Environ. Sci. Technol. 1969,23, 1126-1129
McCall, P. L.; Tevesz, M. J. S.In Animal Sediment Relations; McCall, P. L., Tevesz, M. J. s., Eds.; Plenum Publishing: New York, 1982, p 336. Rhoads, D. C. Mar. Biol. Rev. 1974,12, 263-300. Davis, R. B. Limnol. Oceanogr. 1974, 19, 466-488. Rodgers, P. W.; Swain, W. R. J . Great Lakes Res. 1983,9,
(71) Capel, P. D.; Eisenreich, S. J. In Influence of Aquatic Humic Substances on Fate and Treatment of Pollutants; (72)
Suffet, I. H., MacCarthy, P., Eds.; Advances in Chemistry 219; American Chemical Society: Washington, DC, 1989. Porter, L. K.; Kemper, W. D.; Jackson, R. D.; Stewart, B. A. Soil Sci. SOC.Am. Proc. 1960,24,460-463. Formica, S. J.; Kemper, W. D.; Thibodeaux,L. J.; Valsaraj, K. T. Environ. Sci. Technol. 1988,22, 1435-1440. Geankoplis, C. J. Mass Transport Phenomena; Edward Bros. Inc. Publishing: Columbus, OH, 1972; pp 182-184. Steen, W. C.; Paris, D. F.; Baughman, G. L. Water Res.
548-558.
(73)
Looney, B. B. Ph.D. Thesis, University of Minnesota, Minneapolis, MN, 1984. Rapaport, R. A.; Eisenreich, S.J. Environ. Sci. Technol.
(74)
1988,22, 931-941.
(75)
Rapaport, R. A,; Urban, N. R.; Capel, P. D.; Baker, J. E.; Looney, B. B.; Eisenreich, S.J. Chemosphere 1985, 14,
1978,12,655-657. (76) Eadie, B. J.;Rice, C.; Frez, W. In Physical Behavior of PCBS i n the Great Lakes; Mackay, D., Paterson, S., Eisenreich, S.J., Simmons, M. S., Eds.; Ann Arbor Science Publishers: Ann Arbor, MI, 1983, p 213. (77) Hutzinger, 0.;Safe, S.; Zitko, V. The Chemistry of PCBs; CRC Press: New York, 1974. (78) National Academy of Sciences Polychlorinated Biphenyls; NAS: Washington, DC, 1979. (79) Furukawa, K. In Biodegradation and Detoxification of Environmental Pollutants; Chakrabarty, A. M., Ed.; CRC Press: Boca Raton, FL, 1984; pp 33-58. (80) Safe, S. In Microbial Degradation of Organic Compounds; Marcel Dekker, Inc.; New York, 1980. (81) Brown, J. F.; Wagner, R. E.; Bedard, D. L.; Brennan, M. J.; Carnahan, J. C.; May, R. J.; Toffemire, T. J. Northeast. Environ. Sci. 1984, 3, 166-178. (82) Quensen, J. F., 111; Tiedje, J. M.; Boyd, S. A. Science 1988, 242, 752-754. (83) Capel, P. D. Ph.D. Thesis, University of Minnesota, Minneapolis, MN, 1986.
1167-1 173.
Rapaport, R. A.; Eisenreich, S.J. Atmos. Environ. 1986, 20, 2367.
Kaiser, K. L. E. Environ. Sci. Technol. 1978,12, 520-528. Scrudato, R. J.; DelPrete, A. J . Great Lakes Res. 1982,8, 695-699.
Pickett, R. L.; Dossett, D. A. J . Phys. Oceanogr. 1979, 9, 441-445.
Baker, J. E.; Capel, P. D.; Eisenreich, S.J. Environ. Sci. Technol. 1986,20, 1136-1143.
Elzerman, A. W.; Coates, J. T. In Sources and Fates of Aquatic Pollutants; Hites, R. A,, Eisenreich, S. J., Eds.; Advances in Chemistry 216, American Chemical Society: Washington, DC, 1987; pp 263-317. Hartig, R. In Highlights of Water Quality and Pollution Control i n Michigan; Publ. No. 4833-9804, Michigan Dept. of Natural Resources: East Lansing, MI, 1981. Knap, A. H.; Binkley, K. S.; Deuser, W. G. Nature 1986, 319, 572-574. Lefkovitz, L. M.S. Thesis, University of Wisconsin, Madison, WI, 1987.
Strachan, W. M. J.; Eisenreich, S. J. Mass Balancing of Organic Contaminants in the Great Lakes: the Role of Atmospheric Deposition. Report of the International Joint Commission, Windsor, Ontario, 1988. Mackay, D., Paterson, S., Eisenreich, S. J., Simmons, M. S., Eds.; Physical Behavior of PCBs i n the Great Lakes; Ann Arbor Sciences Publishers: Ann Arbor, MI, 1983. Wu, S.-C.; Gschwend,P. M. Water Resour. Res. 1988,24, 1373-1383.
Received for review June 21,1988. Revised manuscript received April 12,1989. Accepted May 8,1989.This research was supported i n part by Grant DOC-NAB1 -RAH00005 from the National Oceanic and Atmospheric Administration of the US. Department of Commerce, and by the Minnesota Sea Grant College under support by the N O A A Office of Sea Grant, Department of Commerce (Journal Reprint No. 231). The US. Government is authorized to reproduce and distribute reprints for government purposes, not withstanding any copyright notation that may appear hereon.
Nature and Properties of Some Chlorinated, Lipophilic, Organic Compounds in Spent Liquors from Pulp Bleaching. 2. A. Bruce McKague,+ Marie-Claude Kolar, and Knut P. Kringstad
Swedish Pulp and Paper Research Institute (STFI), Box 5604, S-114 86 Stockholm, Sweden
w Lipophilic material isolated from a sample of spent liquor prepared by laboratory chlorination of a softwood kraft pulp was found to contain tetrachlorothiophene (1)) 3-formyl-2,4,5-trichlorothiophene (2), and 3-acetyl-2,4,5trichlorothiophene (3). Quantities found in a spent liquor from mill-scale bleaching of a n oxygen prebleached softwood pulp with a mixture of chlorine (85%)and chlorine dioxide (15%) ranged from 26 to 88 mg/tonne of pulp. The latter liquor also contained a number of isomers of dichloro-p-cymen-8-014 in a total quantity of 1000 mg/ tonne of pulp. Only one of the compounds 2 showed weak mutagenic activity to Salmonella typhimurium strain TA100; however, all were chemically stable in water at pH 7 for a 2-week period and exhibited a significant potential for bioaccumulation. Introduction In recent years, knowledge on the composition and bit Present address:
CanSyn Chemical Corp., 2982 W. 44th Ave.,
Vancouver, BC, V6N 3K4, Canada.
1126 Environ. Sci. Technol., Voi. 23, No. 9, 1989
ological effects of the spent liquors from the bleaching of chemical pulp has improved considerably. Thus, to date 90-95% of the organic material present in such (spent chlorination and alkaline extraction) liquors, including some 300 separate compounds, have been identified or well characterized (1). Some of the identified compounds are known to exert weak acute toxic or genotoxic effects. One question that needs further investigation concerns the existence and properties of lipophilic compounds in spent bleach liquors. This question is of importance from an environmental point of view since such compounds have potential for bioaccumulation in aquatic organisms. In a previous paper, initial results arising from the incorporation of reversed-phase thin-layer chromatography (RPTLC) into the systematic investigation of chlorinated, lipophilic compounds in spent bleach liquors were reported (2). The work described the identification and properties of perchlorocyclopentene-l,3-dione and three new chlorinated enol lactones found in the spent chlorination liquor. Further investigations using the same approach as de-
0013-936X/89/0923-1126$01.50/0
@ 1989 American Chemical Society
scribed in Part 1 have resulted in the identification and characterization of additional compounds. This paper reports the characterization and properties of chlorinated thiophenes and cymenols found in spent chlorination liquor. Experimental Section
Spent Chlorination Liquor. An industrially prepared unbleached softwood kraft pulp having a K number of 37.7 was used to prepare spent chlorination liquor for the isolation and identification of chlorinated thiophenes. The K number is a measure of the lignin content of pulp, higher numbers indicating greater amounts of lignin. The pulp was atypical of pulps produced in most mills in Sweden, which now employ oxygen prebleaching to reduce the K number prior to bleaching with chlorine. The pulp was washed in the laboratory, bleached a t 3.5% pulp consistency a t room temperature with 7.5% chlorine charge on pulp for 1 h, and then filtered to give the liquor having a pH of 1.5. Samples of spent chlorination liquor from a pulp mill producing bleached softwood kraft pulp were used for the isolation and identification of chlorinated cymenols and quantification work. The mill employs oxygen bleaching prior to five successive stages consisting of (C85+D15)E,DED where C means chlorine, D chlorine dioxide, and E alkaline extraction with NaOH. Oxygen is also added during the first E stage. The K number of the oxygen-bleaching pulp was 18.5, and it was bleached a t 40 "C for 25 min. Isolation and Identification of Lipophilic Compounds. The three-step sequence employed involving hexane extraction, RPTLC, and Si02 fractionation was described in Part 1 (2). Identifications of chlorinated thiophenes and cymenols were confirmed by comparison of GC retention times and mass spectra with standards prepared as described below. For quantification a 4-L sample of mill liquor was extracted with hexane (2 X 150 mL). The combined extracts were washed once with saturated NaCl (100 mL), dried over anhydrous MgSO,, and concentrated to 5-10 mL. The volume was then made up to 10 mL with hexane. Lindane internal standard was added to 1 mL of the concentrate and the quantities of formyltrichlorothiophene 2 and acetyltrichlorothiophene 3 were determined by GC using a 30-m DB5 fused-silica capillary column programmed from 120 to 200 "C at 5 "C/min and an ECD detector. To determine the amount of tetrachlorothiophene (l),1 mL of the hexane concentrate was passed through a silica gel column and the column eluted with hexane-CH2Clp (9:l; 10 mL). The eluate was concentrated to 1mL, lindane internal standard added, and 1 determined by GC/ECD. To determine cymenols, 5 mL of the hexane concentrate was evaporated to approximately 0.1 mL, lindane internal standard added, and the sample analyzed by GCMS using conditions described in Part 1 (2). Chemical Standards. Tetrachlorothiophene (1) was purchased from Aldrich Chemical Co., Milwaukee, WI. 3-Formyl-2,4,5-trichlorothiophene (2) was prepared by chlorination of 3-formylthiophene in the presence of AlC13 as described in the literature (3). The reaction was monitored by GC/FID on a 30-m fused-silica capillary column a t 130 OC until the relative amount of 2 reached 70-80% (approximately2 h). The crude product, obtained as a pale yellow solid, was heated a t 190 "C for 2 h. After cooling, fractionation on SiOz and elution with hexaneCHzC12(41) gave a 55% yield of pure 2. Crystallization from hexane gave light yellow needles: mp 56-57 "C [lit. (4) mp 58 "C];
IR (KBr pellet) u, 1680 cm-';UV (hexane) A, 226 nm (15200), 253 (6630), 300 (2070); 13CNh4R (CDCl$6 123.09, 123.64, 130.56, 137.62, 181.71 (C6); mass spectrum, m/e (relative intensity) 218 (25) [M + 4]+, 217 (40) [M + 3]+, 216 (75) [M + 2]+, 215 (98) [M + l]', 214 (75) M', 213 (loo), [M - 1]+. 3-Acetyl-2,4,5-trichlorothiophene (3) was prepared by passing chlorine into a solution of 3-acetylthiophene in CH2C12containing a 2.5 mol ratio of AlC13 below 10 "C for 1h. Ice water was then added and the mixture stirred 10 min. The CH2C12layer was separated and the aqueous layer extracted once more with CH2C12. The combined extracts were washed with water, dried with anhydrous MgS04, and evaporated to give a yellow oil, which was then heated a t 190 "C for 5 h. The product was cooled and fractionated on SO2. Elution with hexane-CH2C12 (3:l) gave a 33% yield of 3 as a pale yellow oil, which was crystallized from hexane to give pale yellow needles: mp 22-23 "C, IR (film)u,, 1690 cm-'; UV (hexane) A, 224 IUII (11200), 249 (6160); 'H NMR (CDC13) 6 2.61; 13C NMR (CDC13) 6 31.04 (C7), 121.94,122.95,128.69,136.14,192.70 (C6); mass spectrum, m/e (relative intensity) 232 (15) [M 4]+, 230 (41) [M 2]+, 228 (43) M+, 217 (33) [M + 4 15]+,215 (100) [M + 2 - 15]+,213 (98) [M - 15]+, 187 (18), 185 (la), 143 (20), 141 (20), 115 (35), 43 (32). Dichloro-p-cymen-8-014was prepared from dichloro-pcymene (5) by bromination with N-bromosuccinimide in refluxing CCll containing a catalytic amount of benzoyl peroxide. After 6 h, the product was cooled, filtered, washed with 5% NaHC03 and water, and dried over anhydrous MgS04. The crude bromination product was heated in water containing a small amount of AgN03 a t 90 "C for 2 h. After cooling, the hydrolysis product was extracted with ether in the usual manner and the crude product fractionated on SOz. Elution with hexane-ether (4:l) gave the major isomer of 4 in 20% overall yield from dichloro-p-cymene as a clear colorless oil. Crystallization from hexane gave colorless needles of 4: mp 49-50 "C; IR (KBr pellet) u, 3350,1470,1440,1410 cm-'; W (hexane) A, 228 nm (9680), 272 (480), 282 (450); 'H NMR (CDC13) 6 1.7 (s, 6 H, C9 and ClO), 2.3 (8,3 H, C7), 7.2 (s, 1 H, arom), 7.7 (s, H, arom); mass spectrum, m/e (relative intensity) 220 (15) [M + 2]+, 218 (22) M+, 205 (66) [M + 2 - E ] + , 203 (100) [M - E ] + , 43 (73). Elution of the Si02 column with hexane-ether (2:l) gave a minor isomer of 4 in -4% overall yield from dichloro-p-cymene as a clear oil. This isomer was not characterized except its mass spectrum was identical to the major isomer described above. Dichlorocarvacrol 5, prepared by the chlorination of carvacrol, had mp 40-42 "C after crystallization from hexane [lit. (6) mp 40-41 "C, (7) mp 45-46 "C]: Mass spectrum, m/e (relative intensity) 220 (20) [M + 2]+, 218 (30) M', 205 (60) [M 2 - 15]+, 203 (100) [M - 15]+,168 (15). Mutagenicity Tests. Ether solutions (20 pL/plate) of the synthesized compounds were tested for mutagenicity in the dose range from 2 pg to 4 mg per plate by using the Ames test (8). Salmonella typhimurium TAlOO was used without metabolic activation. The mutagenic activity of pulp mill effluents is normally lower when S9 is used. Much lower mutagenic activity was observed when strain TA98 was tested. All test values reported are mean values of six plates. Quercetin dihydrate (Fluka AG) was used as a positive control. Determination of the Bioaccumulation Potential. The determination of the bioaccumulation potential was
+
+
+
Envlron. Sci. Technol., Vol. 23, No. 9, 1989
1127
carried out by the method based on RPTLC giving RM' 2.
(9-11).
Stability Tests. A solution containing 10 mg/L of each of the compounds 1-4 in pH 7 phosphate buffer was stirred at room temperature. Aliquots were removed after various periods of time, naphthalene internal standard was added, and the aliquots were extracted with ether. The extracts were washed once with water, dried over anhydrous MgS04, concentrated to a small volume, and analyzed by GC at 130 "C using a 30-m DB1 fused silica capillary column and flame ionization detector. Results and Discussion Identification of Chlorinated Thiophenes a n d Cymenols. Isolation of lipophilic material from the sample of softwood kraft pulp chlorination liquor prepared in the laboratory and fractionated on RPTLC and Si02 as described in Part 1gave a number of components that had mass spectra suggestive of chlorinated thiophenes. The presence of various chlorinated thiophenes, thiophene aldehydes, and acetylthiophenes in spent sulfate bleach liquors was first reported by Lindstrom and Nordin on the basis of mass spectral interpretations (12).Since that time, other reports of the presence of chlorinated thiophenes in kraft bleach liquors have appeared in the literature (13, 14) although, with the exception of a recent report by Carlberg et al. (15), structural assignments for possible isomers of the thiophene aldehydes and acetylthiophenes have not been made, and the biological and chemical properties have not been determined. Tetrachlorothiophene (1) was readily identified in lipophilic material isolated from the sample of spent bleach liquor prepared in thc laboratory. The compound eluted
roo1
i=v) z
203
r
I
L3
E
50
OH
W
1
? c
218
4
I w I :
IJ
ul
L.L .,I .A
125 3
.I
LO.
..
187 .I#
d
i
I.
5'0
260
250
Flgure 1. Mass spectra of dichlorocymen-8-ol4 and dichlorocatvacrol 5.
Table I. Quantities of Chlorinated Thiphenes and Dichlorocymen-8-01s Found in Spent (C85 D1S) Bleach Liquor
+
compd mg/tonne of pulp 1 2
compd mg/tonne of pulp 3 4
26 88
37
1000
In order to determine the position of the hydroxyl group, dichloro-p-cymenolsthat had the hydroxyl group located in both possible positions were synthesized. A comparison of the mass spectra of the major dichloro-p-cymen-8-01 isomer 4 obtained by the benzylic bromination/hydrolysis
p c 1 2
&OH
CI
OH
1
2
2
in the least polar fraction from Si02 with hexaneCH2C12 (9:l) and was identified by comparison with the commercial sample. 3-Formyl-2,4,5-trichlorothiophene (2) and 3-acetyl-2,4,5-trichlorothiophene(3), which were present in the same sample of liquor, were identified in the hexane-CHzC12 (1:l)eluate from SiOa by comparison of their GC retention times and mass spectra with the synthetic compounds. In addition, samples of 2-formyl- and 2acetyltrichlorothiophene, supplied by G. Carlberg, were found to have different GC retention times from the corresponding 3-formyl- and 3-acetyltrichlorothiophene isomers and thus could be readily distinguished on this basis. Both isomers of formyltrichlorothiophene gave the same mass spectra. The acetyltrichlorothiophene isomers also gave the same mass spectra, as expected, the base peak being due to loss of a methyl group from the molecular ion. Lipophilic material isolated from a pulp mill spent liquor from the (C85+D15) bleaching of an oxygen-prebleached softwood kraft pulp was also found to contain a number of isomers of dichlorohydroxycymenes. These compounds, which were not found in the laboratory-prepared liquor, were also reported by Lindstrom et al. (13) while, a t about the same time, Dyrssen (16)and Eklund et al. (17)reported the presence of the corresponding monochlorohydroxycymenes in spent chlorination liquor from sulfite pulping. Whether the hydroxyl group is located on the ring or on a side chain has not been firmly established, although most publications, including a recent report by Voss (18) now appear to favor the a position on the isopropyl group. 1128
Envlron. Sci. Technol., Vol. 23, No. 9, 1989
4 1. of dichloro-p-cymene and of dichlorocarvacrol5 showed both compounds had a base peak of m/e 203 and a molecular ion with a relative intensity of 20-3070 (Figure l). The major differences in the spectra of the two compounds were the presence of an intense mle 43 peak in the spectrum of dichloro-p-cymen-8-01and a small m/e 168 peak in that of dichlorocarvacrol. These differences allowed us to identify the compounds in the lipophilic fraction as three isomers of dichloro-p-cymen-8-014. The retention time of the major isomer in the bleach liquor was identical with that of the synthesized isomer. Quantities of Chlorinated Thiophenes and Cymen8-01s i n (C85+D15)-Stage Liquor. The quantities of chlorinated thiophenes and combined isomers of dichlorocymen-8-01s in spent (C85+D15)-stage liquor from a mill employing oxygen prebleaching are shown in Table I. The quantities of chlorinated thiophenes are in the same range as estimated by Lindstrom and Nordin (12) at a time when standards were not available. A reduction in the K number by oxygen prebleaching undoubtedly reduces the quantities of lignin-derived lipophilic compounds produced in the subsequent chlorine-bleaching stage; however, the amounts of the combined isomers of dichlorocymen-8-01s appear high, suggesting sources other than the lignin in unbleached pulp are involved. For example, cymenols may be present in water condensates used to wash the pulps prior to bleaching. Mutagenicity and Potential for Bioaccumulation. None of the chlorinated thiophenes 1 and 3 or dichlorop-cymen-8-014 possess significant mutagenic activity. The chlorinated thiophene 2 has a weak mutagenic activity when tested with Salmonella typhimurium TAlOO (Table
Table 11. Potential for Bioaccumulation and Mutagenicity of Chlorinated Thiophenes and Dichlorocymen-8-01
net revertants./RM' ('log Po,") pmol for TAlOO a 1 4.68 2 3.21 52 a 3 3.55 a 4 3.91 a No significant mutagenic activity could be observed. compd
11). The bioaccumulation potential was estimated, as in Part 1(2),by measurement of RM ("log Paw") values, which determine lipophilicity. RMo (log Paw)values for the chlorinated thiophenes and dichloro-p-cymen-8-01 are given in Table 11. The values are generally higher than those reported in Part 1for the chlorinated enol lactones identified in bleach liquor and are in the same range as some chlorinated phenols that have been shown to bioaccumulate in fish. Since the chlorinated thiophenes and cymenols appear to be fairly stable (see next section), analysis of fish tissue may also reveal the presence of these compounds. Chemical Stability. Contrary to the results reported in Part 1,where perchlorocyclopentene-1,3-dioneand the chlorinated enol lactones were found to be very unstable a t pH 7, the chlorinated thiophenes 1-3 and dichlorocymen-8-014 were more stable. More than 40% of tetrachlorothiophene (1) and 3-formyltrichlorothiophene (2) and more than 90% of acetyltrichlorothiophene 3 and dichlorocymen-&ol4 were recovered from pH 7 phosphate buffer after 2 weeks a t room temperature. It is not surprising that these compounds are more stable than the chlorinated lactones reported in Part 1 (2)since they are chlorinated aromatic compounds. Voss (18)reported even nonchlorinated acetylthiophenes are only removed to the extent of 50% by an aerated lagoon. Voss also found that chlorinated cymenols were stable to biotreatment. Our stability tests, which were done in buffered aqueous solution, may not be indicative of the stability in mill biotreatment systems.
-
Conclusions Spent chlorination liquors from the bleaching of softwood kraft pulps may contain chlorinated thiophenes and
cymenols that are somewhat resistant to chemical degradation. The compounds have little or no mutagenic activity, however, but have a significant potential for bioaccumulation. Registry No. 1, 6012-97-1; 2, 61200-61-1; 3, 89284-87-7; 4, 92366-35-3; 5, 60741-51-7; 3-Acetylthiophene, 1468-83-3; dichloro-p-cymene, 65724-12-1. Literature C i t e d (1) Jarl, M.; McKague, B.; Kringstad, K. P. Submitted for
publication in Sven. Papperstidn. (2) McKague, A. B.; Kolar, M.-C.; Kringstad, K. P. Environ. Sci. Technol. 1988, 22, 523. (3) Gronowitz, S.; Ander, I. Tetrahedron 1976, 32, 1403. (4) Profft, E.; Petzold, H. E. J . Prakt. Chem. 1962, 16, 26. (5) Bj~neth, A.; Carlberg, G. E.; Maller, M. Sci. Total Enuiron. 1979, 11, 197. (6) Carpenter, M. S.; Easter, W. M. J . Org. Chem. 1955, 20, 401. (7) French Patent 736, 304; Chem. Abstr. 1933,27, 1362. ( 8 ) Maron, D. M.; Ames, B. N. Mutat. Res. 1983, 113, 173. (9) Renberg, L. 0.;Sundstrom, S. G.; RosBn-Olofsson, A X . Toxicol. Environ. Chem. 1985, 10, 333. (10) Butte, W.; Fooken, C.; Klussman, R.; Schuller, D. J . Chromatogr. 1981,214, 59. (11) Kringstad, K. P.; de Sousa, F.; Stromberg, L. M. Environ. Sci. Technol. 1984, 18, 200. (12) Lindstrom, K.; Nordin, J. Sven. Papperstidn. 1978,81,55. (13) Lindstrom, K.; Nordin, J.; Osterberg, F. In Advances in the Identification and Analysis of Organic Pollutants in Water; Keith, L. H., Ed.; Ann Arbor Science Publishers: Ann Arbor, MI, 1981; Vol. 2, p 1039. (14) Talka, E.; Priha, M. Pap. Puu 1987, 69, 221. (15) Carlberg, G. E.; Johnsen, S.; Landmark, L. H.; Bengtsson, B.-E.; Bergstrom, B.; Skramstad, J.; Storflor, H. Paper presented at the Second IAWPRC Symposium on Forest
Industry Wastewaters, Tampere, Finland, June 9-12,1987, (16) Dyrssen, D. Prog. Water Technol. 1978,10, 893. (17) Eklund, G.; Josefsson, B.; Bjarseth, A. J . Chromutogr. 1978, 150, 161. (18) Voss, R. H. Environ. Sci. Technol. 1984, 18, 938. Received for review June 9, 1988. Revised manuscript received November 22,1988. Accepted: April 5,1989. This investigation was supported by the Environmental Research Foundation of the Swedish Pulp and Paper Associations, project *Environment 90-project 1-Bleaching Effluents". GCMS work was done by Pierre Ljungquist.
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