1 R2Sl1 25 Zl 12
1~42- B 4 T 1GlzSl1 5 10 6
W12-B1 T 2G2R2Sl1 10 11 11
W41-B2 T1G1R1S1PZ 1470 11Z5 1035
W11-B3 TZG1R1S1P2 2150 1810 1660
W21-B2 T 1G2R1S1P Z 1570 1290 1100
W31-B3R* T 2GZR1 St 2 1650 1560 1675
W2Z-B3 T 1G1R2S1P 2 1170 1150 895
W32-BZ T2G1R2S1PZ 1710 13Z5 1440
W42-B3 T1G2R2S1PZ 1300 1155 860
W12-B2 TzGl2S1P2 P. 1770 1660 1350
W41-B3 T.1G1R1Slz ~ 1520 1365 1520
o
...:I
W11-BZ T2G1R1Sl2 Z260 2495 Z490
W21-B3 T 1G2R1S/ 2 2070 Z145 1815
W31-BZR* TZG2R1Sl2 1700 1695 1775
W22-B2 T1G1R2Slz 1390 1290 1350
W32-B3 T 2G1 RzSlz 2Z40 Z060 1970
W42-BZ T 1 G2R2Slz 1350 1420 1435
W1Z-B3 T zGzRzSlz 1570 1430 1605
*Va1ues from replicate run were used,
66
-------
TABLE V-O-lO
FIRST FACTORIAL k~ALYSIS
TOTAL RELEASE CHROmlR-1
Week & Bottle Factor Code 6 Hr 24 Hr 48 Hr
W4CB4 TIGIRlSlPl 0.40. 0.42 '0.54
Wll-Bl T2GIRlSlPl 0.50 0.32 0.84
W21-B4 T 1GZRl SIP 1 O.ZO O.Zl 0.Z2
W31-BIR* TzGllSIPl 0.50 0.52 0.95
WZ2-Bl T IGIRZSIP 1 0.20 O.Zl O.Zl
W3Z-B4 T ZGl R2S1P 1 0.40 0.2Z 0.83
W4Z-Bl T 1GZRZSIP 1 0.00 0.20 0.01
W12-B4 T ZG2RZSIP 1 0.30 0,31 0.33
W41-Bl T IGIRlSll 0.20 O.Zl O.ZZ
Wll-B4 TZG1R1Sll 0.00 0.00 0.00
WZ1-B1 T 1Gl1Sll O.ZO . 0.01 0.01
W31-B4R* TzGllSll O.ZO O.Zl O.ZZ
WZz-B4 T1G1RZSll O.ZO O.Zl O.ZZ
W 3Z - B 1 TZG1RZSll 0.20 O.Zl 0.2Z
W42-B4 T 1GZRZSll 0.00 O.ZO 0.01
W1Z-Bl TZGZRZSll O.ZO O.Zl 0.5Z
W41-B2 T1G1R1S1PZ 0.00 O.ZO 0.01
WU-B3 TZG1R1S1PZ 0.00 0.00 0.00
WZI-B2 T 1Gl1S1P Z 0.00 0.00 O.ZO
W31-B3R* TZGZR1S1P Z 0.00 0.70 0.Z3
WZZ-B3 T1G1RZS1PZ 0,00 0.00 0.00
W3Z-BZ TZG1RZS1PZ O.ZO 0.01 0,01
W4Z-B3 T1GZRZS1PZ 0.00 0.00 0.00
W12-BZ TZGZRZS1PZ O.ZO O,Zl O,ZZ
W41-B3 T1GIR1SZPZ 0,00 0.40 O,ZZ
Wn-Bz TZG1R1SZPZ O.ZO 0.01 0,01
WZI-B3 T1GZR1SZPZ 0,00 0.00 0.00
W3l-BZR* TZGZR1SZPZ O.ZO O.Zl O.ZZ
W2Z-B2 T1G1RZSzPZ 0.00 0.00 0.00
W32-B3 TZG1RZSzPZ O.ZO O,Zl O.OZ
W42-BZ T1GZRZSZPZ 0.00 0.00 0.00
W1Z-B3 T ZGZRZSZP Z O.ZO 0.31 O.OZ
*Va1ues from replicate run used.
67
-------
TABLE V-D-ll
FIRST FACTORIAL ~~ALYSIS
TOTAL RELEASE COPPER
Week & Bottle Factor Code 6 Hr . 24 Hr 48 Hr
W41-B4 T1G1R1S1P1 2.7 3.0 2.1
Wll-B1R* T 2G1R1St 1 1.1 3.8 2,2
W21-B4 T 1G2R1 SIP 1 1.3 1,4 0.7
W31-B1R* TZGZR1S1P 1 2.8 2,1 2.4
W22-B1 T 1G1R2S1P 1 7.7 2,7 2.3
W 32 - B 4 T2G1R2S1P1 1.9 2,5 2,1
W42-B1 T 1Gl2S1P 1 3,2 1,7 2.1
W12-B4 T 2G2R2Sll 2.2 1.4 1.2
\'/41-B1 T1G1R1Sll 3.2 1.3 1.7
WU-B4R* T2G1R1Sll 1.8 1.7 2.5
W21-B1 T 1G2R1Sll 4.2 2.5 1.6
W31-B4R* T2Gl1Sll 1.3 1.7 1.4
W22-B4 T 1G1R2Sll 1.3 1.1 1.1
W32-B1 T 2G1R2Sll 3,5 3.5 1.7
W42-B4 T 1Gl2Sll 1.5 1,6 1.2
W12-B1 T 2Gl2Sll 1.7 1.4 4:2
W41-B2 T1G1R1S1P2 2.1 2.5 3.2
WU-B3R* T2G1R1S1PZ 2,0 3.2 6,7
W21-B2 T 1G2R1Sl2 3,5 2,8 1.4
W31-B3R* T2G2R1S1PZ 1,8 2.1 3,2
W22-B3 T1G1R2S1P2 1.3 1,6 1.6
W 32 - B 2 T2G1R2S1PZ 1,9 1.6 2,1
W42-B3 T 1GlzS1P Z 1.8 1,9 1.1
W12-BZ T2GZRZS1PZ 12.9 2.1 2.7
W41'-B3 T 1G1R1Sl2 1.8 2.4 3.5
Wll-BZR* T2G1R1Slz 1.1 2.1 0.9
W21-B3 T 1Gl1Sl2 2.0 1.8 Z.2
W31-BZR* TzGl1Slz 3.2 2.2 2.8
WZZ-BZ T1G1RZSlz 1.6 1.2 1.9
W3Z-B3 TZG1RZSlz 1.3 1.8 2.5
W4Z-BZ T 1GlzSlz Z.5 1,4 1.4
W12-B3 T 2GlzSlz 10.8 3,0 3.5
.Va1ues from replicate runs used.
68
-------
TABLE V-D -lZ
FIRST FACTORIAL ~~ALYSIS
TOTAL RELEASE ~t<\NGANE SE
Week & Bottle Factor Code 6 Hr Z4 Hr 48 Hr
W41-B4 TIGIRlS1Pl 0.8 0.9 1.1
W11-Bl TZGIRlS1P 1 1,4 1.5 Z,4
WZI-B4 T IGZRlSIP 1 0.8 0,7 0.7
W31-BIR* T ZGZRl SIP 1 1.8 1,1 1.3
WZZ-Bl T IGIRZSIP 1 0,9 0,5 0,5
W 3Z- B 4 T ZGIRZSll 0,8 1.0 1.3
W4Z-Bl T IGlzSIP 1 0,4 0,3 0.5
WIZ-B4 TZGZR2S1Pl ~ 1,1 1.1 l.Z
. 'Ii
W41-Bl T IGIR1Sll ..c: 0.5 0,4 0.4
QO
W11-B4 TZGIRlSl1 :E 0.7 0.4 0,6
WZI-Bl T IGZR1Sll 0,7 0,3 0.5
W31-B4R* T ZGZRl Sll 0.5 0,8 0.7
WZZ-B4 T IGIRZSll 0.5 0,3 0,4
W3Z-Bl T ZGIRZSll 0.5 0.5 0.6
W4Z-B4 T IGZRZSll O.Z 0.2 0.2
WIZ-Bl T zGzRzSll 0.5 0.5 0.9
W41-B2 TIGIR1SIPZ 120 144 197
W11-B3 T 2G1RlSlz 113 131 147
W21-B2 T IG2Rl SlP Z 114 134 14Z
W31-B3R* TZG2R1SIP2 105 129 140
WZ2-B3 TIGIRZSIP2 111 124 135
W3Z-B2 TZGIR2S1PZ 117 127 158
W42-B3 TIGlzSIP2 118 139 146
W12-B2 T 2G2RZSIP 2 .,.. 105 139 154
0.
W 41-B3 TIGIR1Sl2 3 114 126 145
o
.....
Wl1-B2 TZGIR1Sl2 91 116 138
W21-B3 T IGZRl Slz 96 121 133
W31-B2R* T 2G2Rl Slz 93 124 134
W22-B2 T IGIRZSlz 99 112 128
W32-B3 T2GIRZSlz 102 122 133
W42-BZ T 1 GZR2Slz 96 135 142
W12-B3 TZGZRZSlz 106 138 144
*Va1ues from replicate run used,
69
-------
an
pH P\NJJ TIME INTERPlCTIBN
~
()
..a
CL.
a..
V
Z
urn
Z
~
U
Z
d:
W
I:ru
a----
I ---------~--K-
/' ----------
--K
I .
/
,
6
2Li 3D
TIME Chr::>
liB
36
Li2
12
19
FIGURE V-D-l:
~RSENIC-F"IRST F"PlCT0RI~L RUN
WESTERN CeJPlL NeJ.~ CD.2S-0.S0 mm:>
JJEIeJNIZEJJ W~TER LEPlCHPlNT
CeJPlL/LEPlCHPlNT RPlTIeJ = 0.2 g./1.0 g.
[?JXYGEN PlNJJ NITRC?JGEN ~TMeJSPHERES
TeJTPlL RELEPISE
f) L0W pH CeNJJITIeJNS
_-+-.HIGH pH CeJNJJITI[?JNS
70
-------
'1
l....
Continuous Flow Releaching Runs
a. Experimental--
The purpose of this study was to determine the quantity of metal ion
which would be mobilized by sequential changes in fresh leachant.
The continuous flow releaching experiments were done in the set-up which
was employed in the first factorial experiment and the releaching factorial
experiment (see appropriate sections of this report).
Experimental conditions were held as listed in Table V-D-13.
TABLE V-D-13.
EXPERIMENTAL CONDITIONS FOR CONTINUOUS FLOW RELEACHING
Variable Set 1 Set 2
Coal Western Coa 1 NO.1 Same
Particle Size 0.250 - 0.500 mm Same
Leachant Deionized Water Acetate Buffer
Flow Rate 20 ml/min Same
Temperature 40°C Same
Sampling Times 48, 96, 144, 192 hrs. Same
Leachant Replacement 48, 96, 144 hrs. Same
Coal -
Western Coal No.1 was dried, ground and sieved as previously
described. See Section V-b.
Leachant - Two different ypes of leachant were used in this experiment:
1. Deionized Water: See Section V-B-5.
2. Acetate Buffer: See Section V-C-2
The different leachants were used to determine the difference
in behavior of the eoal at two levels of pH.
Procedure -
Duplicate samples were prepared, containing 200 grams of Western
Coal No.1 (0.250 - 0.500 mm size) and 1000 ml of the two types
of leachant. This allowed replicate runs to be performed with
each leachant system, thus giving better analytical control for
statistical purposes. Samples were withdrawn, leachant replaced
and the stabilized leachates were analyzed bS f~ameless atomic
absorpti on spectrophotometry. I, 2, 1 U, 11, 1 , 6
71
-------
Samples were taken at 48, 96, 144 and 192
experiment). At each sampling, 800 ml of
and replaced with an equivalent volume of
appropriate type.
hrs (termination of the
leachate was removed
fresh leachant of the
A portion of the fresh leachate was used for pH determination.
Other portions of the leachate were filtered, with suction,
through a 0.45 micron membrane filter and acidified with ultra-
pure nitric acid to stabilize them for storage and analysis.
b. Results and Oiscussion-- .
Total release values versus time are plotted in Figs. V-0-2 through V-
0-21. For each metal, the deionized water leaching graph is followed by the
graph for the acetate buffer leaching.
The nickel samples were lost to analysis because of nickel contamina-
tion. Lead and vanadium values were zero or near zero throughout and not
plotted.
The main features of these results are: (1) metal continues to be re-
moved from the coal with repeated leachings (except perhaps for selenium in
the acetate buffer), (2) greater amounts of metal are leached by the low pH
(acetate buffer) leachant (except for copper, selenium and zinc), (3) excel-
lent agreement between the paired runs is obtained (except for chromium and
manganese in deionized water and copper and selenium in the acetate buffer).
Even the worst cases are not too far off considering the inherent errors of
this type of system, (4) the results agree with the results obtained in the
shaker releaching work (see Table V-0-14).
While the agreement between shaker and continuous flow experiments is
by no means exact, the general consistency certainly implies that shaker
work would make a fair predictor for continuous flow work.
For further implications of these results, see the discussion section
of the shaker releach work.
72
-------
TABLE V-D-14. COMPARISON OF THE SHAKER RELEACHING STUDY WITH THE CONTINUOUS
FLOW RELEACHING STUDY 192 HOUR VALUES (TOTAL RELEASE IN ppb).
Deionized Water Aceta te Buffer
Continuous Continuous
Metal Shaker Flow (Ave.) Shaker Flo'tJ (Ave.)
As 3.5 3.0 11.3 25.1
Ba 124 54.4 4002 5748
Cd 1.6 1.9 5.2 4.3
Cr 2.0 0.7 1.1 2.5
Co 0.9 0.8 4.8 4.9
Cu 3.4 8.1 5.6 4.8
Pb 0 0.15 0 0
Mn 3.4 2.5 324 527
Mo 3.6 2.8 19 32.7
Se 5.6 6.6 5.6 1.2
V 0 0 0 0
Zn 6.25 4.65
73
-------
C@NTINU~US PL~W RELE~CHING
LI1
::r
('\
..Dm
a.:
a..
V
Z
-
U
Z
E1
Uru
~g
~
~-'t
t'i. 'i.
tq2
'i.8
,~
q6- t~ 0
TIME C"h.r.,s.:>
16'S .
FIGURE V-D-2:
F\RSENIC
WESTERN C~F\L N~. J.. CO.2S"-.0.S"0 MM:>
J]EI~NIZEJ] WF\ TER LEF\CHF\NT
C~PtL/LEF\CHPtNT RF\TI~ = 0.2 G"./J...O G"
F\IR F\ TM~S-PHERE
T~TF\L RELEPtSE
e:J = REPLICPt TE Ne. J..
- X = REPLICPt TE Ne. 2
74
-------
~l
CBNTINUBUS FL~W RELE~CHING
!:II
::r
"ca
...",
g,;
Q.
V
1-
u
Z
EJCI
UN
~
--
2..
12
'1& 12JJ
TXM£ Chr::>
I'fSf
168
1'f2
..8
FIGURE V-D-3:
ARSENIC
WESTERN CBAL Nm. 1 CD.2S-D.SC '"'":)
ACETATE e.UF"F"EA LEACHANT
CeJAL/LEACHANT RATJ:!! :: D.2g./1.Cg.
AXR ATME1SPH£RE:
TC3TAL RE:LE:ASE
le1 :: REPLXCA T £: NB. 1
Ii " :: RE:PL:ICAT£ He. 2
75
-------
~J
C:.0'N'T'I.N'U'0'U'S' F L'[~'W' R.E.L.E.Pl.C:.H.I.N'G'
c
ctJ
~c
AUJ
Go:
a..
V
Z
...
U
Z
~C
U:r-
r-
II
(I
fI'
rt
-----K
~----
----~
~--~
c
ru
2Li
LiB.
Iq2
12
Q6' 12D
TIM E C'h rSJ
ILiLi
16B
FIGURE V-D-4:
e:aPlRIUM
WESTERN C13P1L N[3. 1 C'0.2S'-.0.S'0 MM:>
JJEI[3NIZEJJ WPlTE:.R LE:.PI.CHPINT
C0f\L/LEPlCHPI.NT Rf\ T'I[3 :. 0.2 G'./1.0 G'
PlIR f\ T'M[3SP HERE:.
T'[3TPt.L RELEPlS'E
E3 :. REPLIC.PlT'E:. N[3. 1
---H-. :. REPLIC.PlTE N[3. 2
76
-------
C
C
C
C
CBNTINUBUS FLBW RELE~CHING
C
C
C
CD
C
f\C
..DC
~LO
~
V
Z
U
Zc
fgC
U~
C
C
C
ru
2Li
12
qlj 12D
TIME Chrs:>
169
Iq2
ILiLi
LiB
FIGURE V-D -5:
f!:aPlRIUM
WESTERN Ct?JPlL N0. 1 CD.2S-D.SD rnrn::>
. PlCETPlTE esUFFER LEPlCHPlNT
C~PlL/LEPlCHP\NT RPlTIt?J = 0.29./1.09'
AIR P.TMt?JSPHERE
T~TPlL RELEPISE
E9 = REPLICPlTE Nt?J. 1
-]I = REPLICPlTE Nt?J. 2
77
-------
C"0NT"INU0US FL0W RELE~CHIN
1'\1
LI1
.
-
~/
~"
,Z"...
/;'
/"
---g/
------
f\
.a
Q..
11.
V
z-
[j
z
E)
U
LI1
2Y
YB
12
q6 12D
TIME: Chr.s::>
IYY
16B
Iq2
FIGURE V-D-6:
I:PI:DMIUM
WEST"ERN CePlL N~. 1. C"0.2S"-0.SO MM::>
:DEI0NIZE:D WPITER LEPlCHPlNT
CePlL/LEPlCHPlNT" RPlTI[?J :. 0.2 G./J..O G"
PlIR PlTM[?JS"PHERE
T"eT"PlL RELEPlS"E
e9 :" REFLICPlTE: Ne. J.
--if-- :. REFLICPlT"E N[?J. 2
78
-------
in
CBNT"INU0US FLBW RELEP\CHING
:r
---~
----
......
..Dm
a.:
CL
V
Z
-
U
Z
E
UN
2'f
q6 12D
TIME Chrs::>
Iq2
l'f'f
168
'f8
12
FIGURE V-D-7:
CPlJJMIUM
WESTERN C~PlL N~. J. CO.2S-0.S0 mm::>
PlCETPlTE E!JUF"F"ER LEPlCHPlNT
C~PlL/LEPlCHPlNT RPlTI~ = 0.29./J..09.
PlIR PlTM~SFHERE
T~TPlL RELEPISE
E9 = REFLICPtTE N~. J.
]I . = REFLICPtTE N~. 2
79
-------
~J
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TIME Chrs:>
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CHRelMIUM
WESTE;RN CeI~L Nel. ]. CO.2S-0.S0 MM:>
JJEIelNIZEJJ Wf\TER LE:~CHf\NT
CI3f\L/LE:f\CH~NT' Rf\TIeI = 0.2 G'./1.0 G'
f\IR f\ TMI3S'PHE:RE:
T'I3T'f\L RE:LE:f\S'E:
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TIME Chrs::>
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168
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FIGURE V-D-9:
CHR~MIUM
WESTERN C~P\L N~. ~ CD.2S-D.SD mm::>
ACETATE E!:IUF"F"ER LEACHANT
CeJPlL/LEACHP\NT R~TIEJ = D.29./~.D9.
AIR ~TM~SPHERE
TEJT~L RELEASE
E9 = REPLIC~TE NEJ. ~
--H-- = REPLICPlTE N~. 2
81
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JI~'U'S" F"L.f?JW' R.E.L,EPk C.H.IN'G"
0W RELEP\CHING
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TIME Chr~:>
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TERN CEJAL NEJ. ~ ClJ.~S-lJ.SlJ MM:>
3NIZE:D WATER LEf\CHANT .
. L/LEf\CHPtNT Rf\TIa = C.~ G./~.lJ G
~TMaSPHERE
,~L RELEf\SE
- = REPLICf\ TE Ne. J.
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I I
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168
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Na. J.
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82
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C~NTINU~U5 FL~W RELEP\CHING
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TIME Chrs:>
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FI GURE V-D-ll:
CeE!1p.LT
WESTERN Cep.L Ne. 1. CO.2S-0.S0 mm:>
PlCETP.TE E!1UF"F"ER LEPlCHPlNT
CePlL/LEp.CHPlNT RPlT:Ie = 0.29./1..09.
PI:IR p.TMeSPHERE:
TaTp.L RELEPISE
e:I = REPL:ICPlTE Ne.J.
--+-. = REPL:ICPlTE Ne. :2
83
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CI
C,[~'N'T"I.NU'0'U'S" F"L.B'W" R.EL.E.Pt.C.HI.N'G"
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FIGURE V-D-12:
C~PPER.
WESTERN caAL N~. 1 CC.2S...C.SC MM:>
~EIaNIZE~ WATER LEACHANT
C~AL/LEACHANT RATIa ~ C.2 8./1.C G
AIR ATM~SPHERE
T~TAL RELEASE
£9 ~ REPLICATE N~. 1
- X ~ REPLICATE Na. 2
84
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TIME Chrs:>
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~~PPER
WESTERN r:~PlL N~. ~ CD.2S-D.SlJ mrn:>
PlCETPlTE &UF"F"ER LEPlCHPlNT
CElPlL/LEPlCHPlNT RPlT:IEI = lJ.29./~.lJ9.
PlIR PlTM~SPHERE
T~TPlL RELEPISE
e:I = REPLICPlTE N~. :1.
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FIGURE V-D-13:
85
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FIGURE V-D-14:
MP.NGP.NESE
WESTERN C~P.L N~. J. CC.2S-C.SC MM:>
JJEI~NIZEJJ WP.TER LEP.CHP.NT
1:t3~L/LE"~CH~NT R~TIt3 :. C.2 G./J..C G
PkIR ~TMt3S'F'He:Re:
Tt3T"P.L RE:Le:~S-E:
~ : Re:F'LII:~Te: Nt3. J.
--!!-. :. RE:PLICPk T"e: Nt3. 2
86
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CI
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TIME Chr;s::>
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12
FIGURE V-D-15:
MPiNGPINESE
WESTERN CePiL Ne. J. CC.:2S:-C.S:C mm::>
PlCETPITE I!JUF"F"ER LEPICHPINT
CePiL/LEPICHPINT RPiTIe = C.:29./J..C9.
PI:IR PlTMeJSPHERE
TeJTPlL RELEPISE
~ = REPLICPlTE Ne. J.
][ = REPLICATE NeJ. :2
87
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~J
CI~J-N T-I.N-U'[2J U 5 F-L0 W R.E.L.E-P8 C.H.I.N'G-
7
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TJ:ME Chr::>
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FIGURE V-D-16:
M~LYE!:lJJENUM
WESTERN CI2IPlL NI2I. J. CO.25:-0.5:0 MM:>
JJEJ:I2INJ:ZEJJ WPITER LEPlCHPlNT
CI2IPlL/LEPlCHPlNT RPlT-J:13 : 0.2 G./J..C G
PlJ:R PlTMI2ISPHERE.
T'I!T'PlL RE.LE.PlS'E.
a :. RE.PLJ:CPl T-E NI!. 1
--if-- :. RE.PLJ:CPl T'E. NI!. 2
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TJ:ME Chrs:>
FIGURE V-D-17:
M~LY~:DENUM
WESTERN CePaL Ne. :L CD.:2S-D.SD mm:>
PaCETPaTE ~UF"F"ER LEPaCHPaNT
C~PaL/LEPaCHPaNT RPaTJ:e = D.:2g./:L.Dg.
PaIR .PaTMeSPHERE
T~TPaL RELEPaSE
E9 = REPLJ:CPaTE N13. :L
]I = REPLJ:CPaTE N~. :2
89
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FIGURE V-D-18:
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ILiLi
16B
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SELENIUM
WESTERN c:a~L Na. ~ CC.2S-C.SC MM:>
JJEIaNIZEJJ W~TER LE~I:H~NT
c:a~L/LE~C:H~NT R~TIa : C.2 G./~.C G
~IR ~TMetS'F'HERE
T.etT'~L Re:LE:~S'e:
e:I : Re:PLJ:I:~T'E: N£?J. ~
- K :. Re:PLJ:I:~ T.e: Net. 2
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C[2lN'T'I.N'ur~'U'5' F'L~'W' R.E.L.EPI.C:.H.IN'G'
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TIME Chr:s:>
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FIGURE V-D-19:
SELENIUM
WESTERN C:~P.L N~. 1 CO.2S-.0.S0 MM:>
PlCETPlTE ~UFFER LEP.CHP.NT
C~PlL/LEP.C:HF\NT' RF\T':r.~ :. C.2 G./1.0 G'
P\J:R P. T'M~SPHERE
T~TF\L RELEF\SE
~ ~ REPL:r.CF\ T'E N~. 1
-~ K . =- REPLJ:CF\ TE Net. 2
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C£2INTINU£2IUS FL0W RELE~CH.ING'
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TIME Chr»:>
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168
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FIGURE V-D-20:
ZINC
WESTE;RN C[3PkL N[3. 1 CC.2S-.C.SC MM:>
~EIBNIZE~ WATER LEPkCHANT
CePkL/LEP\CHP\NT RA TI[3 :, C.2 13./1.0 G
AIR ATM[3SPHERE
T13TPtL RELEASE
E9 : REPLICF\TE N[3. 1
--H-- : REPLICPk TE N[3. 2
92
-------
d
C:.~'N'T'I.N'U'0'U'5' F'L.B'W' R.E.L.E.P-.L.H.I.N'G'
ctI
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TIME Chr~::>
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168
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FIGURE V-D-21:
ZINC
WESTERN C~PlL N~. ~ CC.2S-0.S0 MM::>
PlCETPlTE f!3UFFER LEPlCHPlNT
C~PlL/LEPlCHPlNT RPlTI~ = C.2 G./1.0 G
PlIR Pl T'Mt3SPHERE
T.t3TPlL RE:LEPlSE
~ ~ REPLICPlT'E: N~. 1
- 11 = R.E:PLICPl TE Nt3. 2
93
-------
3.
Reieaching Shaker Runs
a. Experimental--
The purpose of the releaching shaker runs was to determine how much ad-
ditional metal could be removed from the coal by the use of additional passes
of deionized water leachant.
Two 100 ml TeflonGD bottles were charged with 100 gram portions of 0.250-
0.500 mm sized Western Coal No.1. Deionized water (500 ml) was added to one
bottle, and 500 ml of acetate buffer was added to the other coal sample.
The two bottles were placed in a heated shaker bath, which was maintain-
ed at 40°C for the duration of the run. Shaking rate was 45 cycles per min-
ute, with a travel of 28 mm by the shaker sample tray. Samples were collect-
ed at 48, 96, 144, 192 and 288 hours respectively.
At the time of sampling, 400 ml of each leachant was removed and the
same volume of the appropriate fresh leachant was added to the bottles. This
volume represented an 80 percent replacement of leachant volume at each sam-
pling time.
The pH of the leachates were determined at the time of sampling, and
then filtered through a 0.45 micron membrane filter. The filtered samples
were acidified with ultrapure nitric acid to stabilize them for storage, and
the metals were determined by flameless atomic absorption spectrophotome-
try.l,2, 11, 15,16 All metals except mercury were determined. .
b. Results and Discussion--
Total release values versus time are plotted in Figs, V-D-22 through
V-D-39. For each metal, the deionized water leaching graph is followed by
the graph for the acetate buffer leaching.
The nickel samples were lost to analysis because of nickel contamination.
The zinc values appeared to be very badly contaminated and are not reported.
Lead and vanadium values were zero throughout and not plotted.
The salient features of these results are:
removed from the coal with repeated releachings
(2) greater amounts of metal are leached by the
ant (except for chromium and selenium).
These results, as well as the results of the EDTA study, the releaching
factorial, the spiked runs and the continuous flow releaching, appear to show
that leaching is an equilibrium controlled phenomenon with the metals being
bound to the coal and yet still mobile with respect to an aqueous phase.
(1) metal continues to be
(except perhaps for selenium),
low pH (acetate buffer) leach-
The generally strong agreement of these data with the data on releaching
in the continuous flow system is extremely important. Shaker studies have
long been used for coal leaching work, but there seemed to be some doubt that
such quick and easy experiments would give results analogous to a continuous
flow system. It would seem that this work would place shaker studies on a
firmer foundation.
94
-------
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R.EL.E.f1.C.H.I.N'G' S'H.f1.K.E.R. S'T'U':D y'
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TIME Chrs:>
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FIGURE V-D-22:
P.RSENIC
WESTERN CaPtL N[?J. J. CD.2S-D.SD MM:>
JlE:IaNIZ.EJI WPtTE:R LEP.CHPtNT
CaPtL/LE:PtCH~NT' RPt TIa :. D.2 G./J..D G
PtIR ~TM[3S'PHE:RE
T'[3T'~L Re:Le:~S'e:
95
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TIME: Chrs::>
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2'tD
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FIGURE V-D-23:
PaRSENIC
WESTERN C:~PaL N~. ~ CD.2S-D.SD MM::>
PaC:ETPiTE ~UFFER LEPaCHPaNT
C~PaL/LEPlC:HPlNT RPlTI~ ; 0.2 G./~.O G
PaIR Pl TM~5PH£:RE:
T~TPlL RELE:PlS'E:
96
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c
in
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TIME: Chr%:>
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FI GURE V-D-24:
~PlRIUM
WESTERN CePlL Ne. ~ CC.2S-C.S'C MM:>
JlEIaN:I:ZEJI WPITER LEPlCHPlNT
CaPlL/LEPlCHPlNT' RPlTIa :. C.2 G./~.[] G
PlIR PlTMaSPHERE
T.e T'PlL RELEPlS'E
97
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d
d
d
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R.E.LE.PtC.H.I.N'G 5'H.F~.K"E.R. S'T'U]]Y'
C
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C
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V
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TIME <:hrs::>
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FIGURE V-D-25:
~~RIUM
WESTERN C:[3~L N[3. ~ CO.2S"-.0.SO MM:>
~C:~T~TE &UFFER LE~CH~NT
C:~~L/LE~C:H~NT" R~ TI~ :. 0.2 G./~.O G
~J:R ~TM~SPHERE
T"[3T~L R~L~~SE
98
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in
.
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TIME Chrs:>
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FIGURE V-D-26:
CP.JJMIUM'
WESTERN Cap.L Na. 1 CO.2S-0.S0 MM:>
JJE:I[?JN:!ZEJJ WP.TER LE:P.CHP.NT
Cap.L/LEp.CHP.NT RPlTIB = 0.2 G./1.0 G'
P.IR Pl TMBSPHE:RE:
TBT'PlL RELE:PlSE:
99
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TIME Chr.s:>
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2BB
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FIGURE V-D-27:
CPlJJMIUM
WESTERN C.r~PlL N~. 1 CD.2S-D.SO MM:>
PlCETPlTE ~UFFER LE.PlCHPlNT'
CePiL/LEPICHPINT RPI T'I.B :. 0.2 G./1.0 G
PlIR PlT'MeSPHE.RE.
T'eTPlL RELE:PlSE
100
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R"E"L"E"~"C"H"I"N"G" S"H"~"K"E.R. S"T"U':n y.
an
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T:IME: <:hrs::>
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FIGURE V-D-28:
CHR~M:IUM
WESTERN CI3PtL N~. ~ <:C.2S-C.SC MM::>
J)E:I~N:tZEJ) WF\TER LEPtCHPtNT
c:aPtL/LE:PtCHPtNT RF\T"II3 ~ C.2 G./~.C G
PtIR F\ T"MI3S"P HE:RE:
TaTF\L RE:LE:PtSe:
101
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R.E.L.E.Pt C:.H.I.N'G' S'H.Pt.K.E.R.. S'T'U']] y.
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TIME Chrs:>
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FIGURE V-D-29:
r=HR~MIUM
WESTERN C~PlL N~. l. CO.:2S-0.S0 MM:>
PlCETPlTE ~UrrE.R LEPlCHPlNT
C[3P1L/LE:~r=H~NT R~T:r~ :. 0.:2 G./l..D G
~:rR ~TM[?JSPHE:Re:
T'[?JT~L RE:LE:~SE:
102
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R.E.L.E.~.C.H.I.N'G' S'H.~.K,E:R. S'T'U']]Y'
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FIGURE V-D -30:
C13I!2PtLT
~ESTERN C13PtL N13. ]. <0.2S-0.S0 MM:>
JJEJ:13NJ:ZEJl WPtTER LEPtCHPtNT
cePtL/LEPtCHPtNT RPtT:te : 0.2 G./J..O G
Pt:tR Pt T'M13S'PHE:RE
T'13TPtL RE:LE:PtSE:
103
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R.E.L.E.PtC.H.I.N,[5' S'H.Pa.K.E.R. S'T'U']] y.
m
('a
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a.:
Q.
V
Z
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TIME
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FIGURE V-D-31:
C~~PtLT
WESTERN C~PtL. NB. ~ CC.2S-.C.S'C MM:>
P8.CETPtTE'. ~UF"F"ER LEPtCHP8.NT'
C[3PtL/L.E:PlCHPlNT RP\T'IB :. 0.2 G'./1.0 G
PtIR P8.T'M[3S'PHERE
T'[3T'P\L RE:LEP\S'E
104
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R EL.E.P\.C.HI N'G' S'H.P\.K.E.R. 5 T'U'1J y.
:r"
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TIME Chrs::>
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FIGURE V-D-32:
capPER
WESTERN CaPlL Na. 3. CC.2S-C.SC MM::>
~EIaNIZE~ WPITER LEPlCHPlNT
CaPlL/LE:PlCHPlNT' RPlT'Ia ~ C.2 G./J..C G
AIR A TM~SPHERE
TaTPlL RELE:PlS'E:
105
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in
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TIME: <::hrs:>
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FIGURE V-D-33:
capPER
WESTERN Cap.L Na. l. CC.2S-C.SC MM:>
P.CETP.TE ~Uf"f"ER LEP.CHP.NT
r:ap.L/LEf\CHP.NT' Rf\TIa :. C.2 G./l..C G
P.IR f\TMaS'PHERE
TaTf\L RELEf\S'E
106
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TIME <:hr:r:>
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FIGURE V-D-34:
M~NG~NESe:
WESTERN C:[?J~L N[?J. J. <:0.25:-0.5:0 MM:>
JJEI[?JNIZEJJ W~TER Le:~C:H~NT
C:[?J~L/Le:~C:H~NT R~TJ:[?J = 0.2 G./J..D G
~IR ~TM[?JSPHERE
T[?JT~L RELE~SE
107
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FIGURE V-D-35:
MPtNGPtNESE
WESTERN CeiPtL Nel. J. CC.2S-C.SC MM:>
PtCETPtTE ~U~~ER LEACHPtNT
C13F\L/LE:F\CHANT' RF\TJ:13 :. 0.2 G./J..O G
F\J:R F\ T'M13SPHE:RE:
T13T'F\L RE:LE:F\S'E:
108
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FIGURE V-D-36:
MaLY~JJENUM
WESTERN C~P\L Ne. :1. CO.25:-0.5:0 MM:>
JJEIelN:IZEJJ WP\TER LEP.CHP.NT
ceP\L/LEP\CHP.NT RP.TIeI :. 0.2 G./:1..0 G
P.IR p.TMeSPHERE:
T~T'P\L RE:LE:P.SE
109
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FIGURE V-D-37:
MaJLYI!:IJJENUM
WESTERN C13AL Ne!. 1 ca.2S-C.SC m"':>
ACETATE I!IUrF"ER LEACHANT
c:t?JAL/LE:PtCHANT RATJ:a : C.2g./1.Cg.
AJ:R ATMI3SflH£RE
T13TAL RELEASE:
110
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FIGURE V-D-38:
SELENIUM
WESTERN C:~P.L N~. J. CC.2S-C.SC MM::>
J]EI~N:tZEJ] WP.TER LEP.C:HPlNT
C:~PlL/LEPlC:HPlNT RPlTI~ = C.2 G./J..C G
PlIR PI TM~SPHERE
T'[3T'f\L RELEPISE
111
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FIGURE V-D-39:
SEL.ENIUM
WESTERN CEJAL. Nl3. 1 CeJ.2S-C.SC Ift",j
AC£:TATE e.UF"f"ER L.EACHANT
CEIAL./L.EACHANT RAT1:13 : 0.29./1.09.
AZR ATMBSPHERE
TmTAL RELEASE
112
-------
4.
Releaching Factorial Study
a. Experimental--
A five-factor multivariate analysis on metal ion mobility in coal samples
was performed. Levels of the variables and the types of controlled variables
were as listed in Table V-D-15.
TABLE V-D-15. VARIABLES FOR RELEACHING FACTORIAL STUDY
Variable Symbol Levell Level 2 Level 3
Coal C Western #2 Eastern
Water Leachant W Deionized Lake Water
Gas (atmosphere) G N2 02
Time (hours) H 24 hr 48 hr
Number of Leaches L 1st Leach 2nd Leach 3rd Leach
The previous factorial analysis had determined the.general effects of
temperature, rate of circulation of leachant and particle size of the coal
samples. These variables have significant effects, but not of extremely large
magnitude. Therefore, these variables were eliminated from this study. Tem-
perature was maintained at 37°C, while leachant was circulated through the
0.500-1.00 mm coal at a constant flow rate of 40 ml/min. Self-buffering ac-
tions of the coals were allowed to control the pH of the systems. This was
done to approximate the behavior to be expected under industrial handling
and storage.
b. Discussion of Variables--
Coal - The coal samples that were used were of two types: (1) A sample
of western coal (hereafter referred to as Western Coal No.2) was
obtained from the main coal pile at the ORBA transshipment facil-
ity by digging down to a depth of approximately two meters (five
to six feet) and removing a representative sample of material.
It was assumed that this sample was unchanged by the local Duluth-
Superior environment. (2) A sample of eastern coal (hereafter
referred to as Eastern Coal) was obtained through Detroit-Edison
Company.
The rationale for the use of these two types of coal was two-fold.
First, would be to determine if there were large differences in
the behavior of the two coals. Secondly, the use of the Eastern
Coal would partially demonstrate the feasibility and applicabili4Y
of the current system to other types of coal.
113
-------
Water -
Gas -
Time -
Leaches -
Procedure -
Particie size of coal used in the releaching
in the 0.500-1.00 mm size range.
.c_.....~,...",~-.,
'Q~I.UI 'Q I
study \'Jas
Two types of water were chosen for this experiment. Deionized
water and unfiltered Lake Superior water which was obtained from
the lake water inlet at the Environmental Research Laboratory
(ERL) at Duluth, Minnesota. Rationale for the choice of these
leachants was to determine the presence (or absence) of materials
in the natural waters which would affect the mobilization of met-
als in the coals.
Two atmospheres were maintained over the recirculating leachant.
One was purified oxygen, the other purified nitrogen.
Previous studies show fairly extensive fluctuations in mobilized
metal ion concentrations during the early portions of a run. It
was felt that the use of an initial sampl ing time of 24 hours
would allow stabilization of the system, and the 48 hour period
marked the changeover between successive charges of fresh leach-
ant.
Each of the leaches were allowed to remain in -contact with the
coal sample for 24 hours. At that point, 100 ml (10% of the
leachate volume) of liquid was withdrawn for analyses and replaced
immediately with an equal volume of fresh leachant. At the end
of 48 hours contact time, 800 ml of leachate was removed and an
equivalent volume of fresh leachant was added, A total of three
changes of leachant were used.
A charge of 200 grams of 0,500-1,00 mm sized coal and 1000 ml of
leachate was placed in the continuous flow system, The leachant
was allowed to circulate for a period of 24 hours, at which time
a 100 ml sample was withdrawn and an equal volume replaced as pr~
viously described. At 48 and 96 hours, 800 ml of leachate were
removed and replaced with fresh charges of leachant. Samples
were taken at 72 and 120 hours using the same procedure as for
the 24 hour samples.
The samples which were removed from the system were split into
two portions. One portion was used to determine the current pH
level of the circulating fluid. The other portion was filtered
with suction through a 0.45 micron membrane filter and the fil-
tered sample was stabilized with nitric acid. A separate portion
of the filtered sample was treated with potassium dichromate to
stabilize it for later mercury analysis. As controls: Blanks
and 'spiked' blanks were also run under the same experimental con-
ditions.
Analyses were performed for all metals involved in the study, in-
cluding mercurYi by flameless atomic absorption spectrophotome-
try. 1, 2, 1 0, 1 , 1 5, 1 6
114
-------
c.
Results and Discussion--
The data from the lake water leached runs is not considered reliable
enough to report. The experimental plan was to use fresh lake water for each
run, thus reducing any effects of laboratory storage. Also, the lake water
was not filtered because particulate matter was considered a natural part of
the medium. Unfortunately, the different samples of lake water showed very
wide variations in metal content which precluded any reasonable analysis of
the data.
The results of the deionized water runs are given in Tables V-D-16 and
V-D-17. The data were analyzed on a PDP 11/70 computer using IIANOVARII (a li-
brary supplied analysis of variance program). Detailed results, by metal,
are as follows:
Arsenic -
Barium -
Cadmi urn -
Chromium -
Coba It -
Western Coal No.2: There were no significant variables.
raw data were below detection limits.
Eastern Coal:
Significant variables were:
L
G
HL
The L
a:<0.005
a:<0.01
a:<0.05
and G dependences are
shown in Fig. V-D-40.
Western Coal No.2: There were no significant variables.
raw data were below detection limits.
Eastern Coal: Significant variables were:
G a:<0.01
L a:<0.10
The Land G dependences are shown in Fig. V-D-4l.
Western Coal No.2: There were no significant variables.
Grand Mean = 0.33 ppb; s = 0.15 ppb
Eastern Coal: There were no significant variables.
Grand Mean = 3.94 ppb; s = 0.64 ppb
Western Coal NO.2: There were no significant variables.
raw data were below detection limits.
Eastern Coal: Significant variables were:
G a:<0.0025
LG a:<0.10
The Land G dependences are shown in Fig. V-D-42.
Western Coal NO.2: There were no significant
raw data were below detection limits.
Eastern Coal: Significant variables were:
variables.
G
a:<0.01
115
The
The
The
The
-------
Copper -
Lead -
Manganese -
Mercury -
Molybdenum -
Nickel -
L 0:<0.05
LG 0:<0. 1 0
The Land G dependences are shown in Fig. V-D-43.
Western Coal No.2:
Significant variables were:
L 0:<0.001
G 0:<0.025
The Land G dependences are shown in Fig. V-D-44.
Eastern Coal: Significant variables were:
L
G
LG
HG
H
The L
0:<0.001
0:<0.001
0:<0.001
0:<0.005
0:<0.01
and G dependences are shown in Fig. V-D-45.
Western Coal No.2: G was significant with 0:<0.10 but all but
one raw data point out of twelve were below single point detec-
tion limits so no plot was made. .
Eastern Coal: The statistics were confused and only two out of
twelve raw data points were above detection limits so no plot
was made.
Western Coal No.2: The only significant variable was G at
0:<0.10. The mean, total releases from N2 and 02 are:
0.74 ppb for N2
2.40 ppb for 02
Eastern Coal: Significant variables were:
G 0:<0.001
L 0:<0.10
The Land G dependences are shown in Fig. V-D-46.
Only the N2 run for mercury was analyzed. With the exception
of one sample which seemed to be obviously contaminated, the
Hg concentrations were quite low. No significant trends ap-
peared.
Western Coal NO.2: The variables H, Land G showed high sig-
nificance but the raw data were below single point detection
limits. No plots were made.
Eastern Coal: All Mo concentrations were zero.
Western Coal No.2:
G 0:<0. 1 0
L 0:<0.10
Significant variables were:
116
-------
Selenium -
Vanadium -
Zinc -
The Land G dependences are shown in Fig.
V-D-47.
Significant variables were:
Eastern Coal:
G ~
-------
The Western Coal No.2 also seems
the leachate than Western Coal NO.1.
alkaline water in the aquifer.
to show somewhat higher pH values in
This could, of course, be caused by
The Eastern Coal shows higher concentrations
metals except molybdenum and vanadium. The pH of
coal is much lower than leachate from the western
as expected.
Oxygen saturation increases leaching in the Eastern Coal in all cases
except barium.
in the leachate for all
the leachate from eastern
coals. These effects are
Overall, the following trends emerge:
1. Eastern Coal is acidic and leaches more metals than western coal.
2. There are pronounced differences between different samples of
western coal.
3.
Oxygen enhances leaching in most cases.
118
-------
TABLE V-D-16
Releaching Factorial Western #2 Coal Deionized Water Leaching
--'
~
Levels Total Release Concentrations in ppb
H L G pH As Ba Cd Cr Co Cu Pb Mn Hg Mo Ni Se V Zn
1 1 1 7.62 0.50 5.0 0,70 0,10 0,0 2,40 0,0 2.60 0,06 0.00 2,0 0,0 0,0 2.0
2 1 1 7.48 0,05 2.5 0.27 0.21 0,0 1,54 0,0 0.36 0,15 0,60 0.2 0.0 0.0 6.2
1 2 1 7.91 0.05 2.1 0,33 0.17 0,0 3.28 0.0 0,44 3.98* 0.48 1.2 0.0 0.0 10.0
2 2 1 7,62 0.05 2.1 0.34. 0.17 0,0 3,88 0,0 0.35 0,51 1.08 1.3 0.0 0.0 13.5
1 3 1 8.02 0.05 2.1 0.42 0.17 0.1 5,40 0.0 0.35 0,51 0.96 1,1 0,0 0.0 12.9
2 3 1 8.30 0.05 2.1 0.33 0,17 0,2 5.01 0,0 0.35 0,51 0,96 3.1 1.0 0.0 13.0
1 1 2 7.64 0.50 2,0 0.10 0.10 0,0 1. 50 0.0 0.10 -- 0,50 0,0 1.0 3.0 1.0
2 1 2 7.59 0.05 4.2 0.11 0.11 0.0 2.85 0.0 1',91 -- 0,95 2,0 0.1 16.3 1.1
1 2 2 7.80 0.05 3.4 0.29 0,09 0,0 3.91 0.10 5.33 -- 1.27 1.6 0.1 36.1 1.9
2 2 2 7.78 0.55 5.4 0.31 0.19 0,0 5,47 0.41 2.31 -- 1.32 4,6 0.1 28.5 2.0
-
1 3 2 7,77 0.95 7.0 0.37 0,27 0,0 6,27 0.33 2,33 -- 1,22 4.0 0,1 27.9 3.8
2 3 2 7.84 0,50 5.2 0.38 0.18 0,0 6,21 0,33 2.44 -- 1.62 6,0 2.1 30,1 3.0
-------
N
o
TABLE V-D-17
Releaching Factorial Eastern Coal Deionized Water Leaching
Levels Total Release Concentrations in ppb
II L G pH As Ba Cd Cr Co Cu Pb Mn IIg Mo Ni Se V Zn
1 1 1 3.23 0.00 43.0 4.20 1.10 106 9.30 0.20 700 0.38 0.0 210 0.0 0.0 220
2 1 1 3.31 0.00 36.4 3.92 0.51 109 6.44 0.02 732 0.35 0.0 191 0.0 0.0 143
1 2 1 3.60 0.50 34.0 3.72 0.43 110 8.44 0.02 727 0.32 0.0 187 1.0 0.0 169
2 2 1 3.61 0.05 39.4 3.77 0.43 107 9.16 0.02 756 0.29 0.0 206 0.1 0.0 151
-,
1 3 1 3.80 0.55 42.6 4.07 0.43 III 12.9 0.02 788 0.33 0.0 213 1.1 0.0 155
2 3 1 3.90 0.60 46.1 4.01 0.43 115 13.9 0.02 810 0.42 0.0 218 2.2 0.0 155
1 1 2 3.52 1.00 22.0 2.30 1.00 107 14.2 0.10. 830 -- 0.0 180 0.0 0.0 65
2 1 2 3.28 1.10 26.2 3.43 1.10 114 24.0 0.01 1150 ' -- 0.0 238 0.0 0.0 137
1 2 2 3.21 1.90 35.4 4.79 1.00 123 38.6 0.11 1170 -- 0.0 254 2.0 0.0 151
-'
2 2 2 3.18 1.50 31. 9 4.19 1.71 141 47.2 0.22 1180 .- 0.0 281 2.2 0.0 152
1 3 2 3.27 1.40 35.1 4.25 1.55 147 50.9 0.18 1230 -- 0.0 300 1.8 0.0 162
2' 3 2 3.08 1.90 37.6 4.68 1.95 150 63.9 0.18 1300 -- 0.0 323 1.8 0.0 184
-------
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NUM&ER BF LEBCHE5
FIGURE V-D-40: BR5ENIC
ER5TERN CBPiL CD.2S-D.SD
mETIENIZETOJ WRTER LERCHPiNT
CQPiL/LEBCHBNT RPiTIH CD.2 3/l.D
THTftL RELEB5E JftTB
a = 0XYEEN SPiTURPiTIHN KPiLLJES
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121
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~ 1 RELE~CHING FP.CT~RIP.L STU:DY
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FIGURE V-D-41:
2
NUME!:IER ~F" LEPICHES
3
E!:IPlRIUM
EPISTERN C[3P1L CC.2S:-C.SC mm:>
JJEIBNIZEJJ WPITER LEPlCHPlNT' ,
C[3P1L/LEPlCHPlNT RPITIB <:C.2 9/~.D 9:>
TBTPlL RELE~SE JJPlTPI
I!J = BXYGEN SPlTURPlTJ:BN VPlLUES
X = NITRBG£N SPlTURPlT:IBN VPlL~ES
122
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NUM~ER [3F' LE~CHES
3
FIGURE V-D-42:
CHR[3MIUM
e:P.STERN C[3P.L CC.~S'-.C.SC mm:>
J)EI[3NIZEJ) Wp. TER LEP.CHP.NT
C[3P.L/LE:~CH~NT RP\T'I[3 CC.2 g/J..C g:>
TelTP\L RELEP.SE J)P.TP.
(!) = [3XYGEN SP.TURP.TI[3N VP.LUES
X = NITR[3GEN SP.TURP.TI[3N VP.LUES
123
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RELE~CHING FP._CT~RIPlL STU]]Y
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NUMI!£R ~F'- LEP\CHES
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FIGURE V-D-43:
CEJE!aP\L T-
EP\STERN C~P\L CD.2S"-D.S"D mm:>
:DEI~NIZEJJ WP\ T-ER LEP\CHP\NT
C~P\L/LEP\CHP\NT RP\T-I~ C"D.2 9/J...D 9:>
TI3TP\L RELEP\SE :DP\TP\
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124
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m
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FIGURE V-D-44:
CBPPER
WE:STERN C~P.L Ne. :2 CD.2S-D.SD mm:>
JJEIBNIZ£JJ WP.T£R LEP.CHP.NT
CBP.L/L£P.CHP.NT Rp.TIe CD.2 9/~.D 9:>
TBTP.L R£L£P.SE JJP.TP.
I!J = eXYG£N SP.TURP\T:IBN VP.LU£S
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125
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NUMe:.ER [3F" LEPICHES
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FI GURE V-D-45:
CEIPPER
EPiSTERN C[3P1L <:[J.2S-.[J.S.[J mm::>
JJEI13NIZEJJ WPiTER LEPICHPlNT'
C13P1L/LE~CHPINT RPlTI13 <:[J.2 9/1.[J 9:>
T13TPlL RELEPISE JJPI T~
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126
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FIGURE V-D-46:
M~NGP\NESE
E~STERN C~P\L CD.2S-D.SD mm:>
]JEI~NIZE]J W~TER LE~CH~NT
C~~L/LEP\CHP\NT RP\TI~ CD.2 g/~.D g:>
T~TP\L RELEP\SE J]p\ T~ .
[!) = ~XYGEN SP\TURP\TIBN VP\LUES
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127
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STUJJY
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FIGURE V-D-47:
i!
NUMI!:tER aF LEP.CHES
3
NICKEL
J,.IESTERN Cap.L N13. 2 CO.2S-0.S0 mm:>
JJEI13NIZEJJ J,.IP.TER LE~CHP.NT
Cap.L/LEF\CHF\NT RF\T:IeI <:0.2 g/J...O g:>
TaTF\L RELEF\SE JJF\TF\
[!J = aXYGEN SF\TURF\T:IaN VF\LUES
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128
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FIGURE V-D-47:
STU]]Y
3
NICKEL
.,.,ESTERN CaPtL Na. :2 <:D.2S-D.SD mm:>
JJEIaNJ:ZEJJ .,.,PtTER LEPtCHPtNT
CaPtL/LEPtCHPtNT RPtT:Ia <:D.2 g/~.D g:>
TaTPtL RELEPtSE JJPtTPt
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X = NITRaGEN SPtTURPtT:IBN VPtLUES
128
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FI GURE V-D-48:
NICKEL
EPISTERN CBPlL CC.2S-C.SC rnrn:>
JJEIBNIZEJJ ~PlTER LEPaCHPlNT
CBPlL/LEPlCHPlNT RPaTIB CC.2 9/J..C 9:>
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129 .
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3
FIGURE V-D-49:
SELENIUM
EASTERN CaAL CO.2S-0.S0 mm::>
:DEIaNIZEJJ ""'f\TER LEf\CHf\NT
C13AL/LEf\CHf\NT Rf\TI~ CC.2 9/1.0 9:>
T13TAL RELEASE :DATA
(!) = 13XYGEN SATURATIaN VALUES
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130
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FIGURE V-D-50:
I ~
NUMI!IER BF" LE:~C:HES
3
V~NPaJJJ:UM
WESTERN C:BPaL NB. 2 CD.2S-D.SD mmJ
JJEJ:BNJ:ZEJJ WPaTER LE~C:H~NT
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131
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FIGURE V-D-51:
ZINC
WEST.ERN C[3P.L N[3. :2 CIJ.:2S-IJ.SIJ mm:>
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132
-------
5.
Spiked System Uptake Study
a. Experimental-- .
The purpose of this phase of the investigation was to determine the man-
ner in which the total system (coal, system walls, leachant) interacted with
each other in the absorption and/or release of metal ions which had been found
to be present in the coal.
A "standard" coal leachate was prepared by placing 150 grams of Western
Coal NO.2 and 750 ml of deionized water in a 1000 ml pOlypropylene bottle and
shaking the mixture at similar agitation conditions to other shaker operations,
as previously described, for a period of 64 hours. The leachate was then de-
canted from the coal, filtered and refiltered through 0.45 micron membrane
filters. The "standard" leachate was then spiked to higher metal concentra-
tion levels by adding additional material from the standard solution which
was prepared from the stock solutions of metals. Spiking amounts of metals in
the "standard spiking" solution are listed in Table V-D-18.
TABLE V-D-18. STANDARD SPIKING CONCENTRATIONS
Concentration Concentration
Meta 1 (ppb) Me ta 1 (ppb)
Arsenic 2 Manganese 20
Barium 100 Molybdenum 20
Cadmium 2 N i c ke 1 20
Chromium 10 Selenium 2
Cobalt 10 Vanadium 50
Copper 10 Zinc 10
lead 5
Three different solutions were circulated through
leaching apparatus. The solutions were:
1. Deionized Water (3 spiking levels)
2. lake Superior Water (2 spiking levels)
3. Prepared leachate (5 spiking levels)
the continuous flow
In addition, prepared leachate at two spiking levels were circulated in
the apparatus in the presence of additional coal. Coal/leachate ratio was
200 grams of coal to 1000 ml of leachant.
Also, in order to test system interactions, 250 ml leachate alone, and
250 ml leachate with 7.5 grams of small pieces of silicone tubing were shaken
133
-------
in polypropylene bottles in the mechanical shaker bath to determine if possi-
ble interactions with silicone rubber tubing were a significant factor in this
study. Leachant spiking levels appear in Table V-D-19.
TABLE V-D-19.
LEACHANT SPIKING LEVELS
Leachant
Nominal
Spiking
Level
Leachant
Nominal
Spiking
Level
Deionized Water 3 X 0 X
9 X 1 X
Prepared 3 X
Leachate
3 X 9 X
Lake Water
9 X 27 X
Leachate 0 X Leacha te 0 X
Polypropylene Alone 1 X and Coal 1 X
Bottles Leachate
in Shaker and 0 X X. = "Standard" Spiking
Silicone 0 X Concentrations as
Tubing Listed in Table V-D-18
The fluids were circulated through the system for a total of 48 hours.
Samples were withdrawn without replacement of fluid at 6 and 24 hours peri-
ods, and the experiment was sampled and terminated at 48 hours. In the
shaker portion of the study, contact time was also 48 hours.
All samples except those from the deionized water runs were filtered
through 0.45 micron nlembrane filters and then stabilized with nitric acid.
Initial and final pH values were also determined.
b. Results and Discussion--
The results of the spiked system uptake study are presented in Tables
V-D-20 through V-D-32. The prepared leachate 3 X* run is rejected from fur-
ther consideration because (a) it shows a reverse pH effect and (b) the re-
sults are in complete disagreement with the other runs for many of the met-
als.
Consider first the system uptake from spiked, deionized water. Having
no buffer capacity, these runs had a fairly large pH drop, probably due to
atmospheric carbon dioxide. Consequently, comparisons with the other runs
are probably not significant.
134
-------
In order to get a better visualization of the various metal uptakes,
Table V-D-33 has been constructed. Here, an "uptake ratio" equal to the
initial concentration divided by the 48 hour concentration has been listed
for each metal at 3 X and 9 X for the three systems of interest. A large
value of the uptake ratio signifies a large portion of the metal absorbed
by the system and lost to analysis.
In the lake water and prepared leachate systems, the metal losses would
be due either to adsorption on the system walls or loss in final filtration.
The final filtration loss could be due either to an adsorption on the filter
or the coagulation of particles which would be retained by the filter. No
systematic attempt was made to separate these effects in this work.
In the coal plus leachate system, any losses in addition to the above
should be due to direct sequestering by the coal itself.
The first fact to be derived from Table V-D-33 is that a highly signif-
icant amount of metal ion is usually absorbed by the coal, and significant
amounts of metal are lost to the system in most cases. A rough estimate of
losses to the walls and/or final filter at pH = 7.3 would be from zero to
about 60% except for lead and cadmium where these losses are much larger. A
study to separate the wall and filter effects at slightly basic pH values
would seem to have a highly priority in any future work.
It appears that an equilibrium is established between the various parts
of the system and that in a real leaching situation, the absorptive property
of the coal itself is almost always the controlling factor. If one compares
this section of the study with the releaching work, the coal titration stud-
ies and the EDTA experiments, the following picture emerges: Any single pass
of metal free, aqueous leachant through western coal should quickly assume a
pH slightly above 7.0 and will transfer some metals from the coal. The con-
centrations of these metals should be well below current EPA limits. Con-
tinuous leaching using continuously supplied fresh leachant would add much
larger amounts of heavy metals to the environment.
135
-------
......
w
0)
TAB.V-D-20
SPIKED SYST~TAKE STUDY
I\RSENIC
Nominal Spiking Level: X = 2 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tern Concentration Level (ppb) pH 6 hr 24 hr .48 hr pH
Continuous Deionized 15 j 18 18 21 5.87
3 X 7.6.6
Water 9 X 63 7.62 42 48 40 5.69
Flow
Lake 3 X 12 7.64 12 12 13 7.50
Leaching Wa ter 9 X 35 7.613 30 25 35 7.56
o X 0 7.60 0 0 0 7.21
Columns
Prepared 1 X 4.0 7.64 1.5 1.5 3.0 7.34
3 X* 8.5 7.62 9.5 8.5 10.0 7.80
Leachate 3 X 8.5 7.62 6.0 8.0 8.0 7.55
9 X 40 7.57 30 40 30 6.98
27 X 110 7.64 90 90 110 6.92
Leachate 3 X 11.0 7.48 5.5 . 1.5 2.0 6.99
,
Plus Coal 9 X 40 7.58 20 7.5 5.5 6.81
POlypropylene 0 X 1.0 7.41 ---- ---- 0.5 ----
Leachate
Bottles 1 X 3.0 7.49 ---- ---- 3.5 ----
in Shaker Leachate 0 X 1.0 7.41 ---- ---- 0.0 7.20
Plus
Bath S11 i cone 1 X 3.0 7.49 ---- ---- 3.0 7.17
Tubing
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
--'
W
"-I
TAI3~-D-21
SPIKED SYSTE~AKE STUDY
B/\RIUM
Nominal Spiking Level: X = 100 ppb
Measured
Initial
Nominal Concentra-. Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tern Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized 240 (
3'X 7.66 260 280 305 5.87
Water 9 X 790 7.62 850 850 900 5.69
Flow
Lake 3 X 400 7.64 400 450 450 7.50
Leaching Water 9 X ---- 7.68 ---- ---- ---- 7.56
o X 6 7.60 2 2 2 7.21
Columns
Prepared 1 X 100 7.64 70 35 30 7.34
3 X* 240 7.62 35 15 12 7.80
Leachate 3 X 240 7,62 100 110 75 7.55
9 X 870 7.57 620 470 450 6.98
27 X 2570 7.64 690 400 330 6.92
Leachate 3 X 340 7.48 15 16 18 6.99
Plus Coal 9 X ' 1300 7.58 80 65 75 6.81
POlypropylene 0 X 7 7.41 ---- ---- 5 ----
Leachate
Bottles 1 X 140 7.49 ---- -"""-- 95 ----
in Shaker Leachate 0 X 7 7.41 ---- ---- 5 7.20
Plus
Bath Sil icone 1 X 140 7.49 ---- ---- 95 7.17
Tubing
"
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
'-"
ex:>
TAB~-D-22
SPIKED SYSTE~TAKE STUDY
CADMIUM
Nominal Spiking Level: X = 2 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tem Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized I
3 X 5.0 7.6.6 5.3 5.0 6.1 5.87
Water 9 X 15.4 7.62 14.1 12.7 15.4 5.69
Flow
Lake 3 X 3.6 7.64 3.0 . 2.5 2.2 7.50
Leaching Water 9 X 14.0 7.613 11.0 7.0 6.0 7.56.
o X 0 7.60 0.0 0.1 1.5 7.21
Columns
Prepared 1 X 1.3 7.64 0.2 0.2 1.5 7:34
3 X* 4.9 7.62 0.3 0.1 0.0 7.80
Leachate 3 X 4.9 7.62 0.7 0.4 0.4 7.55
9 X 10.8 7.57 .L6 2.0 3.7 6.98
27 X 65 7.64 7.0 0.8 3.3 6.92
Leachate 3 X 3.4 7.48 0 {) 0 6.99
,
Plus Coal 9 X 11.5 7.58 0 0 0.1 6.81
Polypropylene 0 X 0.8 7.41 ---- ---- 0 ---.
Leachate
Bottles 1 X 2.2 7.49 ---- ---... . 0.9 ----
in Shaker Leachate 0 X 0.8 7.41 --.'... ---- 0 7.20
Plus
Bath Sil i cone 1 X 2.2 7.49 ---- ---- . 0.9 7.17
Tubinq
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
......
w
~
TA~-D-23
SPIKED SYST~TAKE STUDY
CHROMIUM
Nominal Spiking Level:' X '" 10 ppb
r~easured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr ,
Leaching Spiking tion Initial Sample
Sys tern Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized I
3 X 24 7.6,6 19 18 17 5.87
Water 9 X 90 7.62 60 55 50 5.69
Flow
Lake 3 X 25 7.64 25 20 20 7.50
Leaching Water 9 X 95 7.6!3 85 45 40 7.56
o X 0.1 7.60 0,0 0.3 . 0.0 7.21
Columns
Prepared 1 X 12.9 7.64 6.7 5.4 6.5 7.34
3 X* 31 7.62 30 23 25 7.80
Leachate 3 X 31 7.62 25 23 21 7.55
9 X 80 7.57 65 55 55 6.98
27 X 290 7.64 270 190 230 6.92
Leachate 3 X 29 7.48 9.1 '2.7 0.9 6.99
,
Plus Coal 9 X 85 7.58 29 2.2 0.9 6.81
Polypropylene 0 X 0.1 7.41 ---- ---. 0.1 ----
Leachate
Bottles 1 X 8.5 7.49 ---- ---- 8.4 ---~
in Shaker Leachate 0 X 0.1 7.41 ---- ---- 0.1 7.20
Plus
Bath S11 i cone 1 X 8.5 7.49 ---- ---- 8.3 7.17
Tubinq
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
--'
..j:>.
a
TA~ V-D-24
SPIKED SYST~PTAKE STUDY
COI3ALT
Nominal Spiking Level: . X = 10 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking ti on Initial Sample
Sys tem Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized 23 ' 23 24 27 5.87
3 X 7.66
Water 9 X 90 7.62 90 90 90 5.69
Flow
Lake 3 X 27 7.64 28 22 27 7.50
Leaching Water 9 X 100 7.68 gO . 75 65 7.56
o X 0 7.60 0 0 0 7.21
Columns
Prepared 1 X 8.8 7.64 3.2 . 1. 7 1.2 7.34
3 X* 30 7.62 5.2 2.5 1.4 7.80
Leachate 3 X 30 7.62 13.7 12.0 10.6 7.55
9 X 90 7.57 65 45 45 6.98
27 X 320 7.64 120 70 30 6.92
Leachate 3 X 27 7.48 0 Q 0 6.99
,
Plus Coal 9 X 105 7.58 1.7 1.1 0.9 6.81
Polypropylene 0 X 0 7.41 ---- ---- 0 ----
Leachate
Bottles 1 X 7.8 7.49 ---- ---- 8.5 ----
in Shaker Leachate 0 X 0 7.41 ---- ---- 0 7.20
Plus
Bath Silicone 1 X 7.8 7.49 ---- ---- . 8.4 7.17
TubinQ
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
+::-
....J
TAI3~-D -25
SPIKED SYST~TAKE STUDY
COPPER
Nominal Spiking Level:
x = 10 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tem Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized I
J X HJ 7.66 23 22 23 5.87
Water 9 X 75 7.62 70 70 70 5.69
Flow
Lake 3 X 30 7.64 18 19 13 7.50
Leaching Water 9 X 85 7.68 50 25 10 7.56
o X 2.5 7.60 0.5 5.5 1.3 7.21
Columns
Prepared 1 X 10 7.64 3.0 6.5 4.2 7.34
3 X* 26 7.62 4.0 8.0 4.0 7.80
Leachate 3 X 26 7.62 11 10 10 7.55
9 X 80 7.57 35 25 20 6.98
27 X 245 7.64 65 20 10 6.92
Leachate 3 X 27 7.48 6.0 -5.0 3.0 6.99
Plus Coal 9 X 95 7.58 5.0 4.0 3.0 6.81
Polypropylene 0 X 1.0 7.41 ---- -...-- 2.0 ----
Leachate
Bottles 1 X 11 7.49 ---- --.... 6.0 ----
in Shaker Leachate 0 X 1.0 7.41 --.- ..--- 4.0 7.20
Plus
Bath Silicone 1 X 11 7.49 ---- ---- 13 7.17
Tubing
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
.....
+::>
N
TAI~ V-D-26
SPIKED SYST~PTAKE STUDY
LEAD
Nominal Spiking Level: X =
5 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tem Concentration Leve 1 (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized 8.0 i 7.0
3X 7.66 7.4 8.1 5.87
Water 9 X 30 7.62 19 19 21 5.69
Flow
Lake 3 X 7.8 7.64 5.0 4.6 2.3 7.50
Leaching Water 9 X 30 7.68 20 2.0 0.9 7.56
OX. 0 7.60 0 .0 0 7.21
Columns
Prepared 1 X 1.6 7.6'1 0.2 0.0 0.1 7.34
3 X* 7.1 7.62 0.6 2.3 0.2 7.80
Leachate 3 X 7.1 7.62 0.7 0.3 0.3 7.55
9 X 30 7.57 8.0 3.0 1.9 6.98
27 X 80 7.64 60 30 25 6.92
Leachate 3 X 8.0 7.48 0.5 0.2 0.2 6.99
,
Plus Coal g X 25 7.58 0.0 0.2 0.1 6.81
Polypropylene 0 X 0.1 7.41 ---- ---- 0.3 ----
Leachate
Bottles 1 X 2.5 7.49 ---- ---- 1.5 ----
in Shaker Leachate 0 X 0.1 7.41 ---- -.-- 0.3 7.20
Plus
Bath S11 i cone 1 X 2.5 7;49 ---- ---- 1.2 7.17
Tubing
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
TAB~-D-27
SPIKED SYSTE~AKE STUDY
NANGANESE
--
Nominal Spiking Level: X =
20 ppb
+::>
w
Neasured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tem Concentration Leve 1 (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized 50 I
3 X 7.6.6 45 47 50 5.87
Water 9 X 150 7.62 135 130 145 5.69
Flow
Lake 3 X 60 7.64 47 60 38 7.50
Leaching Water 9 X 150 7.613 140 107 95 7.56
o X 0.7 7.60 0.1 0.6 0.1 7.21
Columns
Prepared 1 X 18.3 7.64 5.6 3.8 3.4 7.34
3 X* 50 7.62 11.1 4.6 2.4 7.80
Leachate 3 X 50 7.62 27 17.2 18.1 7.55
9 X 150 7.57 105 .85 80 6.913
27 X 470 7.64 230 100 60 6.92
Leachate 3 X 55 7.48 0.4 .0.4 0.3 6.99
,
Plus Coal 9 X 195 7.58 5.5 2.2 2.3 6.81
POlypropylene 0 X 0.8 7.41 ---- ---.. 0.5 ---.
Leachate
Bottles 1 X 18.4 7.49 ---- ---... 15.2 ----
in Shaker Leachate 0 X 0.8 7.41 ---- ---- 0.3 7.20
Plus
Bath Sil i cone 1 X 18.4 7.49 ---- ---- . 16.4 7.17
Tubing
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
--'
oj:::.
oj:::.
TAI3~-D-28
SPIKED SYSTE~TAKE STUDY
~10L YI3DENUM
Nominal Spiking Level: X = 20 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tern Concentration Leve 1 (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized I 5.87
3 X 50 7.6.6 50 55 60
Water 9 X 180 7.62 160 180 150 5.69
Flow
Lake 3 X 105 7.64 105 100 100 7.50
Leaching Wa ter 9 X 200 7.613 250 . 240 210 7.56
o X 0 7.60 0 0 0 7.21
Columns
Prepared 1 X 12 7.64 12 9 11 7.34
-
3 X* 60 7.62 35 45 50 7.80
Leachate 3 X 60 7.62 45 45 50 7.55
9 X 120 7.57 150 120 160 6.913
27 X 530 7.64 540 430 490 6.92
Leacha te 3 X 63 7.48 40 .42 40 6.99
Plus Coal 9 X 160 7.58 130 110 100 6.81
Polypropylene 0 X 0.4 7.41 ---- ---- 0.0 ----
Leachate
Bottles 1 X 11.1 7.49 ---- --..-. 9.2 ----
in Shaker Leachate 0 X 0.4 7.41 ---- ---- 0.0 7.20
Plus
Bath Silicone 1 X 11.1 7.49 ---- ---- 9.2 7.17
TubinQ
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
.j:::>
U1
TABW-D-29
SPIKED SYSTE~TAKE STUDY
NICKEL
Nominal Spiking Level: . X = 20 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tern Concentration Level (ppb) pH 6 hr 24 hr 48 hr pit
..
I
Continuous Deionized 3 X 67 7.6~ 58 53 53 5.87
-
Water 9 X 170 7.62 150 170 150 5.69
Flow.
Lake 3 X 60 7.64 47 60 38 7.50
Leaching Water 9 X 150 7.6!3 140 . 107 95 7.56
o X 1 7.60 1 3 0 7.21
Columns
Prepared 1 X 17 7.64 17 11 15 7.34
..
3 X* 46 7.62 11 11 7 7.80
..
Leachate 3 X 46 7.62 34 38 25 7.55
9 X 210 7:57 HiO 160 110 6.9!3
27 X 600 7.64 450 110 70 6.92
Leachate 3 X 46 7.48 3 '2 4 6.99
Plus Coal 9 X 170 7.58 9 3 4 6.81
Polypropylene 0 X 1 7.41 ---- 1 ----
Leachate
Bottles 1 X 17 7.49 ---- ---- 19 ----
in Shaker Leachate 0 X 1 7.41 ---- 3 7.20
Plus
Bath Silicone 1 X 17 7.49 ---- ---- 17 7.17
TubinQ
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
.s::>
0'1
TA~ V-D-30
SPIKED SYST.PTAKE STUDY
SELENIUM
Nominal Spiking Level: X =
2 ppb
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tern Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
!
Continuous Deionized 3 X 7 7.6.6 6 7 5 5.87
. Water 9 X 20 7.62 20 19 20 5.69
Flow
Lake 3 X 9 7.64 6 9 8 7.50
Leaching Wa ter 9 X 19 7.68 20 21 20 7.56
o X 0 7.60 0 0 0 7.21
Columns
Prepared 1 X 2 7.64 2 0 2 7.34
3 X* 6 7.62 6 5 3 7.80
Leachate 3 X 6 7,62 6 5 3 7.55
9 X 19 7.57 14 16 14 6.98
27 X 60 7.64 60 60 50 6.92
Leachate 3 X 8 7.48 6 :5 0 6.99
,
Plus Coal 9 X 21 7.58 13 4 2 6.81
Polypropylene 0 X 0 7.41 ---- ---- 0 ----
Leachate
Bottles 1 X 3 7.49 ---- ---- 0 ----
in Shaker Leachate 0 X 0 7.41 ---- ---- 0 7.20
Plus
Bath Silicone 1 X 3 7.49 ---- ---- 2 7.17
TubinQ
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
TAI3W-D-31
SPIKED SYSTE~AKE STUDY
VANADIU~1
Nominal Spiking Level:
x = 50 ppb
--'
~
'-I
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching. Spiking tion Initial Sample
Sys tem Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized ( 150 150 190 5.87
3 X 190 7.6.6
Water 9 X 750 7.62 550 700 650 5.69
Flow
Lake 3 X 240 7.64 210 230 250 7.50
Leaching Wa ter 9 X 650 7.613 850 650 700 7.56
o X 3 7.60 0 0 0 7..21
Columns
Prepared 1 X 130 7.64 45 25 '30 7.34
3 X* 200 7.62 160 190 160 7.80
Leachate 3 X 200 7,62 160 180 180 7.55
9 X 750 7.57 5~0 600 600 6.98
27 X 2200 7.64 1900 1650 1800 6.92
Leachate 3 X 240 7.48 70 30 15 6.99
Plus Coal 9 X 850 7.58 150 70 35 6.81
Polypropylene 0 X 0 7.41 ---- ---- 0 ----
Leachate
Bottles 1 X 70 7.49 ---- ---- 85 ---.
in Shaker Leachate 0 X 0 7.41 ---- ---. 0 7.20
Plus
Bath Silicone 1 X 70 7.49 .--- ---- 85 7.17
Tubing
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
TA~V-D-32
SPIKED SYST~TAKE STUDY
ZINC
Nominal Spiking Level: . X = 10 ppb
~
co
Measured
Initial
Nominal Concentra- Sample Concentrations (ppb) 48 hr
Leaching Spiking tion Initial Sample
Sys tem Concentration Level (ppb) pH 6 hr 24 hr 48 hr pH
Continuous Deionized 15 I 5.87
3 X 7.66 15 15 15
Water 9 X 55 7.62 50 55 55 5.69
Flow
Lake 3 X 15 7.64 7.0 7.0 5.0 7.50
Leaching Wa ter 9 X 50 7.613 40 . 20 20 7.56
o X 1.1 7.60 0.3 1.3 . 0.9 7.21
Columns
Prepared 1 X 8.7 7.64 1.3 8.2 1.5 7.34
3 X* 16 7.62 4.0. 4.2 3.2 7.80
Leachate 3 X 16 7.62 7.2 17 12 7.55
9 X 55 7.57 20 20 15 6.98
27 X 160 7.64 45 35 15 6.92
Leachate 3 X 22 7.48 1.4 1.2 0.9 6.99
Plus Coal 9 X 80 7.58 1.3 1.4 3.4 6.81
Polypropylene 0 X 1.4 7.41 ---- ---- 1.4 ----
Leachate
Bottles 1 X 5.5 7.49 ---- ---- 5.5 ----
in Shaker Leacha te 0 X 1.4 7.41 ---- 1.5 7.20
Plus
Bath Silicone 1 X 5.5 7.49 ---- ---- 6.2 7.17
Tubinq
*This run probably contaminated; data is inconsistent and not used in interpretation.
-------
INITIAL CONCENTRATION
TABLE V-D-33. UPTAKE RAT! 0 =
FINAL CONCENTRATION
Lake Water Prepared Leachate Leachate and Coal
Metal 3 X 9 X 3 X 9 X 3 X 9 X
As 0.92 1.0 1.1 1.3 5.5 7.3
Ba 0.89 3.2 1.9 19 17
Cd 1.6 2.3 12 2.9 00 115
Cr 1.3 2.4 1.5 1.5 32 94
Co 1.0 1.5 2.8 2.0 00 117
Cu 2.3 8.5 2.6 4.0 9.0 32
Pb 3.4 30 24 16 40 250
Mn 1.6 1.6 2.8 1.9 183 85
Mo 1.1 0.95 1.2 0.75 1.6 1.6
Ni 1.6 1.6 1.8 1.9 12 43
Se 1.1 0.95 2.0 1.4 00 11
V 0.96 0.93 1.1 1.3 16 24
Zn 3.0 2.5 1.3 3.7 24 24
149
-------
r.
U.
r-n-rn ("'1.-_1......-- ('"L,..,J..
!:.U I J-\ ")/la"t::ro ..) I.Uuy
a. Experimental--
The purpose of this study was to determine the amount of metal which was
capable of being mobilized by a leachant of extremely high seqkestering pow-
er. A leachant with high sequestering ability could be capable of a more
vigorous competition with complexing sites on the coal matrix and thus give
an indication of the amount of metal which could ultimately be removed by
very prolonged leaching with leachants of lower complexing power.
A 0.01 M solution of ethylenediaminetetraacetic acid, di-sodium salt
(EOTA) was prepared using deionized water as a solvent, and the pH of the
resulting EOTA solution was adjusted to an appropriate level by the use of
either ultrapure nitric acid or sodium hydroxide. pH levels of 7.5 and 3.4
were used in this experiment.
These hydrogen ion concentrations were chosen because the self-buffering
action of the western coals resulted in an alkaline solution when deionized
water was used as a leachant, while the eastern coal sample produced a dis-
tinctly acidic system. By pre-setting the pH of the EOTA leachant, it was
felt that any effect would be due to the initial sequestering ability of the
leachant, rather than to self-titratiOn of the coal-disodium EOTA mixture.
One hundred ml of the EOTA solution which had been adjusted to pH 7.5
was added to separate 20.0 gram samples of Western Coal~ No.1 and No; 2.
The coal sample and EOTA solution were placed into a 125 ml polypropyl-
ene bottle. In a similar manner, 100 ml of EOTA solution (adjusted to pH
3.4) was added to 20.0 grams of eastern coal. Coal samples were in the 0.500-
1.00 mm size range. All three types of samples were run in duplicate.
The coal-EOTA mixtures were placed in a constant temperature shaker
bath and were allowed to shake for 48 hours at a temperature of approximately
40°C. The shaking rate was one oscillation of the sample platform per second.
Sample platform travel was 28 mm.
After 48 hours, the pH of an unfiltered portion of each sample was de-
termined and the remaining portion of the sample was filtered through a 0.45
micron membrane filter, using an all-plastic construction suction filtration
apparatus. After filtration, the samples were acidified to stabilize them,
and the metal concentrations were determined by flameless atomic absorption
spectrophotometry.l, 2, 11, 15, 16
One hundred ml portions of the high and low pH adjusted EOTA solutions
were shaken along with the coal-~DTA samples and used as control blanks in
the analyses. All metals except mercury were determined.
b. Results and Discussion--
The initial observation
more acid levels. See Table
from reactions such as:
is that the EDTA-coal systems shifted pH to
V-O-34. This would, of course, be expected
150
-------
.. ..2- . ..2+ "..2- . "..+
H2 Y + M -> T IVI T LM
where y4- is the completely ionized EOTA ion and M2+ is any di-positive metal
ion. Because the initial pH levels were set to the natural, buffered levels
of coal-deionized water systems, these observed shifts demonstrate that a sig-
nificant amount of EOTA complexation in taking place in the system.
The pH shift also makes interpretation of the data more difficult because
of the dependence of metal leaching on pH.
The leachate analyses for the EOTA runs are shown in Table V-O-34.
table also lists analyses for comparable non-EOTA runs.
Examination of Table V-O-34 shows that EOTA extracts significantly more
metal ion from the coal than pure deionized water with the exceptions of:
(a) a strong reversal for cobalt in the Eastern Coal and (b) a possibly re-
versed value for selenium in the Western Coal No.1. Strong evidence that
the effect is not due to pH alone is given by the comparison between EOTA runs
and the acetate buffered run for Western Coal No.1. Here, the comparison run
has a lower final pH than the EOTA runs and yet the metal extraction is still
significantly higher for the EOTA runs than for the comparison run.
This
From an environmental viewpoint, it would appear that there could be
significant amounts of heavy metal mobilization with strong complexing agents.
151
-------
TABLE V-D-34
Leachate Analysis for EDTA Runs and Values for Comparable Non-EDTA Runs
Coal Western #1 Western #2 Eastern
Continuous Continuous
Shaker Shaker EDTA Flow EDTA Flow
Run Run Runs Run Runs Run
With With (Average With .(Average With
Run Water Acetate of 2 Water of 2 Water EDTA
Designation Deionized Buffer Runs) Deionized Runs) Deionized Runs
lniti a 1 pH 7.51 7.51 3.41
Final pH 7.23 7.74 .5.56 7.48 6.11 3.31 2.66
iv1eta 1 s
As 1.7 3.8 5.1 0.0 0.5 0.0 140
Ba 40 582 405 3 425 32 110
Cd 0.6 1.6 2.6 0.15 1.0 3.5 2.8
Cr 0.3 0.3 (3.6) 0.1 1.1 0.4 18
Co 0.2 1.1 19.6 0.0 10.0 98 13.7
Cu 4.2 3.0 135 1.5 70 5.5 200
Pb 0 0 62 0.0 30 0 70
~~n 1.3 80 1250 0.1 950 660 1130
r~o 0.7 5.1 4 0.6 1 0 12
Ni 5* 5* 65 0.5 40 170 285
Se 1 6 (0.8) 0.0 0.2 0 3.0
V 0 0 50 0.0 10 0 10
Zn 35 8 53 6 29 120 225
Values in parenthesis are doubtful because of high blanks
*Approximate values from 1st factorial run.
152
-------
7.
Short Term Shaker Study
a. Experimental--
A short term shaker run was undertaken to determine whether or not a
higher concentration of metals would be found in leachate samples which were
obtained at less than two hours of contact time between 1eachant and coal,
than from those in which samples were obtained after four or more hours of
contact between 1eachant and coal. This experiment was performed in order to
determine if there was an initial "surge" of metal from the coal, with subse-
quent redeposition on the coal and/or the walls of the leaching system.
Six 125 m1 polypropylene bottles, each containing 15.0 grams of 0.500-
1.00 mm sized Western Coal No.2 (obtained from the ORBA transshipment facil-
ity) and 75 m1 of deionized water were placed in a constant temperature shaker
bath. The samples were maintained at a temperature of 40°C and were shaken
gently at a cycle rate of approximately one oscillation per second for the
specified lengths of time.
Samples were removed from analysis at the following times: 15 min, 30
min, 1 hr, 2 hr, 4 hr and 6 hr. After the removal of the sample bottle from
the shaker bath at a designated time, a portion of the unfiltered leachate
was removed for a determination of the pH of the 1eachate~
The remainder of the leachate was filtered with suction through a 0.45
micron member filter supported in an all-plastic filtration apparatus,. and
then acidified to a pH of approximately 2 with ultrapure nitric acid. The
acidified, filtered leachate was preserved for metal analysis by flameless
atomic absorption spectrophotometry. All metals except mercury were deter-
mined.
b. Results and Oiscussion-- .
Of the metals analyzed, only barium, cadmium, cobalt, copper, manganese,
nickel, selenium and zinc gave results at or above detection limits. The data
for these metals are given in Fig. V-O-52 through V-O-59. Initial spikes seem
to appear for all of the above metals. There is no adequate explanation at
present for the phenomenon.
Throughout this work, metal analyses at very short times showed wild
fluctuations with initial spikes. This experiment was done to confirm this
effect. .
. The results of this experiment support the decision to accept 6 or more
hours contact as a first sampling time for most of the work. The basic model
for this research was a static coal pile subjected to slow, flow-through,
leaching. Short term, initial fluctuations should have little effect on the
longer, more equilibrium-like, metal levels.
153
-------
~l
.'
U1
-
(\
A
Q.
Q.
V
Z5!
-
U
Z
fg
u
en
5 H.0'R T" T"I.M.E. S'H Pt.K.E.R. ST"UJ] Y"
FIGURE V-D-52:
I
C!
:I 't
TIME: Chr:t:>
6
5
E!lP\RIUM
WESTERN c:eP\L NEt 2 CC.SC--1.CC MM:>
~EI~NIZE~ WATER LEACH~NT
C13AL/LEP.CHANT RP\ TIEl :: C.2 8./1.0, 13
~IR ~TMeSPHERE
TElT~L RELEASE
154
-------
-
m
".
.aLII
a. .
a.
V
Z
_.
U
Z
eJ
U~
f\I
.
S'H.0RT" T"I.M.E. SH.PtK.E.R. S'T'U.:nV"
i!
3 If
T:IME Chr2:>
5
6
FI GURE V- D- 53:
I:AJJM:IUM
WESTERN C~AL Nel. 2 CD.SC~J..CC MM:>
JJE:If3NIZEJJ WATER LEACHANT
I:I3AL/LEACHANT RAT:Ia :: C.2 13./J..C 13
AIR A TMelSPHERE
TelT~L RELEPtSE
155
-------
~J
aD
.
SH.0'R.T" T I.M.E. S'H.F\.K.E.R S'.T"U']] Y"
i!
! 't
TIME Chra:>
6
'"
..a LD
a. .
a.
V
Z
-
U
Z
e:J
U~
11\1
.
5
FIGURE V-D -54:
CB~ALT .
WESTE;RN caAL Na. 2 CC.SC'"'<1.DD MM:>
~EIaNIZE~ WATER L£ACHANT
c:aAL/LEACHANT RATIa = C.2 G./1.D G
AIR ATMaSPHERE
TaTPtL RELEASE:
156
-------
~J
:r
S'H.~ R T' T"IME.. SH.P\K E.R. S'T"U.J] Y"
i!
:I If
TJ:ME Chrz:>
5
6
~
..am
a.:
II.
V
Z
-
U
Z
EJ
Una
....
FIGURE V-D-55:
c:apPER
WESTERN c:aAL Na. 2 CC.SC-J..CC MM:>
JJEIBNJ:ZE:JJ WATER LEAC:HANT
c:aAL/LEAC:HANT RAT::IEJ :: C.2 G./J..O G
AJ:R ATMaSPHERE
TaTPaL RELEASE
157
-------
~J
SH0'R.T'-. T-'IME. SHPlKE.R. ST--UJJY-'
m
.
f\
..a UI
a. .
a.
V
Z
-
U
Z
EJ
U:r:
ru
.
i!
5
6
I
3 "
TIME: Chl"'~:>
MANGANESE
WESTE;RN C:~AL N~. 2 CD.SD-1.CD MM:>
~e:J:BNIZE~ WATER LEACHANT
c:aAL/LEAC:HANT' RATJ:~ = C.2 G./1.D G
AIR ATMBSPHERE:
Tt3TPtL RELEASE
FIGURE V-D-56:
158
-------
~J
III
.
'H'[~"RT T"I.M.E. S'H.PtKE.R. ST"U']]Y"
FIGURE V-D-57:
~
~UI
a. .
a.
V
Z
-
U
Z
EJ
U~
"'
.
i!
:I 'I
T:I:ME: Chr~:>
6
5
N:I:CKEL
WESTERN l:eJAL NeJ. 2 <:C.SC"'l..DC MM:>
~E:I:eJN:I:ZE~ WATER LEAI:HANT
CBAL/LEACHANT RAT:I:eJ = C.2 G./l..C G
A:I:R ATMeJSPHERE:
TBTAL RELEASE:
159
-------
~J
:r
"
~'"
a.:
a.
V
Z
-
U
z
e
Uru
-
SH.r~J-R.T" To'I.M.E. S'H.~.KE.R. S'T'U.:nY"
:I 'I
T:tME Chr-3:>
.SELEN1:UM
WESTE;RN I:I3AL NEI. 2 CD.SD~~.DD MM:>
JJE:J:I3N:J:ZEJJ WATER LEAI:HANT
I:ElAL/LEAI:HPtNT RAT:IEI :: C.2 G./~.D G
AIR ATMeJSPHER£
TEJTAL RELEASE
c
5
6
FIGURE V-D-58:
160
-------
CI
SH.r~RT" TIM.E.. S'H.~K.ER. STUJJY
m
"
.alii
a.;
a..
V
Z
-
U
Z
19
U:r
"'
I
i!
&
3 't
T~ME Chrs::>
s
FIGURE V-D-59:
ZINC:
WESTERN c:aAL NB. 2 CC.SC-1.CC MM::>
JJE~BN~ZEJJ WATER LEAC:HANT
C:BAL/LEAC:HANT RAT:IB := C.2 G./J..C G
A~R ATMBSPHERE
TBTAL RELEASE
161
-------
VI.
ERROR STATISTICS OF ANALYTICAL DATA
Aside from the pooled higher order interactions which were used in the
analysis of variance work~ some independent statistical measures of precision
were needed. These statistics were calculated from three sources:
1. Duplicate atomic absorption runs were made on some of the analate
solutions. These measurements, especially ones made at low metal
ion concentrations, furnish excellent data for an estimation of
detection limits.
A few analate solutions were run repeatedly in the atomic absorp-
tion spectrophotometer as a measure of relative instrumental error.
Certain entire runs were duplicated. These data were analyzed
for an estimate of run to run variance~
2.
3.
1. The Duplicate Atomic Absorption Runs:
The calculated statistics for the low level duplicates are tabulated in
Table VI-l where:
s =
d. f. =
y =
sly =
the pooled standard deviation in ppb
the degrees of freedom
average ppb of metal to give 0.001 absorbance unit on the A.A.
(y is listed for both unpyrolized and pyrolized furnace tubes)
the calculated ratio of s to y
The blanks in the table are explained as follows: (a)
by standard addition so that no direct y was available, (b)
lyzed in unpyrolized cells and (c) no V was found in any of
this series.
Cd was always run
Se was not ana-
the samples in
The average of the sly values from Table VI-l is 1.57 which gives an
average s of 1.57 y. Then cr = 1.57 y. Assuming an ~ probability of 0,05
gives 95% confidence limits of 1 .96cr = 3.08 y so that an ~ = 0.05 detection
limit would be about 3 x (concentration to give 0.001 A unit).
This overall estimate compares favorably with the 4 x (concentration to
give 0.001 A unit) which has been used as a detection limit estimate (Ref. l~
1973, unrevised). .
These detection limit estimates are used as a basis for rejection of the
data for certain metals in certain experiments where the level is too low to
warrant further analysis.
162
-------
"" Ih,... ,...L.........J.........J ....I,....>~_.....~.........,... ........ """""> 1....... 1__...- .J....~....,.......";,........ 1 ~_.:~, -.....-,..............---.L-
L. IIIC ;:)l.QIIUQJU UCVIQI.IUII;:) Ql. vcry IUVV \IICQI UCI.Cl.l.lUl1 '"IIIl.J IIICQ;:)UICIlICIIl.;:)
are not equal to the error expected at larger metal ion concentrations.
This type of error was briefly checked for three metals at medium con-
centrations. The results are shown in Table VI-3 and show relative measure-
ment-to-measurement standard deviations in the 3% to 18% range with an aver-
age of 11%. This agrees with the rule of thumb that atomic absorption mea-
surements are precise to within about 10%.
There are, of course, extensive variations in precision depending on
metal, metal concentration, age of furnace tube, dilution technique, etc.
However, such an investigation is not needed here. In general, the effects
observed are either well above 10% or are based on a sufficient number of
observations to reduce the error to tolerable limits.
3. Run-to-run variances were estimated from the continuous flow, releaching
study.
These relative standard deviations between runs at each particular time
were calculated using:
5 relative = ~ = (I X2 - Xl 1\ . 2 = 12 I X2 - Xl
x\;/2 ) X2 + Xl X2 + Xl
The s relative values for each metal and condition were then averaged
over the four sampiing times using:
srelative,
The results are
k: i\ 1/2
average = \~ (Si))
tabulated in Table VI-4.
Evaluating those runs which are at or near detection limits yields a
pooled srelative overall metals and conditions of 18.9%.
The statistical calculations are for the most part, a posteriori to the
experiments and do not represent the best estimators that could be designed.
Nevertheless, it is felt that valuei of srelative ~ 10% for A.A. analyses
and srelative e 20% for overall run to run results are reasonable estimates
of experimental precision when the data is well above detection limits.
163
-------
TABLE VI-1
Statistics for Low Level Duplicate Runs
Y
d.f. Weighted
Metal s (for s) Unpyro1ized Pyro 1 i zed Average sly
As 0.319 23 0.173 0.20 0.186 1.72
Sa 1.45 7 4.45 2.21 3.45 0.42
Cd 0.0267 7
Cr 0.0866 18 0.172 0.072 0.122 0.71
Co 0.463 7 0.34 0.108 0.166 2.79
Cu 0.253 24 0.152 0.096 0,124 2.04
Pb 0.248 15 0.155 0.045 0.073 3.40
Mn 0.0809 13 0.078 0.072 0.075 1.08
Mo 0.346 6 2.19 0.553 0.961 0.36
Ni 0.805 9 1. 36 0.252 0.569 1.41
Se 0.339 7 0.31 0.31 1.09
Zn 0.127 8. 0.06 0.053 0,056 2.27
V 7.85 3.02 4.23
164
-------
TABLE VI-2
Calculated 95% (0:=0.05) Detection Limits for Analysis at Low Concentrations
95% Detection Limits (ppb)
M:ta 1 Unpyrolized Pyro 1 i zed
As 0.52 0.60
Ba 13 6.6
Cr 0.52 0.22
Co 1.0 0.32
Cu 0.46 0.29
Pb 0.47 0.14
Mn 0.23 0.22
Mo 6.6 1.7
Ni 4.1 0.76
$e 0.93
V 24 9.1
Zn 0.18 0.16
Overall estimate for Cd = 0.080 ppb
165
-------
TABLE VI-3
Relative Analytical Errors at Moderate Concentrations
Relative
Number of Error
M=ta 1 Measurements - six %
x s
9 3.71 0.33 9.0
Pb
8
Ba
8
8
178
135
27.3
24.3
15.4
18.0
Mn
8
8
9.60
18.0
0.293
0.667
3.0
3.7
166
-------
TABLE VI-4
Run to Run Relative Standard Deviations For
Continuous Flow Re1eaching Studies
Mean sre1ative in %
Mi 11 i pore Acetate
Water Buffer
Runs Runs
Metal (%) (%)
As 5.10 1.53
Ba 6.63 4.88
Cd 16.5 11.5
Cr 32.0* 14.6
Co 0.0* 5.63
Cu 7.03 42.4
Mn 29.3 7.29
Mo 15.4 2.81
Se 27.9 49.7*
Zn 34.8 15.4
Pb, Ni and V were below detection limits, Hg was not analyzed.
*Raw data for these values are at or very near detection limit.
167
-------
VI!.
CHEMISTRY REFERENCES
1.
2.
Analytical Methods for Atomic Absorption Spectrophotometry.
Technical Manual 303-0152, March 1973, Revised March 1977.
Analytical Methods for Atomic Absorption Spectrophotometry Using the HGA
Graphite Furnace. Perkin-Elmer Technical Manual 990-9972, 1974.
Perkin-Elmer
3.
Babu, S. P. 1975. Trace Elements in Fuel. Advances in Chemistry Series
141, American Chemical Society, Washington, D.C.
4.
Bilenchi, T. H., H. R. Yates and R. J. Sinnott. 1975.
Decker Coal at Detroit Edison's St. Clair Power Plant.
the American Power Conference, Vol. 37.
Experience with
Proceedings of
5.
Capes, McIlhinney, Russell and Serianic. 1974. Rejection of Trace Met-
als from Coal During Beneficiation by Agglomeration. Env. Sci. and
Technology ~, 35-38.
Chadwick, R. A., R. A. Woodruff, R. W. Stone and C.'~~. Bennett. 1975.
Lateral and Vertical Variations in Sulfur and Trace Elements in Coal--
Colstrip Field, Montana. Proceedings of the Fort Union Coal Field Sym-
posium, Vol. 3, Montana Academy of Sciences, Eastern Montana College,
Billings, Montana, April 25-26. '.
6.
7.
Davies, O. L. 1963. The Design and Analysis of Industrial Experiments.
Hafner Publishing Company, New York.
B.
Environmental Impact Report, Coal Transshipment Facility, Superior,
Wisconsin. 1974. Prepared by Roy F. Weston, Inc., Wilmette, Illinois,
July.
9.
Glass, G. E. and J. E. Poldoski. 1974. Interstitial Water Components
and Exchange Across the Water Sediment Interface of Western Lake Superior.
XIX Congress, International Association of Limnology (SIL) Winnipeg,
Canada, April 22-29.
Manning, D. C. 1970. Non-Flame Methods for Mercury Determination by
Atomic Absorption--A Review. Atomic Absorption Newsletter ~, 97.
.10.
11.
Manual of Methods for Chemical Analysis of Water and Wastes. 1974.
Methods Development and Quality Assurance Laboratory, U.S. Environmental
Protection Agency, Publication EPA-625-6-74-003.
168
-------
12. Paus, P. E. 1972. Bomb Decomposition of Biological Materials. Atomic
Absorption Newsletter 11_, 129.
13. Poldoski, J. E. and G. E. Glass. 1974. Methodological Considerations
in Western Lake Superior Water-Sediment Exchange Studies of Some Trace
Elements. Presented at the 7th Materials Symposium, National Bureau of
Standards, Gaithersburg, Maryland, October 7-11.
14. Report to the International Joint Commission by the Upper Lakes Refer-
ence Group. 1976. The Waters of Lake Huron and Lake Superior. Vol. 1,
Windsor, Ontario.
15. Smeyers-Verbeke, Michotte, Van den Winkel and Massart. 1976. Matrix
Effects in the Determination of Copper and Manganese in Biological Ma-
terials Using Carbon Furnace Atomic Absorption. Anal. Chem. 48, 125.
16. Sturgeon, R. E. and C. L. Chakrabarti. 1977. Evaluation of Pyrolytic-
Graphite-Coated Tubes for Graphite Furnace Atomic Absorption Spectro-
photometry. Anal. Chem. 49, 90.
169
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