enriched CHsI and Me2SO and stirred for 1h a t room temperature ( 1 7 ) .The enriched compounds were examined by NMR. Somewhat less intense bands in the 56-62-ppm region were observed at the same chemical shifts as in the rigorous methylation procedure (Figure 3). The ratio of carbohydrate hydroxyl groups of carboxyl groups was calculated in the following manner: methyl ether band areas in the 57-62-ppm region were compared to methyl ester band areas in the 51-53-ppm region. A ratio of 0.46 was obtained, which is very close to the ratio of 0.47, which was calculated from the data of Gamble and Schnitzer (18) pertaining to aliphatic hydroxyl groups and acid groups in this fulvic acid. These results demonstrate that Contech fulvic acid contain carbohydrate-like hydroxyl groups, in addition to carboxyl and phenolic groups. The relative abundances of these three groups COOH/carbohydrate/phenolic are 2.5/1,1/1.0, in close agreement with literature values (18). The methylation method described in this study enables one to distinguish between various OH groups in complex macromolecules, by selectively enhancing the I3C concentration of the derivatized OH groups, and to calculate their relative concentrations. Preliminary results suggest that the relative concentration measurements are reliable; however, further work is necessary in order to verify the results and to determine those factors which limit the accuracy of the results. There is some overlap of the carbohydrate methyl ether region by the methyl ethers of other alcohols. Acid hydrolysis of humic and fulvic acids yields identified monosaccharides. Comparison of the saccharide ion concentration obtained by hydrolysis with that calculated from the NMR spectrum should allow us to determine whether other hydroxylated species are contributing to the observed NMR spectrum in the carbohydrate methyl ether region.
Literature Cited (1) Steelink, Cornelius. J. Chem. Educ., 1977,54, 599. ( 2 ) Thurman, E. M.; Malcolm, R. L. U S . Geol. Suru., Water-Supply Pap. 1979,1817-G, G-1. (3) Wershaw, R. L.; Pinckney, D. J.; Booker, S. E. U.S. Geol. Surv., J . Res. 1977,5,565. (4) Ludemann, H. D.: Lentz, Harro: Ziechmann, Wolfgang. Erdoel Kohle, Erdgas, Petrochem. Brennst.-Chem. 1973,26,566. ( 5 ) Oka, Hiroshi; Susaki, Mitsuo; Itoh, Mitsuomi; Suzuki, Akira. Nenryo Kyokaishi 1969,48,295. (6) Gonzalez Vila, F. J. Biochem. Biophys. Res. Commun. 1976,72, 1063. ( 7 ) Wilson, M. A.; Goh, K. M. Plant Soil 1977,46,287, (8)Wilson. M. A.: Jones. A. J.: Williamson. Bruce. Nature (London) ‘ 1978,276,487. ’ (9) Hatcher, P. G.; Rowan, R.; Mattingly, M. A. Org. Geochem. 1980, 2.77.
(16j Wershaw, R. L.; Pinckney, D. J. Science 1978,199,906. (11) Burch, R. D.; Langford, C. H.; Gamble, D. S. Can J. Chem. 1978, 56,1196. (12) Scott, K. N., Jr. J. Am. Chem. Soc. 1972,94,8564. (13) Sundholm, E. G. Tetrahedron 1977,33,991. (14) Ludemann, H. D. Biochem. Biophys. Res. Commun. 1973,52, 1162. (15) Wershaw, R. L.; Pinckney, D. J.; Cary, Lewis, presented a t the 20th Annual Rocky Mountain Conference on Analytical Chemistry, Denver, CO, 1978. (16) Blunt, J. W.; Munro, M. H. G.; Paterson, A. J. Aust. J. Chem. 1976,29,1115. (17) Johnstone, R. A. W.; Rose, M. E. Tetrahedron 1979,35,2169. (18) Gamble, D. S.; Schnitzer, Morris. In “Trace Metals and Metal Organic Interactions in Natural Waters”; Singer, P. C., Ed.; Ann Arbor Science: Ann Arbor, MI, 1973; p 265.
Received for review September 22, 1980. Revised Manuscript Received April 20, 1981. Accepted July 6, 1981. This work was supported in part by funds provided by the officeof Water Research and Technology, A-094, US.Department of Interior, Washington, DC, as authorized by the Water Research and Development Act of 1978.
Gas-Chromatographic Technique for the On-Line Evaluation of Solvent Emission Abatement Devices Larry P. Haack,* Rick S. Marano, Tim t. Riley, and Steve P. Levine Ford Motor Company, Engineering and Research Staff, P.O.Box 2053, Rm S-3061,Dearborn, Michigan 48121
Government regulations have been enacted which limit the amount of volatile organic compounds (VOCs) that can be emitted into the air from painting facilities (1-3). A number of hardware abatement devices are being evaluated to achieve compliance with these regulations ( 4 ) . Continuous totalhydrocarbon (THC) analyzers employing flame ionization detection (FID) are most frequently used to measure VOC emissions ( 5 ) .However, when monitoring an abatement device, the THC analyzer cannot provide information about the abatement efficiency for specific solvents. This type of information is especially useful in the evaluation of a carbon adsorber which adsorbs certain solvent vapors with high efficiency while being relatively ineffective with others (6, 7). Furthermore, the THC analyzer is calibrated by using a single-component standard, usually propane in air or nitrogen. As a result, the analyzer cannot be used to determine accurately the mass emission rate of an abatement device unless the composition of the inlet and outlet vapor streams is known. This is because the FID response (i.e., relative to 0013-936X/81/0915-1463$01.25/0
@
1981 American Chemical Society
propane) to each particular compound depends on its molecular structure. Gas-chromatography (GC) compositional results can be used to transform the THC-FID values in terms of equivalent propane to an actual solvent basis through the use of effective carbon number (ECN) response values which represent an apparent number of carbon atoms as seen by the FID (4,8,9). Thus, a more accurate measure of mass emission rate and abatement efficiency can be determined. Therefore, in order to correctly assess the operational performance of an abatement device, instrumentation has been developed based on an on-line gas chromatograph equipped with an automated inlet system. The utility of this instrument is demonstrated with data gathered through its application to a carbon adsorber used for automobile paint spraying emission control. This type of application may be subject to a number of difficulties including the following: (1)a rapidly varying inlet vapor concentration and composition, (2) high inlet vapor concentration (150-1000 ppm THC as propane) and low outlet vapor concentration (as low as 10 ppm or less) Volume 15, Number 12, December 1981
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E Carbon adsorption is one of the methods currently under study for the reduction of volatile organic compounds (VOCs) from industrial painting facilities. In order to understand the operational parameters of a 20 000 ft3/min pilot carbon adsorber, semiautomated sampling and gas-chromatographic techniques were routinely used for simultaneous compositional analysis of both the inlet and outlet airstreams. The inlet air, which varies in composition and concentration with
a 1-min frequency, was sampled by using a heated mixing chamber followed by a heated gas sampling loop injector. The outlet airstream was sampled by using an adsorbent cartridge in order to concentrate the solvent vapors before analysis. By application of the appropriate effective carbon number to the gas-chromatographic data, total-hydrocarbon values were predicted which agreed with measurements obtained by using a total-hydrocarbon analyzer.
that can increase to high values under breakthrough conditions, and (3) the presence of solvents of widely differing volatilities. The GC data are correlated with results obtained in parallel with an FID-based THC analyzer.
for 3 min, ramp to 70 "C at 39.9 "C/min, hold for 2 min, ramp to 225 "C at 7.0 "C/min, final hold for 15 min. Injection ports and FID detectors were maintained at 250 "C. The GC peak identifications were confirmed by using a Hewlett-Packard GC-mass spectrometer (Model 5992B) operated under similar chromatographic conditions.
Experimental Section Process Description. The process selected for the application of this instrument was a 20 000 ft3/min dual fixed-bed carbon adsorber system (Vulcan, Inc.) attached to the main enamel spray booth at a full-scale automobile production facility. The exhaust air from the spray booth was routed through a low-pressure (2 in. H20) water scrubber and a four-stage filter house to remove paint particulates before being treated by the adsorber. Sampling System. A heat-traced stainless-steel sampling system (Beckman, Inc., and Technical Heater, Inc.) equipped with two heated stainless-steel pumps (Metal Bellows Co., Model MB-158HT) was used to sample inlet and outlet vapors from the adsorber system. The sample lines fed gases continuously to a heated, dual FID-based THC analyzer (Beckman, Inc., Model 402X). The THC analyzer was located in an oven maintained at 85 "C which also contained all of the flow and pressure control devices needed to ensure a constant flow to the FID detector and to the gas chromatograph via two heated, stainless-steel bypass lines. All sample lines were maintained a t 85 "C. GC Inlet System (Figure 1). After exiting the sampling system bypass lines, the carbon adsorber inlet sample flowed a t a rate of 100 cmg/min through a 5-L heated glass mixing chamber equipped with an electrically driven stirrer (IO).The mixed (compositionally averaged) vapors were then passed through a heated six-port gas sampling valve (Valco Inc., Model AH 4V) equipped with a 2-cm3sample loop. The loop was purged by the vapor continuously until injection into the gas chromatograph was initiated by the GC data system. After exiting the sampling system bypass line, the carbon adsorber outlet sample passed directly into a concentrating cartridge attached to a second six-port gas sampling valve. The cartridge consisted of a 16-cm Pyrex tube of 4-mm i.d. packed with 12 cm of Tenax-GC adsorbent (60/80 mesh; Supelco, Inc.) followed by 2 cm of activated carbon (40/60 mesh; Burrel Corp., High Activity Grade) ( I I , I 2 ) . Sampling time and flow rate were adjusted to optimize sample size. Vapors trapped on the cartridge were quantitatively heat desorbed by a reverse flow of helium (see Figure 1).A tube furnace (Spex Industries, part no. 1022R) was used to heat the cartridge to 250 "C in -10 s and to maintain that temperature for 10 min. The heat desorber was initiated by the GC data system immediately following the simultaneous injection of the inlet and outlet vapor samples. GC System, The gas chromatograph was a Perkin-Elmer Sigma 3 equipped with dual FID detectors and an additional electrometer (Model 332-5100). The gas chromatograph was interfaced to a Sigma 10 chromatographic data station with extended memory and a tape cartridge system. The GC columns were matched 1.8 m X 6.4 mm 0.d. X 2 mm i.d. glass packed with 0.1% SP-1000 on 80/100 mesh Carbopack C (Supelco Corp.). The oven programming initiated at injection of samples was as follows: initial temperature -20 "C, hold 1464
Environmental Science & Technology
Results and Discussion The rapidly varying inlet vapor concentration is illustrated in the total-hydrocarbon tracing appearing in Figure 2 (trace A). Concentrations are shown to vary over a range of -20-700 ppm during a 2-h period. Rapid fluctuations with a time constant of -1 min are also observed. These correspond to the time required to paint 1 unit at a given spray station. Since each of these 1-min peaks may correspond to as many as 10 different paint colors, the composition of the VOC emissions may vary significantly. In contrast, the solvent vapor concentration at the adsorber outlet is effectively time averaged by the carbon bed (Figure 2, trace B). Since the carbon adsorber solvent breakthrough characteristics are proportional to the average inlet solvent composition, the analysis of the "averaged" inlet vapor is justified in determining VOC emission abatement efficiencies. Samples of average composition were obtained by using a stirred mixing flask. The effectiveness of this device is illustrated by comparing Figures 2A and 3, which indicate the magnitude
I N L E T A N D OUTLET LOAD P O S I T I O N S
HE CARRIER
I N L E T COLUMN
--
SUPPLY OUTLET AIR
-
SIGMA 3 GC O V E N
HEATED VALVE ENCLOSURE
I
f ?\
I
I
OUTLETCOLUMN
-
I
-
EXHAUST
m,
O R B E N T CARTRIDGE
H E A T E R OFF
H E CARRIER
I N L E T COLUMN
SIGMA 3 GC OVEN
HEATED VALVE ENCLOSURE
OUTLET COLUMN OUTLET AIR
\HE
CARRIER
I N L E T A N D O U T L E T I N J E C T POSITIONS
Figure 1. GC inlet system for simultaneous analysis of inlet and outlet vapor streams of a VOC emission abatement device.
of variation in the THC concentration of typical inlet and outlet vapor streams. The 2-cm3 gas sample loop used to inject the adsorber inlet airstream was not adequate for the low hydrocarbon levels encountered in the adsorber outlet airstream. The adsorber outlet vapor analysis was therefore accomplished through the use of a concentration cartridge packed with Tenax and a back section of activated carbon. Recovery studies were performed by using the concentration cartridge packed with Tenax only, and with Tenax backed with activated carbon. In separate experiments the outlet vapor stream (200-cm3sample volume) was passed through two identical cartridges in series. Each cartridge was then heat desorbed onto the gas chromatograph for analysis. The studies showed that breakthrough of the higher-boiling and nonpolar organics was minimal with or without carbon backing (less than 2% breakthrough for most components). However, breakthrough of volatile, polar organics was greatly reduced by use of the carbon backing (Table I). Experiments were also performed by using the concentration cartridge to determine component percent recovery 1
A ADSORER I NLET
600 a
EP n 0
> >
\ I
E
a
after thermal desorption. The percent recovery for nonpolar organics (i.e., toluene and xylene) was essentially 100'70. However, polar organics such as n-butyl acetate, methyl isobutyl ketone (MIBK), and methyl amyl ketone (MAK) showed typical recoveries between 80% and 90% only. For this reason, component calibrations were accomplished by injecting standards directly onto the adsorbent cartridge, and then heat desorbing the organics onto the gas chromatograph to obtain FID-response values. Since percent recovery was found to be independent of component concentration (within the concentration limits encountered in these analyses), this calibration technique alleviated the necessity of generating thermal desorption-percent recovery data. With this analysis method, the combined error was less than 10%for each of the organic solvent vapors determined. Reproducibility was better than f5%. Typical chromatograms of the adsorber inlet and outlet airstreams are illustrated in Figure 4. The utility of the GC system is best demonstrated in its ability to generate component-specific analyses for an abatement device. Figure 5 gives the major components in the effluent vapor stream of the pilot carbon adsorber tested at the production facility during the course of an 8-h adsorb cycle. The solvent breakthrough curves demonstrate that the exit vapor composition is not representative of the inlet vapor stream. This type of solvent component information is essential for understanding the operational parameters of a carbon adsorber. Eight GC compositional analyses of the inlet/outlet vapor streams were converted from ppm actual vapor concentration (AVC) to ppm as propane through ECN conversions and then combined for a comparison with data obtained in parallel using an FID-based THC analyzer. Table I1 indicates the
-
I 2 3 4 5 6
30 min
I
7
w
8 9 IO II
u)
z
0
1 $
a
m w
o z n 300 - 0
I2
a
I3
0
14
-
METHANOL ETHANOL ACETONE ISOPROPANOL M E T H Y L E T H Y L KETONE ETHYL ACETATE n-BUTANOL CELLOSOLVE METHYLISOBUTYL KETONE B U T Y L ACETATE TOLUENE C E L L O S O L V E ACETATE M E T H Y L A M Y L KETONE XYLENE
IL
I
TIME
Figure 3. THC analyzer trace showing typical variations in adsorber inlet vapor stream concentration as measured at mixing flask outlet.
Table I. Breakthrough of Volatile Solvents on Tenax Cartridge with and without Carbon Backing Component
methanol ethanol acetone
breakthrough on Tenax only, %
breakthrough on Tenax wlth carbon backing, %
100
2 1 1
7
6
0
5
IO
15
20
25
30
35
RETENTION TIME (min) Figure 4. Typical GC profiles obtained during analysis of carbon adsorber inlet/outlet: (upper trace) adsorber outlet using adsorbent cartridge (200-cm3concentrate); (lower trace) adsorber Inlet (2-cm3sample loop injection).
Volume 15, Number 12, December 1981
1465
~
~~
Table II. Comparison of Carbon Adsorber Inlet/Outlet THC Measurementsa Obtained by GC and THC Analyzers total inlet concn THC anal.
total outlet concn THC anal.
sample no.
GC
1
855
850
0.6
12.0
15
-20.0
2
922
875
5.4
875
7.8
4
943 1023
14 24.5
-23.1
3
10.3 23.3
963
6.2
37.9
39
-2.6
54.0
52
97.1
100
3.9 -3.0
176
170
3.5
335
330
% devlation
5
557
6
905
875 1000
-36.3 -9.5
7
928
950
-2.3
8
994
950
4.6 1.8 (6.1)
mean (RSD)
GC
% devlatlon
-4.2
1.5 -5.5 (10.4)
a Measurements are as ppm propane. Sample 5 was obtained just after a lunch break. The GC inlet value was low because of plant air dilution of the GC-inlet mixing chamber. This value was not included in the calculation for mean and RSD.
Table 111. Comparison of Abatement Efficiency Determinations Calculated by Using Measurements as Propane vs. as AVC
no.
method
total inlet concn as propane (as AVC)
1
GC THC analyzer
855 (374) 850
12.0 (13.7) 15
98.6 (96.3) 98.2
0.4 (-1.9)
4
GC THC analyzer
1023 (437) 963
37.9 (32.6) 39
96.3 (92.5) 96.0
0.3 (-3.6)
6
GC THC analyzer GC
905 (400) 1000 994 (434)
97.1 (77.4) 100 335 (214)
89.3 (80.7) 90.0
-0.8 (-10.3)
66.3 (50.8) 65.3
1.5 (-22.2)
GC sample
8
THC analyzer
950
SOLVENT
........X Y L E N E ---BUTYL ACETATE MAK --------n - B U T A N O L MlBK
1
2
3
‘z? 36
0
I.”
//’
0 I’
,/
1‘
20 /
4
5
6
7
8
A D S O R P T I O N TIME ( H R S )
Figure 5. Carbon adsorber outlet vapor composition during an 8-h adsorption cycle.
typical precision achieved between these two methods of analysis. With solvent compositional information, a more accurate mass emission rate efficiency of an abatement device can be obtained. To illustrate this, we compared GC samples 1 , 4 , 6 , and 8 of Table 11,including the data interpreted as AVC, with ?HC analyzer data for their resulting calculated abatement efficiencies (Table 111).The methods are in close agreement with measurements in terms of propane. However, the true abatement efficiency is that value calculated by using AVC measurements. Observe that the deviation in calculated abatement efficiencies between the THC analyzer and GC (as AVC) becomes significant under high outlet breakthrough conditions. A large portion of the outlet vapor composition 1466
Environmental Science & Technology
% devlatlon with THC analyzer abatement elflclency as propane (as AVC)
consists of volatile oxygenated compounds which, on a mole to mole basis, exhibit a low FID response relative to propane, the THC analyzer calibration gas. This causes a lower THC analyzer outlet reading. As the outlet vapor concentration gets higher, the absolute deviation between measurements as propane and as AVC increases. Thus, the deviation in calculated abatement efficiency increases. Using GC, supported by GC-MS for peak identity conformation, it would be feasible to obtain the ECN of the inlet/ outlet vapor streams of an abatement device and incorporate these into the response factors of a THC analyzer. Thus, through routine monitoring by GC, correct mass emission rate efficiencies could also be obtained by employing the continuous monitoring capabilities of the THC analyzer.
I0
CONCENTRATION ‘PPM
abatement efficiency In % as propane (as AVC)
330
AVERAGE
OF I N L E T VAPOR
total outlet concn as propane (as AVC)
Acknowledgment We thank Bob Stordeur and Jeff Johnson for their cooperation in conducting the experiments, and Elaine Beckwith and Kim Murray for their assistance in performing the analyses. Literature Cited (1) Environmental Protection Agency. Fed. Regist. 1979, 4 4 , 57792. (2) Office of Air Quality Planning and Standards. “Study to Support New Source Performance Standards for Automotive and LightDuty Truck Coating”; Springfield Laboratories, Inc., Enfield, CT 06082. Contract No. 68-02-2062. Publication No. EPA-450/3-77020, June 1977, p 3-24. (3) Office of Air Qualitv Planning and Standards, Environmental Protection Agency, Washington, DC, May 1977, Publication No. EPA-450/2-77-008. (4) Office of Air Qualitv Planning and Standards. “Study to Support New Source Performance Standards for Automotive and LightDuty Truck Coating”; Springfield Laboratories, Inc., Enfield, CT 06082, Contract No. 68-02-2062, Publication No. EPA-450/3-77020, June 1977, p 4-38. ( 5 ) Mack, D. A.; Hollowell, C. D.; McLaughlin, R. D. “Techniques for Continuous Monitoring of Hydrocarbons”, Instrumentation
for Monitoring Air Quality, ASTM STP 555, American Society for Testing and Materials, 1974, p 52. (6) Forsythe, R.; Czayka, M.; Madey, R.; Povlis, J. Carbon 1978,16, 27. (7) Cheremisinoff, P. N.; Ellerbusch, F. “Carbon Adsorption Handbook”; Ann Arbor Science: Ann Arbor, MI, 1978. (8) David, D. J. “Gas Chromatographic Detectors”; Wiley: New York, 1974; pp 42-75. (9) Riley, T. L.; Marano, R. S.; Chladek, E.; Hoggatt, J. H.; Levine,
s. p.; Devlin, R. W. ;Reinke, J.M., presented at the 73rd Air Pollution Control Association Meeting, Montreal, Quebec, June 22-27, 1980, Paper No. 8-41.2. (10) Hammarstrand, K. Varian Instrum. Appl. 1976,10, 14. (11) Pellizzari, E. D.; Bunch, J. E.; Carpenter, B. H. Enuiron. Sci. Technol. 1975,9, 552. (12) Russel, J.W. Enuiron. Sci. Technol. 1975,9, 1175. Receiued f a r reuiew October 31,1980. Accepted July 31,1981.
Migration through Soil of Organic Solutes in an Oil-Shale Process Water Jerry A. Leenheer* and Harold A. Stuber U.S. Geological Survey, Box 25046, Denver Federal Center, Denver, Colorado 80225
The migration through soil of organic solutes in an oil-shale process water (retort water) was studied by using soil columns and analyzing leachates for various organic constituents. Retort water extracted significant quantities of organic anions leached from ammonium-saturated-soil organic matter, and a distilled-water rinse, which followed retort-water leaching, released additional organic acids from the soil. After being corrected for organic constitutents extracted from soil by retort water, dissolved-organic-carbon fractionation analyses of effluent fractions showed that the order of increasing affinity of six organic compound classes for the soil was as follows: hydrophilic neutrals nearly equal to hydrophilic acids, followed by the sequence of hydrophobic acids, hydrophilic bases, hydrophobic bases, and hydrophobic neutrals. Liquid-chromatographic analysis of the aromatic amines in the hydrophobic- and hydrophilic-base fractions showed that the relative order of the rates of migration through the soil column was the same as the order of migration on a reversed-phase, octadecylsilica liquid-chromatographic column.
Introduction Production of shale oil by various in situ retorting technologies will likely result in equivalent volumes of process wastewaters that contain relatively large concentrations of organic solutes ( I ) . Significant volumes of these wastewaters are brought to land surface during shale-oil recovery, where they are separated from the oil, stored in tanks and holding basins, and treated for ammonia recovery and disposal. During the separation, storage, and treatment, processes, the possibility exists for spillage of these wastewaters on the land surface. A small-volume spill of retort water may have little impact because of rapid evaporation in the semiarid climate, but the potential for retort-water leaching exists for largevolume spills or leakage from holding ponds. Such leaching would most likely contaminate the shallow groundwater resources. This report describes experimental studies of the processes that affect migration through soil of organic solutes in an oil-shale process water. The soil’s pedology is typical of regions where oil shales of the Eocene Green River Formation occur. A report describing interactions with the same soil of inorganic solutes from the same process water has been presented ( 2 ) . A study similar to this report has investigated the retention of organic solutes in retort water by processed oil shale ( 3 ) . Experimental Procedures Experimental Design. Three soil-column experiments were conducted to differentiate between soil organic constituents that are leachable with distilled water, soil organic This article not subject to
constituents that are extracted by inorganic solutes in oil-shale process water, and organic solutes that are adsorbed from process water by soil. In the first experiment, a soil column was leached with distilled water until solute concentrations in the column effluents were relatively constant. In the second experiment, a soil column was leached with a synthetic retort water, reconstituted according to major inorganic species found in retort water, to leach the soil column and to determine soil organic solutes extracted by retort water. In the third experiment, a soil column was leached with an actual retort wastewater to assess the migration of organic solutes in retort water through soil. This experimental design compensated for solubility effects of inorganic species in retort water on soil organic matter; it did not compensate for interactions between organic species in retort water and soil organic matter. Distilled-water leaching followed the retort water of the second and third experiments to simulate rainwater leaching of a soil after a retort-water spill. Soil and Water Descriptions. The soil was from the Haterton soil series described in the soil survey by WoodwardClyde Consultants ( 4 ) . This soil is classified as a fine-loamy, mixed (calcaereous j frigid, shallow family of Typic Torriorthents, whose surface (A) horizon is a light gray, alkaline loam, -50 mm thick, with various subsoil (C) horizons consisting of alkaline clay loams. The soil was sampled -120 m east of site 9 at the experimental in situ oil-shale retorting site operated by Laramie Energy Technology Center near Rock Springs, WY. The soil was subdivided into the following horizons during sampling: A (0-50-mm depth); CI (50-360-mm depth); C2 (360-660-mm depth); and C3 (660-1000-mm depth). Directly below the C3 horizon is weathered oil shale of the Eocene Green River Formation. This soil is the deepest soil found near site 9; most of the soils surveyed were only 150-300-mm thick. The in situ oil-shale process water, designated Omega-9,was produced in the site-9 retort; its acquisition, processing, and storage are described by Farrier et al. ( 5 ) .This water was extensively analyzed by a series of independent laboratories, and the results of these analyses are summarized in a report by Fox et al. (6). Synthetic retort water used in the second experiment was based on the Omega-9 analysis of Fox et al. (6) for inorganicsolute concentrations. The composition of synthetic retort water is given in Table I. Soil-Column Packing and Leaching. Air-dried soil was sieved through a 4.75-mm sieve, and stone and shale fragments were discarded. As the soil was very dry and friable when sampled, no additional drying and aggregate-crushing steps were necessary before sieving. Plant roots, removed during sieving, were reincorporated into the column because of their
U S . Copyright. Published 1981 American Chemical Society
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