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Chemical characterization of industrial wastewaters by gas chromatography-mass spectrometry
The Science o f the Total Environment, 3 (1974) 87-102 © Elsevier Scientific Publishing Company, Amsterdam - Printed in Belgium
CHEMICAL CHARACTERIZATION OF INDUSTRIAL WASTEWATERS BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY
L A W R E N C E H. KEITH U.S. Environmental Protection Agency, National Environmental Research Center-Corvallis, Southeast Environmental Research Laboratory, Athens, Ga., 30601 (U.S.A.) (Received February 19th, 1974)
ABSTRACT
Organic pollutants in seven industrial wastewaters being discharged into the Calcasieu River in Louisiana were identified by gas chromatography-mass spectrometry. Discharge of compounds not indicated from the manufacturer's lists of products and raw materials were revealed. Chemical characterization provided information beyond that obtainable from traditional pollution measurements and information especially suitable for pollution legislation enforcement.
INTRODUCTION
Hundreds of thousands of organic compounds are probably being discharged into the environment from both municipal and industrial wastewaters. In a recent literature survey Davis et al. 1 listed only 66 organic chemicals actually identified in fresh water and 430 more than were suspected to be present; industrial sources were responsible for the largest number and variety of chemical structural types. Existing knowledge is also scant for the identification of specific organic compounds in wastewaters that pass through waste treatment systems. Fifty-two different compounds were identified from the industrial wastewaters in this study, but only ten of these were included in the 1970 survey. Although industrial wastes and domestic sewage differ markedly in composition, concentration, physical characteristics, and toxicity, the same types of treatment are often used for both z. However, industrial wastes frequently contain organic compounds that are resistant to the classical biological treatments applied to domestic sewage, and traditional parameters (biological oxygen demand, total organic carbon) do not always define adequately the effectiveness--or ineffectiveness--of treatment. Specific identification and quantification of pollutants characterize industrial effluents much better than these traditional parameters. The combination of gas chromatography and mass spectrometry (GC-MS) has been used for several years at the Southeast Environmental Research Laboratory 87
for the identification of specific organic pollutants a-a. It has proved to be a useful technique and was used to characterize these seven industrial wastewaters for an Environmental Protection Agency (EPA) survey of wastes discharged into the Louisiana Calcasieu River and its tributaries. EXPERI M ENTA L
Wastewaters discharged from two petrochemical, one synthetic rubber, two petrorefinery, and two chemical companies were characterized. One-liter grab samples of each effluent were taken at a point close to the discharge into the receiving waters. A chloroform extract of each sample was concentrated in a micro Kuderna-Danish apparatus to about 0.25 ml, and optimum GC conditions were determined on a 15.25 m ×0.05 cm support coated open tubular (SCOT) column. Mass spectra (70 eV ionizing energy) of all samples were obtained on a Perkin-Elmer/Hitachi* RM U-7 magnetic and electrostatic focusing mass spectrometer. One sample was also analyzed on a Finnigan* 1015 computerized quadrupole mass spectrometer described elsewhere 9. Lists of products and raw materials were obtained from each company for comparison with experimental results. DISCUSSION
Petrochemical wastewater analyses Petrochemical Company A, producing olefins and oxygenated hydrocarbons, discharged an estimated 4 million gal (15,140 m 3) of wastewater per day from 5 acres (2.03 ha) of partially aerated lagoons having a 5-6 day retention time. Samples were taken at an overflow structure at the terminal end of the lagoons. Fourteen compounds were identified by G C - M S analysis of the wastewater extract (Fig. 1); 13 were confirmed by comparison with standards. Table 1 shows little relationship between the lists of products and raw materials obtained from the company and the compounds identified. Few, if any, of the compounds found in this wastewater could Lave been expected from the lists of products and raw materials. Polycyclic aromatics, such as the indenes and naphthalenes found in this effluent, may be primarily responsible for the odor of oil products ~°. They may cause taste and odor problems in drinking water when petroleum by-products are discharged into waters eventually used as municipal water supplies. Some of these compounds have been identified in contaminated well water from Ames, Iowa 11 Included in Table 1 are the traditional pollution measurements, the approximate concentration (based on GC peak areas) and daily discharge of each compound. Some of these quantitations are erroneously low because the chloroform extraction efficiency is less than 100%, and some volatilization of lighter compounds may have occurred during concentration. * Trade names mentioned herein are for identification purposes only and do not imply endorsement by the Environmental Protection Agency.
88
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Because of the diversity of compounds found in this wastewater and the ability of the Finnigan system to obtain better spectra of the small peaks (with computerized background subtraction) and the higher molecular weight and more polar compounds (with the Gohlke separator), this sample was re-examined with the quadrupole mass spectrometer-computer system. Many additional compounds were tentatively identified. Computerized data reduction and spectra matching greatly reduced the analysis time. When the run was complete, a computer-reconstructed gas chromatogram (RGC) of ion-current summation versus spectrum number was plotted (Fig. 2). Although many peaks exhil~it a variation in peak height (or in peak area) relative to a flame ionization detector (FID) chromatogram, the resemblance is sufficient to relate the FID GC peaks to their RGC counterparts. Mass spectra of interest are chosen by spectrum number from the RGC. Plots of ion-current summation at specified mass ranges versus spectrum number (Fig. 3) enhanced RGC peaks containing significant amounts of these masses and were helpful in determining which mass spectra should be examined. Detection of rule's indicative of particular fragments revealed much about the character of the compounds in the wastewater even before their mass spectra were plotted. Identification of the remaining compounds is summarized in Table 2. Approximately 70% of all the peaks and shoulders in the gas chromatogram (Fig. 2), and all of the major peaks, were identified. Many were confirmed by comparison with standards. Concentrations of about 0.002 mg/i to 0.060 mg/I are represented. Petrochemical Company B, producing alcohols and paraffins, discharges about 2,840 mS/day of wastewater into a ditch leading to a bayou. Effluent from the plant's alcohol unit (80% of the total) is not treated~ but effluent from the paraffin 89
TABLE I CHEMICAL CHARACTERIZATION AND GROSS POLLUTION MEASUREMENTS OF PETROCHEMICAL COMPANY A GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
180 mg/l 612 mg/l 868 mg/l 78 mg/l 1,100 M.Q-~/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compoundsidentified
Approximate concentration (mg/I)
Approximate discharge (lbs/day)*
Propylene Ethylene Butadiene Butane Octane Ethylene glycol Ethylene oxide Polyglycols Ammonia
Raw gas Ethane Refinery gases Refinery C2 stream Refinery Ca stream Propane Butadiene Nitrogen Hydroformer gas Platformer gas
m-Xylene p-Xylene o-Xylene Styrene o-Methylstyrene lndane Indene 1-Methylindene 3-Methylindene Naphthalene 2-Methylnaphthalene 1-Methylnaphthatene 2,6-Dimehthylnaphthalene Phenol
0.008 0.002 0.006 0.031 0.001 0.007 0.026 0.002 0.003 0.053 0.030 0.025 0.015 0.060
0.3 0.1 0.2 1.1 0.1 0.3 0.9 0.1 0.1 1.9 1.1 0.9 0.5 2.1
* Multiply by 0.454 to convert to units of kg/day.
unit passed t h r o u g h an A m e r i c a n P e t r o l e u m Institute ( A P I ) separator. O n l y unb r a n c h e d , short-chain alcohols were f o u n d in significant a m o u n t s (Fig. 4); this is consistent with the lists o f p r o d u c t s and r a w materials (Table 3). n - H e x a n o l was present in the largest a m o u n t with lower c o n c e n t r a t i o n s o f n - b u t a n o l a n d n - o c t a n o l and a trace o f n-decanoi. The 272 kg daily discharge o f alcohols into a small b a y o u by p e t r o c h e m i c a l c o m p a n y B might be expected to cause some oxygen depletion.
Petrorefinery wastewater analyses Petrorefinery A p r o d u c e s a b o u t 230,000 barrels o f refined p r o d u c t s p e r d a y a n d has a wastewater discharge o f a b o u t 1.10 million m3/day from an u n a e r a t e d 11.3 ha lagoon (retention time o f a b o u t 8 h) a n d small tidal p o n d . The c o m p o u n d s identified in the effluent (Fig. 5) are consistent with the nature o f the industry a n d the lists o f p r o d u c t s a n d raw materials in T a b l e 4. A l t h o u g h the c o n c e n t r a t i o n of each c o m p o u n d 90
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TABLE 2 C O M P O U N D S IDENTIFIED
IN WASTEWATER OF P E T R O C H E M I C A L
R G C spectrum No.
Compound name
2 4 I0 16 29 36 47 65 70 75 86 89 109 121 129 140 145 156 160 168 177 193 202 206 2 l0 221 233 233 244 249 256 265 278 287 292 296 356
m-xylene* p-xylene* 1,5-cyclooctadiene o-xylene* isopropylbenzene (cumene) styrene* o-ethyltoluene o-methylstyrene* diacetone alcohol indan* 2-butoxyethanol B-methylstyrene indene* dimethylfuran isomer n-pentadecane l-methylindene* 3-methylindene acetophenone n-hexadecane ~t-terpineol naphthalene* ct-methylbenzyl alcohol 2-methylnaphthalene* benzyl alcohol l-methylnaphthalene* ethylnaphthalene isomer phenol* 2,6-dimethylnaphthalene* methyl ethyl naphthalene isomer cresol isomer acenapbthene acenaphthalene methylbiphenyl isomer fluorene phthalate diester (undetermined) 3,3-diphenylpropanol phthalate diester (undetermined)
COMPANY A
* Identification was confirmed with a standard.
is less than 1 mg/l, the total daily discharge is estimated to be 363 kg of phenol and cresol, 23 kg of naphthalenes, and more than 300 kg of aliphatic hydrocarbons. The small peaks appearing between the n-alkanes on the gas chromatogram (Fig. 5) were shown by mass spectrometry to be mostly isomeric branched alkanes. Petrorefinery B produces about 71,000 barrels of refined products per day and has a waste water discharge of about 4,160 m3/day. It also has a more extensive effluent 92
(E) toe
29] Isopropylbenzene
I~ Styrene
80.
LMRGC m/e 105
l] 140 II II 147 o-Ethyltotuene
~ 6o
• • r ~ " ~ "CzH4 r ~ ' ~ "C----O
156 Acetophenone
I
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0 0
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(D)
60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 N0 380 SPECTRUMNUMBER
100
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292
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0 0
20 40
60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 SPECTRUMNUMBER
(C) 10080.
Naphthalene177i 193.-Methylbenzylalcohol I] I 206 Benzylalcohol
IIII II t
36 Styrene
I
20 40
60
gO
233,heo0,, I 249 Cresol
I
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100 120 140 160 180 200 220 240 260 280 300 320 340 NO 380 SPECTRUM NUMBER
(B) 100
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100 120 140 160 180 200 220 240 260 280 300 320 NO 360 380
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233
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 40 60 80 100 120 140 160 180 200 220 240 NO ?80"300 320 J~0 360 380
SPECTRUMNUMBER Fig. 3. Reconstructed gas c h r o m a t o g r a m (A) with limited mass reconstructed gas c h r o m a t o g r a m s above it: (B) Search f o r m/e 57 fragments, (C) Search f o r m/e "/7 fragments, ( D ) Search f o r m/e 149 f r a g m e n t s , (E) S e a r c h f o r
m/e
105 f r a g m e n t s .
treatment than petrorefinery A: an API separator, a corrugated plate interceptor (CPI), an activated sludge unit with clarifier, and a small aerated lagoon (total retention time about 1 day). Only hydrocarbons were identified in the discharge (Fig. 6), which is consistent with the products and raw materials listed in Table 5. Although the hydrocarbon concentrations were 5-20 times greater in refinery B than in refinery A wastewater, refinery B's daily discharge of hydrocarbons was estimated to be less than 23 kg. Apparently phenols and naphthalenes were removed by refinery B's more extensive treatment, and the daily discharge of aliphatic hydrocarbons per barrel of product in the treated wastewater of refinery B was one-fifth that of refinery A. Correspondingly, the total organic carbon (TOC) content per barrel of product in the treated wastewater of refinery B was one-sixth that of refinery A.
Synthetic rubber and chemical companies wastewater analyses A synthetic rubber company discharges about 22,700 m3/day of wastewater with only primary treatment. Of the three compounds identified (Fig. 7), only styrene was listed as a raw material (Table 6). Chemical company A, a producer of chlorinated hydrocarbons, (Table 7) discharges about 15,100 m3/day of untreated wastewater. The total daily discharge of
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Fig. 4. Chemically characterized gas chromatogram of Petrochemical Company B.
94
TABLE 3 GROSS POLLUTION MEASUREMENTS A N D CHEMICAL CHARACTERIZATION OF PETROCHEMICAL COMPANY B
GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
130 mg/l Not available 2,650 mg/l 34 mg/l 4,000 M.Q-~/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compounds identified
Approximate Approximate concentration discharge (lbs/day)* (mgll)
Normal paraffin Industrial alcohols Ethylene Methyl chloride Ethoxylates
Ethylene Aluminum Hydrogen Raffinate Sulfuric acid Ethylene oxide Acetic acid Caustic Phosphoric acid Kerosene Ethane Propane Methanol HCI
l-Butanol l-Hexanol 1-Octanol 1-Decanol
16.0 65.0 19.0 2.5
90 375 I 10 15
* Multiply by 0.454 to convert to units of kg/day.
the two main contaminants, 1,1,2-trichloroethane and l,l,2,2-tetrachloroethane (Fig. 8), was estimated to be 150 kg. Although there was no evidence that tetra- and trichloroethane were present in acutely toxic concentrations, the daily discharge of 150 kg of them into a bayou could cause chronic toxicity problems to marine life. Chemical company B, a polymer producer, discharges about 7,600 m3/day of wastewater that has been subjected to unaerated lagooning. The two compounds found in the greatest amounts were n-decane and n-undecane (Fig. 9) and their daily discharge was estimated to be only about 0.5 kg per day. However, their presence was not expected from the list of products and raw materials in Table VIII. 95
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Fig. 5. Chemically characterized gas chromatogram of Pctrorefinery A.
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Fig. 6. Chemically characterized gas chromatogram of Petrorefinery B.
96
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Fig. 8. Chemically characterized
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of Synthetic Rubber Company.
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gas chromatogram
of Chemical Company A.
97
TABLE 4 GROSS POLLUTION MEASUREMENTS AND CHEMICAL CHARACTERIZATION OF PETROREFINERY COMPANY A GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
15 mg/l Not available 9,220 mg/l 38 mg/l 13,700 Mr2-1/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compoundsidentified
Approximate concentration (mgfl)
Approximate discharge (lbs/day)*
LPG propane Propylene Orthoxylene Aromatics
Crude oil Express gas oil Extracts
Undecane Dodecane Tridecane Tetradecane Pentadecane Hexadecane Heptadecane Octadecane Nonadecane 2-Methylnaphthalene 1-Methylnaphthalene Phenol o-Cresol
0.027 0.031 0.042 0.039 0.030 0.026 0.022 0.017 0.013 0.013 0.005 0.200 0.120
69 79 107 99 76 66 53 43 33 33 12 510 300
* Multiply by 0.454 to convert to units of kg/day.
CONCLUSION
The chemical characterization of seven industrial effluents has (1) provided specific compound identifications and quantitations that will be used for pollution legislation and enforcement; (2) revealed the discharge of unexpected compounds that were not indicated by the manufacturer's lists of raw materials and products; (3) furnished knowledge of treatment effectiveness beyond that provided by gross pollution measurements; (4) helped to determine the significance of an effluent and the specific pollution problems it may cause. Computer controlled GC-MS systems (1) reduce the time required for sample analysis; (2) permit computerized matching of unknown spectra with reference spectra 98
TABLE 5 GROSS POLLUTION MEASUREMENTS AND CHEMICAL CHARACTERIZATIONS OF PETROREFINERY COMPANY B GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
210 mg/l 676 mg/l 2,430 rag/1 182 mg/l 3,900 Mr2-l/cm
CHEMICAL CHARACTERIZATIONS
Products
Raw materials
Compoundsidentified
Approximate concentration (rag~I)
Approximate discharge (lbs/day)*
LPG Propane Butane Gasoline Kerosene Diesel fuel Heating oil No. 6 Fuel oil Coke
Crude oil Isobutane PVC
Undecane Dodecane Tridecane Tetradecane Pentadecane Hexadecane Heptadecane Octadecane Nonadecane Eicosane Heineicosane
0.05 0.22 0.39 0.58 0.49 0.42 0.34 0.33 0.31 0.30 0.19
0.4 2.2 3.8 5.6 4.8 4.0 3.3 3.2 3.0 2.9 1.8
* Multiply by 0.454 to convert to units of kg/day.
in a continuously expanding library; (3) reduce the mass spectral expertise required for routine GC-MS analyses; (4) allow rapid, routine characterization of industrial wastewaters and identification of pollutants in natural waters. Specific identification and quantification of polluting compounds are significant in characterizing an industrial effluent for enforcement of pollution control legislation. The widespread capability to quickly identify specific organics responsible for actual or potential pollution problems overcomes a major obstacle of the past --working with unknown organic pollutants. A C K N O W L E D G M ENTS
The author gratefully acknowledges the help of A. L. Alford and M. H. Carter, who obtained the mass spectra, and the technical assistance of J. M. McGuire, A. W. Garrison, F. R. Allen, T. L. Floyd and T. O. Meiggs. 99
TABLE 6 GROSS POLLUTION M E A S U R E M E N T S A N D C H E M I C A L C H A R A C T E R I Z A T I O N SYNTHETIC RUBBER C O M P A N Y GROSS POLLUTION M E A S U R E M E N T S
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
52 168 3,210 76 5,000
mg/l mg/l mg/l mg/l M~-1/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compounds identified
Approximate concentration (mg/l)
Approximate discharge (Ibs/day)*
Synthetic rubber
Butadiene Styrene Carbon black
Styrene Furfural
0.0026 0.0017 0.0017
1.3 0.9 0.9
l-Methylnaphthalene
* Multiply by 0.454 to convert to units of kg/day.
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Fig. 9. Chemically characterized gas chromatogram of Chemical Company B. 100
OF
TABLE 7 CHEMICAL CHARACTERIZATION OF CHEMICAL COMPANY A
Products
Raw materials
Compoundsidentified
Approximate concentration (rag~I)
Approximate discharge (Ibs/day)*
Chlorine Caustic soda Aliphatics Chlorinated hydrocarbons Silica pigments Sodium chloride HCI
Sodium chloride Ethylene
1,1,2-Trichloroethane
5.4 2.2
240 95
1,1,2,2-Tetrachloroethane
* Multiply by 0.454 to convert to units of kg/day.
TABLE 8 CHEMICAL CHARACTERIZATION OF CHEMICAL COMPANY B
Products
Raw materials
Compoundsidentified
Approximate concentrat•n (mg[I)
Approximate discharge (Ibs/day)*
Polyoleflns Polyethylene Polypropylene
Ethylene Propylene Alcohol Aluminum alkyls Titanium chloride
Decane Undecane
0.03 0.02
0.6 0.4
* Multiply by 0.454 to convert to units of kg/day. This p a p e r was presented, in part, before the Division o f W a t e r , Air, and W a s t e C h e m i s t r y at the 163d A C S N a t i o n a l Meeting, Boston, Mass., April, 1972, and the 164th A C S N a t i o n a l Meeting, N e w Y o r k , N . Y . , August, 1972. REFERENCES 1 T. R. A. Davis, A. W. Burg, J. I. Neumeyer, K. M. Butters and B. D. Waddler, Water Quality Criteria Book, VoL 1--Organic Chemical Pollution of Freshwater, Water Pollution Control Research Series 18010 DPV, 12/70, p. 1, 1970. 2 W. J. Lacy, Projects of the Industrial Pollution Control Branch, U.S. Department of Interior, Federal Water Quality Administration publication 12000-07/70, pp. 1-6, 1970. 3 L. H. Keith, Division of Water, Air, and Waste Chemistry, 157th Meeting, ACS, Minneapolis, Minn., April, 1969. 4 L. H. Keith, A. W. Garrison, M. M. Walker, A. L. Alford and A. D. Thruston, Jr., Division of Water, Air, and Waste Chemistry, 158th Meeting, ACS, New York, N.Y., September, 1969. 5 L. H. Keith, Division of Water, Air, and Waste Chemistry, 163rd Meeting, ACS, Boston, Mass., April, 1972. lOl
6 L. H. Keith and J. M. McGuire, Division of Water, Air, and Waste Chemistry, 164th Meeting, ACS, New York, N.Y., August, 1972. 7 A. W. Garrison, L. H. Keith and M. M. Walker, American Society for Mass Spectrometry, 18th Annual Conference, San Francisco, Calif., June, 1970. 8 A. W. Garrison, L. H. Keith and A. L. Alford, "Fate of Organic Pesticides in the Aquatic Environment, " Advances in Chemistry Series 11 l, (American Chemical Society, Washington, DC, 1972), Ch. 3, pp. 26-54. 9 J. M. McGuire, A. L. Alford and M. H. Carter, American Society for Mass Spectrometry 20th Annual Conference on Mass Spectrometry and Allied Topics, Dallas, Texas, June, 1972. 10 B. C. J. Zoeteman, A. J. A. Kraayeveld and G. J. Piet, HeO, 4, 367 (1971). 11 A. K. Burnham, C. V. Calder, J. S. Fritz, G. A. Junk, J. H. Svec and R. Willis, Anal. Chem., 44, 139 (1972).
102
CHEMICAL CHARACTERIZATION OF INDUSTRIAL WASTEWATERS BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY
L A W R E N C E H. KEITH U.S. Environmental Protection Agency, National Environmental Research Center-Corvallis, Southeast Environmental Research Laboratory, Athens, Ga., 30601 (U.S.A.) (Received February 19th, 1974)
ABSTRACT
Organic pollutants in seven industrial wastewaters being discharged into the Calcasieu River in Louisiana were identified by gas chromatography-mass spectrometry. Discharge of compounds not indicated from the manufacturer's lists of products and raw materials were revealed. Chemical characterization provided information beyond that obtainable from traditional pollution measurements and information especially suitable for pollution legislation enforcement.
INTRODUCTION
Hundreds of thousands of organic compounds are probably being discharged into the environment from both municipal and industrial wastewaters. In a recent literature survey Davis et al. 1 listed only 66 organic chemicals actually identified in fresh water and 430 more than were suspected to be present; industrial sources were responsible for the largest number and variety of chemical structural types. Existing knowledge is also scant for the identification of specific organic compounds in wastewaters that pass through waste treatment systems. Fifty-two different compounds were identified from the industrial wastewaters in this study, but only ten of these were included in the 1970 survey. Although industrial wastes and domestic sewage differ markedly in composition, concentration, physical characteristics, and toxicity, the same types of treatment are often used for both z. However, industrial wastes frequently contain organic compounds that are resistant to the classical biological treatments applied to domestic sewage, and traditional parameters (biological oxygen demand, total organic carbon) do not always define adequately the effectiveness--or ineffectiveness--of treatment. Specific identification and quantification of pollutants characterize industrial effluents much better than these traditional parameters. The combination of gas chromatography and mass spectrometry (GC-MS) has been used for several years at the Southeast Environmental Research Laboratory 87
for the identification of specific organic pollutants a-a. It has proved to be a useful technique and was used to characterize these seven industrial wastewaters for an Environmental Protection Agency (EPA) survey of wastes discharged into the Louisiana Calcasieu River and its tributaries. EXPERI M ENTA L
Wastewaters discharged from two petrochemical, one synthetic rubber, two petrorefinery, and two chemical companies were characterized. One-liter grab samples of each effluent were taken at a point close to the discharge into the receiving waters. A chloroform extract of each sample was concentrated in a micro Kuderna-Danish apparatus to about 0.25 ml, and optimum GC conditions were determined on a 15.25 m ×0.05 cm support coated open tubular (SCOT) column. Mass spectra (70 eV ionizing energy) of all samples were obtained on a Perkin-Elmer/Hitachi* RM U-7 magnetic and electrostatic focusing mass spectrometer. One sample was also analyzed on a Finnigan* 1015 computerized quadrupole mass spectrometer described elsewhere 9. Lists of products and raw materials were obtained from each company for comparison with experimental results. DISCUSSION
Petrochemical wastewater analyses Petrochemical Company A, producing olefins and oxygenated hydrocarbons, discharged an estimated 4 million gal (15,140 m 3) of wastewater per day from 5 acres (2.03 ha) of partially aerated lagoons having a 5-6 day retention time. Samples were taken at an overflow structure at the terminal end of the lagoons. Fourteen compounds were identified by G C - M S analysis of the wastewater extract (Fig. 1); 13 were confirmed by comparison with standards. Table 1 shows little relationship between the lists of products and raw materials obtained from the company and the compounds identified. Few, if any, of the compounds found in this wastewater could Lave been expected from the lists of products and raw materials. Polycyclic aromatics, such as the indenes and naphthalenes found in this effluent, may be primarily responsible for the odor of oil products ~°. They may cause taste and odor problems in drinking water when petroleum by-products are discharged into waters eventually used as municipal water supplies. Some of these compounds have been identified in contaminated well water from Ames, Iowa 11 Included in Table 1 are the traditional pollution measurements, the approximate concentration (based on GC peak areas) and daily discharge of each compound. Some of these quantitations are erroneously low because the chloroform extraction efficiency is less than 100%, and some volatilization of lighter compounds may have occurred during concentration. * Trade names mentioned herein are for identification purposes only and do not imply endorsement by the Environmental Protection Agency.
88
50' S.C.O.T CARBOWAX 2 0 M - T P A 70 = ISO./ 2 MIN ~PROGRAM- " 2 0 0 " AT 8"/MIN
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~TES
Fig. I. C h e m i c a l l y c h a r a c t e r i z e d g a s c h r o m a t o g r a m o f P e t r o c h e m i c a l C o m p a n y A .
Because of the diversity of compounds found in this wastewater and the ability of the Finnigan system to obtain better spectra of the small peaks (with computerized background subtraction) and the higher molecular weight and more polar compounds (with the Gohlke separator), this sample was re-examined with the quadrupole mass spectrometer-computer system. Many additional compounds were tentatively identified. Computerized data reduction and spectra matching greatly reduced the analysis time. When the run was complete, a computer-reconstructed gas chromatogram (RGC) of ion-current summation versus spectrum number was plotted (Fig. 2). Although many peaks exhil~it a variation in peak height (or in peak area) relative to a flame ionization detector (FID) chromatogram, the resemblance is sufficient to relate the FID GC peaks to their RGC counterparts. Mass spectra of interest are chosen by spectrum number from the RGC. Plots of ion-current summation at specified mass ranges versus spectrum number (Fig. 3) enhanced RGC peaks containing significant amounts of these masses and were helpful in determining which mass spectra should be examined. Detection of rule's indicative of particular fragments revealed much about the character of the compounds in the wastewater even before their mass spectra were plotted. Identification of the remaining compounds is summarized in Table 2. Approximately 70% of all the peaks and shoulders in the gas chromatogram (Fig. 2), and all of the major peaks, were identified. Many were confirmed by comparison with standards. Concentrations of about 0.002 mg/i to 0.060 mg/I are represented. Petrochemical Company B, producing alcohols and paraffins, discharges about 2,840 mS/day of wastewater into a ditch leading to a bayou. Effluent from the plant's alcohol unit (80% of the total) is not treated~ but effluent from the paraffin 89
TABLE I CHEMICAL CHARACTERIZATION AND GROSS POLLUTION MEASUREMENTS OF PETROCHEMICAL COMPANY A GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
180 mg/l 612 mg/l 868 mg/l 78 mg/l 1,100 M.Q-~/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compoundsidentified
Approximate concentration (mg/I)
Approximate discharge (lbs/day)*
Propylene Ethylene Butadiene Butane Octane Ethylene glycol Ethylene oxide Polyglycols Ammonia
Raw gas Ethane Refinery gases Refinery C2 stream Refinery Ca stream Propane Butadiene Nitrogen Hydroformer gas Platformer gas
m-Xylene p-Xylene o-Xylene Styrene o-Methylstyrene lndane Indene 1-Methylindene 3-Methylindene Naphthalene 2-Methylnaphthalene 1-Methylnaphthatene 2,6-Dimehthylnaphthalene Phenol
0.008 0.002 0.006 0.031 0.001 0.007 0.026 0.002 0.003 0.053 0.030 0.025 0.015 0.060
0.3 0.1 0.2 1.1 0.1 0.3 0.9 0.1 0.1 1.9 1.1 0.9 0.5 2.1
* Multiply by 0.454 to convert to units of kg/day.
unit passed t h r o u g h an A m e r i c a n P e t r o l e u m Institute ( A P I ) separator. O n l y unb r a n c h e d , short-chain alcohols were f o u n d in significant a m o u n t s (Fig. 4); this is consistent with the lists o f p r o d u c t s and r a w materials (Table 3). n - H e x a n o l was present in the largest a m o u n t with lower c o n c e n t r a t i o n s o f n - b u t a n o l a n d n - o c t a n o l and a trace o f n-decanoi. The 272 kg daily discharge o f alcohols into a small b a y o u by p e t r o c h e m i c a l c o m p a n y B might be expected to cause some oxygen depletion.
Petrorefinery wastewater analyses Petrorefinery A p r o d u c e s a b o u t 230,000 barrels o f refined p r o d u c t s p e r d a y a n d has a wastewater discharge o f a b o u t 1.10 million m3/day from an u n a e r a t e d 11.3 ha lagoon (retention time o f a b o u t 8 h) a n d small tidal p o n d . The c o m p o u n d s identified in the effluent (Fig. 5) are consistent with the nature o f the industry a n d the lists o f p r o d u c t s a n d raw materials in T a b l e 4. A l t h o u g h the c o n c e n t r a t i o n of each c o m p o u n d 90
E ,ID
.C
_o
2
e4 ._=
9!
TABLE 2 C O M P O U N D S IDENTIFIED
IN WASTEWATER OF P E T R O C H E M I C A L
R G C spectrum No.
Compound name
2 4 I0 16 29 36 47 65 70 75 86 89 109 121 129 140 145 156 160 168 177 193 202 206 2 l0 221 233 233 244 249 256 265 278 287 292 296 356
m-xylene* p-xylene* 1,5-cyclooctadiene o-xylene* isopropylbenzene (cumene) styrene* o-ethyltoluene o-methylstyrene* diacetone alcohol indan* 2-butoxyethanol B-methylstyrene indene* dimethylfuran isomer n-pentadecane l-methylindene* 3-methylindene acetophenone n-hexadecane ~t-terpineol naphthalene* ct-methylbenzyl alcohol 2-methylnaphthalene* benzyl alcohol l-methylnaphthalene* ethylnaphthalene isomer phenol* 2,6-dimethylnaphthalene* methyl ethyl naphthalene isomer cresol isomer acenapbthene acenaphthalene methylbiphenyl isomer fluorene phthalate diester (undetermined) 3,3-diphenylpropanol phthalate diester (undetermined)
COMPANY A
* Identification was confirmed with a standard.
is less than 1 mg/l, the total daily discharge is estimated to be 363 kg of phenol and cresol, 23 kg of naphthalenes, and more than 300 kg of aliphatic hydrocarbons. The small peaks appearing between the n-alkanes on the gas chromatogram (Fig. 5) were shown by mass spectrometry to be mostly isomeric branched alkanes. Petrorefinery B produces about 71,000 barrels of refined products per day and has a waste water discharge of about 4,160 m3/day. It also has a more extensive effluent 92
(E) toe
29] Isopropylbenzene
I~ Styrene
80.
LMRGC m/e 105
l] 140 II II 147 o-Ethyltotuene
~ 6o
• • r ~ " ~ "CzH4 r ~ ' ~ "C----O
156 Acetophenone
I
.,.i
0 0
20 40
(D)
60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 N0 380 SPECTRUMNUMBER
100
LMRGC m/e 149
3s6
0
0 20
..
292
I.Phlha.lat~) . . . . . . . . . . . . . .
..> . . . .
~-.-- ~
.~. .
0 0
20 40
60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 SPECTRUMNUMBER
(C) 10080.
Naphthalene177i 193.-Methylbenzylalcohol I] I 206 Benzylalcohol
IIII II t
36 Styrene
I
20 40
60
gO
233,heo0,, I 249 Cresol
I
LMRGC m/e 77 ^ ,, m
100 120 140 160 180 200 220 240 260 280 300 320 340 NO 380 SPECTRUM NUMBER
(B) 100
I
so~
LMRGC
2-Butoxyethanol
m /e
57
-
<
. 200
20
40
60
80
100 120 140 160 180 200 220 240 260 280 300 320 NO 360 380
SPECTRUMNUMBER
(A)
so
RGC
t 17/
I
0
0
233
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 40 60 80 100 120 140 160 180 200 220 240 NO ?80"300 320 J~0 360 380
SPECTRUMNUMBER Fig. 3. Reconstructed gas c h r o m a t o g r a m (A) with limited mass reconstructed gas c h r o m a t o g r a m s above it: (B) Search f o r m/e 57 fragments, (C) Search f o r m/e "/7 fragments, ( D ) Search f o r m/e 149 f r a g m e n t s , (E) S e a r c h f o r
m/e
105 f r a g m e n t s .
treatment than petrorefinery A: an API separator, a corrugated plate interceptor (CPI), an activated sludge unit with clarifier, and a small aerated lagoon (total retention time about 1 day). Only hydrocarbons were identified in the discharge (Fig. 6), which is consistent with the products and raw materials listed in Table 5. Although the hydrocarbon concentrations were 5-20 times greater in refinery B than in refinery A wastewater, refinery B's daily discharge of hydrocarbons was estimated to be less than 23 kg. Apparently phenols and naphthalenes were removed by refinery B's more extensive treatment, and the daily discharge of aliphatic hydrocarbons per barrel of product in the treated wastewater of refinery B was one-fifth that of refinery A. Correspondingly, the total organic carbon (TOC) content per barrel of product in the treated wastewater of refinery B was one-sixth that of refinery A.
Synthetic rubber and chemical companies wastewater analyses A synthetic rubber company discharges about 22,700 m3/day of wastewater with only primary treatment. Of the three compounds identified (Fig. 7), only styrene was listed as a raw material (Table 6). Chemical company A, a producer of chlorinated hydrocarbons, (Table 7) discharges about 15,100 m3/day of untreated wastewater. The total daily discharge of
50' S.CO,T CARBOWAX 2OM-TPA 50" ISO,/2 MIN ; PROGRAM-->2 0 0 = AT 8°/MIN
m
!
_= @ v O
•
L
o
~
,'
,'~
,',
22
~',
2'6 2;
MINUTES
Fig. 4. Chemically characterized gas chromatogram of Petrochemical Company B.
94
TABLE 3 GROSS POLLUTION MEASUREMENTS A N D CHEMICAL CHARACTERIZATION OF PETROCHEMICAL COMPANY B
GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
130 mg/l Not available 2,650 mg/l 34 mg/l 4,000 M.Q-~/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compounds identified
Approximate Approximate concentration discharge (lbs/day)* (mgll)
Normal paraffin Industrial alcohols Ethylene Methyl chloride Ethoxylates
Ethylene Aluminum Hydrogen Raffinate Sulfuric acid Ethylene oxide Acetic acid Caustic Phosphoric acid Kerosene Ethane Propane Methanol HCI
l-Butanol l-Hexanol 1-Octanol 1-Decanol
16.0 65.0 19.0 2.5
90 375 I 10 15
* Multiply by 0.454 to convert to units of kg/day.
the two main contaminants, 1,1,2-trichloroethane and l,l,2,2-tetrachloroethane (Fig. 8), was estimated to be 150 kg. Although there was no evidence that tetra- and trichloroethane were present in acutely toxic concentrations, the daily discharge of 150 kg of them into a bayou could cause chronic toxicity problems to marine life. Chemical company B, a polymer producer, discharges about 7,600 m3/day of wastewater that has been subjected to unaerated lagooning. The two compounds found in the greatest amounts were n-decane and n-undecane (Fig. 9) and their daily discharge was estimated to be only about 0.5 kg per day. However, their presence was not expected from the list of products and raw materials in Table VIII. 95
50' SCOT CARBOWAX 20M-TPA 6 0 ° ISO, / 2 MIN ; PROGRAM " ~ 2 0 0 " AT 8 " / M I N
oo
.°~C,
u ¢ •
•
• ¢
¢
•o
• v
v •
v •
a
O
I 2
41
¢ @ u
~ ¢
• ¢ •
"11 •
• 1
• '1
L
I
I
I
6
8
I0
I/
I
I
r
,
I
14
16
18
2'0
22
214
MINUTES
Fig. 5. Chemically characterized gas chromatogram of Pctrorefinery A.
5 0 ' S.C.O.T. CARBOWAX 2 0 M - T P A 6 0 ° l S O . / 2 MIN ; PROGRAM ~ 2 0 0 " AT 8 ° / M I N
•
•
v
v
v
•u
"u
•
1
.,,
.,,
.,,
• *"
• L
• Z
o. u
u O,Z
•
•
g •
•
m
m
v
e
•
•u
v ~
w Z~
o=.;
MINUTES
Fig. 6. Chemically characterized gas chromatogram of Petrorefinery B.
96
50’ S.C:QT. CARBOWAX 20M - TPA 70. ISO. /2 MIN : PROGRAM - 2tWAT
Fig. 7. Chemically characterized
50’ S.CL0-cCARBOWAX 20M-TPA 70. ISO./ 2 MN; PROGRAM + 200.
Fig. 8. Chemically characterized
6.5*/hUN
gas chromatogram
of Synthetic Rubber Company.
AT 8*/MIN
gas chromatogram
of Chemical Company A.
97
TABLE 4 GROSS POLLUTION MEASUREMENTS AND CHEMICAL CHARACTERIZATION OF PETROREFINERY COMPANY A GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
15 mg/l Not available 9,220 mg/l 38 mg/l 13,700 Mr2-1/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compoundsidentified
Approximate concentration (mgfl)
Approximate discharge (lbs/day)*
LPG propane Propylene Orthoxylene Aromatics
Crude oil Express gas oil Extracts
Undecane Dodecane Tridecane Tetradecane Pentadecane Hexadecane Heptadecane Octadecane Nonadecane 2-Methylnaphthalene 1-Methylnaphthalene Phenol o-Cresol
0.027 0.031 0.042 0.039 0.030 0.026 0.022 0.017 0.013 0.013 0.005 0.200 0.120
69 79 107 99 76 66 53 43 33 33 12 510 300
* Multiply by 0.454 to convert to units of kg/day.
CONCLUSION
The chemical characterization of seven industrial effluents has (1) provided specific compound identifications and quantitations that will be used for pollution legislation and enforcement; (2) revealed the discharge of unexpected compounds that were not indicated by the manufacturer's lists of raw materials and products; (3) furnished knowledge of treatment effectiveness beyond that provided by gross pollution measurements; (4) helped to determine the significance of an effluent and the specific pollution problems it may cause. Computer controlled GC-MS systems (1) reduce the time required for sample analysis; (2) permit computerized matching of unknown spectra with reference spectra 98
TABLE 5 GROSS POLLUTION MEASUREMENTS AND CHEMICAL CHARACTERIZATIONS OF PETROREFINERY COMPANY B GROSS POLLUTION MEASUREMENTS
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
210 mg/l 676 mg/l 2,430 rag/1 182 mg/l 3,900 Mr2-l/cm
CHEMICAL CHARACTERIZATIONS
Products
Raw materials
Compoundsidentified
Approximate concentration (rag~I)
Approximate discharge (lbs/day)*
LPG Propane Butane Gasoline Kerosene Diesel fuel Heating oil No. 6 Fuel oil Coke
Crude oil Isobutane PVC
Undecane Dodecane Tridecane Tetradecane Pentadecane Hexadecane Heptadecane Octadecane Nonadecane Eicosane Heineicosane
0.05 0.22 0.39 0.58 0.49 0.42 0.34 0.33 0.31 0.30 0.19
0.4 2.2 3.8 5.6 4.8 4.0 3.3 3.2 3.0 2.9 1.8
* Multiply by 0.454 to convert to units of kg/day.
in a continuously expanding library; (3) reduce the mass spectral expertise required for routine GC-MS analyses; (4) allow rapid, routine characterization of industrial wastewaters and identification of pollutants in natural waters. Specific identification and quantification of polluting compounds are significant in characterizing an industrial effluent for enforcement of pollution control legislation. The widespread capability to quickly identify specific organics responsible for actual or potential pollution problems overcomes a major obstacle of the past --working with unknown organic pollutants. A C K N O W L E D G M ENTS
The author gratefully acknowledges the help of A. L. Alford and M. H. Carter, who obtained the mass spectra, and the technical assistance of J. M. McGuire, A. W. Garrison, F. R. Allen, T. L. Floyd and T. O. Meiggs. 99
TABLE 6 GROSS POLLUTION M E A S U R E M E N T S A N D C H E M I C A L C H A R A C T E R I Z A T I O N SYNTHETIC RUBBER C O M P A N Y GROSS POLLUTION M E A S U R E M E N T S
Total organic carbon Chemical oxygen demand Total solids Suspended solids Specific conductivity
52 168 3,210 76 5,000
mg/l mg/l mg/l mg/l M~-1/cm
CHEMICAL CHARACTERIZATION
Products
Raw materials
Compounds identified
Approximate concentration (mg/l)
Approximate discharge (Ibs/day)*
Synthetic rubber
Butadiene Styrene Carbon black
Styrene Furfural
0.0026 0.0017 0.0017
1.3 0.9 0.9
l-Methylnaphthalene
* Multiply by 0.454 to convert to units of kg/day.
I00' S.COT. SE-50 60"
I S O . / 2 M I N : P R O G R A M " ~ 2 0 0 " AT 1 2 " / M I N
o v
i
4
i
I
6 II MINUTES
I
I0
t
12
I
14
Fig. 9. Chemically characterized gas chromatogram of Chemical Company B. 100
OF
TABLE 7 CHEMICAL CHARACTERIZATION OF CHEMICAL COMPANY A
Products
Raw materials
Compoundsidentified
Approximate concentration (rag~I)
Approximate discharge (Ibs/day)*
Chlorine Caustic soda Aliphatics Chlorinated hydrocarbons Silica pigments Sodium chloride HCI
Sodium chloride Ethylene
1,1,2-Trichloroethane
5.4 2.2
240 95
1,1,2,2-Tetrachloroethane
* Multiply by 0.454 to convert to units of kg/day.
TABLE 8 CHEMICAL CHARACTERIZATION OF CHEMICAL COMPANY B
Products
Raw materials
Compoundsidentified
Approximate concentrat•n (mg[I)
Approximate discharge (Ibs/day)*
Polyoleflns Polyethylene Polypropylene
Ethylene Propylene Alcohol Aluminum alkyls Titanium chloride
Decane Undecane
0.03 0.02
0.6 0.4
* Multiply by 0.454 to convert to units of kg/day. This p a p e r was presented, in part, before the Division o f W a t e r , Air, and W a s t e C h e m i s t r y at the 163d A C S N a t i o n a l Meeting, Boston, Mass., April, 1972, and the 164th A C S N a t i o n a l Meeting, N e w Y o r k , N . Y . , August, 1972. REFERENCES 1 T. R. A. Davis, A. W. Burg, J. I. Neumeyer, K. M. Butters and B. D. Waddler, Water Quality Criteria Book, VoL 1--Organic Chemical Pollution of Freshwater, Water Pollution Control Research Series 18010 DPV, 12/70, p. 1, 1970. 2 W. J. Lacy, Projects of the Industrial Pollution Control Branch, U.S. Department of Interior, Federal Water Quality Administration publication 12000-07/70, pp. 1-6, 1970. 3 L. H. Keith, Division of Water, Air, and Waste Chemistry, 157th Meeting, ACS, Minneapolis, Minn., April, 1969. 4 L. H. Keith, A. W. Garrison, M. M. Walker, A. L. Alford and A. D. Thruston, Jr., Division of Water, Air, and Waste Chemistry, 158th Meeting, ACS, New York, N.Y., September, 1969. 5 L. H. Keith, Division of Water, Air, and Waste Chemistry, 163rd Meeting, ACS, Boston, Mass., April, 1972. lOl
6 L. H. Keith and J. M. McGuire, Division of Water, Air, and Waste Chemistry, 164th Meeting, ACS, New York, N.Y., August, 1972. 7 A. W. Garrison, L. H. Keith and M. M. Walker, American Society for Mass Spectrometry, 18th Annual Conference, San Francisco, Calif., June, 1970. 8 A. W. Garrison, L. H. Keith and A. L. Alford, "Fate of Organic Pesticides in the Aquatic Environment, " Advances in Chemistry Series 11 l, (American Chemical Society, Washington, DC, 1972), Ch. 3, pp. 26-54. 9 J. M. McGuire, A. L. Alford and M. H. Carter, American Society for Mass Spectrometry 20th Annual Conference on Mass Spectrometry and Allied Topics, Dallas, Texas, June, 1972. 10 B. C. J. Zoeteman, A. J. A. Kraayeveld and G. J. Piet, HeO, 4, 367 (1971). 11 A. K. Burnham, C. V. Calder, J. S. Fritz, G. A. Junk, J. H. Svec and R. Willis, Anal. Chem., 44, 139 (1972).
102