Environ. Sci. Technol. 1987, 21, 875-883
(16) Pitts, J. N.,Jr.; Sweetman, J. A.; Zielinska, B.; Winer, A. M.; Atkinson, R. Atmos. Environ. 1985, 19, 1601-1608. (17) Code of Federal Regulations, Title 40, Protection of the Environment; Part 50, Subchapter C, Appendix B; p 533. (18) Bidleman, T. F.; Olney, C. E. Bull. Enuiron. Contam. Toxicol. 1974, 11, 442-447. (19) Simon, C. G.;Bidleman, T. F. Anal. Chem. 1979, 51, 1110-1113. (20) Billings, W. N.; Bidleman, T. F. Atmos. Enuiron. 1983, 17, 383-391. (21) Billings, W.N.; Bidleman, T. F. Environ. Sci. Technol. 1980, 14, 679-683. (22) CHN Analyzer Model 185B Operating and Service Manual No. 00185-93001; Hewlett-Packard: Avondale, PA, 1971. (23) Shah, J. J.; Johnson, R. L.; Heyerdahl, E. K.; Huntzicker, J. J. J. Air Pollut. Control Assoc. 1$36, 36, 254-257. (24) Mackay, D.;Bobra, A.; Chan, D. W.;Shiu, W. Y. Environ. Sci. Technol. 1982, 16, 645-649. (25) Yamasaki, H.; Kuwata, K.; Yoshio, K. Nippon Kagaku Kaishi 1984,1324-1329; Chem. Abstr. 1984,101,156747p. (26) Bidleman, T.F.; Simon, C. G.; Burdick, N. F.; Feng, Y. J . Chromatogr. 1984, 301, 448-453. (27) Feng, Y.; Bidleman, T. F. Environ. Sci. Technol. 1984, 18, 330-333. (28) Mackay, D.Environ. Sci. Technol. 1982, 16, 274-278. (29) Eiceman, G. A.; Vandiver, V. J. Atmos. Environ. 1983, 17, 461-465. (30) Oberg, T.;Aittola, J.-P.; Bergstrom, J. G. T. Chemosphere 1985,14, 215-221. (31) Bidleman, T. F. Anal. Chem. 1984, 56, 2490-2496.
5103-71-9; trans-nonachlor, 39765-80-5;Aroclor 1016, 12674-11-2; Aroclor 1254, 11097-69-1; toxaphene, 8001-35-2; benzo[k]fluoranthene, 207-08-9; benzo[a]pyrene, 50-32-8; benzo[ghi]perylene, 191-24-2; dibenz[a,h]anthracene, 53-70-3; indeno[1,2,3-cd]pyrene, 193-39-5; coronene, 191-07-1. L i t e r a t u r e Cited (1) Bidleman, T.F.; Billings, W. N.; Foreman, W. T. Environ. Sci. Technol. 1986,20, 1038-1042. (2) Keller, C. D.; Bidleman, T. F. Atmos. Environ. 1984, 18, 837-845. (3) Yamasaki, H.; Kuwata, K.; Miyamoto, H. Environ. Sci. Technol. 1982, 16, 189-194. (4) Bidleman, T. F.; Foreman, W. 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; p p 27-56. (5) Schwartz, G. P.; Daisey, J. M.; Lioy, P. J. Am. Znd. Hyg. ASSOC.J. 1981, 42, 258-263. (6) Konig, J.; Funke, W.; Balfanz, E.; Grosch, G.; Potts, F. Atmos. Environ. 1980, 14, 609-613. ( 7 ) Spitzer, T.;Dannacker, W. Anal. Chem. 1983,55,2226-2228. (8) Grosjean, D. Atmos. Environ. 1983, 17, 2565-2573. (9) Broddin, G.; Cautreels, W.; Van Cauwenberghe, K. Atmos. Enuiron. 1980, 14, 895-901. (10) Van Vaeck, L.; Van Cauwenberghe, K.; Janssens, J. Atmos. Environ. 1984, 18, 417-430. (11) Van Vaeck, L.;Van Cauwenberghe, K. Atmos. Environ. 1984, 18, 323-328. (12) Brorstrom, E.; Grennfelt, P.; Lindskog, A. Atmos. Enuiron. 1983, 17, 601-605. (13) Brorstrom-Lunden, E.; Lindskog, A. Enuiron. Sci. Technol. 1985,19, 313-316. (14) Yokley, R. A.; Garrison, A. A.; Mamantov, G.; Wehry, E. L. Chemosphere 1985, 14, 1771-1778. (15) Pitts, J. N., Jr.; Zielinska, B.; Sweetman, J. A.; Atkinson, R.; Winer, A. M. Atmos. Environ. 1985, 19, 911-915.
Received for review J u l y 3, 1986. Revised manuscript received February 9, 1987. Accepted April 3, 1987. This project was supported by a g r a n t from the Agricultural Research Service, U S . Department of Agriculture, Specific Cooperative Agreement 58-32U4-4-750.
Linear Alkylbenzenes in Urban Riverine Environments in Tokyo: Distribution, Source, and Behavior Hideshige Takada" and Ryoshi Ishiwatari
Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Fukasawa, Setagaya-ku, Tokyo 158, Japan
and The distribution Of linear linear alkylbenzenesulfonates (LASS) in river sediments, suspended river particles, domestic wastes, and waste effluents around the Tokyo city area was investigated. LABs as well as LASS with alkyl carbon chain lengths in the range from to 14 were found in all environmental ples and LAS-type synthetic detergents examined. These results indicate that LABS are carried into aquatic environments as a result of the use of synthetic detergents around the Tokyo metropolitan area. Further results are (1)LABS in urban river sediments originate predominantly from untreated domestic wastes, final effluents contributing only a minor portion of the LABs in sediments, (2) the isomeric composition of the LABs changes systematically during biodegradation, and (3) the ratio of LAS to LAB decreases as fo~~ows: mnmercial synthetic detergents > suspended Particles in domestic wastes > river sediments > Tokyo Bay sediments. Introduction
Linear alkylbenzenes (LABS)whose alkyl carbon num*Address correspondence to this author at his present address: Department of Environmental Science and Conservation, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183, Japan. 0013-936X/87/0921-0875$01.50/0
bers are 10-14 are used as a raw materaial for synthesizing linear alkylbenzenesulfonates (LASs). The latter are major constituents of commonly used synthetic detergents. Recently the po~~ution of aquatic environments by LABs has been recognized In a previous paper ( I ) , we reported the presence of LABs in surficial sediments of Tokyo Bay and the Tamagawa River, which flows through the area adjacent to Tokyo and into the bay. We concluded that the LABS in these sediments have Probably ~ ~ l t from e d incomplete sulfonation of LABS during the synthesis of LAS-type surfactants and subsequent discharge to aquatic environments by the use of synthetic detergents (LASS). Eganhouse et al. (3) have also drawn a similar conclusion on the basis of detailed studies of the distribution and homologous composition of LAB in coastal sediments, suspended matter, and waste effluents in LOS Angeles and in commercial laundry detergents. Since LABs are thought to be more resistant to microbial degradation in aquatic environments than LASs ( I ) , LABs are useful as molecular tracers of domestic wastes and, more specifically, synthetic detergent pollution. In urban areas, a significant portion of domestic wastes is usually discharged into adjacent rivers, causing heavy river pollution. Ammonium (413 ABS (5),LAS (6, 71, and COprOStanOl (8-12) are well-known pollutants originating from domestic wastes. In order to control the pollution
0 1987 American Chemical Society
Environ. SCI.Technol., Vol. 21, No. 9, 1987 875
E
on Site of Suspended
35O2L N Flgure 1. Sampling stations of sediment, suspended particles from rivers, and waste water treatment plant,
of rivers, it is important to know how much domestic wastes are discharged into rivers and to what extent these wastes remain in rivers. LABs are expected to be an indicator of domestic waste pollution. However, little is known about the distribution and behavior of LABs in urban aquatic environments. The purpose of this study is (1)to describe the distribution of LABS in rivers, domestic wastes, and waste effluents in the Tokyo metropolitan area, (2) to discuss the source(s), degradability, and behavior of LABs in comparison with LASS, and (3) to evaluate LABs as molecular indicators of domestic waste pollution. Site DescriptionlSampling Tokyo with an area of 13 500 km2 and a population of 28.7 X lo6 people [Tokyo city and adjacent areas (Tokyo, Saitama, Kanagawa, and Chiba prefectures)] is one of the most urbanized cites in the world (13). A large amount of domestic sewage is discharged into adjacent rivers or coastal regions with or without treatment. Domestic wastes from about 57% of the population, most of which is concentrated in the Tokyo city area, are directly discharged into rivers without treatment (14). Sediment samples and suspended river particles were taken from the nine major rivers entering Tokyo Bay (Tables I and I11 and Figure l),in particular from the Tamagawa and Sumidagawa Rivers. The Tamagawa River is a typical urban river 140 km in length with a mean flow of approximately 15 m3/s (station 15). The population and area of its drainage basin are 3.0 X lo6 and 1240 km2, respectively (14). Both untreated and treated wastes are discharged into the river. Fifty-five percent of the people inhabiting this drainage basin are served by sewerage treatment, and untreated domestic wastes are discharged into the middle and lower stream. The Sumidagawa River is also a typcial urban river having a length,of 50 km and a mean flow of approximately 30 m3/s (station 1). The population and area of its drainage basin are 5.0 X lo6 and 611 km2, respectively (15). This river also receives untreated and treated wastes. Seventy percent of the people inhabiting this drainage basin are served by sewerage treatment, and untreated domestic wastes are discharged into the upper stream. River sediment samples were taken in 1982 and 1983, with an Ekman dredge. The sediments were stored in glass or stainless steel jars a t -20 "C. 876
Environ. Sci. Technol., Vol. 21, No. 9, 1987
Suspended river particles were collected by in situ filtering 200-600 L of grab water sample through a glass fiber filter (Toyo Roshi GB 100R, nominal pore size = 0.6 pm) that had been previously baked a t 400 "C for 5 h to prevent organic contamination. The glass fiber filter on which the suspended particles were attached was wrapped with aluminum foil and stored at -20 "C. The locations of six municipal waste water plants, from where suspended particle samples were taken, are shown in Figure 1. In all the plants, waste water receives primary and secondary treatment (by activated sludge). The secondary effluent is discharged into the rivers and Tokyo Bay. The activated sludges are incinerated or landfilled after solidification with cement. Suspended particle samples in both influents and treated effluent were collected by in situ filtering 20-1000 L of grab water sample. The details of the method for collecting these suspended particles were the same as those for the riverine samples. For some influent samples, LABs in filtrates were also analyzed. Three 600-mL benzene extractions were performed on the 8-L filtrate samples with a glass separatory funnel within 2 h of in situ filtering. The combined organic extracts were concentrated to a small volume for analyses. Commercial synthetic detergents (LAS type) were bought in the Tokyo area in 1983. Experimental Section Alkylbenzenes. The procedure for analysis of alkylbenzenes has been previously described (16) and will not be further detailed here. Freeze-dried sediment samples (ca. 5 g) were Soxhlet-extracted with 150 mL of benzenemethanol (6:4) for 18 h. In the case of suspended particles, a freeze-dried glass fiber filter containing suspended particles was Soxhlet-extracted with 1.5 L of benzenemethanol (6:4) for 18 h. The cycling rates for the extractions were 15 min/cycle for sediment samples and 45 rnin/cycle for suspended particle samples. The organic solvent extract was concentrated to dryness and taken up in 5 mL of benzene. Elemental sulfur in the extract was converted to copper sulfide by addition of 0.5 g of activated copper. The extract was then applied to a Florisil column (1.0 cm i.d. X 8 cm) for removal of copper sulfide and polar materials (pigments). The first 30 mL of benzene eluate was collected and evaporated to dryness. The eluate was then taken up in 0.3 mL of n-hexane and subjected to silica
gel column chromatography (Mallinckrodt 100 mesh, 0.5 cm i.d. X 18 cm). Normal hexane was used as an eluent to give three fractions: 0-5, 5-18, and 18-60 mL. The second n-hexane fraction, containing LABs, was evaporated to just dryness and taken up in an appropriate volume of isooctane. A small portion was then injected into a Hewlett-Packard 5880A gas chromatograph equipped with a flame ionization detector (FID) and a 25 m by 0.3 mm i.d. SE-54 fused-silica capillary column in the splitless mode a t 50 "C. The column was maintained at 50 "C for 2 min, followed by heating to 120 "C at 30 deg/min, and then temperature programmed from 120 to 220 "C at 3 deg/min with He as the carrier gas. The FID was maintained at 310 "C and the injection port at 300 "C. Peak identification was performed by the use of retention indexes and/or the coinjection with a standard mixture of linear alkylbenzenes supplied by Mitsubishi Petrochemical Co. (16). Alkylbenzene concentrations reported here were computed by using response factors of 1-Clo-AB, l-Cll-AB, 1-C12-AB,l-CIS-AB, and 1-Cl4-ABthat were determined from a gas chromatographic run on the same day, assuming that the response factor of n-C,-AB is the same as that of 1-C,-AB (n-C,, n indicates the position of substitution of benzene to the alkyl chain and m indicates the number of carbons in the alkyl chain). In order to test LAB recovery, 2.5 pg of l-Clo-AB, 1Cll-AB, 1-C12-AB,and l-CIS-ABwas added to the organic solvent extract from 5 g of sediment samples from the Tamagawa River and analyzed by GC after taking all steps of the analytical procedure. The percent recovery was 94 f 4, 84 f 5, 89 f 3, and 81 f 2 for 1-Clo-AB, l-Cll-AB, l-C,,-AB, and l-CIS-AB,respectively. The reproducibility was determined by triplicate analyses of the well-homogenized sediment sample. The relative standard deviation of individual LAB concentration is below 14%. The detection limits are 0.01 ng of total LABs/g of dry sediment and 0.1 ng of total LABs/L. For analysis of synthetic detergents, a 100-mg sample was transferred to a 50-mL centrifuge bottle and extracted with 10 mL of n-hexane for 1 h in an ultrasonic bath. Then, 30 mL of 3 N HC1 was added to the bottle and vigorously shaken. After centrifugation (10 min, 2000 rpm), the n-hexane layer was transferred to a 50-mL round-bottom flask. The residual aqueous solution was reextracted with n-hexane and centrifuged. The extraction was repeated 3 more times, followed by evaporation of the combined extracts to a small volume (-0.3 mL). The extract was then subjected to silica gel column chromatography, and the LABs were quantified by the same procedure as used for the sediment samples. Linear Alkylbenzenesulfonates (LASs). For freeze-dried sediment and suspended particulate samples, LAS was Soxhlet-extracted with benzene-methanol (6:4), and the extracts were evaporated to dryness under reduced pressure. The residue containing LAS was dissolved into about 20 mL of distilled water, and 1 mL of 0.025% methylene blue solution was added to the solution. LAS-methylene blue complex was then extracted with 10 mL of chloroform. The chloroform layer was transferred to a 50-mL round-bottom flask, after which the residual aqueous solution was reextracted 3 times with chloroform. The combined extract was evaporated to dryness under reduced pressure, dissolved in a small amount of ethanol, and passed through a cation-exchange column (Dowex 50W-X8, 50-100 mesh; 1.0 cm i.d. x 5 cm) for removal of methylene blue. The first 10 mL of ethanol eluate (containing LAS) was then evaporated, and the residue was
dissolved in about 20 mL of water. The aqueous solution was washed with chloroform and concentrated to a small volume (below 1 mL). LAS was quantified by gas chromatography following derivatization as methyl sulfonates (17) or by an HPLC method (18,19). The gas chromatographic analyses were applied to sediment and the suspended river particulate samples, whereas the HPLC method was applied to detergents and suspended particles from the influents and the effluents. For gas chromatographic analysis of LAS, an aqueous solution purified by procedure described above was evaporated to dryness. LAS was derivatized into methyl sulfonates by reaction with phosphorus pentachloride at 110 "C for 10 min and then with methanol at 70 "C for 20 min. The methanol solution containing methyl sulfonate derivatives was evaporated, and the residue was dissolved in n-hexane and transferred to a glass bottle (1mL). The n-hexane solution was evaporated to dryness and taken up to an appropriate volume of n-hexane. LAS methyl esters were analyzed with a 25 m by 0.3 mm i.d. SE-54 fused-silica capillary column on a HewlettPackard 5880A gas chromatograph. Samples dissolved in n-hexane were injected onto the capillary column in the splitless mode at 50 "C. The column was maintained at 50 OC for an initial 2 min, followed by heating to 220 "C at 30 deg/min, and then temperature programmed from 220 to 300 "C at 6 deg/min with He as a carrier gas. The FID was maintained a t 310 "C and the injection port at 300 "C. LAS methyl esters were identified by GC/MS and/or the coinjection with methyl esters of standard mixture of LAS supplied by Kao Corp. Ltd. HPLC analytical conditions were essentially the same as those reported by Nakae et al. (18, 19). Briefly, LAS was analyzed on a Hitachi 655 high-performance liquid chromatograph with a fluorometric detector (excitation at 225 nm and emission at 295 nm). Ten microliters of an aqeuous sample solution was injected via a Rheodyne 7125 syringe loading injector fitted with a 20-pL sample loop and separated on a 15 cm X 4.6 mm i.d. Hitachi Gel 3053 ODS (5-pm particle) reversed-phase column at a flow rate of 1.0 mL/min. Sodium perchlorate (0.1 M) in acetonitrilelwater (45:55) was employed to separate LAS. LAS was identified by coinjection with a standard mixture of LAS supplied by Kao Corp. Ltd. and/or the comparison of retention times with those reported by Nakae et al. (19). In both methods, LAS concentrations were computed by using the response factor of Cl,-LAS authetnic standard (a mixture of 6-C12-LAS 5-C1,-LAS + 4-CI2-LAS 3Cl,-LAS 2-Cl,-LAS) that was determined from a run on the same day. The C12-LASstandard was purchased from Wako Chemical Ltd. In order to test LAS recovery, 50 pg of the CI2-LAS standard was added to the organic solvent extract from a sediment sample (Tamagawa River) and analyzed. The recovery was 98.6 f 0.2% for the gas chromatographic method and 100 f 11% for the HPLC method, respectively. The reproducibility was determined by replicate analyses of the well-homogenized sediment. Total LAS concentration was 138 f 6 pg/g of dry sediment (duplicate) by gas chromatographic method and 146 f 5 pg/g of dry sediment (triplicate) by HPLC method.
+
+
+
Results and Discussion In the following, we describe the results of LABs and LASs in river sediments, commercial LAS-type detergents sold in the Tokyo area, municipal waste water influents (untreated domestic waste), and secondary effluents as well as suspended river particles in order to gain insight into Environ. Sci. Technot., Vol. 21,No. 9, 1987
877
Table I. Linear Alkylbenzenes (LABs) and Linear Alkylbenzenesulfonates (LASs) in River Sediments LABs
river
sampling date
Sumidagawa Sumidagawa Sumidagawa Sumidagawa Sumidagawa Sumidagawa Tamagawa Tamagawa Tamagawa Tamagawa Tamagawa Tamagawa Tamagawa Tamagawa Tsurumigawa Arakawa Nakagawa Edogawa Edogawa Muratagawa Yorogawa Obitsugawa
10/29/82 10/29/82 10/29/82 10/29/82 12/1/82 2/5/83 2/12/83 2/12/83 2/15/83 2/13/83 2/5/83 2/5/83 2/5/83 2/5/83 2/5/83 2/9/83 2/9/83 2/9/83 2/9/83 2/6/83 2/6/83 2/6/83
location 1
2 3 5 6 7 8 10 11
13 14 16 17 18 19 20 21 22 23 24 25 26 avd SD 27
Tokyo Baye
concn, Pg/g of dry sediment
9/80
0.56 3.24 3.95 12.11 4.25 7.07 0.01 4.04 15.79 5.33 4.57 0.64 3.40 1.75 4.29 4.01 2.35 0.91 0.15 0.02 0.12 0.01 3.60 3.90 0.59
relative abundance"
G O
C11
ClZ
C13
C14
2 5 4 4 4 4
19 25 25 26 26 19
37 37 33 28 29 37
12 10 6 11 12 12
3 3 3 3 3 4 2 3 5 3 0
21 23 20 20 17 23 19 20 26 16 13
33 33 35 34 44 33 37 34 26 35 38
11
10 12 12 10 6 9 13 14 15 26
3 1
21 4
0
11
30 31 31 31 29 30 nd' 31 32 30 31 25 34 31 30 29 31 23 nd nd nd nd 30 3 29
34 4 47
12 4 13
I/Eb ratio 1.47 1.29 1.68 1.09 1.74 1.33 nd 1.62 1.85 1.44 1.45 1.51 1.29 1.54 1.72 1.18 1.66 1.82 nd nd 1.35 nd 1.48 0.20 1.47
LAS concn, Pg/g of dry sediment
LAS/ LAB ratio
67.4 155 106 42 2 72.1 109 nd 173 567 143 142 50.8 48.2 36.3 65.8 63.1 19.0 7.4 1.5 0.6 4.7 0.6 107 138
120 48 27 35 17 15 nd 43 36 27 31 79 14 24 15 16 8 8 10 29 40 5 31 26 1
1
4Percent of total LAB represented by each homologous group. bRatio of 6-Ci2-AB + 5-C12-ABrelative to 4-Clz-AB + 3-CI2-AB+ 2C1,-AB. Not determined. dArithmetic mean computed bv weighting each measurement eauallv. 'Ref 1. Table 11. Linear Alkylbenzenes (LABS) and Linear Alkylbenzenesulfonates (LASs) in Commercial Synthetic Detergents
use
maker
clothes
A
B
C dishes
D A B
sample 1
2 3-1 3-2 4- 1 4-2 5 6 7 8 9 10 avd
form granular granular granular granular granular granular granular granular liquid granular liquid liquid
SD
concn, Pg/g
LABs rrelative e l a w abundance"
CIO ClO
CH Cl1
C CIZ~ Z
C13
C14
3 2 3 4
18
27 27 34 36 33 32 32 32 35 36 36 29 32 3
31 32 40 35 42 36 39 30 13 44 34 23 34 8
21 23 1
106 117 440 702 222 222 98 486 184 230 95 537 290 190
3
4 2 3 9 2 8 8 4 2
16
;:
20 20 16 17 35 18 22 28 21 5
1
2 8 11 18 7 0 0 12 9 8
I/Eb ratio
LAS concn, mg/g
LAS/ LAB ratio
0.63 0.63 0.69 0.64 0.95 0.96 0.89 0.87 0.68 0.97 0.70 1.08 0.81 0.15
299 299 327 ndc 216 nd 131 368 292 323 278 250 278 63
2720 2490 740 nd 980 nd 1310 750 1620 1400 2780 460 1550 860
"Percent of total LAB represented by each homologous group. bRatio of 6-CIz-AB + 5-C12-ABrelative to 4-ClzAB + 3-Culz-AB + 2Ciz-AB. Not determined.i2 Arithmetic mean computed by weighting each measurement equally.
the detailed behavior of LABs in the aquatic environment in the Tokyo area. Linear Alkylbenzenes in River Sediments. Figure 2a shows a representative gas chromatogram of LABs isolated from sediments. As reported in a previous paper ( I ) , the alkyl chain length of the LABs ranges from 10 to 14. All isomers except for l-C,-AB were found in these samples. Table I gives analytical results of the LAB determinations in the river sediments, and Figure 3a shows the distribution of LABs in sediments around Tokyo. Total LAB concentrations in the river sediments examined range from 0.01 to 15.8 Kg/g of dry sediment. Except for two sediment samples with high concentrations (stations 5 and 11),most samples give values below 5 pg/g. These values 878
Environ. Sci. Technol., Vol. 21, No. 9, 1987
are slightly higher than those found in Tokyo Bay sediments ( I ) . Similar values (1.1-33.0 Kg/g of dry sediment) have been reported in Los Angeles coastal sediments ( 3 ) . LABs are dominated by CI2-ABand CIS-ABhomologues, Clo-ABand CI4-ABhomologues being minor constituents. The composition of the LAB homology in the sediment samples is on the average 3% (range, 0 4 % ) C,o-AB, 21% (13-26%) CIl-AB, 30% (23-34%) CIZ-AB, 34% (26-44%) CIB-AB,and 12% (6-2670) C14-AB,respectively. The homologous compositions show no major differences between rivers or between sites of a given river. Linear Alkylbenzenes in Commercial LAS-Type Detergents. Figure 2b shows a representative gas chromatogram of LABs in a commercial synthetic detergent. Table I1 gives analytical results of 12 synthetic detergents
Table 111. Linear Alkylbenzenes (LAB*) a n d Linear Alkylbenzenesulfonates (LASs) i n Suspended Particles from River Water suspended LABs
river
sampling date
Sumidagawa Sumidagawa Tamagawa Tamagawa Tamagawa
7/29/83 7/29/83 8/7/83 8/7/83 8/10/83
station 1 4 10 12 15
suspended solids, mg/L
ng/ L
concn wg/g of dry material
23.0 9.7 7.9 8.9 8.0 11.5 5.8
721 226 57 37 205 249 248
31.3 23.3 7.2 4.2 25.6 18.3 10.7
avc
SD
relative abundance" Clo Cll Clz C13 C14
I/Eb ratio
suspended LAS concn, pg/L
LAS/ LAB ratio
31 27 36 27 29 30 3
1.09 1.61 1.45 2.67 1.47 1.66 0.53
53.8 4.8 1.3 0.5 2.5 12.6 20.7
75 21 23 14 12 29 33
2 0 4 1 1
2 1
19 11 20 12 13 15 4
37 46 32 43 43 40 5
11 16 9 17 14
13 3
"Percent of total LAB represented by each homologous group. bRatio of 6-C12-AB+ 5-Clz-AB relative to 4-C12-AB+ 3-C12-AB+ 2ClZ-AB. e Arithmetic mean computed by weighting each measurement equally. Table IV. Linear Alkylbenzenes (LABs) a n d Linear Alkylbenzenesulfonates (LASs) i n Suspended Particles from Waste Water Influent suspended LABS treatment plant A
C E avd SD
sampling date 8/24/84 10/5/84 11116/84 12118/84 3/22/85 7/22/85 12/17/85 5/16/86 8/7/86 avc SD 8/7/84 6/29/84
suspended solids, mg/L
ng/L 2150 4710 1990 3610 3340 4270 5560 3310 5040 3780 1160 1040 1020 1970 1330
114 169 115 171 137 149 94 184 153 143 29 162 87 131 32
concn rg/g of dry material 18.9 27.9 17.2 21.2 24.4 33.6 59.1 18.0 32.9 28.1 12.4 6.4 11.7 15.4 9.2
Clo 1 3 3 3 3 1 0 2 1 2 1 0 3 2 1
relative abundancen C11 C ~ Z C13 10 19 17 15 17 15 8 12 15 14 3 9 14 12 2
26 34 34 22 31 32 28 27 32 30 4 29 33 31 2
39 32 30 35 32 40 46 36 39 37 5 46 34 39 5
I/Eb c 1 4
ratio
24 12 16 15 17 12 18 23 13 17 4
0.64 0.76 0.81 0.77 0.78 0.67 0.72 0.66 0.71 0.72 0.06
16 16 16 1
0.62 0.73 0.69 0.05
suspended LAS concn, I%/L
LAS/ LAB ratio
789 1504 876 1225 768 447 987 871 621 899 297 1216 236 780 410
370 320 440 340 230 89 180 260 123 260 110 1170 230 550 440
apewent of total LABS represented by each homologous group. *Ratio of 6-C12-AB+ 5-C12-ABrelative to 4-CI2-AB + 3-C12-AB+ 2-CI2-AB. e Arithmetic mean computed by weighting each measurement equally. Arithmetic mean computed by weighting each influent equally. Table V. Linear Alkylbenzenes (LABs) a n d Linear Alkylbenzenesulfonates (LASs) i n Suspended Particles from Waste Water Effluent suspended LABS treatment plant A B C D E
F avd SD
sampling date 8/1/83 8/1/83 7/29/83 8/10/83 6/29/84 11/2/84 7/16/84
suspended solids, mg/L 2.2 3.8 0.9 1.6 ndc 1.6 2.4 2.1 0.9
concn ~
ng/L
wg/g of dry material
72.5 138 8.1 45.2 55.9 45.3 51.3 61.0 39.4
33.0 36.3 9.5 28.3 nd 28.3 21.4 26.1 8.7
relative abundance" Clo C1, Clz C13 1 2 0 1 1 0 3 1 1
13 18 12 17 11 11
19 15 3
29 30 26 31 31 37 34 31 3
40 38 45 36 43 43 36 40 3
C14
I/Eb ratio
suspended LAS concn, wg/L
LAS/ LAB ratio
17 12 16 15 15 9 9 13 3
3.01 2.73 7.28 2.59 2.95 3.92 1.95 3.50 1.74
0.673 1.22 0.100 0.230 0.350 0.178 0.293 0.463 0.381
9 9 12 5 6 4 6 8 3
"Percent of total LABS represented by each homologous group. bRatio of 6-CI2-AB + 5-C12-ABrelative to 4-C12-AB+ 3-CI2-AB 2-CI2-AB. Not determined. dArithmetic mean computed bv weighting each effluent eauallv.
sold by different Japanese companies. All detergent samples examined contain Clo-AB to Cl4-ABat concentrations ranging from 95 to 702 hg/g. No big differences in LAB content are observed among the commercial detergents. Similar values have been obtained for those sold in the U.S. (20). ABS in most detergents are dominated by C12-ABand CIS-ABhomologues, while sam-
+
ples 7 and 10 show more Cll-AB and C12-ABthan other LABs. C,,-ABs are minor and the most variable homologues representing 0 4 3 % of total LABS. The homologous composition of LABS in these LAS detergents is essentially the same as that used in the U.S. (20). Linear Alkylbenzenes in Suspended River Particles and Suspended Particles in Waste Water InEnviron. Sci. Technoi., Vol. 21, No. 9, 1987
879
Time + Figure 2. Representative gas chromatograms of alkylbenzenes in (a) river sediment (station 13),(b) synthetic detergent (sample l), (c) suspended particles from river water (station 15),(d) suspended particles from waste water influent (plant A, 11/16/84), and (e) suspended particles from waste water effluent (plant A).
fluents and Effluents. Figure 212-e shows representative gas chromatograms of LABs in suspended particles from rivers, waste water influents, and effluents. Tables 111, IV, and V give the corresponding analytical results. Total suspended LAB concentrations in the river water samples range from 37 to 721 ng/L, which is 10-100 times 880
Environ. Sci. Technol., Vol. 21, No. 9, 1987
lower than those in the domestic wastes and 1-10 times higher than those (8-138 ng/L) in the effluents of sewage treatment plants. Thus, LAB concentrations determined on a volume basis decrease in the following order: domestic wastes (waste water influents) >> river water > waste water effluents. LAB concentrations determined on a dry weight basis for suspended river particles, domestic wastes, and final effluents are similar (tens of micrograms per gram of dry material). These concentrations are about 10 times higher than those for river sediments. LABs in suspended particles are again dominated by CI2-ABand C13-ABhomologues, and CIo-ABand CII-AB homologues are minor. Figure 4 compares the homologous compositions of LABs in synthetic detergents with those in environmental samples. As shown in Figure 4, homologous compositions of LABs in river sediment samples and in suspended river and waste water particles resemble those in the detergents, except for the following minor points: Clo-ABand Cll-AB are slightly low and Cl4-AB is slightly high for the suspended particles as compared with those in the detergents. These minor differences could be explained by chemical and biological changes suffered in the environment and/or slightly higher solubility of lower molecular weight LABs than higher molecular weight LABs to water. Comparison of Amounts of LABs in Waste Waters with Those Expended for Domestic Use. Here, we move into the comparison of the amounts of LABs in waste waters with those expended for domestic use. Waste water treatment plant A (cf. Figure 1)was used in the following calculation as a representative because this plant is one of the largest waste water treatment plants in the Tokyo area, and the influents contain mainly domestic waste water (24). In making this calculation, the following assumptions are made: (1)All LAS detergents produced in Japan are consumed by the people in Japan (1.2 X lo8) (23). (2) Only domestic LAS detergents enter into the treatment plant. This assumption may be reasonable because 90% of LAS produced in Japan is for domestic use (22). (3) No LABs are lost during usage of detergents. (4) LABs enter into the treatment plant only in the form of suspended particles. The annual production of LAS detergents for domestic use in Japan is estimated to be 745 X lo9 g (21, 22). Therefore, the average consumption rate of LAS detergents per person is calculated to be 17.0 g/(capita.day). Treatment plant A receives domestic sewage from approximately 1.3 X lo6 persons (24). Consequently, the daily discharge of LAS detergents in this drainage basin should be 2.2 X lo7 g/day. Since the LAB concentration in LAS detergents determined in this study (Table 11) is 290 pg/g on the average (range, 95-700 pg/g), the daily discharge of LABs in this drainage basin amounts to 6.4 X lo3 g/day (range, 2.1 X lo3 to 15 X lo3 g/day). On the other hand, the amount of waste water treated by this plant is approximately 4.3 X lo5 m3 per day (24), and the measured LAB concentration (present as suspended particles) in untreated waste waters (influents to this plant) is 3.78 pg/L on the average (range, 1.99-5.56 pg/L). Consequently, LABs actually reaching treatment plant A amount to 1.6 X lo3 g/day (range, 0.86 X lo3 to 2.2 X lo3 g/day). Therefore, LABs found in the influents of treatment plant A amount to approximately 25% of those estimated to be carried into the plant. Most of the remaining 75% is probably accounted for by LABs entering the treatment plant in dissolved form by the following reason. The concentration of LABs in dissolved form was found to be
16pg/g-dry sediment
___I_
580 pg/g-dry sediment
Figure 3. Distribution of LABS (a) and LASS (b) in river sediments. Number indicates station number 501 Synthetic detergent 1 River sediment
Table VI. Linear Alkylbenzenes (LABs) in Dissolved Phase and Suspended Phase from Waste Water Influentn
LO 30 s 20
s 10 ,g
LABS concn
I / E ratio sampling dissolved, suspended, dissolved/ dissusdate ng/L ng/L suspended solved pended
-e
8l
9
cia
6 1 c12 c13 ClL
6 0 c11 6 2 c13 Cli
7/22/85 12/17/85 5/16/86 8/7/86
LO
5 30 = 20
4980 4940 9690 4300
4270 5560 3310 5040
1.2 0.9 2.9 0.9
0.82 0.77 0.71 0.81
0.67 0.72 0.66 0.71
From treatment plant A.
10 ClO cll c12 c13 ClL
ClO cl1 c12 6 3 c1L
ClO cl1 6 2 c13 ClL
Figure 4. Homologous composition of LABS in synthetic detergents and environmental samples. n indicates the number of samples. Bar indicates the standard deviation.
1-3 times greater than those in suspended phase as shown in Table VI. These mass balance calculations indicate that unsulfonated hydrocarbon residues (alkylbenzenes)associated
with LAS detergents are supplied in large enought amounts to account for the LABs found in the wastes. Similar mass balance calculations were conducted for the Joint Water Pollution Control Plant (JWPCP) in the Los Angeles area by Eganhouse et al. ( 3 ) . In that case, only 1390 of the LABs found in waste in Los Angeles can be accounted for by unsulfonated hydrocarbon residue. This difference in mass balance between the treatment plant in the Tokyo area and the one in Los Angeles reamins unexplained so far. Environ. Sci. Technol., Vol. 21, No. 9, 1987
881
Contribution of Untreated Waste Water Derived LABs to LABs in Urban Rivers, Relative to Treated Waste Water Derived LABs. As shown in Tables IV and V, the average suspended LAB concentrations of waste water influents and effluents of the treatment plants examined are 1970 f 1330 and 61 f 39 ng/L, respectively. This result indicates that 97% of LABs in domestic waste waters (influents) is removed by the sewage treatment. LABS are probably removed by biodegradation and solids removal, because the municipal waste water receives primary and secondary treatment in the plants. Since the isomeric composition of LABs was different between the influents and the effluents, as described later (Changes in Isomeric Composition of LABS Caused by Selective Biodegradation), LABs may be biodegraded during treatment. Solids removal appears also very effective in removing LABs since there is no practical difference between LAB concentrations per unit weight of suspended particles in influent and effluent waters. This interpretation is supported by the fact that the activated sludge taken at treatment plant C was found to contain considerable amounts of LABs (60.8 pg/g of dry material). This high efficiency of removal of LABs indicates that a sewage treatment plant plays a very important role in minimizing LAB pollution in aquatic environments (rivers and estuarine), because activated sluge is not discharged to the aquatic environment in the Tokyo area, as described before (Site Description/Sampling). This also suggests that LABs found in river suspended particles and sediments in the Tokyo are originate primarily from untreated domestic waste water rather than from treated waste water effluents. The relative contribution of untreated domestic waste water and treated effluents to LAB pollution to two major rivers in the Tokyo area (the Sumidagawa and Tamagawa Rivers) can be calculated. The following assumptions were used in making these calculations: (1)In the area where people are not served by waste water treatment plants, the per capita amount of LABs discharged into a river is same as that in influents to treatment plants. (2) In the area where people are served by waste water treatment plants, the per capita amount of LABs discharged into a river is 3% of that in influents, on the assumption that 97% of LABs are removed by sewage treatment. In the drainage basin of the Sumidagawa River, 30% of the population are not served by waste water treatment plants. Therefore, the amount of LABs coming from untreated domestic wastes relative to that from treated waste water is (100x 0.30):(3 x 0.70) = 141, indicating that 93% of the LABs in the river are of untreated domestic waste origin. In the case of the Tamagawa River, the approximate contribution of untreated waste water derived LABS relative to that of treated waste water derived ones is (100 x 0.45):(3 x 0.55) = 27:1, indicating that 96% of the LABS in the river are derived from untreated domestic waste. These calculations indicate that LABs in these rivers are almost entirely derived from untreated domestic wastes. Changes in Isomeric Composition of LABs Caused by Selective Biodegradation. Figure 2a-e shows isomeric distributions of LABs in synthetic detergents and environmental samples, For the detergents and untreated domestic wastes (suspended particles) the relative abundance of isomers is almost equal. For river sediments and suspended particles from river water and effluents the internal isomers (e.g., 6-CI2-AB)dominate over external isomers (e.g., 2-C12AB). For a quantitative comparison of internal isomers against external isomers, we adopted the phenyldodecanes 882
Environ. Sci. Technol., Vol. 21, No. 9, 1987
Table VII. Variation i n I / E Ratios among Synthetic Detergents a n d Environmental Samples no. of samples
average
range
synthetic detergents
12
0.81 f 0.15 0.63-1.08
suspended particles from waste water influent suspended particles from waste water effluent suspended particles from river water river sediments
11
0.69 f 0.05 0.62-0.81
7
3.50 zk 1.74 1.95-7.28
5
1.66 f 0.50 1.09-2.67
Tokyo Bay sediment
18 1
1.48 f 0.20 1.09-1.85 1.47
as a representative because they are the most abundant among LABs for all environmental samples examined. Table VI1 gives ratios of 6-C12-AB+ 5-Cl,-AB relative to 4-Cl2-AB + 3-C12-AB 2-C12-AB(I/E ratio is used hereafter) for synthetic detergents and environmental samples. The difference in I / E ratio among environmental samples is thought to be caused by selective biodegradation of external isomers relative to internal isomers, as suggested by Eganhouse et al. (3). The following preliminary laboratory biodegradation experiment was conducted to test this hypothesis. Three hundred liters of waste water (influent water at treatment plant A) was collected in a large plastic bottle without filtration and incubated at room temperatures (27-29 OC) with stirring and continuous aeration for 6 days. At appropriate time intervals, a water sample (20 L) was taken and filtered through a glass fiber filter (Toyo Roshi GB 100R) and analyzed for LABs. The total LAB concentration in suspended particles for the initial water sample of this incubation experiment was 4.3 pg/L. The results clearly demonstrated an increase in the I / E ratio by incubation (biodegradation) as follows: 0.67 (0 day), 0.93 (1 day), 1.18 (2 days), 2.10 (3 days), 3.65 (4 days), 5.95 (5 days), and 7.00 (6 days). These results support the interpretation that the difference in I / E ratios among environmental samples is probably caused by microbial degradation. Another possible cause that alters the isomeric composition of LABs is fractionation due to physicochemical partitioning. For the influents, however, the I / E ratios of LABs in the dissolved phase are almost the same as those in the suspended phase as shown in Table VI. This indicates that partitioning has practically no effect on the isomeric composition of LABs. The average I / E ratios for suspended river particles is 1.66 f 0.50 and that for river sediments is 1.48 f 0.20. These values fall between those for waste water influents (0.69) and those for effluents (3.50). This supports our interpretation that the treated effluents are not the major contributor to LABs in river sediments. Moreover, I / E ratios suggest that although LABs were degraded in river water, the degree of degradation was less than those in the treatment plants. Here, the following interesting fact should be pointed out on the difference in I/E ratios of LABs in treatment effluents between the Tokyo area and the Los Angeles area (JWPCP, Joint Water Pollution Control Plants) (3). I/E ratios for JWPCP show no difference from those for LAS detergents, suggesting that in JWPCP no practical biodegradation has occurred. On the other hand, those ratios for the plants in the Tokyo metropolitan area are much higher than those for LAS detergents, as already shown in Table VII. This big difference in I / E ratios of LABS between the treatment plants in the Tokyo area and
+
Table VIII. Variation in LAS/LAB Ratios among Synthetic Detergents a n d Environmental Samples no. of samples synthetic detergents suspended particles from waste water influent suspended particles from waste water effluent suspended particles from river water river sediments (upper and middle streamIc river sediments (lower stream)b Tokyo Bay sediment
10 11
average
range
1550 f 860 460-2930 550 f 440 120-1170
7
8f3
4-13
5
29 f 23
12-75
8
46 f 29
27-120
13
22 f 19
5-79
1
Samples at stations 1-5, and 8-15. and 16-26.
1
Samples a t stations 6, 7,
JWPCP is clearly due to the difference in treatmnet process. In the municipal treatment plants in the Tokyo area, waste waters receive primary and secondary treatment. On the contrary, in JWPCP, waste waters receive no secondary treatment (25). The extent of biodegradation of LABs in the rivers can be estimated in light of our incubation experiment of waste water described above, by assuming that the results of the incubation experiment are valid for the natural environment. I/E ratios (1.1-2.7) of LABs in the riverine suspended particles as well as the river sediments roughly correspond to those observed on 2-4 days from the start of the incubation experiment, where 30-50% of the total LABs in the initial waste water were decomposed. Thus, the degree of biodegradation of LABs in the suspended river particles and sediments may be 30-50%. The similarity of the degree of biodegradation of LABs between river suspended particles and river sediments indicates that suspended particles are deposited quickly to sediments and degraded only slowly thereafter. Differences in Behavior between LABs and LASs in Aquatic Environment a n d T h e i r Implications. LABs and LASs are discharged into the aquatic environment a t the same time as a result of detergent use. The distributions of both compounds in river sediments were examined to gain insight into the differences in their behavior in the aquatic environment. Tables I-V give LAS concentrations and LAS/LAB ratios in the environmental samples and the detergents. As in obvious in Figure 3, the distribution of total LABs in the river sediments is similar to total LASs. Concentrations are high at stations 5 and 11 and low at stations 22-26. However, LAS/LAB ratios for the environmental samples are extremely small as compared with that of commercial synthetic detergents. As summarized in Table VIII, the ratios decrease in the following order: synthetic detergents >> suspended particles in domestic wastes >> river suspended particles = river sediments > estuarine sediments > Tokyo Bay sediment. This order of decreasing LAS/LAB ratio indicates the progressive depletion of LASs relative to LABs with exposure to the aquatic environment. This result can be explained by the higher water solubility and biodegradability of LASs compared to LABs. Therefore, if the factors regulating the LAS/ LAB ratio are studied in greater detail, it may be possible to estimate the approximate time of exposure of LAS detergents in the aquatic environment.
Conclusions This study has demonstrated that LABs occur as ubi-
quitous constituents in the riverine environment of Tokyo and that untreated domestic wastes are a major source of LAB pollution in the rivers in this study area. Thus, these results have given evidence to support the hypothesis that LABs in aquatic environment result from incomplete sulfonation of LABs during LAS surfactant production with subsequent disposal into the environment with LAS-type detergents. Furthermore, the results of this study provide support for the utility of LABS as molecular tracers of domestic wastes in aquatic environment. In particular, the following results are important in getting information on the degree of biodegradation and the residence time of LAS detergent in aquatic environment: (1)the isomeric composition of LABs changes systematically during biodegradation, and (2) the ratio of LASs to LABs decreases with progressive exposure of LAS-type detergent to the aquatic environment.
Literature Cited Ishiwatari, R.; Takada, H.; Yun, S.-J.; Matsumoto, E.
Nature (London) 1983, 301, 599. Takada, H.; Ishiwatari, R.; Yun, S.-J. Jpn. J. Water Pollut. Res. 1984, 7, 172. Eganhouse, R. P.; Blumfield, D. L.; Kaplan, I. R. Environ. Sci. Technol. 1983, 17, 523. Ogura, N. Jpn. J. Limnol. 1980, 41, 138. Ambe, Y. J. Oceanogr. Soc. Jpn. 1973,29, 1. Hon-nami, H.; Hanya, T. Water Res. 1980, 14, 1251. Utsunomiya, A.; Itoh, S.; Setsuda, S.; Naito, S.; Shimozato, T. Eisei Kagaku 1980,26, 159. Hatcher, P. G.; McGillivary, P. A. Enuiron. Sci. Technol. 1979, 13, 1225. Hosoya, K.; Ogura, N. Jpn. J. Limnol. 1982, 43, 199. Ogura, N.; Ichikawa, Y. Chikyu Kagaku (Nippon Chikyu Kagakkai) 1983,17, 76. Ogura, K. Chikyu Kagaku (Nippon Chikyu Kagakkai) 1983, 17, 68. Brown, R. C.; Wade, T. L. Water Res. 1984, 18, 621. Planning of Tokyo; Bureau of City Planning, Tokyo Metropolitan Government: Tokyo, Japan, 1981.
Data of Quality of Riverine and Estuarine Water in Tokyo; Tokyo Metropolitan Bureau of Environmental Protection: Tokyo, Japan, 1983. Fukushima, K.; Takada, H.; Hanya, T. Compr. Urban Studies 1984, 21, 21. Takada, H.; Ishiwatari, R. J. Chromatogr. 1985,346,281. Hon-nami, H.; Hanya, T. J . Chromatogr. 1978,161, 205. Nakae, A.; Tsuji, K.; Yamanaka, M. Anal. Chem. 1980,52, 2275. Nakae, A.; Tsuji, K.; Yamanaka, M. Anal. Chern. 1981,53,
1818. Eganhouse, R. P.; Ruth, E. C.; Kaplan, I. R. Anal. Chem. 1983, 55, 2120. “Year Book of Chemical Industries Statistics”; Research and Statistics Department Minister’s Secretariat, Ministry of Trade and Industry: Japan, 1983. 7379 no Kagakushohin; Chemical Daily: Tokyo, Japan, 1979. 1980 Population Census of Japan Abridged Report Series NO. 1, Population of Japan; Statistics Bureau, Prime
Minister’s Office: Japan, 1980.
Sewerage in Tokyo; Sewerage Bureau of Tokyo Metropolitan Government: Tokyo, Japan, 1983. Eganhouse, R. P.; Kaplan, I. R. Environ. Sci. Technol. 1982, 16, 180.
Received for review May 19, 1986. Revised manuscript received December 10, 1986. Accepted May 14, 1987. This work was partly supported by the Ministry of Education, Science and Culture, Japan (Grants 58030062,59030064,and 6030069), and The Tokyu Foundation for the Better Environment (Grant 5724). Environ. Sci. Technol., Vol. 21, No. 9, 1987 883
