v-xEPA
                                  United States
                                  Environmental Protection
                                  Agency
                                  Industrial Environmental Resean
                                  Laboratory
                                  Cincinnati OH 45268
                                  Research and Development
                                  EPA-600/S7-81-082  June 1981
Project  Summary
                                  Water  Pollution  Potential  of
                                  Coal-Slurry  Pipelines
                                  Howard S. Peavy
                                   Coal is expected to assume an in-
                                  creasingly important role in meeting
                                  America's energy needs during the
                                  remainder of this century and, perhaps.
                                  to become the principal source of
                                  energy during the next. It has been
                                  predicted that coal production will
                                  double during the next decade, with
                                  much of the increase coming from
                                  low-sulfur deposits in the West. The
                                  economics of using coal is dependent
                                  in large measure on the economics of
                                  transporting it, since shipment costs
                                  can amount to as much as two-thirds
                                  of the delivered price. Coal-slurry
                                  pipelines have been proposed as one
                                  economical means of transporting
                                  coal over long distances to specific
                                  markets.
                                   The objective of this research project
                                  was to characterize those contami-
                                  nants associated with transport waters
                                  from coal-slurry pipelines. This was
                                  accomplished through tests using a
                                  rotating bench-scale reactor. Tests
                                  consisted of  coal mixed with tap
                                  water, tap water with additives, syn-
                                  thetic saline water, and synthetic
                                  saline water with additives. Tests
                                  were performed for a period of  12
                                  days each.
                                   The results of this project indicate
                                  that chemical interactions do occur
                                  between water and coal under condi-
                                  tions simulating coal-slurry pipelines.
                                  These interactions include:
                                   (1) A decrease in pH of approximately
                                      two units (from approximately 8
                                      to approximately 6). Dissolution
                                      of metals at a pH of 6 was not
                                      significant.
                                   (2) An increase in mineral content
                                      of fresh water. Alkalinity, total
                                      dissolved solids (as indicated by
                                      electrical conductivity), and sul-
                                      fates each show increases. Use
                                      of phosphorus-based chemical
                                      additives for corrosion control
                                      result in substantial concentra-
                                      tions of phosphate.
                                   (3) Turbidity remains in the water
                                      after separation of the coal by
                                      centrifugation. Although some
                                      color may be present as a result
                                      of humic acids and manganese,
                                      colloidal particles appear to be
                                      the main cause of turbidity.
                                   (4) Dissolved organic carbon levels
                                      that may be significant if reuse
                                      (either prior to or after discharge)
                                      requires chlorination. These or-
                                      ganics are potential percursors
                                      of chlorinated hydrocarbons.
                                   This Project Summary was devel-
                                  oped by EPA's Industrial Environmen-
                                  tal Research Laboratory, Cincinnati,
                                  OH, to announce key findings of the
                                  research project that is fully docu-
                                  mented in a separate report of the
                                  same title (see Project Report ordering
                                  information at back).
                                  Coal-Slurry Operations
                                   The technology for coal-slurry pipe-
                                  lines is well established. As early as
                                  1891 a patent was granted for pumping
                                  pulverized coal in a fluid medium, and
                                  the first slurry line operated from 1914
                                  to 1924 in England, transporting coal
                                  from barges in the Thames River to a

-------
power plant some 600 m away. To date,
two coal-slurry pipelines have  been
constructed in the United States. The
first connected mines near Cadiz, Ohio,
to a power plant near Cleveland. This
line operated from 1958 to 1963 when
more favorable rail freight rates  were
negotiated. The second  pipeline has
been operating between Black Mesa,
Arizona, and Mohave, Nevada, since
1970. This line, 45 cm diameter and 440
km in length, carries approximately 5
million metric tons per year over terrain
considered too rough for a rail line.  As
Figure 1 shows, many other coal-slurry
pipelines are presently being planned.
  A coal-slurry  pipeline operation is
depicted in Figure 2. Coal is ground to
the approximate consistency of table
salt and is mixed approximately 50% by
weight  with water. The  mixture is a
pumpable fluid with  a specific gravity
slightly greater than water. A minimum
velocity of approximately  1.2 m/sec is
required to maintain all particles  in
suspension. Pump stations must be
strategically located to maintain this
velocity and to overcome head loss due
to pipeline friction and elevation changes.

Potential For Pollution
  Basically, coal  is composed of carbo-
naceous material formed from the
compaction and subsequent partial
decay of plant remains. However, many
inherent and  extraneous inorganic
substances are interspersed within the
mass of carbon molecules in bulk coal.
Inherent inorganic matter had its origin
in the vegetative matter which eventually
became coal while extraneous inorganic
matter entered the  coal bed from non-
plant origin, either  during or after the
coalification process.
  The principal  forms  of extraneous
matter found in bulk coal  are alumino-
silicates, sulfur compounds, carbonates
and silica. As Table 1 illustrates, various
metals  are also associated  with the
extraneous inorganic matter.
  Many of the  metals in Table 1 are
recognized as poisons and some are
known to be cumulative poisons. Al-
though  most of these  are  virtually
insoluble in pure, metallic form,  salts
and oxides of many of them are quite
soluble, as  illustrated in Table 2.
  Should these compounds already
exist in the coal seam, or should they be
formed due to  exposure of coal  to
oxygen or chlorides in the slurry water,
the potential exists for serious contami-
nation of transport water.
                                                                Miami
Existing Pipelines	
Planned Pipelines	
Proposed Pipelines	
Pipeline Corridors Studied.
Figure 1.     Existing and proposed coal-slurry pipelines. (Courtesy of Slurry
             Transport Association,  Washington, D.C.)
             Run of Mine
      Coal Stockpile*.
            Cleaned Coarse
             Coal Stockpile
                                                            'Slurry
                                                             Preparation
   Coal
  Mine

  Pump Station
              Dewatering
                      Plant
                      Agitated
                      Storage


                Process/Flush Water
Slurry Storage         Reservoir
                              Reservoir
                      Power Plant
               Agitated
               Storage
                             Slurry Storage    Cooling
                                  '    .        Water
                                Reservoir
                                    Cooling
                             	   Water
                              Blow-Down
 Figure 2.    Coal-slurry system.

-------
 Table 1.     Trace Element Analyses of Rosebud Seam Coal

  Element      Analyses in parts per million (ppm) of whole coal, moisture-free basis
                       Maximum           Average          Minimum
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Fluorine
Germanium
Lead
Manganese
Mercury
Nickel
Selenium
Zinc
2.55
21.30
1.91
1.510
31.20
40.3
173.0
16.35
94.0
404.5
0.61
163.5
6.62
361.0
0.61
6.02
0.44
0.129
5.37
12.5
51.0
2.64
8.8
66.1
0.20
37.3
1.29
49.6
<0.07
0.68
0.11
0.021
<0.40
4.6
4.0
 30C
5> 20C
Very soluble
61.7  0C
!> 0C
i> 20C
PbO
MnClz
HgClz
Ni C/3
Se Oz
ZnCIt
0.0017 d
72.3 4
6.9 d
64.2 
38.4 d
432  20C
 25C
J> 20C
S> 20C
5) 14C
p 25C
 Slurry Water Disposal
  Slurry dewatering at the pipeline
 terminus recovers from 60 to 70% of the
 transport water. It is generally assumed
 that this water will be used in the power
 production operation at the pipeline
 terminus. The most common proposal is
 to use it as a part of the make-up water
 for  cooling towers. Although cooling
 tower water  may have fewer quality
 constraints than does water for many
 other operations at power plants, highly.
 mineralized waters create scaling prob-
 lems. Furthermore, since cooling tower
 blow-down necessitates discharge,
 portions of the slurry will eventually
 become an effluent, even if used for
 cooling water.
  Only recently have studies been
 conducted to document the pollution
 potential of coal slurry pipelines. In an
 effort to determine the nature and
 extent of chemical interaction of water
and coal in coal slurry pipelines, and to
 identify the likely contaminants in the
spent slurry water, a research project
was conducted at Montana State  Uni-
versity from 1977 to 1979.
                      Project Description
                        A laboratory scale reactor was con-
                      structed to maintain a coal-in-water
                      suspension for an appropriate contact
                      time. The apparatus consisted of a 102
                      cm length of 38 cm PVC pipe which
                      could be rotated about its longitudinal
                      axis. The ends were closed by 2.5 cm
                      aluminum plates drawn together by tie
                      rods.  A 0.64 cm sampling port was
                      tapped into the center of one end plate.
                      A 5 cm plug was drilled and threaded
                      into the side of the pipe for loading
                      water. Baffles were installed longitudi-
                      nally to prevent the coal from packing
                      into a lump and slipping along the
                      bottom as the drum rotated.
                       The reactor sat on steel bars mounted
                      in pillow blocks. Torque was provided by
                      an electric motor attached to the drum
                      by a chain and sprocket arrangement.

                      Coal
                       Coal used in the experiment was from
                      the Western Energy mine at Colstrip,
                      Montana. The coal came from  the
                      Rosebud Seam discussed previously
                      and was shipped in run-of-the-mine
 condition to the Mineral Research
 Center in Butte, Montana, for grinding.
 The coal was ground by roller-crusher
 and hammer-mill to the specifications
 shown in Table 3.
  After grinding, the coal was placed in
 55 gallon drums, sealed to prevent
 oxidation, and shipped to the lab in
 Bozeman.

 Water
  Several proposals have been made
 concerning sources for transport water.
 In addition to the use of fresh water from
 surface or relatively shallow aquifers,
 suggestions  have been made to import
 sea water or to tap deep aquifers whose
 waters are too saline for other local
 uses.  Experiments were run using
 water which approximated the quality of
 saline water in  parts of the aquifer
 underneath  the  Northern Plains coal
 fields. Quality of  the water is shown in
 Tables 4 and 5.

 Methodology
  The following  methodology was ad-
 hered to in all the experiments. Approxi-
 mately 62 kg of ground coal were placed
 in the reactor and the end plates bolted
 tight. The reactor was then placed on
 the roller. Sufficient water (63 liters)
 was added for an approximate 50-50
 mixture.  The  reactor was turned at
 approximately 10 revolutions per minute.
 Nitrogen was injected to expel the sam-
 ple and to prevent air entrapment. A
 positive pressure of approximately 10
 psi of nitrogen was  maintained in  the
 system at all times.
  Samples were taken immediately
 after  mixing and after six hours, 12
 hours, one, two, four, eight and 12 days.
 The 12-day period is sufficient to model
 the detention time in the longest of the
 proposed pipelines.

Analysis
  Samples were analyzed  for the  fol-
 lowing parameters:
Physical Parameters
  pH
  Specific conductance
Mineral Parameters
  Alkalinity
  Chloride
  Sulfates
Metal Parameters
  Arsenic
  Chromium
  Copper
  Lead
  Manganese

-------
  Mercury
  Nickel
  Sodium
  Zinc
Organic Parameters
  Dissolved organic carbon
  High Performance Liquid Chroma-
   tography Profile (HPLC)

  The pH values were measured imme-
diately after samples were drawn using
a Corning Model 12 Research pH meter.

Table 3.    Grain Size of Ground Coal

     Sieve No.     % Weight Retained
Electrical conductivity was measured
using a Lab-line Lectro mHO-Meter
(Model MC-1, Mark IV) conductivity
meter. Samples for mineral and metal
parameters were first centrifuged at
about 2000 RPMs (approximately 81 OxG)
for about 20  minutes. The liquid was
decanted and, since it remained highly
colored in dark brown hues, wasfiltered
through  a 0.45// filter. The resulting
sample was clear and contained only
dissolved species. Aliquots for metals
 Sieve No.
% Weight Retained
were separated, placed in glass jars and
acidified with nitric acid.
  Alkalinity and chloride analyses were
performed titrametrically while sulfates
were measured by the turbidimeter
method. Analysis for metals was per-
formed by atomic adsorption spectro-
photometry.  All procedures conformed
to those outlined in Standard Methods
for  the  Examination  of  Water  and
Wastewater 14ed. or Methods for Chem-
ical Analysis of Water and Waste.
  Samples for analysis of dissolved
organic carbon were handled in the
following manner. Approximately 100
ml aliquots were centrifuged at 8K for
16
20
40
50
70
100

0.88
10.24
36.45
15.53
10.57
9.36
740
200
325
400
Pan
5.51
4.30
4.96
0.88
1.32
100.00
approximately 20 minutes using a
Beckmann ultracentrifuge. The water
was decanted and filtered through a
0.25/u silver metal membrane (Selas
Corporation) using a Gelman pressure
filtering apparatus. Triplicate 5 ml
aliquots were transferred to precom-
busted glass ampoules (Oceanography
Table 4. Solubility of Inorganic Chemical Parameters in Fresh Transport Water

Parameter"
pH (Units)
Electrical
Conductivity
M mhos/cm
Alkalinity
Chloride
Sulfate
Arsenic
Chromium
Copper
Lead
Manganese
Mercury"*
Nickel
Sodium
Zinc
Mix
Water
7.8

197

97
4.12
12
0.011
0.0005
0.07
0.006
<0.01
0.74
0.005
3.0
0.02

0
6.6

1190

32
4.6
700
0.014
0.0010
0.02
0.004
0.25
7.60
0.005
55
0.006
Hours
6
6.0

1190

52
4.6
860
0.014
0.0015
0.03
0.036
0.34
0.30
0.005
65
0.04

12
5.9

1220

75
4.9
866
0.014
0.0015
0.03
0.035
0.37
0.28
0.005
66
0.05

1
5.9

1430

102
5.5
866
0.021
0.0010
0.03
0.030
0.38
0.37
0.005
69
0.05

2
5.8

1430

179
4.7
866
0.013
0.0010
0.03
0.020
0.45
0.12
0.005
71
0.03

Days
4
6.0

1680

290
5.0
900
0.018
0.0010
0.03
0.033
0.53
0.22
0.005
68
0.05


8
6.3

1420

471
4.4
900
0.028
0.0010
0.03
0.035
0.63
0.52
0.005
76
0.04


12
6.2

1940

558
4.3
960
0.026
O.OO05
0.03
0.045
0.66
0.30
0.005
79
0.04
 "All values in mg/l except as noted.
 "Parts per billion.
Table 5.    Solubility of Inorganic Chemical Parameters in Saline Transport Water
Parameter*
pH (Units)
Electrical
Conductivity
M mhos/cm
Alkalinity
Chloride
Sulfate
Arsenic
Chromium
Copper
Lead
Manganese
Mercury**
Nickel
Sodium
Zinc
Mix
Water
8.3

52.400

96
15.200
2.080
0.012
0.093
0.48
0.038
0.04
0.78
0.010
9080
0.10
0
6.2

48.200

20
14.400
2,250
0.017
0.60
0.09
0.037
2.46
0.75
0.010
8390
0.25
Hours
6
6.0

48.700

29
13.800
2.175
0.023
0.072
0.07
0.025
3.56
0.66
0.010
7360
0.64
12
5.9

46.300

34
13.800
2.175
0.020
0.072
0.13
0.022
3.88
0.58
0.010
7520
0.02
1
6.2

49.2OO

54
13.400
2.175
0.024
0.045
0.07
0.017
3.88
0.31
0.010
7080
0.70
2
6.2

49.700

110
13.600
2.046
0.024
0.067
0.07
0.016
4.13
0.25
0.010
7450
0.81
Days
4
6.3

47.200

183
14.400
1.900
0.027
0.057
0.07
0.020
4.30
0.34
<0.010
7240
1.20
8
6.3

51.200

317
13.700
1.900
0.027
0.057
0.07
0.015
4.41
0.22
<0.010
7200
1.85
12
6.3

49.100

385
13.600
1.750
0.027
0.067
0.07
0.030
4.36
0.29
<0.010
7300
0.74
 'All values in mg/l except as noted.
 "Parts per billion.

-------
International) containing 0.24 gm po-
tassium persulfate. A Hamilton "Gas-
Tite" syringe was used for the transfer.
Six percent H3P04 (0.25 ml) was added
to each ampoule. Each sample was
purged for 8 minutes with oxygen which
had been passed over a catalyst at
500C and sealed immediately. This
procedure was carried out on an Ocean-
ography International ampoule sealing
unit. Sealed ampoules were autoclaved
at 15 psi for about 15 hours (overnight).
Samples were then analyzed using a
Total Carbon Analyzer (Oceanography
International).

Results and Discussion
  Data obtained  from the  fresh water
experiment are shown in Table 4 and
data from  the saline water run are
displayed in Table 5. A discussion of the
parameter groups follows.

Physical Parameters
  The pH of the coal-slurry system is of
importance for several reasons. Drastic
departure from neutral conditions results
in a caustic or acidic solution which may
be either corrosive or erosive to pipeline
components and to appurtenances at
the terminus. Extreme  values of pH
could be significant constraints on the
reuse and/or discharge of the slurry
water.
  Perhaps the most important effect of
pH in the slurry  system is its effect on
the solubility of the metals and minerals
encountered in  the coal.  Metals and
minerals are more soluble at low pH
values while high pH values result in the
formation of hydroxide species which
precipitate.
  As noted in Tables 4 and 5, pH values
for both fresh and saline water dropped
approximately two units during the
initial stages of  the  run. Most of the
decrease occurred immediately upon
mixing with  only small fluctuations
noted thereafter. More than  likely, the
pH change resulted  from solution of
reduced sulfur compounds in the coal
and subsequent  production of  sulfuric
acid. Although pH values observed here
are not sufficiently low to  solubilize
metals, care should be exercised in
extrapolating pH data to  other coals
which might have a higher sulfur con-
tent, notably eastern coals.
  Electrical conductivity (EC) is an
indirect measurement of total dissolved
solids (TDS). A multiplication factor of
0.65 is used to convert EC to TDS. The
 esults of the EC  test shown  in Table 4
indicate that the TDS is  increased
considerably when fresh water is used
as the transport medium.  Using the
above  multiplier, the TDS  is seen to
increase from approximately 125 to
1250 mg/l, with most of the increase
occurring during  the initial mixing
period. The TDS  continues to increase
steadily, however, indicating that longer
contact times would produce higher
TDS.
  The EC of the saline water is seen to
decrease with time, indicating that
precipitation is occurring or that some of
the dissolved substances are adsorbing
to the  coal surfaces. Over the 12-day
run, the TDS decreases by approximately
2000 mg/l. The inorganic solids thus
removed with the coal would quite likely
cause an increase in fly ash and possibly
other problems in  the furnace. Water
with this TDS would be unsuitable for
reuse and would present a pollution
problem unless discharged to the ocean
or some other salt water body.

Mineral Parameters
  Mineral parameters measured in this
experiment included alkalinity, chlorides
and sulfates. Alkalinity is defined as any
substance which neutralizes acids. In
most cases, alkalinity can be attributed
to hydroxide, carbonate and bicarbonate
ions, although salts of borate, phosphate
and  other material can contribute to
alkalinity. The alkalinity of a coal-slurry
system is important primarily from the
buffering capacity standpoint. If suf-
ficient  alkalinity  is present, significant
pH reductions due to the solution of
sulfur compounds will be avoided.
  The alkalinity of both fresh water and
salt  water runs dropped initially and
then increased. A logical deduction is
that  acetic material, which  resulted in
the initial pH drop noted earlier, also
consumed virtually all of  the initial
alkalinity. After this initial reduction, the
alkalinity increased steadily and con-
sistently throughout both runs, coupled
with slight pH increases. In terms of
buffering capacity, the critical period is
indicated to be the initial mixing time. It
should be pointed out, however, that
this should not be extrapolated to high
sulfur, low alkali coals from eastern
regions.
  In  coal-slurry pipeline systems, the
most important characteristics of chlo-
rides would be their corrosive nature.
Chlorides in concentrations as low as
45 mg/l have been reported to have an
adverse effect on metals  associated
with water-handling systems. Excessive
concentrations would be expected to
have a more pronounced effect.
  As noted in Table 4, chloride concen-
trations were very low in the freshwater
and the change over the 12-day period
was insignificant. In the saline water
(Table  5), chlorides decreased by ap-
proximately 10%, or 1600 mg/l. The
chlorides could have been precipitated
as metal salts, or could have become
adsorbed to the coal particles. Chlorides
of the magnitude used in saline water
would  present corrosion potential in
both the pipeline system and the power
plant using the coal. Discharge to  fresh
water bodies would definitely present a
pollution potential.
  Sulfate is an oxidized form of sulfur.
Sulfates  in coal slurry transport water
could have several origins. Oxidation of
sulfur in  the coal during  mining, trans-
porting and crushing operations would
result in  the dissolution of sulfates in
the slurry water. Oxidation could also
occur after mixing as a result of dissolved
oxygen in the slurry water. Formation of
sulfuric acid (H2S02) and the neutraliza-
tion of the hydrogen ions by the alkalinity
would also result in free sulfate ions.
  When  fresh  water, initially low in
sulfates,  was  used  as  the transport
medium,  sulfates increased immediately
by several hundred mg/l (Table 4) with
only a slight increase thereafter. Saline
water with a  high initial concentration
of sulfates (Table 5) lost approximately
3000  mg/l after 12 days of contact in
the slurry water.  In terms of water
quality, both the fresh and saline water
could present a problem if discharged to
fresh water bodies. On the other hand,
the use  of fresh water results in a
washing  of coal which should produce
less sulfur compounds in the stack
gases. The opposite was true when high
sulfate saline water was used.

Metal Parameters
  An examination of the data in Tables 4
and 5 indicates that most of the metals
did not dissolve to any significant
extent. Arsenic, chromium, copper,
lead, mercury, nickel and zinc were all
present in measurable quantities in the
transport water, and in most cases their
concentrations decreased slightly upon
contact with the coal. The observed
concentrations of these metals were too
low to be of concern from a water quality
standpoint.
  Concentrations of manganese in-
creased slowly but steadily in the  fresh

-------
water run to approximately 0.7 mg/l
after 12 days.  In the salt water run,
manganese was seen to increase rapidly,
then level off at concentrations in
excess of 4.0 mg/l. The reduced form of
manganese (Mn*+) is soluble in water
and can cause color problems at con-
centrations as low as 0.05 mg/l. In the
slurry water, manganese was probably
in the oxidized form or complexed with
other material  in a particulate form,
since filtration of the slurry resulted in a
clear sample. Although it is possible
that manganese precipitate  could ac-
cumulate on pipeline and power plant
appurtenances, it is doubtful that signif-
icant problems will result from concen-
trations  of this level.
  The increase in sodium concentra-
tions in the  fresh water run  is not
significant from a water quality stand-
point. It  is interesting to note, however,
that sodium concentrations in the saline
water decreased by approximately 1800
mg/l. Although this decrease is not
significant from a water quality stand-
point, removal of  the sodium with the
coal would result in greater quantities of
fly ash and possibly some corrosion of
furnace parts. Tests for sodium on
samples of the coal before  and after
contact  with the water confirmed that
the sodium remained with the coal.

Organics
  Dissolved  organic carbon analysis
indicated average concentrations of 24
mg/l in the fresh water run and 13 mg/l
in the salt water run. The solubility of
organic carbon is pH dependent with
saturation levels in the low 20s at pH
values between 6.0 and 7.0.  Thus, the
DOC values for the fresh water run are
probably at saturation. Lesser values for
the saline water may be duetoa "salting
out," or a complexing of  the organics
with some of the inorganic ions and
subsequent precipitation.
  Organic analysis using High Perform-
ance Liquid Chromatography (HPLC)
indicated that the organic carbon was
probably in the form of humic and fulvic
acids. Concentrations of organic acids
of this  magnitude  should have little
direct threat to water quality. A potentially
serious  condition  could develop, how-
ever, if the spent slurry water were to be
chlorinated. Humic and fulvic acids are
percursors  of  haloforms  which are
known carcinogens. Since it is a common
practice to chlorinate cooling tower
water to control biological growths, use
of the spent slurry water for make-up
water to the cooling tower would almost
certainly result in haloforms. Blow-
down of the cooling water could result
in discharge of these carcinogenic com-
pounds.
Summary and Conclusions
  Coal-slurry pipelines have proven to
be a reliable and economical means of
transporting coal over long distances to
specific markets. At the pipeline ter-
minus, large volumes of water must be
separated from the coal. Although reuse
of this water, probably as cooling water,
in the power plant operation is antici-
pated, portions of the transport water
are likely to be discharged  ultimately.
The quality of the spent slurry water is
therefore of importance.
  Experiments at Montana  State Uni-
versity which modeled coal-slurry sys-
tems indicated that some chemical
interaction between coal and transport
water will occur in the pipeline. Fresh
water will experience an increase in
total dissolved solids while the TDS of
saline water will decrease. Analysis of
coal samples prior to and after the
experiment indicated that the material
lost from the water remained on or with
the coal.
  The pH of the slurry tested dropped by
approximately two units almost instan-
taneously and then stabilized. Alkalinity
initially dropped and then  increased
significantly. Apparently acetic com-
pounds  in the coal  dissolved quickly,
neutralizing the alkalinity. Whether the
dissolution of the acetic material ceased,
or alkalinity from the dissolution of
alkali material was more than sufficient
to neutralize the acid is not known. The
pH values remained sufficiently high
(around pH 6.0) that significant dis-
solution of metals did not occur.
  Analysis for organics indicated aver-
age dissolved organic carbon concen-
trations  of 24 mg/l  in fresh water and
13 mg/l in saline water. These values
are close to saturation concentrations at
pH  6 and the DOC  was found to be
primarily humic and fulvic acids.
  Conclusions can be drawn that saline
water is not a satisfactory transport
medium since it increases the mineral
content of the coal which would produce
greater quantities of fly ash and exacer-
bate corrosion of furnace components.
Use  of the saline water in  the power
plant operations would be limited and
discharge to fresh water bodies would
probably be prohibited.
  Solubilization of minerals and organics
in initially fresh transport water will
limit its usefulness in the power plant
and will probably necessitate treatment
prior to re-use and/or discharge. Removal
of the dissolved organics, or use of
algalcides other than chlorine will be
necessary to prevent formation of halo-
form compounds.
                                  6

-------
Howard S. Peavy is with the Department of Civil Engineering and Engineering
  Mechanics, Montana State University, Bozeman, MT 59715.
Jonathan G. Herrman is the EPA Project Officer (see below}.
The complete report, entitled "Water Pollution Potential of Coal-Slurry Pipe-
  lines." (Order No. PB 81-187 221; Cost: $9.50, subject to change) will be
  available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield, VA 22161
        Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
        Industrial Environmental Research Laboratory
        U.S. Environmental Protection Agency
        Cincinnati, OH 45268
                                                                                     4 US OOVEBNMENT PRINTING OFFICE 1M1-757-012/7144

-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300

RETURN POSTAGE GUARANTEED
                                     PS    0000329

-------