Acknowledgment We thank John Small, William Articola, Elizabeth Bailey, and Eugene Mroz for their help with sample collection; Harry Dodson, Robert Halbrook, and the staffs of the Alexandria Municipal Incinerator and the Solid Waste Reduction Center # 1 for access to their plants and help in sampling; and the staff of the Natural Bureau of Standards reactor for their help with irradiations. Computer time was provided in part by the University of Maryland Computer Science Center. Literature Cited (1) Council on Environmental Quality, “Toxic Substances”, GPO, Washington, D.C., 1971. (2) Schroeder, H., Environment, 13(8),18 (1971). (3) Gladney, E. S., Small, J. A., Gordon, G. E., Zoller, W. H., Atmos. Enuiron., 10,1071 (1976); Gladney, E. S., PhD thesis, University of Maryland, College Park, Md., 1974. (4) Klein, D. H., Andren, A. W., Carter, J. A., Emery, J. F., Feldman, C., Fulkerson, W., Lyon, W. S., Ogle, J. C., Talmi, Y., Van Hook, R. I., Bolton, N., Enuiron. Sci. Technol., 9,973 (1975). (5) Kaakinen, J. W., Jorden, R. M., Lawasani, M. H., West, R. E., ibid., p 862. (6) Natusch, D.F.S., Wallace, J. R., Evans, C. A., Science, 183,202 (1974). (7) Small, J. A., PhD thesis, University of Maryland, College Park, Md., 1976. (8) Bertine, K. K., Goldberg, E. D., Science, 173,233 (1971). (9) Hegdahl, T. S., “Report on a Study of the Alexandria, Virginia Incinerator”, USHEW, Public Health Service, Bureau of Solid Waste Management, Rep. No. SW-12ts, 1970. (10) D.C. Bureau of Solid Waste Disposal, Dept. of Environmental Services, “Solid Waste Reduction Center # l”, 1975. (11) Pilat, M. J., Ensor, D. S., Bosch, J. C., Atmos. Enuiron., 4,671 (1970). (12) Zoller, W. H., Gordon, G. E., Anal. Chem., 42,257 (1970). (13) Ondov, J. M., Zoller, W. H., Olmez, I., Aras, N. K., Gordon, G. E.. Rancetelli. L. A.. Abel. K. H.. Filbv. R. H.. Shah. K. R.. Ragaini. R.’C., ibid., 47,1102 (1975). (14) Greenberg, R. R., PhD thesis, Universitv of Maryland, College Park, Md., 1377. (15) Sullivan, P. M., Makar, H. V., “Quality of Products from Bureau of Mines Resource Recovery Systems and Suitability for Recycling”, Proc. of 5th Mineral Waste Utilization Symp., 1976. (16) Gordon, G. E., Zoller, W. H., Gladney, E. S., in “Trace Substances in Environmental Health-VII”, pp 161-6, D. D. Hemphill, Ed., University of Missouri, Columbia, Mo., 1974. (17) Wedepohl, K. H., in “Origin and Distribution of the Elements”, pp 999-1016, L. H. Ahrens, Ed., Pergamon Press, London, England, 1968. (18) Kowalczyk, G. S., Choquette, C. E., Gordon, G. E., Atmos. Enuiron., to be published. i
“
I
I
-
.
I
(19) Mass. Dept. of Public Health, Bureau of Environ. Sanitation, “Special Report on Investigation and Study of Air Quality in the Metropolitan (Boston) Air Pollution Control District, 1965-1966”, Sept. 1968; Morganstern, P., Goldish, J. C., Davis, R. F., “Air Pollution Emission Inventory for the Metropolitan (Boston) Air Pollution Control District”, Walden Research Corp., June 1970. (20) USHEW, Nat. Air Pollution Control Admin., “Air Quality Criteria for Particulate Matter”, Publ. No. AP-49,1969. (21) State of Maryland, Dept. of Natural Resources, Power Plant Cumulative Impact Rep. PPSP-CEIR-1, Sept. 1975. (22) Bay Area Air Pollution Control District, “Source Inventory of Air Pollutant Emissions in the San Francisco Bay Area”, 1972. (23) Hopke, P. K., Gladney, E. S., Gordon, G. E., Zoller, W. H., Jones, A. G., Atmos. Enuiron., 10,1015 (1976). (24) Akland, G. G., “Air Quality Data for Metals 1970 through 1974 from the National Air Surveillance Networks”, EPA Rep. No. EPA-600/4-76-041, 1976; Akland, G. G., private communication, 1974. (25) Trout, D., “Analysis of Ambient Air Quality in the Vicinity of the Parkway Incinerator”, Battelle Columbus Labs, 1975. (26) Friedlander, S. K., Enuiron. Sci. Technol., 7,235 (1973). (27) Hammerle, R. H., Pierson, W. R., ibid., 9, 1058 (1975). (28) John, W., Kaifer, R., Rahn, K., Wesolowski, J. J., Atmos. Enuiron., 7,107 (1973). (29) Brar, S. S., Nelson, D. M., Kline, J. R., Gustafson, P. F., Kanabrochi, E. F., Moore, C. E., Hattori, D. M., J . Geophys. Res., 71, 2939 (1970). (30) Dams, R., Robbins, J. A., Rahn, K. A., Winchester, J . W., in “Nuclear Techniques in Environmental Pollution”, pp 139-57, Int. Atomic Energy Agency, Vienna, Austria, 1971. (31) Eisenbud, M., Kneip, T. J., “Trace Metals in Urban Aerosols”, Electric Power Res. Inst. Rep. No. EPRI-117, Oct. 1975. (32) Dzubay, T., Stevens, R., Enuiron. Sci. Technol., 9, 663 (1975). (33) Young, J., Laulaine, N., Wendell, L., Tanner, T., “The Use of Elemental Concentration Ratios to Distinguish between Plumes of Different Northeastern Cities”, Battelle Pacific Northwest Labs, Annual Rep., Dec. 1975. (34) Andren, A. W., Klein, D. H., Talmi, Y., Enuiron. Sci. Technol., 9,856 (1975). (35) Hoffman, G. L., Duce, R. A., ibid., 5 , 1134 (1971). (36) Ondov, J. M., PhD thesis, University of Maryland, College Park, Md., 1974. (37) Gladney, E. S., Zoller, W. H., Jones, A. G., Gordon, G. E., Enuiron. Sci. Technol., 8, 551 (1974). (38) Carotti, A., Smith, R. A., “Gaseous Emissions from Municipal Incinerators”, EPA Rep. No. SW-18C, 1974. (39) Staff Rep., Enuironment, 13 (4), 24 (1971). (40) Sheng, H., Alter, H., Resour. Recou. Conuersion, 1 (3) (1976). (41) Campbell, W. J., Enuiron. Sci. Technol., 10,436 (1976). Receiued for review May 31,1977. Accepted November 10,1977. Work supported by the National Science Foundation RANN Program under Grant No. AEN75-02667.
Aquatic Environmental Safety Assessment for a Nonphosphate Detergent Builder Alan W. Maki” Environmental Safety Department, The Procter & Gamble Co., lvorydale Technical Center, Cincinnati, Ohio 452 17
Kenneth J. Macek EG&G, Bionomics Inc., Wareham, Mass. 0257 1
Research efforts to formulate builder systems to act as effective alternatives for phosphate-containing detergent formulations have led to the development of a particular crystalline compound termed Type-A zeolite. I t is a synthetic hydrated sodium aluminosilicate crystallized from aluminosilicate gels and is empirically similar to naturally occurring kaolin clay (Figure 1) (1).Its structure is based on a sharing of all oxygens by linked A104 and Si04 tetrahedra in the form of a porous, three-dimensional solid. The unit cell formula, exclusive of the cations, is (A102)12(Si02)12.27H20. Zeolites have been used for many years in various water 0013-936X/78/0912-0573$01 .OO/O
0 1978 American Chemical Society
treatment operations including water softeners and as ionexchange resins. An extensive literature has accumulated based on the use of natural materials, such as green sand or glauconite, and synthetic zeolite water softeners ( 2 ) . At present there are over 30 identified naturally occurring zeolite minerals as well as over 90 synthetically produced varieties. The purpose of this investigation was to develop an aquatic safety assessment program for the evaluation of risk to aquatic organisms associated with the use of Type-A zeolite in detergent formulations. The effects of clay suspensions and sediments on aquatic life have been examined by numerous Volume 12, Number 5, May 1978
573
The results of a testing program designed to assess the aquatic safety of Type-A zeolite as a nonphosphate builder in detergent formulations are summarized. Type-A zeolite is a synthetic sodium aluminosilicate empirically similar to naturally occurring kaolin clay. Laboratory toxicity tests were designed to estimate concentrations of zeolite safe to aquatic species under both freshwater and marine exposure conditions in order that observed effect concentrations could be compared to expected environmental levels. Surface water con-
natural clay material. This paper summarizes the results of these investigations carried out with laboratory populations of algae, aquatic macroinvertebrates, and fish. Environmental safety factors were determined for freshwater and marine aquatic species based on calculated surface water concentrations of zeolite.
0
Two-dimensional Representation of an AluminosilicateFramework
I
0-Si-0
I I
0
0
I
0-AI;O-Si-O-AI:O-Si-
I
I
0
0
I
0-Si-0
I
0 Form
Mean Particle Size rU) Origin Chem cal Composition Empwcal Formula AI SI Molal Ratio Percent M ~ i s l ~ r e
Kaolln Clay
Type A Zeolite
Fine pawdir 4
Fine pawder
Georgia
3 Syn1neliC
AlUminOstliCate
AlUminOSiliCsle
A I Q O S~i 0 1 ZHOH
NarO A1201 ZSIO, 4 5HOH i t 21 1%
11
13 9%
centrations resulting from zeolite use at a level equivalent to 20% in all US.detergent formulations are estimated to be less than 0.20 mg/L. Ratios of observed no-effect concentrations of zeolite on aquatic life to this expected surface water concentration range from greater than 250 to greater than 1000, indicating that the proposed use of Type-A zeolite as a nonphosphate builder for detergents would result in no significant environmental impact at expected usage levels.
Figure 1. Chemical and physical structure of synthetic Type-A zeolite as related to naturally occurring kaolin clay
investigators (Table I). The most widely held view appears to be that suspended solids in rivers harm fish indirectly by damaging food supplies or spawning grounds through siltation of eggs and that sediments do not harm adult fish directly unless present at concentrations of several g/100 mL ( 4 4 ) . A review of this literature tends to substantiate the minimal effects of clay suspensions on aquatic species (Table I). Since effect levels for macroinvertebrates and fish food organisms are among the lowest reported effect concentrations for clay suspension, the aquatic safety program reported here for Type-A zeolite was designed to consider the impact of zeolite suspensions on fish food organisms, benthic species, and hatchability of fish eggs, including effects on adult fish and commercially important marine macroinvertebrates. Several of the zeolite toxicity tests were replicated using kaolin clay as the test material to assess the comparative effects of this
Materials and Methods Preparation of Test Material. The sodium salt of Type-A zeolite, the form used as a detergent builder, exhibits strong cation-exchange behavior in aqueous solutions, the net results being a reduction of ambient calcium and magnesium ions from solution, which explains its value as a builder. To avoid the effects of hardness ion depletion during all freshwater tests, including acutes, longer-term chronics and critical life stage testing, the zeolite used in these tests was pre-exchanged with Ca2+, Mg2+, Na+, and K+ ions. A 100-L batch of reconstituted water was prepared at lOOX recommended salt concentrations (5). A 500-g sample of zeolite was added, mixed for 1h, and allowed to settle. Three subsequent suspensions were mixed with new batches of reconstituted water until no further depletion in total hardness of Ca2+concentration was recorded. Atomic absorption analyses of the zeolite at this time indicated that 90% existed in the Ca2+exchanged form with a total of 10%as Mg2+,Na+, and K+ salts. This exchange was deemed appropriate to model the environmental form of zeolite since it is highly unlikely that the sodium form of zeolite would predominate in natural surface waters. The unexchanged sodium form of zeolite was used during all marine tests since the abundance of metal ions in ambient seawater greatly exceeds the complexing capacity of zeolite to significantly alter these metal concentrations. Due to the insoluble nature of type-A zeolite, special provisions in the conduct of these tests were made to ensure consistent suspensions throughout the exposure period. All acute freshwater and marine fish tests were gently and continuously stirred. The oyster and fathead minnow chronic
Table 1. Summary of Reported Effects of Clay and Sediments on Fish, Macrolnvertebrates, and Natural Stream Communities hlaterlal
Kaolin Kaolin China clay wastes Coal washery wastes Total dissolved solids Bentonite Stonedust sediment
574
Specles
Rainbow trout Rainbow trout Natural stream brown trout population Rainbow trout Striped bass
Silicon dioxide Kaolin
4 Marine mollusca Stream macroinvertebrates American oyster American oyster
Fuller's earth
American oyster
Environmental Science & Technology
EWect noted
No effect Partial mortality No effect No effect Blocked spawning migration Siphon rate 60% Reduction in population density No effect Decrease in normal egg development Decrease in normal egg development
Concn (mglL)
30
Ret
270
(22) ( 23)
60
( 3)
200 350
( 22) (24)
50-100 120
( 25) ( 26)
4000 3000
(27) (27)
4000
(27)
tests were done under conditions of continuous water and zeolite introduction to achieve food introduction for oyster growth and supply sufficient dissolved oxygen for fish survival. Since midges are benthic insects typically found on or in close association with the bottom substrate, a static test wherein the zeolite was allowed to settle to the bottom was employed. Alternatively, to ensure a maximal exposure of the freeswimming Daphnia, a continuously rotating system was used to maintain a consistent suspension of zeolite. Freshwater Fish Acute Toxicity Tests. All freshwater fish testing was done at Bionomics, EG&G Inc., in Wareham, Mass. Bluegill, Lepomis macrochirus, were acquired from a commercial hatchery in Nebraska and had a mean wet weight and standard length of 1.0 g and 35 mm, respectively. Rainbow trout, Salmo gairdneri, were obtained from a hatchery in Massachusetts and had a mean wet weight of 1.2 g and mean standard length of 56 mm. Channel catfish, Ictalurus p u n c tutus, were acquired from a commercial producer in Missouri and had a mean wet weight and standard length of 0.9 g and 50 mm, respectively. Fathead minnows, Pimephales promelas, were obtained from a hatchery in Arkansas and had a mean wet weight of 1.3 g and a mean standard length of 53 mm. The test animals were held in laboratory holding facilities for at least 30 days prior to testing; during this period fish were fed once daily with commercial trout chow, mortality was less than 296, and no mortality was observed during the 48 h immediately prior to testing. Standard procedures for static toxicity tests ( 5 ) were followed for all acute fish tests with minor modifications to maintain suspensions of test materials. Tests were conducted in 19.6-L glass containers kept in water baths at 12 f 1"C for the rainbow trout and 21 f 1 "C for the remaining species. Fish were not fed 48 h prior to or during testing, test containers were not aerated, and fish were added to each test container within 30 min after the compound was added. Ten fish were exposed to each concentration of the pre-exchanged form of zeolite. To maintain suspensions of zeolite and kaolin, for the individual tests, a piece of PVC tubing, 10 cm diameter by 30 cm long was attached to the bottom of the test container with silicone sealant. The tubing was perforated with 5-mm holes, and a motor-driven stirrer was supported at the top of the tubing so that the propeller was within 7 cm of the container bottom. This mixing method kept the insoluble test material in suspension by providing a water current through the tubing holes while preventing fish from coming in contact with the propeller blades. It also served to maintain dissolved oxygen levels above 6.0 mg/L during all tests. Dilution water used in all tests was reconstituted deionized water ( 5 )with a pH of 7.1 and hardness of 35.0 mg/L CaC03. A control consisting of the same dilution water and test conditions was maintained for each species tested. Marine Species Acute Toxicity Tests. All marine species were tested at Bionomics, EG&G Inc., Pensacola, Fla. Eastern oysters, Crassostrea uirginica, 20-30 mm umbo-distal valve edge; pink shrimp, Penaeus duorarum, 30-45 mm rostrumtelson length; and pin fish, Lagodon rhomboides, 30-45 mm standard length, were collected from Big Lagoon, Pensacola, Fla. All test animals were acclimated to laboratory test conditions in natural seawater (salinity of 24%0and pH 8.0 f 0.5) for a minimum of seven days prior to testing. Due to the abundance of metal ions in ambient seawater, all marine tests were done with the unexchanged sodium form of zeolite. Since concurrent testing with freshwater species indicated no differences in toxicity between kaolin and zeolite, kaolin was not tested with marine species. Methods for the 96-h dynamic oyster test were those of Butler et al. (6) and Butler (7).Single oysters were cleaned of attached organisms, ground by hand on a fine-grit grinding wheel to remove approximately 2-5 mm of peripheral shell,
and 10 were placed in each 8-L g l a s aquarium receiving 30 L/h of seawater and a suspension of Type-A zeolite provided by a peristaltic pump. Oysters were placed on stainless steel screen platforms approximately 3 cm above the aquaria bottoms to avoid being covered by test material which settled to aquaria bottoms. Oysters could obtain plankton and other particulate matter from the unfiltered seawater in which they were tested. The oysters were removed from the test containers after 96 h of continuous exposure, and new shell growth was measured to the nearest 0.5 mm for each individual. The percentage reduction in shell growth from each concentration relative to the controls was calculated from the formula: Percent reduction = Mean control growth-Mean test concentration growth Mean control growth x 100
,
Shrimp and fish were unfed during the exposure period and were tested at concentrations up to 780 mg/L in seawater under static conditions following methods previously described for the freshwater fish species. Algal Tests. Algal toxicity and growth stimulation studies were done with the green alga, Selenastrum capricornutum; a blue-green, Microcystis aeruginosa; and a diatom, Navicula seminulum. Cultures were maintained and tested according to the Algal Assay Procedure: Bottle Test (8).Test concentrations of zeolite were made from a 100 000 mg/L suspension and added to test flasks by syringe. Algal toxicity tests were done at Bionomics EG&G Inc., Pensacola, Fla. Algal growth stimulation studies with a sewage effluent containing zeolite were done a t the Environmental Safety Department of Procter & Gamble. Bench scale activated sludge units were fed with municipal sewage influent with and without 20 mg/L zeolite (sodium form) additions. Aluminum concentrations in the influent, effluent, and settling basins were periodically monitored. Dilutions of this effluent were then tested for algal growth stimulation in natural surface waters collected from Shagawa Lake, Wis., thus simulating the discharge of a sewage effluent containing zeolite into a natural water. Dipteran Midge Chronic Test. Midge larvae constitute some of the most common benthic macroinvertebrate species found in lake and stream habitats under the influence of sewage treatment plant effluents. Their singular ability to withstand the high BOD and suspended solids loadings allows them to be uniquely competitive and often attain populations of several thousand per square meter in receiving waters. As such, they represent an ideal species for the examination of toxic effects of materials contained within sewage effluents potentially settling to the stream bottom in these areas of highest effluent concentration prior to further assimilation and dilution by these receiving waters. Static tests were done to assess the chronic toxicity of naturally occurring kaolin slay and ion-exchanged zeolite to a representative Dipteran midge, Paratanytarsus parthenogenica. Test chambers were crystallization dishes (60 mm diam) covered with glass to prevent winged adults from escaping. Three replicate chambers per concentration were filled with 30 mL of the appropriate test material and allowed to settle for 4 h prior to inoculation with 10 midge eggs from newly produced egg masses. Midge larvae in each chamber were fed daily with 2 mg organic trout chow suspension (9)and 0.1 mL of the green alga Selenastrum. Well water with a hardness of 300 mg/L and pH 7.6 f 0.2 was used as the diluent. The following parameters were recorded every other day with the aid of a Wild M5 Stereomicroscope: Fo hatchability, growth of larvae, adult emergence, egg production, and F1 hatchability. Volume 12, Number 5, May 1978
575
Daphnia Chronic Test. A 21-day full chronic test with Daphnia magna was initiated with Daphnia 24 f 12 h old. The test chambers were 1000-mL flat-bottom flasks completely filled with well water of 120 mg/L hardness and pH 7.3 f 0.4, and appropriate dilutions of zeolite. The test containers were placed on a specially designed continuously rotating table, minimizing the settling characteristics of the test material and ensuring exposure to nominal test concentrations. The test was a replacement assay wherein the test individuals were placed in fresh dilutions of test material each week. Daphnia were fed on alternate days with 0.5 mL organic trout chow suspension (9)and 1.5 ml of Selenastrum (standardized to 30 X lo6 cells/mL). Fo survival, total young production, average brood size, percentage of days reproduction occurred, pH, and dissolved oxygen were monitored every other day. All midge and Daphnia chronic toxicity testing was done at the Environmental Safety Department of Procter & Gamble. Fathead Minnow Egg a n d F r y Tests. Partial chronic toxicity tests designed to include exposures of the sensitive egg and fry life stages of the fathead minnow, Pimephales promelas, were done with both kaolin and zeolite following methods modified from USEPA (10). The test system was designed to keep the test material in suspension without critically stressing the fragile eggs and fry. A proportional diluter (11) delivered untreated well water to individual chemical metering devices for all concentrations. The metering devices consisted of glass venturi siphons designed to deliver the suspension of test material to each of two replicate chambers. The test chambers were bottomless 12.5 cm diam X 18 cm tall battery jars fitted with a funnel, airstone, and stopper at the small end of the funnel. The circulating action from the airstone provided turbulence to maintain suspensions of kaolin and zeolite throughout the chamber. Eggs and fry cups on rocker arm assemblies were used to simplify observation of test individuals (12). Suspensions of test material were delivered to all chambers at approximately 6 tank volumes per 24 h.
Eggs were obtained from the USEPA National Water Quality Laboratory in Duluth, Minn. Exposure of eggs in each test began within 48 h after fertilization. Fifty eggs were incubated in each replicate, and dead eggs were removed and counted daily until hatch was completed (3-5 days). Percentage hatch was based on the number of live fry in each egg cup when the hatch was complete. After hatching was completed, 25 fry were randomly selected and transferred to the fry cups. These cups were placed in the growth chambers and continuously oscillated during the 30-day posthatch exposure. Fry were fed brine shrimp nauplii ad libitum three times per day beginning on the first day after hatch and continuing throughout the exposure period. All fry cups and growth chambers were brushed and siphoned three times per week. When siphoning the growth chamber, the airstones were turned off long enough to allow the heavier clumped fecal matter and excess food material to settle. For each group of fry, total length and average weight were determined a t 30 days posthatch by measuring anesthetized fry directly. Percentage survival based on cumulative mortality was also recorded at this time. Test water was monitored twice weekly for dissolved oxygen, pH, hardness, and soluble and insoluble silica (SiOp) (13). Hardness averaged 36 mg/L CaC03, pH 7.6 f 0.3, and dissolved oxygen was never less than 86% saturation. Analytical. Actual test concentrations of zeolite were measured during all partial and full chronic studies with macroinvertebrates and fish by digesting the aluminosilicate to molybdate-reactive silica after APHA (13).Kaolin concentrations were measured in all tests after USEPA (14).
Results Acute Toxicity Studies. Type-A zeolite showed no evidence of acute toxicity to four species of freshwater fish (Table 11). No mortality was observed for either cold water or warm water fish exposed to suspensions of 680 m g L under continuously mixed conditions for 96 h. Similarly, no mortality was
Table II. Acute Effects of Type-A Zeolite on Representative Freshwater and Marine Aquatic Species as Determined During Laboratory Toxicity Tests Test species
Test conditlons
Effects measured
Effect concn (mg/L)
Freshwater Lepomis macrochirus,
bluegill
Continuously mixed
Mortality
>680
Continuously mixed
Mortality
>680
Continuously mixed
Mortality
>680
Continuously mixed
Mortality
>680
Continuously mixed
Morta I ity
>860
lctalurus punctatus,
channel catfish Salmo gairdneri,
rainbow trout Pimephales promelas,
fathead minnow Pimephales promelas*
fathead minnow
Marine Crassostrea virginica,
eastern oysters
Continuous flow
Shell Deposition
>780
Penaeus duorarum, pink shrimp Lagodon rhomboides,
Continuously mixed
Mortality
>780
Continuously mixed Algae Reciprocating shaker Reciprocating shaker Reciprocating shaker
Mortality
>780
Growth Growth Growth
100-1000
pinfish Selenastrum capricornutum Microcystis aeruginosa Navicula seminulum Single test with kaolin clay.
576
Environmental Science & Technology
50-100 50- 100
I
lo'
-10'
0
106
Cellsimi
o 0
-
Shagawa Lake Water Conlrol a -Sewage Effluent Control -Sewage Effluent T Type.AZeolile -Type-AZeolite I--rlSD L a b r a t o r v, ActIvaIBd .. Sludge Unit Effluents Shagawa Lake Influent Spiked Water Control at 20 mall zeolite
0
A
-Control - 0.5 ppm - 1 .O ppm - 5.0 ppm - 10.0 ppm -50.0 ppm
-
~
Total P Ortho P Organic N
Al"ml""m 1\11 as mg
lV
12 8
124
010
12 4 30
11
24 0 180
42 0
02
03
076 15 0
Tole1 C OrQsnCC
105
032
90
,
6
2 65 14
0
Days
Figure 3. Effect of domestic secondary sewage effluent and effluent containing Type-A zeolite on growth of Anabaena flos-aquae grown in Shagawa Lake water
0
4
8
12
Days
Flgure 2. Cell numbers (as determined by hemacytometer) during 14day continuous exposure of blue-green alga Microcystis aeruginosa to Type-A zeolite concentrations ranging from 0.5 to 50 mg/L
observed for fathead minnows exposed to suspensions of kaolin clay for the same period. The growth of eastern oysters, Crassostrea uirginica, as measured by new shell deposition, was not affected in concentrations of Type-A zeolite up to 780 mg/L in flowing seawater (Table 11). In fact, oysters from the 780-mgL test concentration had slightly more new shell growth than did the controls. Pink shrimp, Penaeus duorarum, and pin fish, Lagodon rhomboides, also exhibited no mortality in test concentrations of Type-A zeolite up to 780 mg/L. After 96 h of exposure to the test material, continuously stirred in static seawater with aeration, there were no deaths in any test concentration or control. Chronic Toxicity Studies. Algae. The concentrations of zeolite which allowed no increase in cell numbers for three algal species, Selenastrum capricornutum, Microcystis aeruginosa, and Navicula seminulum during a 5-day exposure, but did not kill the test species, ranged from 50 to 1000 m g b (Table 11).There was no demonstrable difference in cell
numbers among cultures of M . aeruginosa exposed to various concentrations of zeolite and the control throughout a 14-day exposure (Figure 2). The ion-exchange capacity of zeolite suggests that effects observed during exposure to suspensions greater than 50 mg/L are due to the reactions of zeolite with nutrients essential for algal growth. T o test this assumption, a 1000-mg/L suspension of zeolite was placed inside a dialysis membrane bag impermeable to algal cells and zeolite and immersed in the culture vessel with algal inoculum and nutrient media. Growth in these flasks was reduced to an extent similar to flasks in which zeolite was mixed directly with the media, thus indicating the observed effects on algae could be reproduced without direct exposure of algal cells to zeolite, supporting the theory that nutrient exchange with high concentrations of zeolite was responsible for reduced algal growth. Additional algal growth studies were designed to examine the effects of zeolite contained within a sewage effluent in an attempt to model actual exposure conditions. A laboratory bench scale activated sludge unit was fed with domestic sewage containing 20 mg/L zeolite, and the effluent from the unit was shown to produce an -tenfold growth stimulation of algal species grown in Shagawa Lake water from Wisconsin (Figure 3). There was an 8-10% reduction in Anabaena cell counts
Table 111. Survival and Reproduction of Dipteran midge, P. parthenogenica, in Concentrations of Type-A Zeolite and Kaolin Clay Under Static Conditionsa lntttat concn,b Type-A reollle
-% Hatch
(mgW
from eggs
0 50 75 100 200 300
Fg
% Pupatlon of larvae
93 97 77 80 73 67
100 100 100 100 100 47
100 100 100 100 20
% Adult emergence from eggs
Mean
# eggsladults
67 100 93 80 100 27
112 92 104 108 61 73
87 73 40 60
80 67 40 40
127 129 124 125
0
0
Halchabllity of F1 eggs
100 90
100 70 100
80
Kaolin clay
0 50 100
500 1000 Parameter
Fo hatchability Fo pupation Fo adult emergence f egg production
EC50 (mg/L)
Type-A reollle 95% Contldence Ilrnits
551.a2 298.1 274.2 364.g2
(370.9-1 175.4) (287.1-308.8) (264.9-283.9) (31 1.6-455.8)
a7
>434
Cladoceran, Daphnia magna
Fathead minnow, Pimephales promelas
erage weight of fry at 30 days post hatch during all exposures to kaolin and zeolite. The concentrations of test materials in suspension varied considerably during the exposure period, reflecting the difficulty of maintaining uniform suspensions of these particulates and the propensity of the compounds to clump and settle on the exposed surface of the chambers. The highest test concentration of kaolin varied from 31 to 220 mg/L with a mean concentration of 85 mg/L during the exposure period. Highest zeolite concentrations varied from 33 to 182 mg/L with a mean of 87 mg/L. Thus, the observed noeffect concentration of MATC for kaolin and zeolite with the fathead minnow was determined to be a concentration greater than the highest mean exposure of these two materials, 85 mg/L for kaolin clay and 87 mg/L for zeolite.
Discussion Projected Environmental Levels. To critically assess the environmental impact associated with the use of a particular compound, it is imperative to have accurate estimates of the concentrations ultimately reaching the aquatic environment. With these data it is then possible to position the results of laboratory toxicity studies relative to the probability of reaching observed effect concentrations in natural surface waters. The determination of the surface water levels of Type-A zeolite expected from the use of this material in detergent formulations initially involves estimates of market volume and expected routes of entry to surface waters. Based on a heavy duty detergent market volume of 1.36 X lo9 kg (19),an assumed zeolite usage equivalent to 20% of this volume (2Wh anhydrous sodium form in product), an average water consumption on a U S . national basis of 650 L/day/ capita by 1980 with 60-80% of this consumption becoming sewage (20), the expected maximum concentration of zeolite contained in raw sewage influent is estimated to be about 10 mg/L.
To determine the fate of zeolite upon entering various sewage treatment processes, numerous laboratory and field studies have been completed (21).Removal studies during dynamic settling tests in coarse-filtered raw domestic sewage indicated that zeolite is removed during primary sewage treatment (sedimentation) by approximately 40-60%, an efficiency equal to suspended solids removal. Similar experiments with continuous activated sludge units fed zeolite indicated mean removal across the aeration tank, and final clarifier was 80-90% with no observed effects on the operation of these units. Therefore, using a sewage influent concentration of 10 mg/L, a removal figure during sewage treatment of 80%, and a dilution of sewage effluents by natural surface water of 1:lO (28, 29), the surface water concentration of Type-A zeolite expected from total detergent industry use is approximately 0.20 mg/L. In those limited instances where raw sewage containing zeolite at 10 mg/L is discharged to receiving waters, local zeolite concentrations could reach 1.0 m g b prior to further dilution. It is also recognized that a small percentage of receiving waters may seasonally have dilution factors less than 1:lO. Although these lower dilution ratios will indicate locally higher zeolite concentrations, projected estimates remain 2-3 orders of magnitude below observed biological effect concentrations. A summary of the MATC values based on full chronic and critical life stage testing for representative freshwater algae, macroinvertebrates, and fish indicates a substantial safety factor associated with the use of Type-A zeolite in detergent formulations (Table VI). The ratio of observed no-effect concentrations during laboratory tests to an estimated maximum environmental surface water concentration of 0.2 mg/L yields values ranging from 250 to 1300 for these freshwater species. Results of acute tests with marine species indicate that marine fish and commercially important macroinvertebrates are no more susceptible than are freshwater species.
Conclusions Type-A zeolite is empirically similar to naturally occurring clay materials. The experiments described in this paper demonstrate that this zeolite is nontoxic a t projected environmental levels to aquatic species representing three major trophic levels of freshwater and marine aquatic communities and does not contribute to the eutrophication potential of surface waters. The material is efficiently removed from wastewaters through conventional waste treatment processes, and projected surface water concentrations are significantly lower than observed acute and chronic effect concentrations. As a nonphosphate builder for heavy duty detergents, this zeolite is projected to have no significant environmental impact. Acknowledgment We thank Robert Bentley, Tom Heitmuller, and Jerry Dean of Bionomics, EG&G Inc., for technical assistance in conVolume 12, Number 5, May
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ducting the freshwater and marine acute tests, and egglfry exposures, respectively; Shirley Shorter and Margie Bauer of the Environmental Safety Department, Procter and Gamble, for assistance with the Daphnia and midge chronic studies; and Richard Hall for supervision of the algal studies.
Literature Cited (1) Savitsky, A. C., Household Pers. Prod. Ind., 52-66 (Mar.
1977). (2) Breck, D. W., J. Chem Educ. 41 (12), 678-89 (1964). (3) Herbert, D.W.M., Alabaster, J. S., Dart, M. C., Lloyd, R., Int. J. Air Water Pollut., 5 ( l ) , 56-74 (1961). (4) Doudoroff, P., “The Physiology of Fishes”, pp 403-30, Academic Press, New York, N.Y., 1957. (5) U S . Environmental Protection Agency, “Methods for Acute Toxicity Tests with Fish, Macroinvertebrates, and Amphibians”, Ecological Res. Ser., EPA-660/3-75-009, 1975. (6) . . Butler. P. A,. Wilson.. A. J.., Rick., A. J.., Proc. Nat. Shellfish Assoc.. 51 23-32 (1960). (7) Butler, P. A., “Reaction of Some Estuarine Mollusks to Environmental Factors”, Public Health Service Publ. No. 999-WP24:92-104, USHEW, 1965. (8) U S . Environmental Protection Agency, “Algal Assay Procedure: Bottle Test”, Pacific Northwest Water Lab, Corvallis, Ore., 1971. (9) Biesinger, K.E., Christensen, G. M., J. Fish. Res. Board Can., 29, 1691-700 (1972). (10) U.S. Environmental Protection Agency, “Proposed Recommended Bioassay Procedures for Egg and Fry Stages of Freshwater Fish”, Duluth, Minn., 1972. (11) Mount, D. I., Brungs, W. A,, Water Res., 1,21-4 (1967). (12) Mount, D. I., ibid., 2,215-23 (1968). (13) American Public Health Assoc., “Standard Methods for. the Examination of Water and Wastewater”, 13th ed., Washington, D.C., 1971.
(14) U S . Environmental Protection Agency, “Methods for Chemical Analysis of Water and Wastes, Residue, Total Nonfilterable”, p 269, MDQARL, NERC, Cincinnati, Ohio, 1974. (15) Finney, D. J., “Probit Analysis”, 333 pp, Cambridge Univ. Press, London, England, 1971. (16) Nebeker, A. V.,Puglisi, F. A., Trans. Am. Fish. SOC.,103 (4), 722-3 (1974). (17) Mount, D. I., Stephan, C. E., ibid., 96,185-93 (1967). (18) Macek, K.J., Sleight, B. H., 111, “Utility of Toxicity Tests with Embryos and Fry of Fish in Evaluating Hazards Associated with the Chronic Toxicity of Chemicals to Fishes”, Aquatic Toxicol. and Hazard Evaluation, ASTM STP634, F. L. Maver and J . L. Hamelink, Eds., p p 137-47, ASTM, 1977. (19) Maxwell, J. C., Advertis. Age, 80 (June 21, 1976). (20) Metcalf & Eddy, Inc., “Wastewater Engineering”, pp 25, 33, McGraw-Hill, New York, N.Y., 1972. (21) Hopping, W. D., J . Water Pollut. Control Fed., in press (1978). ~ - -_,. .
(22) Herbert, D.W.M., Richards, J. M., Int. J. Air WaterPollut., 7, 297-302 (1963). (23) Herbert, D.W.M., Merkens, J. C., ibid., 5 (1),56-74 (1961). (24) Radtke, L. D., Turner, J. L., Trans. Am. Fish. Soc., 96 (4), 405-7 (1967). (25) Chiba, K.,Ohshima, Y., Bull. Jpn. Soc. Sci. Fish., 23 (7/8), 348-53 (1957). (26) Gammon, J. R., “The Effect of Inorganic Sediment on Stream Biota”. 141 DD. USEPA Water Pollut. Control Res. Ser.. Program 18050 Dwc-, i970. (27) Davis, H. C.. Hidu. H.. Veliger. 2 (4). 316-23 (1969). (28) U S . Environmental Protect& Agency, “Inventory of Municipal Waste Facilities and Facility Needs”, Div. of Tech. Support, Tech. Data and Information Branch, Storet Data Retrieval System, May 1975. (29) U.S. Geological Survev. “Water Resources Data for the United States”, Geolo&al Surve; Water Data Rep., Water Resources Div., USGS-WDR-76-1,1976. Received for review August 15,1977. Accepted November 10,1977.
Transport of Sulfate to New York State Philip J. Galvin”, Perry J. Samson, Peter E. Coffey, and David Romano New York State Department of Environmental Conservation, 50 Wolf Road, Room 102A, Albany, N.Y. 12233
Trajectory analysis provides evidence that high sulfate concentrations observed during summer high-pressure systems a t three rural sites in New York State are products of sulfur dioxide emissions to the south and southwest of New York State. The highest concentrations occur in air that first stagnates over the area surrounding the Ohio River Valley and then is advected into New York State as the high-pressure system begins to move eastward. The amount of oxides of nitrogen that emissions data indicate should accompany these high sulfate concentrations is not present in the particulate samples as inorganic nitrate. H
There has been a growing concern over the effects of elevated sulfate and nitrate concentrations in the atmosphere. In the western Adirondack Mountains of New York State, Likens and Bormann ( I ) and Schofield ( 2 ) have suggested that the pH of several lakes has been lowered by the presence of sulfate and nitrate in precipitation. Schofield reports that fish no longer reproduce in many of these lakes. High sulfate concentrations have been observed in rural areas of New York State coincident with the influence of anticyclonic weather systems. Stasiuk et al. ( 3 )found that high sulfate and ozone concentrations a t Whiteface Mountain, N.Y., are associated with the southwest flow on the back of summer high-pressure systems. Lioy et al. ( 4 ) studied sulfates 580
Environmental Science & Technology
at seven rural sites in New York and New Jersey, and observed high sulfate concentrations a t all seven under the same conditions. It has been difficult to discern whether this phenomenon is caused by the stagnant conditions created by these systems or transport of sulfates from areas of high sulfur dioxide emissions by the southwesterly air flow associated with these systems. This paper continues the study with emphasis on specifying the origins of these high concentrations of sulfate.
Methods Suspended particulates were collected for 24 h by highvolume air samplers on 8 X 10 Whatman 41 filter media at three rural sites-Whiteface Mt., N.Y., Schoharie, N.Y.; and Holland, N.Y.; and one moderately sized urban area, Albany, N.Y., from July 6 to August 4 of 1976. The water-soluble extracts of these filters were analyzed by ion chromatography employing the method described by Mulik et al. ( 5 ) .Sulfate concentrations were calculated by dividing the total sulfate present in each filter extract by the total air flow through the filter. The three rural sites chosen form a triangle that encompasses most of upstate New York. Whiteface Mountain, surrounded by the Adirondack State Park, is virtually free of any local sources of pollution. Schoharie, located just to the northeast of the Catskill Mountains in an agricultural region, is similarly isolated. Holland is also in a relatively isolated agricultural region, but pollutants are occasionallytransported
0013-936X/78/0912-0580$01 .OO/O
0 1978 American Chemical Society
