transmitted through the atmosphere may create a nuisance as great as though they were audible.
atmosphere may not be an air pollutant, but public reaction was the same as if they were.
I n one particular instance, three large cycloidal-type positive rotary blowers were used t o supply low pressure air for process use. An electrostatic precipitator was used to remove dust and debris from the intake air. The purified air then entered an intake tunnel which served as a suction header for the three blowers, which were driven a t a fixed rate by electric motors. Consequently, pulsations in the intake air occurred at a constant frequency. The air column in the intake tunnel was in resonance. The subsonic vibrations thus generated rattled the walls arid windows of homes adjacent t o the plant. Plate glass windows in stores vibrated audibly within a radius of one mile. The problem waR eliminated by installing a reinforced concrete block building around the air intake, in order t o draw the air through a series of baffles. The dimensions and placement of the baffles were designed to damp out pulsations of the same frequency generated by the blowers. Subsonic vibrations in the
In Xovember 1952 the sanitary and industrial waste facilities installed and in use a t the plants were valued a t $2,152,000, an increase of $787,000 since March 1946. Table I1 summarizes data as t o liquid, solid, and gaseous facilities. LITERATURE CITED
( 1 ) Ellis, RI. M., U. S. (1937).
Bur. Fisheries, 48, Bull. 22, 378, 381, 395
(2) Hebbard, G. M., Powell, S. T., and Rostenbach, R. E.,
IKD.
ENG.CHEW,3 9 , 5 8 9 (1947). (3) Rostenbach, R. E., Sewage and Ind. Wastes, 24, 1138-43 (September 1952). RECEIVED for review April 10, 1953.
ACCEPTED September 19, 1953.
Disposal of California Winery Wastes T h e major problems concerned with the disposal of California winery wastes result, in large measure, from the tremendous volume of brandy stillage produced in an intermittent, seasonal operation. The still.age, estimated to average about 200 gallons per ton of grapes crushed, is extremely variable in potential putrescibility. Therefore, land disposal by intermittent irrigation is the best method of disposal at present although complete treatment of the stilIage can be effected by a combination of neutralization, anaerobic digestion, and biological oxidation.
REESE H. VAUGHN AND GEORGE L. MARSH Department of Food Technology, University of California, Davis, Calif.
A
DEQUATE disposal of liquid winery wastes has been a continuously perplexing problem since the revival of the industry in California in 1933. In the years immediately following resumption of large scale production, the pollution of streams with concentrated winery wastes was acute (4, 9). When the further discharge of concentrated liquid winery wastes to the rivers was prohibited by the Division of Fish and Game, state of California, use of deep ponds or lagoons became standard practice, even though this gave rise to widespread odor nuisances resulting from anaerobic fermentation of the wastes. Abatement of these odors has become of immediate concern to many California vintners. It is anticipated that odor control and other requirements for sanitary disposal of liquid winery wastes will be magnified with time because of the continual increases in the population of the state. NATURE OF THE WASTES
Winery wastes may, for convenience, be defined as liquid, semiliquid, and solid residues which are removed from the wine by natural or artificial means during the process of vinification. These residues, for the most part, are natural to the grape. A few arise from other sources. The following kinds are enrountered: Liquid Waste wash water Brandy distillery wastes Condenser water Stillage (still-slop)
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Semiliquid Lees Dessert wine Table wine Refrigeration Clarification and filtration sediments (bentonite, FilterCel, etc.)
Solid Pomace Cream of tartar deposits (argo18 or wine stone)
It has always been customary t o utilize certain of these wastes in making by-products. The argols are collected and used for manufacture of tartrate or tartaric acid. (During World War I1 tartrates were recovered from other sources, such as pomace, refrigeration lees, and stillage. This recovery is not economical a t present.) The pomace may be used as a soil mulch or dried and used for prepared stock feed. Lees from table or dessert wines generally are used for the recovery of brandy, but their distillation adds t o the over-all waste-disposal problem created by the enormous volumes of brandy distillery wastes, together with the other liquid wastes of the wine industry in California. VOLUME O F BRANDY DISTILLERY WASTES
It is difficult to estimate the total volume of brandy distilleiy wastes, either for an individual winery or for the whole California industry. The volume of these wastes depends upon a great many variables: the seasonal character of the industry, the tonnage of grapes crushed, the ratio of wine to brandy made from the grapes that are crushed, and variations in winery and distillery operation and practice, particularly those used to produce the wine “distilling material” from which neutral brandy for fortification is derived. Every effort is made to obtain fortifying spirit from the materials at hand. Brandy distillery wastes, therefore, may originate from distillation of distilling materials produced from pomace and lees, as well as wines. The volume, as well as the chemical composition of the stillage, will vary significantly from time to time, although the majority of the spirit used is derived from distilling material produced from wines rather than the grape residues.
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
Vol. 45, No. 12
Industrial Process Water -
TABLEI. CALIFORNIAWINE
AND BRANDYPRODUCTION IN 1951 AND 1952
(Data from 13) Product 1951 Grape crush. tons 1,642,000 Wine production, gal. 163 569 000 Total 46 :e23 :OOO Table wine Dessert wine 116,946,000 Brandy production, tax ga1.b 40,792,000 Total 4 600 000 Beverage brandy 36: 192 :OOO Neutral brandy Preliminary estimate. b Same as proof gallons
195P 1,202,000 120,816,000 37,392,000 83 ,424,000 29,007,000 2,450,000 26,557,000
Q
The volume of brandy distillery wastes per ton of grapes has been observed to vary between about 130 and 300 gallons as limits, but for the industry as a whole is estimated as 200 gallons per ton of grapes crushed a t the present time (1,4, 9). The figures on California wine and brandy production in 1951 and 1952 shown in Table I emphasize the tremendous volume of liquid waste which will be produced intermittently during about 90 days each year.
Figure 1. English Walnut (Juglans regia) Killed b y Lateral Seepage of Stillage Pond depth 3 to 4 feet
CHARACTERISTICS O F WINERY DISTILLERY WASTES
Complete data which would give the best indication of the strength of distillery wastes are not available. Although De Martini (4), Shaw (Q),Brown and Mills (2),Hodgson and Johnston (6),and Vaughn et al. (11) have published some analyses of winery distillery wastes, their data are not extensive enough t o emphasize the very concentrated nature of the wastes. Nevertheless, i t is apparent from Table I1 that winery distillery waste is very concentrated (from the standpoint of its potential putrescibility), even when diluted with condenser or cooling water, wash water, or other liquid waste which might serve as a diluent, is very acid, has a high organic matter content, chiefly carbohydrate in nature, and compares in strength with distillery wastes from other fermentation industries. A comparison of the strength of these same wastes with that of domestic sewage by use of the “population equivalent” is shown in Table 111. The data presented in Table I1 and I11 do not reflect the extreme variability in the strength of the waste. Variability in potential putrescibility, as measured by oxygen consumed (10 X permanganate) and 5-day biological oxygen demand values, together with the tremendous volume of waste produced in a n intermittent, seasonal operation, constitute the major problems in the disposal of California winery wastes. TREATMENT AND DISPOSAL OF WASTES
The first requirement for disposal of a n industrial waste should be recovery of a profitable by-product, if at all possible. At present, no available constituent is currently in sufficient economic demand to warrant by-product recovery from winery distillery
wastes, even though these residues were a major source of tartrates for the United States during World War I1 (7,8). This is an unfortunate situation, because Marsh and Vaughn ( 8 , 10)found that during the recovery of the tartrates as calcium tartrate the potential putrescibility of these wastes in terms of 5-day B.O.D. was reduced at least 50 and sometimes 75%. Consequently, if tartrate recovery was an economical practice, detartration would be the first mandatory step in disposal of these wastes. The only recourse at present is t o try t o dispose of these almost valueless wastes as economically as possible. As a result, some form of land disposal has been used when possible. Application of these wastes to land prepared LANDDISPOSAL. as ponds or lagoons is accompanied b y many problems. Land disposal is satisfactory when the soil characteristics permit rapid filtration and percolation of the wastes. I n many localities the impervious layer of subsoil, known as “hardpan,” is close to the surface. In such cases disposal in ponds or lagoons is not satisfactory. The surface layers of soil become plugged, filtration and percolation cease, and losses by evaporation alone are not sufficient t o prevent the accumulation of large quantities of impounded wastes, which then decompose and emanate extremely malodorous compounds and permit the breeding of mosquitoes. Too, because of this accumulation above the hardpan, there is a marked lateral spreading of the liquids in the shallow layer of pervious soil above the impervious area. As the degradation of the wastes is continuous in the layer of soil thus affected, plant life around the disposal area often is fatally damaged (Figure 1). A system of intermittent irrigation is, perhaps, the best way t o
II
TABLE11. CHARACTERISTICS OF SOMEDISTILLERY WASTES Apple Jack
Grape Brandy
Constituent Spirit Bourbon Molasses B.O.D., p.p.m., 28,700 2 1 , 0 0 0 20,000“ 5-day 34,100 26,000 Total solids, p.p.m. 47,345 37,388 71,053 18,860 20,000 Suspended solids, Variable 17,900 40 24,800 50 p.p.m. Total volatile matter, p.p.m. 43,300 34,226 24,800 16,948 16,000 4.2 4.5 3.6-4.1 pH value 4.1 3.8 0 0 1250 to Potassium acid tar0 0 7250 trate, p.p.m. 5-day B.O.D. 0 Limits of 4000 to 40,000 p.p.m. Sources of data: Brown and Mills ( 8 ) . Coast Laboratories (3): Hodgson and Johnston (6): Hoover and Burr (6);supplemented by data collected by authors since 1943.
. December 1953
TABLE111. POPULATION EQUIVALENTS OF SOMEDISTILLERY SLOPS” Spirit
flt’p?;, --.., --
Bourbon Molasses Apple Jack P.P.M. B.O.D. (5-Day) from Table I
Brandy
34,100 26,000 28,700 21,000 20,000 Hours Population Equivalents 25,000 42,625 32,500 35 875 26,250 25,000 50,000 85,250 65,000 71:750 52,500 50,000 75,000 127,875 97,500 107,625 78,750 75,000 100,000 170,500 130,000 143,500 105,000 100,000 200.000 200,000 341.000 260.000 287.000 210,000 a “Population equivalent” is used to compare strength of organic industrial waste with >hat of domestic sewage. The following formula may-be used for calculation: Volume (gallons per day) X parts per million B.O.D. (5-day) X 0.00005 = population equivalent of waste
INDUSTRIAL AND ENGINEERING CHEMISTRY
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Figure 2. Masses of Putrefying Rat-Tailed Larvae 4 to 6 Inches in Depth Floating on Stillage Pond Killed by compound claimed to assist in odor control
use land for disposal of winery distillery wastes. I n this method it is customary t o discharge the polluted liquid wastes from each 24-hour operation into an irrigation check a t the rate of 100,000 gallons per acre at a depth not to exceed 4 inches. Each check so treated then is allowed to stand for a t least 6 days before receiving another application of wastes. At least seven irrigation checks are involved for proper operation of this method and preferably more, if the soil characteristics are not ideal. The one application of wastes followed by 6 days’ rest for each check permits the rapid filtration and percolation of the liquids into the soil, and also permits the drying, cracking, and curling of the solids filtered out at ground level, thus leaving the soil surface ready to receive another application of waste. [A more detailed discussion of this method is contained in a report from the Coast About twice as long a rest period Laboratories in June 1947 ($).I is required for checks dosed with stillage from pomace stills, unless the disintegrated pomace solids are removed by vibrating screens or some other means. The use of varioue chemicals alleged to assist in odor control in impounded winery distillery wastes has not been particularly effective. I n a t least one instance (Figure 2) their use disrupted normal biological processes to the extent that the already disagreeable odor nuisance was greatly intensified by the putrefaction of countless numbers of dead rat-tailed larvae. The most important problem of disposal of winery distillery wastes by intermittent irrigation is the amount of land required. Even when all of the unpolluted waters are segregated, the largest wineries may still discharge 500,000 or more gallons of waste per day. With this volume, a t the recommended rate of application, 35 or more acres of land would be required for adequate disposal of the wastes. In some areas this problem has been intensified further by lack of available land or markedly increased land values which have resulted from real estate developmentq in close proximity to the wineries. Consequently, interest in partial and complete treatment of winery distillei y wastes has been increased.
TREATMENT PRIOR TO DISPOSAL. Precedent for various combinations of biological, chemical, and physical treatments of industrial wastes is well established. I n the case of winery distillery wastes it has been shown that either detartration (7, 8, 10) or lime flocculation to pH 11 (3)will result in about 50% reduction in the organic load. Both of these chemical treatments have
been used to advantage to conserve land area for the intermittent irrigation system of disposal. Other chemical flocculation treatments, which under laboratory conditions could be used to flocculate the very tenacious colloidal suspension so characteristic of winery distillery wastes, are not practical for economic reasons. Experiments made to date indicate that vibrating screens are most effective for the removal of pomace solids before subsequent treatment of the wastes. However, as yet, no completely satisfactory conventional device has been found for separation of the very light and bulky sludge that results from chemical flocculation. Efficient removal of suspended solids from the winery distillery wastes remains an important problem. Biological treatment of the wastes after chemical and physical separation of the solids has been studied by Brown and Mills ( d ) , Hodgson and Johnston ( 5 ) , and Vaughn et al. (11). It can only be concluded from the results of these investigations that complete disposal of concentrated winery distillery wastes by oxidation in the conventional biological filter is a difficult task which must be accompanied by Pretreatment. Chemical pretreatment can he depended upon to remove about 50y0 of the &day B.O.D. Vaughn et al. (11) resorted to dilution with condenser water to effect still further reduction before application to filters operated in tandem. Experiments still under way by the authors indicate that simple liming to p H 7.0 followed by mesophilic (35’ C.), anaerobic digestion for 24 hours may result in as much as 75% reduction in the 5-day B.O.D. value of the stillage. Some average results are shown in Table IV. Further reduction is obtained if the settled, digested effluent is filtered to remove all or nearly all colloidal matter. However, the extremc fluctuation in the potential putrescibility of the raw “slops,” combined with their seasonal, intermittent production, still must be considered if a combined system for complete disposal is to be an economic solution to the problem of disposal of winery distillery waste.
TABLEIv. REDUCTION IN B.0.D. VALIJES BY DIGESTION .4T 35’ C .
O F L E E S STILL.4GE
Average B.O.D., P.P.M., 5 Day@ Stillageb digested Undigested stillage, 24 hours (settled limed to pH 7.0 effluent) Yo Reduction 4250 1060 75.0 6360 1510 76.2 3370 950 71.8 a Average of determinations on 10 samples collected over 3-week period after develonment of seed. b Lees stillage added to seed digestion at rate of s’,1 volume of limed stillage each day. Seed digestion incubated 2 weeks prior to start of test.
ACKNOWLEDGMENT
Funds to support part of the w o r k reported were made available by contract with the Wine Advisory Board of the state of California. LITER4TURE CITED
Berti, L. A., Am. Soc. Enologists Proc., 2, 186 (1951). Brown, E. M., and Mills, D., “Shewan-Jones R e p o r t , ” Wine Institute, San Francisco, 1938 Coast Laboratories, “Report on Grape Stillage Disposal by I n t e r m i t t e n t Irrigation,” Wine Institute, San Francisco, 1947. De M a r t i n i , F. E., Calif. Sewage W o r k s J . , 7 , 1 (1934). Hodgson, H. G. N., and Johnston. J . , Sewage W o r k s J., 12, 321 (1940). Hoover, C. R., a n d B u r r , F. K., IYD. END-. CHEM.,28, 38 (1936), Marsh, G. L., Proc. Inst. Food Technol., 1943, 183. Marsh, G. L., and Vaughn, R. If.,Wines and V i n e s , 25 (6), 15 I1 944) \_l--,.
Shaw, P. A , , Seuuge Works J., 9,599 (1937). Vaughn, R. H., a n d Marsh. G. L., Wine Rev., 13 (11). 8 (1945). Vaughn. R. E., Nightingale, M . S., Pridmore, J. A., Brown, E. M., a n d Marsh, G. L., W i n e s and Vines, 31 (2), 24 (1950). Wine Inst., San Francisco, Calif., Bull. 636 (1953). RECEIVED for review April 10, 1933.
ACCEPTED September 3, 1953.
End of Symposium Reprints of this symposium may be purchased for 75 cents each from the Reprint Department, AMERICAN CHEMICALSOCIETY,1155 Sixteenth St., N.W., Washington 6, D. C.
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INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 45, No. 12
