Water-Supply and Irrigation Paper No. 179 Series L, Quality of Water, 14

DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

CHARLES D. WALCOTT, DIRECTOR

PREVENTION OF STREAM POLLUTION BY 

DISTILLERY REFUSE

BASED ON INVESTIGATIONS AT LYNCHBURG, OHIO

BY

I LER.MAN STABLER

PROPERTY OF 

U.S. GEOLOGiCAL SURVEY

WASHINGTON

GOVERNMENT PRINTING OFFICE

1906

CONTENTS.

Page.

Scope of investigation...................................................... 5

Acknowledgments ......................................................... 5

Distillery processes and sources of pollution .................................. 5

Grain distillation ...................................................... 5

Treatment of slop ..................................................... 8

Sources and character of pollution ....................................... 9

Effect of polluting effluents on the stream.................................... 12

Disposal of distillery effluent without stream pollution ......................... 16

Filtration ............................................................ 16

Precipitation ......................................................... 17

Fermentation......................................................... 18

Evaporation.......................................................... 18

Amount of slops and recoverable solid matter......................... 18

Method of evaporation.............................................. 21

Cost of plant ..................................................... 26

Cost of process.................................................... 28

Value of products ................................................. 28

Profits........................................................... 30

Result at Lynchburg distillery ...................................... 31

Summary ................................................................ 34

ILLUSTRATIONS.

Page.

PLATE I. Smith-Vaile filter press............................................ 22

FIG. 1. Vacuum mash cooker............................................... 6

2. Continuous beer still................................................ 7

3. Yaryan's triple-effect evaporator..................................... 23

4. American process dryer............................................. 25

5. Hoffman-Ahlers triple-effect vacuum evaporator....................... 32

3

PREVENTION OF STREAM POLLUTION BY DISTILLERY

REFUSE.

By HERMAN STABLER.

SCOPE OF INVESTIGATION.

This report gives an account of investigations carried on near Lynchburg, Ohio, to discover 

feasible means of preventing the pollution of streams by distillery refuse. Lynchburg is in 

Highland County, Ohio, a few hundred yards east of the East Branch of Little Miami River 

and about 60 miles northeast of Cincinnati. It has a population of a little less than 1,000. 

Above and below Lynchburg the East Branch of Little Miami River flows through an agricultural district, and as the town has no sewerage system the stream is not seriously polluted 

except by the distillery refuse. The investigation was therefore confined to the following 

subjects: (1) The processes at the distillery and the sources of pollution; (2) the effect of 

the pollution on the stream; (3) the economical disposal of distillery wastes in such way 

that there will be no pollution of streams.

ACKNOWLEDGMENTS.

This work was done under the cooperative agreement between the United States Geological Survey and the Ohio State board of health.o

Ail laboratory work, both chemical and bacteriological, on the analyses in table 1 (6 samples from East Branch of Little Miami River) was performed by officials of the Ohio State 

board of health under the direction of Dr. E. G. Horton, bacteriologist and chemist. All 

laboratory work by the writer was done in the laboratory of the Ohio State board of health. 

The investigation was directed by Mr. M. O. Leighton, chief of the division of hydro-economics, United States Geological Survey, to whom is due in very great measure the value of 

the results obtained. The investigation received the hearty support of Messrs. Freiburg and 

Workum, owners of the distillery, through their superintendent, W. M. Cleveland, and his 

principal assistant and chemist, G. L. Bering. Much of the value of the examination is due 

to the special facilities for work and information offered by these gentlemen at no little inconvenience to themselves.

The courtesy of the Hoffman-Ahlers Company, of Cincinnati, Ohio; the Platt Iron Works, 

of Dayton, Ohio, and the Yaryan Company and American Process Company, of New York 

City, in furnishing illustrations to accompany this report, is also acknowledged with thanks.

DISTILLERY PROCESSES AND SOURCES OF POLLUTION. 

GBAIJST DISTIULATIOJST.

The distillery at Lynchburg manufactures grain liquors, including principally rye and 

bourbon whisky. The process of manufacture in such an establishment is generally about 

as follows: The grain, freed from husks or chaff and other impurities, is ground to a coarse

aTweniy-sixth Ann. Kept. U. S. Geol. Survey, 1605, pp. 215-217.
6 STREAM POLLUTION BY DISTILLERY REFUSE.

meal in roller mills, the fineness of grinding being varied somewhat with the grade of spirits 

to be produced.

Definite amounts of the meal are weighed out for "mashing" by Government internal-revenue officers and conveyed to cookers. The cooker is a closed iron digester, cylindrical in 

shape, horizontally placed, and provided with stirring apparatus.

The Hoffman-Ahlers vacuum mash cooker is illustrated by fig. 1. In operation with corn 

the cooker is about half filled with water (20 gallons of water being used for each bushel of 

grain to be mashed) and the stirring apparatus, seen within the shell of the cooker on the left 

and actuated by the belt pulley at the end of the machine, is started. Steam is then admitted, and the grain meal is introduced through the manhole on top. The manhole is then 

closed and steam forced in until a pressure of about 55 pounds per square inch is reached. 

To accomplish a thorough digestion, this pressure is maintained about half an hour after the 

steam is shut off. A vacuum pump connecting at the bell on top of the machine is then 

started and by reduction in pressure the contents of the cooker are. cooled down to about 

63° C. Ground barley malt mixed with a little water is then added and thoroughly mixed 

with the contents of the cooker for about half an hour. During this time the diastase of the 

malt acts upon the starch in the digested grain meal and converts it into maltose and dextrinous matter, the object of the distiller being to increase the maltose and decrease the dextrinous product.

FIG. 1. Vacuum mash cooker.

The distiller desires to produce from his grain the greatest possible amount of alcohol, 

and therefore fixes the narrow limit of 60° to 63° for mashing. A higher temperature 

would favor the production of a greater quantity of compounds not readily convertible 

into ethyl alcohol. In addition to the temperature, the quality of the malt and of the water 

has a considerable effect upon mashing. Distiller's malt is now generally specially prepared 

to produce a rapid and thorough conversion of starch, the germ of the malted grain being 

highly developed to produce a maximum diastatic power. The water used may retard or 

accelerate the action of diastase. Generally speaking, absence of organic matter or putrefactive products thereof and the presence of calcium sulphate are favorable to rapid conversion of starch. *

After cooling the wort is conveyed from the cooker to the fermenting vats. These vats 

are large, open wooden tubs, cylindrical in shape and vertically placed. The wort is diluted 

to a desired consistency and there is then added to it a yeast mash, which produces a fermentation by which the maltose is broken up and forms, chiefly, alcohol and carbon dioxideAll the maltose having been disposed of, the residuum of diastase in the wort attacks the 

dextrinous matter, producing more maltose, which in turn is fermented. As in the previous 

processes, the production of a maximum amount of alcohol is kept to the fore. The yeast
GRAIN DISTILLATION. 7

used is prepared from pure cultures to avoid loss of alcohol by the action of wild yeasts producing acetic, lactic, or other acids. The temperature is not made any higher than the 

point at which a healthy fermentation can be started, in order to avoid the production of an 

excess of aldehyde and fusel oil (the chief impurities in the manufacture of alcohol) and the 

loss of alcohol by evaporation. The maximum time allowed by law for fermentation is 

seventy-two hours. The distiller therefore uses an active top fermentation, by which all 

sugar is converted into alcohol -as rapidly and as completely as possible. Carbon dioxide 

bubbles up from the surface of the liquid in the tubs in great quantity soon after fermentation is started, and a top coating, composed of the suspended matter in the wort, rapidly

FIG. 2. Continuous beer still.

forms to a thickness of several inches. As the fermentation nears completion the gas 

escapes in diminishing quantity and the top coating of suspended matter gradually subsides, leaving a light yellow liquor a slimy mixture of solid matter, water, alcohol, fusel 

oil; aldehyde, acids, etc. known technically as beer.

The beer contains a small percentage of alcohol, which is separated from the other products by distillation. This separation is now generally accomplished by means of a continuous distilling apparatus, modeled more or less upon the plan of the Coffey still. Such a still 

is shown in fig. 2. The pump D forces the beer through the check valve / into the tubular 

heater and condenser B. In passing through the tubes of B the beer is heated by the vapor 

which surrounds them and then passes into the still A through the pipe K. On entering
8 STREAM POLLUTION BY DISTILLEEY REFUSE.

the still the Leer starts on a downward course, but is met by an upward rush of steam introduced through the perforated pipe 0.

The still is fitted with an ingenious arrangement of perforated plates having tubular overflows (shown near the center of the illustration), which brings each particle of beer into contact with the ascending steam. Since alcohol is vaporized at a much lower temperature 

than water, the steam pressure (and consequently the temperature) is so regulated with observation of the steam gage F as to effect a complete vaporization of the alcohol, which, together 

with some water vapor, passes off through L into the tube chamber of B. Here the alcoholic vapor surrounding the tubes is cooled by the beer within them and some impurities 

are condensed and returned to the still through M. The purer product, however, escapes 

through N to the condenser and cooler G. As may be seen in the illustration, the alcoholic 

vapor takes a spiral course between two bodies of water, which cool and condense it until 

it emerges in the try box J as a mixture of alcohol and water, or raw spirits. The try box 

is locked and sealed by an internal-revenue officer, and the degree of concentration of the 

spirits may be read from a hydrometer floating in the liquor. It may be here mentioned that 

the distiller has no access to the spirituous liquor after it leaves the still, all subsequent 

operations being under the supervision of internal-revenue officers, who lock and seal all 

means of access until the liquor is barreled, gaged, and stored in a warehouse, from which 

it can be legally removed only by payment of the revenue tax.

The spirit product of the still accounts, of course, for only a small portion of the beer. 

The dealcoholized liquid, known as slop, gravitates to the bottom of the still and is blown 

out at H. At E is a contrivance, known as the slop tester, used in determining the efficiency 

of the still. The slop is variously wasted, pumped back for further use, fed to cattle, or 

treated for recovery of a dried stock food. It forms the great body of liquid waste from a 

distillery.

The crude spirit as it comes from the still contains aldehyde and fusel oil, which give it a 

nauseating odor and taste. These are partially removed by filtration through wood charcoal. The spirit is further purified by a second distillation in a rectifier. This is an intermittent process, the spirit being introduced by charges. The first vapor is chiefly aldehyde 

and fusel oil and is collected and sold as such. Of the remainder a part may be sold as 

alcohol or the whole may be reduced to a suitable proof and stored in oak barrels for the production of whisky by aging. During the aging process, which generally lasts from two to 

eight years, the residuum of fusel oil is broken up and the liquor acquires the characteristic 

aroma and taste of commercial whisky. Coloring matter is absorbed from the barrels by 

the spirit, which changes from colorless to whisky brown.

From the rectifier a small amount of waste slop and wash water passes off. This is 

dilute, and not usually sufficient in quantity to produce a nuisance. It will be hereinafter referred to as waste A. At Lynchburg this waste water was run directly into the 

stream. Its quantity was so small and its flow so irregular, as compared with the other 

wastes, that it received no detailed consideration in the investigation.

TREATMENT OF SLOP.

In the distillery at Lynchburg, as in many other distilleries, a portion of tht slop from 

the still was used again as a diluent_in the fermenting vats; the greater part of the suspended matter was screened out, dried, and sold as stock food; a portion of the remainder 

was fed to cattle; the rest was wasted. A detailed description of the treatment is given 

in order to furnish a complete understanding of the proposed method of slop disposal. 

This description may be considered as characteristic, though details vary somewhat in 

the practice of different distilleries.

For clearness and convenience the slops from corn and rye distillation, respectively, 

will be denominated '"corn" and "rye" slops. As the treatment of the liquor is described, 

the various slops will be further designated by numbers and letters.

The slop as it comes from the still will be referred to as "slop rye 1" and " slop corn 1."
TREATMENT OF SLOP. 9

Slop rye 1 flows by gravity through a flume and pipe line to a receiving well at a building 

known as the ''slop house;" thence it is pumped to a perforated brass sheet or screen, 

which is set at such an inclination that the greater part of the slop passes through and is 

carried away in a wooden flume to settling vats. This thin slop from the screen will be 

designated ''slop rye 2." The coarser suspended matter, with some thin liquor, passes 

over the screen and falls into a wooden tub. This is slop rye 3.

Slop rye 2 is allowed to stand in settling vats for a few hours, when the supernatant, 

slop rye 4, is allowed to run into a pool of accumulated slops and filth. The heavier liquor 

from the vat bottoms, slop rye 5, is drawn off and fed to cattle, hundreds of which are kept 

for the sole purpose of disposing of this slop.

Slop rye 3 is forced into filter presses, which give a product of a thin liquor, slop rye 6, 

and damp feed, rye 7. The feed, containing about 60 per cent of moisture, is passed through 

a revolving horizontal cylindrical hot-air dryer, which reduces the moisture to less than 

10 per cent. It is then sacked and sold as a concentrated cattle feed. Slop rye 6 joins 

slop rye 4 in the pool mentioned above.

Slop corn 1 flows over a preliminary screen set in the flume bottom, and is thereby separated into a thin slop, corn la, and a thicker slop, corn Ib. Slop corn la is pumped back 

to the fermenting-vats, where it is used to dilute the wort from the cookers. Slop corn Ib 

follows the same course as slop rye 1, and is divided in exactly the same manner. The 

only variation in the treatment of the two is that slop corn 6, instead of passing to the pool, 

is pumped back to join slop corn la.

To recapitulate, the products are as follows:

1. Slops from still, rye 1 and corn 1.

2. Slops from preliminary screen for corn, corn la and corn Ib.

3. Slops passing to main screen, rye 1 and corn Ib.

4. Thin slops from screen passing to settling vats, rye 2 and corn 2.

5. Thick slops from screen passing to filter presses, rye 3 and corn 3.

6. Thin slops from settling vats discharged into poo], rye 4 and corn 4.

7. Thick slop from settling vats, fed to cattle, rye 5 and corn 5.

8. Thin slops from filter presses, rye 6 and corn 6.

9. Feed grains from filter presses, rye 7 and corn 7, to be dried.

10. Dried cattle food, rye 8 and corn 8, to be sacked and sold.

The cattle to which slops rye 5 and corn 5 are fed, and which subsist largely on this liquid 

food, produce quantities of semiliquid manure. A portion of this is hauled away to be 

used as compost on adjacent farms. The remainder, with all the more dilute wash water 

from the cleansing of the cattle pens, joins slops rye 4, rye 6, and corn 4 in an open barnyard pool, forming the chief liquid waste from the distillery. This pool drains, by a continuous stream and by large charges, into the creek, and will be referred to as waste B.

SOURCES AND CHARACTER OF POLLTUTIOlSr.

It will be observed that there were two sources of pollution waste A, a thin slop liquor 

of milky appearance, and waste B, a thin slop liquor mixed with filth from cattle stables. 

From 10,000 to 15,000 gallons were discharged each day, bearing into the stream from 

three-fourths ton to 1J tons of solid matter.
10 STREAM POLLUTION BY DISTILLERY REFUSE.

The slop was essentially a corn or rye extract, containing all the ingredients of the grains 

except starch (which had been removed in the form of alcohol and carbon dioxide) in approximately the same proportions that the grains originally contained them. The following table 

of analyses of these grains, by Richardson, is taken from Thorpe's Dictionary of Applied 

Chemistry, vol. 1 (1890), page 490:

TABLE 1. Average analyses of corn and rye. 

[Based on 114 analyses of corn and 57 analyses of rye.]

Constituent.

Water ..................................................................................

Fat.....................................................................................

Ash. ...................................................................................

Corn.

10.0

10.5

5.2

70.7

2.1

1.5

100.0

Rye.

8.7

11.3

1.9

74.5

1.5

2.1

100.0

As corn and rye contain about 55 and 45 per cent, respectively, of starch, the slop will 

receive 35 to 45 per cent of the grain as solid matter.

TABLE 2. Solid matter of corn and rye found in distiller's slop.

Constituent.

Fat.....................................................................................

Fiber ...................................................................................

Ash. ...................................................................................

Corn.

10.5

5.2

15.7

2.1

1.5

35.0

Rye.

11.3

1.9

29.5

1.5

2.1

46.3

As about 6.7 parts of water are used to 1 part of grain in the distillery processes, it is evident that the slop contained something less than 10 per cent probably about 5 per cent 

of solid matter.

Of the constituents named, those containing nitrogen make up the tissue-forming protein 

so important in animal food. Carbohydrates, fat, and iiber, digestible in greater or less 

degree, are producers of energy and fat. By the extraction of the starch the proportional 

content of protein is greatly increased, and the solid matter of distillery slop when separated 

from the water and dried thus becomes a valuable concentrated animal food. The ash also, 

chiefly potassium phosphate, has some food value.

Since these constituents have been taken largely from the soil in producing the grain, it is 

obvious that they will be suitable for use as a compost, which, by decay, would return to the 

soil much of the material taken from it. The use of these substances as food for animals, 

however, possesses much the greater monetary value.

Additional information regarding the constitution of distillery effluents is furnished by the 

following analyses of the slop, or "pot ale," of English distilleries, adapted from Trades 

Waste: Its Treatment and Utilization, by W. Naylor:
SOURCES AND CHAEACTEE OF POLLUTION. 11

TABLE 3. Analyses of pot ale from English distilleries.a

[Parts per million.] 

SOUCIL AND HARVIE'S DISTILLERIES.

Constituent.

Soucil (Paisley) .6

Harvie's.c

Dissolved matters:

Total solids.................................................................... 39,378 28,955

Organic carbon................................................................. 17,057 10,008

Organic nitrogen.................................. ............................ 2,373 2,041

Ammonia......................................... ........................... 180 90

Nitrogen as nitrites and nitrates................................................... 0 0

Total combined nitrogen........................................................... 2,522 2,115

Suspended matters:

Mineral .......................................................................... 836 53

Organic........................................................................ 33,372 2,776

Total......................................................................... 34,208 2,829

oNaylor, op. cit., p. 152. 6 July 21, 1870. c March 15, 1872. 

CRUDE SOUR POT ALE, SOURCE UNKNOWN.**

[Parts per million.] 

Free ammonia...................................................................................... 81

Albuminoid ammonia............................................................................ 55

Chlorine..........................................................................................^388

Mineral solids.................................................................................... 2,100

Volatile solids ...............................*.................................................... 23,850

Total solids................................................................................ 25.,950

POT ALE, SOURCE UNKNOWN.*

[Parts per million.]

Total solid matter (soluble)..................................................................... 31,300

Ash.............................................................................................. 7,210

Phosphoric acid.................................................................................. 1,990

Saline ammonia.................................................................................. 100

Albuminoid ammonia.................................\.......................................... 890

Sugar............................................................................................ 400

Carbohydrates, aldehydes, and organic acids (lactic and succinic)............................... 14,700

Oxygen absorbed in four hours.................................................................. 1,270

It would appear from these analyses that most of the suspended matter had been removed 

from all samples except that taken fr,om the Soucil distillery. They indicate that nearly 

half of the solid matter.of the slop is in solution, and that the total solids amount to between 

5 and 10 per cent. The varying nitrogen values indicate that in some samples decomposition 

of nitrogenous matter had begun. The high values of nitrogenous matter and carbohydrates 

and especially the high ratio of nitrogenous to nonnitrogenous material argue well for the 

food value of the slop.

Almost the whole substance being organic, subject to putrefaction, and undergoing 

secondary fermentations, the ordinary sewage tests, both chemical and bacteriological, were 

considered suitable for tracing the effect of such an effluent upon the stream at Lyachburg.

oNaylor, op. cit., p. 153. &Ibid, p. 149.
12 STREAM POLLUTION BY DISTILLEEY REFUSE.

EFFECT OF POLLUTING EFFLUENTS ON THE STREAM. 

/

A reconnaissance of the East Branch of Little Miami was made from Lynchburg to 

Fayetteville, a distance of about 9 miles. At suitable intervals samples were taken for 

chemical analysis, and field tests for dissolved oxygen were made. In addition, plates were 

made in the field for total bacterial count on agar, for count of acid-forming bacteria on 

lactose litmus agar, and cultures of strong agar were made for subsequent transplanting 

and examination for the colon bacilli.

The reconnaissance developed the following physical evidences of pollution:

1. The condition of the stream above the distillery was very good. No evidence of 

pollution was apparent. The water was generally clear and nearly colorless.

2. The stream waters were colored a light yellow upon the entrance of the distillery waste. 

This yellow cast was noticeable for perhaps a mile, giving way gradually to a dark murky 

appearance; such as is commonly ascribed to stagnant water. The stream presented this 

darker appearance for about 6 miles.

3. A slimy sediment (or possibly a growth of some organism) covered the stream bed for 

6 or 7 miles below the distillery. Near Lynchburg this was yellow and heavy. It decreased 

in amount downstream and changed in color to a dark brown or green.

4. At Bateman Bridge, 3 miles below the distillery, and at St. Martins Bridge, 6 miles 

below, the stream banks were edged with numbers of small dead fish.

5. An odor of putrefaction was very distinct a few yards from the stream at the two 

points above mentioned.

The stream, when examined, was somewhat above its average stage of flow. The foregoing conditions would, of course, be accentuated with decrease in flow. Fortunately 

the distillery is closed from July to October, inclusive. During the season of lowest flow, 

.therefore, pollution is obviated. The difficulty is greatest during the late fall and early 

winter.

It was stated by a resident 6 miles below Lynchburg that the stench from the creek is at 

times so great as to be very offensive. Others stated that during the distillery season ihere 

is no fishing between Lynchburg and Fayetteville, but that during the summer numerous 

carp can be caught. At Fayetteville there were no visible evidences of pollution when the 

reconnaisance was made.

The results of the chemical and bacteriological determinations, together with the estimated 

dilution of the distillery effluent by the stream waters, are shown by the accompanying 

table. The chemical constituents were determined as follows: Dissolved oxygen, by the 

Winkler method in the field; oxygen consumed, by permanganate method, boiling five 

minutes; organic nitrogen, by the Kjeldahl method; free ammonia, by the distillation 

method; chlorine, by titration with silver nitrate, potassium chromate indicator; alkalinity, 

by lacmoid, boiling; solids, in platinum, drying at 100° C.; loss on ignition, by threeminute ignition at a shade under dull-red heat.
EFFECT OF POLLUTION ON STREAM. 13*

TABLE 4. Effect on East Branch, Little Miami River, of effluent from distillery at Lynchburg,

Ohio.

[Chemical constituents expressed in parts per million.]

Organic nitrogen: 

Total.....................

Chlorine. .....................

Solids: 

Total.....................

Loss on ignition: 

Total.....................

Number of bacteria per c.c... 

Acid-forming bacteria in 5 c .c . 

(lactose litmus agar plate) .

Colon bacilli in 1 c. c. (strong 

agar culture).

Dam 

above 

distillery.

4292,4286

7.6

5.46

.75

.66

09

.05

4

183

289

272

17

67

61

6

5,200 

Absent.

Absent.

Ford below distillery.

4293,4287

1 in 150

5.9

41.26

6.59

2.58

4.01

.05

3.5

201

425

346

79

171

112

59

172,000 

Absent.

Absent.

Lower 

bridge at Lynchburg.

4291,4297

1 in 150

4

13.24

2.09

.85

1.24

.17

5

205

305

294

11

74

63

11

47,000 

Absent.

Absent.

Bateman 

Bridge.

4294,4288

3 miles.

1 in 250

2.3

10.89

1.49

1.16

.33

1.6

3.7

187

272

266

6

70

59

11

143,000 

Absent.

Present.

St. Martins 

Bridge.

4289,4295

6 miles.

1 in 300

1.4

52

15.13

8.02

7.:.1

4.62

7.2

238

483

431

52

238

172

66

473,000 

(a)

Present.

Fayetteville 

Bridge.

4290,4296

9 miles.

1 in 350

6.9

9.16

.83

.8

.03

.14

5

184

282

273

4

68

73

None.

2,000 

Absent.

Absent.

a Overgrown.

The results for St. Martins Bridge are far out of proportion to the others. There is 

almost no dissolved oxygen; oxygen consumed is 9.5 times the normal; suspended organic 

nitrogen is 79 times the normal; dissolved organic nitrogen is 12 times the normal;total 

organic nitrogen is 20 times the normal; free ammonia is 92 times the normal; chlorine is 

1.8 times the normal; alkalinity is 1.3 times the normal; total solid matter is 1.67 times the 

normal; dissolved matter is 1.58 times the normal; total suspended matter is 3.06 times 

the normal; the loss on ignition is 3.6 times the normal for total, 2.8 for dissolved, and 11 

for suspended solid matter; bacteria are 91 times as numerous as above the distillery. 

Colon bacilli were present in 1 cubic centimeter; the water had a dark, stagnant appearance; stench was noticeable some yards from stream; numbers of small dead fish were 

found lining the banks. The conditions at this place, 6 miles below point of pollution, 

constitute a very serious menace to property values, and render the stream unfit for use. 

These conditions are unusual and are not considered in the following discussion of normal 

pollution, and may be easily explained on the supposition that a few hours before the samples 

were taken a large amount of matter was discharged from the pool of filth at the distillery 

and had just reached the St. Martins Bridge.

In order to trace the diminution of evidences of pollution and the progress of the purification of the distillery refuse as it passes downstream, the results of analyses have been reduced 

to show percentage of normal values, the stream at the dam above the distillery being 

taken as normal. The results of this reduction are shown numerically in the following 

table:
STREAM POLLUTION BY DISTILLERY REFUSE.

TABLE 5. Percentage variation from normal in constituents determined in water taken a> 

certain points on East Branch, Little Miami River.

[Ingredients in water at dam above distillery taken as normal, or 100 per cent.]

Organic nitrogen: 

Total.................................

Solids: 

Total..................................

Loss on ignition: 

Total....................... .........

Ford below distillery.

78

756

879

391

4,456

100

88

110

147

1271

465

255

184

983

3,308

Lower 

bridge at 

Lynchburg.

53

242

279

129

1,378

340

125

112

106

108

65

114

103

183

904

Bateman 

Bridge.

30

199

199

176

370

3,200

92

102

94

98

35

104

97

183

2,750

St. Martins 

Bridge.

18

952

2,017

1,215

7,900

9,240

180

130

167

158

306

355

282

1,100

9,096

Fayetteville 

Bridge.

91

168

111

121

33

280

125

101

97

102

24

101

38

As the slop entering the creek is heavily charged with solid matter, suspended and in solution, nearly all of which is organic, it is to be expected that the total dissolved and suspended 

solids and losses on ignition would rise suddenly on the entrance of the distillery refuse. 

The fall in content of these matters, particularly those in suspension, during the first halfmile below the distillery, indicates that nearly all suspended matter is deposited upon the 

stream bed in that distance. This is evidenced by the heavy yellow sediment readily noticeable and gradually diminishing in quantity going downstream. The reduction in dissolved 

solids is also fairly rapid, in the first 3 miles being reduced to a trifle less than that above the 

distillery.

At Bateman Bridge and Fayetteville the total solid matter is less than above the distillery, 

and the content of volatile solids is only 4 per cent greater at Bateman Bridge and 1 per cent 

greater at Fayetteville. So far as these tests indicate, therefore, the variations from normal 

pollution is inappreciable more than three miles below the distillery (at Bateman Bridge), the 

stream having almost entirely purified itself by natural means. The stream has a moderate 

flow and consists of a succession of comparatively deep pools connected by rapids. These 

pools apparently act as a crude form of septic tank, and oxygen robbed from the stream by 

putrefying organic, matter is gradually restored by aeration in the rapids.

The chlorine and alkalinity determinations serve only to show that the polluting effluent 

is somewhat higher in chlorine and alkalinity than the normal stream water. The chlorine 

seems to rise and fall in a manner that can not be attributed to any influence of the distillery 

refuse. The influence of the slop in increasing the alkalinity of the stream was first viewed 

with surprise, it being known that the slop as it comes from the still is distinctly acid. Tests 

made afterward, however, brought to light the fact that upon standing several days the slop 

changes (with lacmoid indicator) from an acid to a strongly alkaline liquor. The changes 

in alkalinity downstream fromJLynchburg corroborate the conclusions already reached from 

the determination of solids.

The organic-nitrogen determinations are parallel with those previously discussed, inasmuch as they show an immense increase in organic matter with, the entrance of the distillery
EFFECT OF POLLUTION ON STEEAM. 15

refuse, followed by a gradual reduction in the pollution thus caused. Bateman Bridge, however, does not mark the limit of pollution indicated by these determinations. At that point 

the organic nitrogen is still twice as great as above the distillery, that in suspension showing 

the greatest proportional reduction. At Fayetteville the organic nitrogen is but little above 

the normal.

What has been said regarding organic nitrogen applies also to the oxygen-consumed test, 

an index to carbonaceous matter. The avidity for oxygen due to the distillery refuse has 

been nearly satisfied at Bateman Bridge, a reduction of less than one-third the normal 

oxygen-consuming power occurring in the 6 miles traversed between that point and Fayetteville.

The two chemical tests not already discussed, dissolved-oxygen and free-ammonia, are of 

more than usual interest in this case, because they mark the crisis in putrefactive action or 

the breaking up of carbonaceous and nitrogenous organic compounds into gases, water, and 

soluble mineral substances. The dissolved-oxygen tests, showing immediate decrease of a 

large proportion of free oxygen on the advent of the distillery refuse, serve to corroborate 

the unusual oxygen-consuming power of such refuse, as indicated by the oxygen-consuming tests. Bateman Bridge shows the lowest value for dissolved oxygen which can be attributed to normal state of pollution. It may be assumed, therefore, that the carbonaceous 

material has at this point been nearly all oxidized, further action of this kind being more 

than compensated for by oxygen naturally supplied to the stream waters. A gradual 

increase in dissolved oxygen is assumed to Fayetteville, where it is practically normal.

Comparing the stream action with a sewage-disposal system, Bateman Bridge may be 

looked upon as at the exit of a septic tank, further action being similar in result to that of oxidizing filtration. The diminution of dissolved oxygen may account for the death of the fish.

The tests for free ammonia indicate the absence of advanced putrefaction in the refuse 

that enters the stream. The nitrogenous matter is gradually broken up until a crisis is 

reached, as before indicated, near Bateman Bridge, from which point to Fayetteville the 

free ammonia decreases from 32 to 2.8 times the normal.

The bacterial counts indicate that the slop refuse contains a large number of organisms, 

probably such as produce secondary ferments; that stream conditions are not favorable to 

such organisms, and that they are reduced in number thereby; that the organisms originally 

present give place to bacteria which thrive on putrefying organic matter; that these bacteria 

assist largely in the purification of the stream and are not found, extensively at least, in the 

purified water at Fayetteville. The significance of the tests for B. coli communis is somewhat doubtful. It will be noted that this organism was found at but two points, Bateman 

Bridge and St. Martins Bridge, at which places all evidences of putrefaction were greatest. 

It is probable that its presence is due to the passage of a charge of concentrated filth from the 

cattle pens.

The important results of the reconnaissance of East Branch of Little Miami River from 

Lynch burg to Fayetteville may be summed up as follows:

1. The pollution by 1 part of distillery refuse in 150 parts of water is shown by a heavy 

sediment, deposited principally in the first mile below the distillery.

2. Such pollution causes a disagreeable stench for 2 or 3 miles along the stream and probably causes the death of fish.

3. The putrefaction of the polluting material in general is about complete 3 miles below 

the distillery, the stream at that point being similar in character to the dilute effluent of a 

septic tank.

4. Nine miles below Lynchburg the stream is apparently nearly as pure as it is above the 

distillery.

5. Large amounts of refuse discharged into the stream at other than flood stages produce 

extreme pollution, cause a strongly disagreeable stench, kill fish, and, in a word, render the 

stream unfit for its natural uses for more than 6 miles below the distillery.
16 STREAM POLLUTION BY DISTILLERY REFUSE.

DISPOSAL OF DISTILLERY EFFLUENT WITHOUT STREAM

POLLUTION.

To dispose of the distillery refuse without polluting the stream, four easily apparent 

methods could be used with more or less success: Filtration, precipitation, fermentation, and 

evaporation.

FILTEATIO1ST.

Simple filtration for such refuse has never been attended with satisfactory results. Nearly 

one-half of the solid matter being in solution, mere straining can not produce satisfactory 

purification. Bacterial filters manipulated with special care and unusual precautionary 

measures on an experimental scale have given an effluent which does not produce appreciable 

pollution, but the tendency of distillery slop to sour by rapid growth of acid ferments 

makes such a method of disposal extremely difficult. Naylor describes a method of bacterial 

treatment which depends upon the principle that 

the activity of one micro-organism is arrested by the introduction oi media suitable for the rapid development of other competitive forms. * * * Putrid sewage, or sewage sludge, is introduced, the active 

anaerobic organisms in which come into competition with the acid-producing bacteria, and in a short 

time the action of the latter ceases; moreover, the ammonia and other unstable compounds in the sewage 

neutralize the acids if already present, the resulting putrid liquid becoming quite amenable to treatment 

on bacterial niters. The treatment as a whole is similar to septic treatment, but the "septic" tank is in 

this case not used for the purpose of liquefying sludge, but for that of rendering inert the acid-forming 

organisms. It is therefore better described as an antisouring tank, a

Experimental tests were made upon a small quantity of crude sour "pot ale," or slop, 

which was neutralized with lime, passed through a tank containing sewage, and then subjected to bacterial filtration. A decrease of 96.5 per cent in free ammonia, 88.3 per cent in 

albuminoid ammonia, 16.7 per cent in mineral solids, and 97 per cent in volatile solids was 

thus effected, b This may be considered a substantial purification. Naylor's method was 

applied with success to the waste from the brewery of the Hook Norton Brewery Company, 

Hook Norton, Banbury, England, and plants of similar character have been installed at 

several breweries in England, not, however, with universal success. The failure of such a 

process at the Old Brewery, Rothingham, resulted in experimentation on a large scale by 

H. McLean Wilson for a better method of treatment. He was able to secure a satisfactory 

effluent at this brewery only under the following process: (a) Yeast was excluded; (?>) milk of 

lime in quantity equal to 45 grains per gallon of lime (643 parts per million) was added to 

produce a neutral liquor; (r) sludge was removed at frequent intervals; (d) the supernatant 

from anti-acid tanks was passed through double-contact ash filters; (e) ash-filter effluent was 

treated in a coke sprinkler in intermittent doses every five minutes for eight hours, amounting to 140 gallons per square yard per day; (f) effluent from coke sprinkler was strained 

through sand. This process resulted in purification of 96 per cent as measured by albuminoid ammonia, or 93 per cent as measured by oxygen absorbed in four hours at 80° F. c

Brewery liquors are of the same general character as distillery slops, though more dilute. 

It is probable, therefore, that the successful treatment of distillery liquors by such means as 

those described requires merely their adaptation to local conditions.

James Hendrick, in transactions of the Aberdeen congress, 1900, describes experiments 

with distillery refuse upon contact beds without preliminary treatment. The purification 

as measured by albuminoid ammonia and by oxygen absorbed in four hours at 80° F., 

respectively, was as follows: Seven contacts, 5 with coke followed by 2 with sand, 98.9 

and 98.7 per cent; first six contacts, 97 and 98 per cent; first five, 96.4 and 97.9 per cent; 

first four, 89 and 95 per cent; first three, 73 and 65 per cent; first two, 40 and 61 per cent; 

first contact, 20 and 23 per cent. The last four effluents contained nitrates, as did the 

effluent obtained by Wilson in the brewery experiments. 

a Naylor, W., Trades Waste, 1902, p. 153. 

& Naylor, op. cit., p. 153. 

c Wilson, II. McLean, Jour. Royal Sanitary Inst., vol. 25, pt. 3, p. 574 et seq.
FILTKATION AND PKECIPITATION . 17

The results of these English experiments, while indicating the practicability of bacterial 

filtration, with or without preliminary treatment, as a means of purifying such waste liquors 

as are produced by breweries and distilleries, demonstrate clearly that such a method of 

purification is very difficult and requires an .extensive and costly plant and constant, intelligent supervision. The sludge produced in antisouring tanks is considerable and has but 

little actual value as a manurial compost. It may readily be the cause of a nuisance if not 

frequently removed and so disposed that its offensive odor shall not be objectionable.

Above all other objections to bacterial filtration of these wastes is the primary fact that 

this method is one of destruction and precludes the possibility of the recovery of any valuable 

by-products which they may contain. Distillery slop, as is well known, has appreciable 

value as a compost and a much greater intrinsic worth as an animal food. The high dilution 

of the valuable material and the fact that it is largely in solution prevent its more general use 

in either or both of the ways mentioned. The food or manurial value of the slop depends 

upon its content of organic matters, chief among which are the valuable compounds of 

nitrogen grouped under the term protein. The same matters form the element of nuisance 

in stream pollution by putrefaction after they enter bodies of water not relatively very large. 

Treatment in bacterial filters depends for its success upon the action of the bacteria-laden 

filtering medium upon the same constituents. In such treatment, however, the valuable 

material is regarded merely as an element to be destroyed as such, and is changed into 

gaseous, mineral, or stable organic compounds. This treatment is regarded as successful 

only in proportion as the food or manurial value of the organic carbon and nitrogen is 

destroyed. It is effective as a preventive of stream pollution only in so far as it renders 

devoid of value a product which with proper treatment may be made a source of considerable revenue. It follows that such a system must necessarily be a source of constant expense 

for which no direct monetary return can be expected. It is therefore a method of treatment to be employed only when more economic purification can not be accomplished. This 

being the case, and this field having already been well exploited in England, no experiments 

in filtration were made in connection with the investigation at Lynchburg.

PRECIPITATION.

Chemical precipitation as applied to distillery refuse is, in principle, a purification system 

of doubtful efficiency and economy. In practice, so far as known, it has never proved even 

fairly satisfactory in either particular. In his experiments upon brewery waste at the 

Old Brewery, Rothingham, Wilson tried lime, copperas, manganate of soda, and aluminoferric in various amounts and with varied combinations. As compared to lime alone, the 

use of the other precipitants served to hasten deposition of the precipitate, but made no 

practical difference in the effluent. « In every case the supernatant was unfit to discharge 

into a stream because of the failure of the precipitants to throw out of solution the large proportion of organic matter it held. Ir^ other words, the effect was similar to that of mechanical 

filtration or straining. These experiments show the futility of attempts to purify brewery or 

distillery wastes by means of the precipitants in common use. To be efficient as a means of 

purifying such liquors the precipitation must be carried on by means of a substance that will 

throw the organic matter out of solution. Even were such a substance known, the problem 

of 'disposing of tons of sludge daily would be left for solution. In the interests of economy 

the initial cost of the precipitant should be a minimum and its composition should be such 

that the sludge produced will have a maximum value. The solids of distillery slop have 

value either as fertilizer or as food stuff for stock, and in order to make the value of the sludge 

greatest the precipitant should also have one of these values, preferably the latter, since in 

that lies the greater value of the refuse. It is evident that the greatest economy might be 

secured by a high-priced precipitant that would produce a more valuable sludge. It is really 

the difference between the cost of precipitant and value of sludge that should be taken as a 

criterion of the economy of the process.

IRR 179 06 2

a Jour. Royal Sanitary Inst., vol. 25, pt. 3, p. 574.
18 STEEAM POLLUTION BY DISTILLERY REFUSE.

A successful i. e., economical and efficient purification of distillery refuse by chemical 

precipitation must therefore be accomplished by means of some substance as yet unknown 

that will precipitate the organic matter in solution as well as the suspended matter, and that 

shall itself be a suitable constituent of a fertilizer or a food stuff. Experimentation along 

the line of chemical precipitation should therefore include primarily a search for such a precipitant. In view of the manifest difficulties attending such experimentation, the improbability of success, and the success attending research in other lines, no attempt was made to 

exploit this method of purification.

FERMENTATION.

It might be inferred from the rapid souring of distillery slops by secondary fermentations 

that these could be utilized in the disposal of the slop by the production of lactic or acetic 

acids or some other resultant of fermentation. Such use has been made of brewery liquors 

for the preparation of malt vinegar.a Objections would be the great storage area required; 

the impurity of the product, several different fermentations being active; the great dilution 

of a product so obtained; the general low market price of products that could probably 

be so obtained, and the residual sludge from such a process, composed of matters otherwise 

valuable as a foodstuff, but rendered useless for such purpose by the fermentation process.

Here also the probabilities of success lying rather with another process, this means of 

disposal was abandoned without experimentation.

EVAPORATION.

The increased efficiency of modern evaporating apparatus suggested the possibility of 

conserving all the valuable food material of the slop by evaporation. This process possesses intrinsic merit absent in the other methods of disposal considered. The products 

of an evaporator would be: (a) A distillate of nearly pure water, incapable of polluting 

the stream and probably more valuable than the water of a natural supply for use in the 

distillery processes; (&) the solid matter of the slop, practically unchanged in composition. 

The basic principle of this method is practically ideal. Nearly perfect purification is attained 

by the conservation of the valuable material in the refuse. As the theory of this method 

of disposal was extremely attractive, and as a rough estimate of costs and values indicated 

large economic possibilities, it was investigated in detail.

AMOUNT OF SLOPS AND RECOVERABLE SOLID MATTER.

Table 6 shows the quantity of slops, both for rye and corn distillation, discharged at - 

the brewery at Lynchburg, arranged by daily discharge and by discharge per bushel of grain 

mashed. The figures given represent, it is believed, within about 5 per cent the actual 

conditions and are therefore sufficiently accurate to be used as a basis of costs and values 

in estimating the economic possibilities of any disposal system.

oKoller, The Utilization of Waste Products, p. 20.
EVAPOKATION. 19

TABLE 6. Daily discharge of slops at Lynchburg distillery.

Source. Slop (designation) .

Cornl..... 

Corn la

To screen.. ..... .. .. . .. Cornlb__.

Corn 2..... 

Corn 3... .

CoruG..... 

Corn 7... .

To screen. ...... ..... .. ' Rvel.....

Rye 2.....

Rye 3.....

Rye 4..... 

Rye 5.....

Rye 6.....

Rye7.....

Rvo 8

Total discharge.

Gallons.

7'7 ,ooo

16,300 

60,700 

37,300 

23,400 

7,300 

30,000 

19,500

61,500 

44,900 

16,600 

14,900 

30,000 

13,000

Pounds.

651,600 

136,900 

514,700 

314,700 

200,000 

60,700 

254,000 

163,300 

36,700

17,500

542,200 

380,300 

143,900 

125,200 

255,100 

109,300 

34,600

11,600

Discharge per 

bushel of grain 

mashed.

Gallons.

44.0 

9.3 

34.7 

21.3 

13.4 

4.2 

17.1 

11.1

44.2 

32.3 

11.9 

10.7 

21.6 

9.3

Pounds.

372 

78 

294 

180 

114 

35 

145 

93 

21 

10 

377 

273 

103 

90 

183 

79 

25 

8.3

As a means of estimating the amount of recoverable foodstuffs in the slop, hourly composite samples representing the entire working day were taken. Selected samples of the 

present slop product after screening, after pressing, and after the final drying were also taken 

for purposes of comparison and computation. Partial analyses of these samples were 

made in the laboratory of the Ohio State board of health, at Columbus, the results of which 

are shown in table 7.

The evaporation was effected by means of a water bath. A preliminary drying was given 

at 100° C. and a final drying at about 135° C. The figures show, therefore, values somewhat less than would be obtained by an accurate determination of solids under more favorable conditions. They will approximate very nearly, however, the true values for solid 

matter recoverable by evaporation.

In table 8 the proportional composition of the solid matter is shown, this having been 

prepared from table 7.

The amount of recoverable matter is shown in pounds per day in table 9, and in pounds 

per bushel of grain mashed in table 10.
20 STREAM POLLUTION BY DISTILLERY REFUSE.

TABLE 7. Recoverable solid matter in classified distillery slops.

m cfl

O

c

m

H 

X 

m

I 

< 

o

m

n 

O

H

O

z

H

m

"^ Source.

rn

H

^Through screen «...

From presses o ...... .

VDried feed *...........

_/To screen a ........... 

T-Through screen a. . . . .

Vat supernatant « . . . .

QDried feed & ..........

Slop (designation).

Corn Ib. 

Corn 2 . . 

Corn 3. .

Corn 6. . 

Corn 7. .

Ryel... 

Rye 2... 

Rye 3...

Rye 4... 

Rye 6... 

Rye 7...

Rye 8...

Sample 

No.

39 

40 

42

41

43 

44

34 

35 

37

32 

33 

38

36

Dissolved.

Volatile.

19.5 

19.9

18.9

19.8 

18.3

18.2 

19.9

Fixed.

2.1 

2.2

2.2

1.9 

1.8

1.8 

1.9

Total.

21.6 

22.1

21.1

21.7 

20.1

20.0 

21.8

Suspended.

Volatile.

24.9 

10.3

1.3

27.4 

11.9

.1 

1.4

Fixed.

0.5 

.2

Tr.

.3 

.2

Tr. 

Tr.

Total.

25.4 

10.5

1.3

27.7 

12.1

.1 

1.4

Total.

Volatile.

44.4 

30.2 

94.7 

20.2 

426.4 

917.3 

47.2 

30.2 

89.6 

18.3 

21.3 

307.3 

851.2

Fixed.

2.6 

2.4 

3.1 

2.2 

7.2 

16.7 

2.2 

2.0 

2.8 

1.8 

1.9 

5.1 

17.7

Total.

47.0 

32.6 

97.8 

22.4 

433.6 

934.0 

49.4 

32.2 

92.4 

20.1 

23.2 

312.4 

868.9

o

>TABLE 8.- 

C/5

m

o Grams per liter. b Grams per kilo.

* 

-Proportional composition of recoverable solid matter in classified distillery slops.

[Per cent of total solid matter.]

GO

&j Source. 

TJ

.-p. Through screen .......

To screen .............

Through screen ....... 

Over screen

Vat supernatant. ..... 

From presses .........

Slop 

(designation) .

Corn Ib. 

Corn 2. .

Corn 6. . 

Corn 7. . 

Corn 8. . 

Rye 1 ... 

Rye 2... 

Rye 3...

Rye 4. . . 

Rye 6... 

Rye 7...

PTTP 8

1 J

Sample 

No.

39 

40 

42

41 

43 

44 

34 

35 

37

32 

33 

38

36

Dissolved.

Volatile.

41.5 

61.0

84.4

49.1 

56.8

90.5 

85.8

Fixed.

4.5 

6.7

9.8

3.8 

5.6

9.0 

8.2

Total.

46.0 

67.7

94.2

43.9 

62.4

99.5 

94.0

Suspended.

Volatile.

53.0 

31.6

5.8

55.5 

37.0

.5 

6.0

Fixed.

1.0

.7

Tr.

.6 

.6

Tr.

Tr.

Total.

54.0 

32.3

5.8

56.1 

37.6

.5 

6.0

Total.

Volatile.

94.5 

92.6 

96.8 

90.2 

98.3 

98.2 

95.6 

93.8 

97.0 

91.0 

91.8 

98.4 

98.0

Fixed.

5.5

7.4 

3.2 

9.8 

1.7 

1.8 

4.4 

6.2 

3.0 

9.0 

8.2 

1.6 

2.0

Total.

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100

TABLE 9. Weight, in pounds, of solid matter discharged daily in classified distillery slops.

Source.

Through screen .....

To screen ............

Through screen ......

From presses ........

Slop (designation).

Corn Ib. 

Corn 2...

Corn 6...

Ryel... 

Rye 2...

Rye 6... 

Rye 7...

Rye 8. . .

Dissolved.

Volatile.

12,350 

6,200

3,150

10,200 

6,850

2,150

Fixed.

1,350 

700

350

950 

700

200

Total.

13,700 

6,900

3,500

11,150 

7,750

2,350

Suspended.

Volatile.

15,800 

3,200

200

14,100 

4,500

150

Fixed.

300 

100

Tr.

150 

50

Tr.

Total.

16,100 

3,300

200

14,250 

4,550

150

Total.

Volatile.

28,150 

9,400 

18,950 

3,350 

15,650 

15,550 

24,300 

11,350 

12,900 

2,300 

10,600 

10,500

Fixed.

1,650 

800 

650 

350 

250 

250 

1,100 

750 

400 

200 

200 

200

Total.

29,800 

10,200 

19,600 

3,700 

15,900 

15,800 

25,400 

12,100 

13,300 

2,500 

10,800 

10,700
EVAPORATION. 21

TABLE 10. Weight, in pounds, of solid matter discharged daily in classified distillery slop

per bushel of grain mashed.

Source.

Through screen. .....

To screen............ 

Through screen. .....

From presses. . ...'...

Dried feed. ..........

Slop (designation).

Corn Ib . 

Corn 2...

Corn 6... 

Corn 7...

Byel... 

Bye 2... 

Rye 3...

Rye 6... 

Rye 7...

Rye 8...

Dissolved.

Volatile.

7.06 

3.54

1.80

7.33 

4.92

1.55

Fixed.

0.77 

.40

.20

.68 

.50

.14

Total.

7.83 

3.94

2.00

8.01 

5.42

1.69

Suspended.

Volatile.

9.03 

1.83

.11

10.13 

3.23

. .11

Fixed.

0.17 

.06

Tr.

.11 

.04

Tr.

Total.

, 9.20 

1.89

.11

10.30 

3.27

.11

Total.

Volatile.

16.09 

5.37 

10.83 

1.91 

8.94 

8.89 

17.46 

8.15 

9.27 

1.66 

7.61 

7.54

Fixed.

0.94 

.46 

.37 

.20 

.14 

.14 

.79 

.54 

.28 

.14 

.14 

.14

Total.

17.03 

5.83 

11.20 

2.11 

9.08 

9.03 

18.25 

8.69 

9.55 

1.80 

7.75 

7.68

From table 9 we find the total solid matter available each day on corn distillation to be 

29,800 pounds (corn Ib), less 3,700 pounds (corn 6, used over in fermenting vats), or 26,100 

pounds. Of- this amount, 15,800 pounds (corn 8) was formerly recovered, leaving a total 

of 10,300 pounds run into the stream or fed to cattle. Possibly 100 pounds were wasted 

under the old recovery system. If, therefore, we deduct 300 pounds as waste under the 

extended system, we have provided a wide margin of safety and still have an increased 

product of 5 tons a day, or a total product of 12.9 tons a day.

For rye, none of the slop being used over, a proportionally larger product is obtainable. 

Deducting the 10,700 pounds (rye 8), recovered by the old method from the total of 25,400 

pounds (rye 1), and allowing, as in the case of corn, 300 pounds for waste, we have an 

increased product of 14,400 pounds (7.2 tons), or a total product of 12.55 tons of dry solids.

METHOD OP EVAPORATION.

The first question arising which will affect the mode of procedure is in relation to the point 

of application of the evaporation process. What slops shall be evaporated? The stream 

pollution is caused chiefly by the waste each day of some 10,000 to 15,000 gallons of a fairly 

thin slop, the supernatant from the settling vats and the waste liquor from the rectifier. 

The remainder is now recovered or fed to cattle. Will it be more profitable to evaporate 

only those liquors that cause pollution or to apply the process to the entire slop output 

of the distillery? This question involves the abandonment of the cattle-fattening industry. 

It is generally conceded that this industry is financially precarious, being valuable chiefly 

as a means of disposing of slops. In some years it produces substantial profits; in others 

there are equally great losses. The cattle must be herded together in sheds, where the 

spread of communicable diseases is rapid. There is always great danger of loss by fire. 

Fluctuation in .the market value of stock is another element of uncertainty. Although 

the business averages a small profit, few distillers would not be glad to exchange it for 

any other method of slop disposal that would not be a continued source of financial loss. 

Another objection to the cattle business is the great accumulation of manure, which from 

slop feeding is copious-and in a semifluid condition. Great quantities are hauled away 

by farmers, but there is generally a remainder to cause a nuisance on the spot or to be 

run into the stream with the thin slops. From these considerations and the knowledge 

that the cost of evaporation is proportionally less with greater quantities, it is obvious that 

cattle fattening can well be abandoned if any part of the slop is to be utilized by 

evaporation.

Suspended matter will retard evaporation, causing a higher temperature for vaporization, 

forming scum, and having a tendency to adhere to the heating surface. Zn laboratory tests
22 STREAM POLLUTION BY DISTILLERY REFUSE.

in glass and iron dishes much difficulty was caused by the burning of adhering particles in 

the evaporation of slops containing considerable suspended matter. Filtered samples or 

thin slops, such as those coming from the filter presses (corn 6 and rye 6), could be concentrated to contain only 50 per cent of moisture without serious difficulty. Tests on speed of 

evaporation of rye slops, the most difficult to treat because of the slimy nature of the liquid, 

showed an inappreciable difference between the speed of evaporation of the first half of 

equal volumes of distilled water and slop rye 4, the vat supernatant containing 100 parts per 

million of suspended matter. Rye 6, slop from presses containing 1,400 parts per million of 

suspended matter, was somewhat slower. A comparison of rye 6 (slop from presses), rye 2 

(slop passing through screen), and rye 1 (slop before passing screen) showed that the volumes 

evaporated in a given time were approximately in the ratio 6:2:1. The suspended solids in 

these slops are approximately in the ratio 0.05:44:1. Although these experiments .were not 

conducted with sufficient care to warrant great dependence upon numerical relations that 

might be deduced from them, they prove that the suspended matter seriously interferes with 

evaporation; that previous to evaporation the slop should be more thoroughly screened than 

at present; and that the screening should be at least as thorough as that effected by the filter 

presses.

In the conduct of an evaporation system, therefore, the first process should consist of passing slops rye 1 and corn 1 over a series of rotary or oscillating brass or copper screens. The 

screens should be designed to separate the slops into a thin liquid containing about 2.15 per 

cent of dissolved and 0.1 per cent of suspended solids and a thick, pulpy mass containing 

about 2.15 per cent of dissolved and 10 per cent of suspended solids.

PI. I gives a view of an approved type of machine designed to filter-press distiller's slop. 

This machine is composed of 93 plates (one of which is shown in the foreground), which rest 

upon the iron frame of the press. Any two adjoining plates are separated by a filtering 

medium (a fine-brass screen or piece of stout cloth) and form a filter. The substance to be 

filtered is introduced through the opening in the center and is forced outward toward the 

perimeter. The clear liquid passes through the filtering medium and is drained off, while the 

suspended matter is retained between the plates.

It will be observed in the illustration that the machine is arranged in three sections. The 

substance to be filtered is introduced at the left end of each section and is distributed to the 

various plates by a sort of screw conveyor operating in the central aperture. It is customary 

to force the material into the machine at a pressure of 150 to 200 pounds to the square inch. 

When the machine is filled in this manner, a further pressure is used to force the plates (which 

have been up to this time slightly separated) closer together and thus to reduce still further 

the moisture retained in the coarse material between the plates. This pressure is variously 

applied. In the illustration the hydraulic piston shown on the right is used for this purpose. 

A very high pressure is thus attained with consequent high efficiency in drying the suspended 

matter retained in the filter.

The moisture having been reduced as far as possible, the plates are separated, the caked 

material within is removed, and the machine is prepared for a new charge.

From this process two products are obtained: First, a thin slop of about the same composition as the thin slop from the screens; second, a damp, caked feed, half moisture and half 

solid matter. The first of these products should be pumped back to join the thin slop from 

the screens, the second should be conveyed to a mixer to be joined by the evaporated slop.

The thin slop from the screens should pass to a feed reservoir for the evaporator, where it 

should be joined by the thin slop from the filter presses and the thin slop from the rectifier, 

herein referred to as waste A. Waste A is an irregular flow of small amount. On this 

account it is excluded from the calculations. From this reservoir, in the case of corn distillation, 35,800 gallons will be carried back for use in the fermenters, this use of slop as a 

diluent in the fermentation process materially increasing the yield of spiritous liquors.

We have now reached that point in the disposal system where evaporation becomes 

necessary as a means of separating the water from the dissolved solid matter in the dilute 

slop liquors which are practically free from suspended matter. For this process vacuum
U, S, GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 179 PL. I

SMITH-VAILE FILTER PRESS
 WJ'

A 

I

III J 
EVAPORATION. 23

multiple-effect machines, of types such as the Yaryan or Chapman, are eminently suitable. 

The principles involved are primarily: (1) That the temperature at which a liquid will vaporize is decreased by decrease of pressure within the vessel containing it; and (2) after the 

temperature of a liquid has been raised to the point of vaporization an additional supply of 

heat is required to vaporize it, which supply of heat increases with decrease in temperature and will be given off when the vapor is condensed to a liquid.

Yaryan's triple-effect vacuum evaporator (fig. 3) may be taken as a type of this class of

 nachines, the general principles of operation being alike in all. This machine consists 

ssentially of three cylindrical chambers or "effects," in each of which is a series of coils of 

nail tubing. Each effect is also provided with a separator to free the concentrated liquor 

im the vapor before it leaves the 

ect. A vacuum pump draws the 

>or from the last effect and thus 

automatically regulates the pressures in the various effects. The 

operation is as follows: Steam is led 

intj the cylindrical chamber surro> .iding the coils of the first effect, 

anc1 he liquid to be evaporated is 

intri duced within the first tube of 

these -".oils in a small but continuous 

strea i. The surrounding steam 

immc diately causes the liquid to boil, 

and the steam thus generated causes 

it to n sh through the heated coils, 

where becomes more and more 

concer ited as it progresses. Finally, the mixture of liquid and 

steam discharged from the last 

tnv^ j the separator. Theconcenliquor from the separator of 

*e first effect passes to the coils of 

e second effect for further concenion. The vapor generated in the 

iLoi effe< nasses to the chamber 

surround! l,he coils of the second 

effect, w, i it is condensed and 

gives up its itent heat. The same 

operation tt es place in each succeeding effec , the vapor from the 

final effect goaig to the condenser 

and vacuum ,)ump, a high vacuum 

being therebj maintained in the

coils of the fin effect. This reduces the boiling point of the liquor in the coils below that 

of the surroui ng steam, which, condensing, not only gives up its heat to the liquor in 

the tubes, b'-t forms a vacuum of lesser degree in the next preceding effect. The relative pressure m;." itained in the various effects is automatically adjusted to accomplish a 

vaporization of - liquid in each effect, except the first, by means of the vapor generated

 its own evapor. ^,ion in the next preceding effect. The highly concentrated liquor from 

the final effect is amoved by a magma pump as may be desired.

This utilizatior f the steam generated by evaporation will accomplish in a triple-effect 

rnar,hine about th) 3 times as much evaporation with a given amount of fuel as the ordinary 

"single-effect" evaporator. Radiation and the expense of maintaining the low pressures 

will of course reduce the theoretical economy of the machine. It is claimed, however, that

FIG. 3. Yaryan's triple-effect evaporator.
24 STREAM POLLUTION BY DISTILLERY REFUSE.

the Yaryan evaporators in practical operation, assuming that 1 pound of coal will vaporize 

8J pounds of water, will evaporate the following amounts of water with 1 pound of coal: 

Double effect, 16 pounds; triple effect, 23.5 pounds; quadruple effect, 30 pounds; quintuple 

effect, 37 pounds.

Advantages of evaporators of this type are rapid circulation of liquid and consequent 

short time exposure to heat, low temperature of evaporation because of vacuum, and an 

arrangement by which a small quantity of liquid is exposed to an extensive heating surface. 

These advantages are of considerable importance in dealing with distillery slops, the 

organic compounds of which are likely to be broken up by high temperature and long 

exposure to heat, so as to impair possibly their food value. Within reasonable limits, by suitable arrangement of pressures, the temperature of vaporization may be regulated as 

desired, and thus any possible injury to recoverable material avoided.

Chief among the disadvantages are the great cost of the machines and their doubtful 

economy of operation in dealing with highly concentrated liquors.

In connection with the process of evaporation the matter of condensation of exhaust 

steam must be considered. For the proposition in hand this can be accomplished by about 

350,000 gallons daily of cooling water to be used in connection with condensers of ordinary 

type. At laynchburg this supply of water can probably be had at the cost of pumping from 

the adjacent stream, though it may be found necessary to sink shallow wells. As an 

extreme measure in case of limited water supply, cooling tanks or reservoirs may be constructed in which the water, heated by reason of its use as a condensing agent, may regain 

its normal temperature, and thus be made ready for use again. By such means an 

initial supply of water can be used over and over, a loss of only 2 to 10 per cent taking place 

daily through leakage and evaporation. There are in practical use many types of cooling 

towers in which artificial air draft or natural radiation is utilized for reducing the temperature. Simple open reservoirs are also used for such purpose, but these are generally considered to be less advantageous than specially constructed towers.

From the evaporation process, including condensation, we shall have two products, the 

first a magma or evaporated slop of 2,600 gallons on corn and 4,000 gallons on rye; and 

second, a distillate or condensed steam, amounting to 34,900 gallons on corn or 55,000 

gallons on rye. (See table 11.) The distillate, a nearly pure water, is specially suitable for 

use in the mashing process, for which it has considerably greater value than a natural water. 

It should therefore be pumped to the cookers.

The magma, containing not more than 75 per cent of moisture (manufacturers of evaporators claim a reduction to 50 per cent moisture), should be passed to a tub and thoroughly 

mixed with the damp feed from the filter presses preparatory to drying. A cylindrical tub 

with central revolving vertical shaft having horizontal arms attached will prove a satisfactory mixer.

In this description of the disposal-recovery process we have now reached a point where all 

the waste from a distillery has been reduced to a pulpy mass of material suitable in composition for cattle feed. It remains only to prepare this for shipping. In the pulpy condition, 

although it is well adapted for immediate feeding, it is not marketable, because of its large 

moisture content and its liability to heat and ferment. To prepare it for the market, its 

moisture content should be reduced to about 10 per cent. In the present food-stuff process 

at Lynchburg this is accomplished by passing the damp feed from the filter presses through 

a hot-air drier, the product of the drier being sacked for shipment. With the process we are 

proposing, this treatment would be insufficient. Even in the present process considerable 

difficulty is experienced in the caking of the feed and consequent irregular drying. W'hen 

it is considered that in the proposed process the material to be dried will contain more 

moisture and that much of it will be in extremely fine grains, it will be obvious that this 

difficulty would be enormously increased. It is proposed, therefore, to accomplish the drying in two stages. In the first a reduction to about 20 per cent of moisture will be obtained. 

The material should then be conveyed to a thrasher to break up all cakes formed, and finally 

to a second drier in which an even drying to a moisture content of 10 per cent or less may be
EVAPORATION. 25

accomplished. The usual types of hot-air or steam revolving feed driers and the ordinary 

feed thrasher would be suitable for this work.

A modern drier of considerable efficiency is shown in fig. 4. It consists essentially of a 

cylindrical steel shell provided on the interior with longitudinally placed shelves. Near 

each end of the shell is a steel tire which rests on friction roller wheels. These wheels are 

rotated by gearing or chain belting and they in turn rotate the shell. The drier as a whole 

is set on a gentle slope. Its operation is as follows: The wet material is introduced at the 

higher end by means of an intake hopper and falls to the bottom of the shell. It is then 

caught by the shelves and elevated by the rotation almost to the top of the shell and is then 

showered to the bottom again. This cycle is repeated again and again as the material slowly

FIG. 4. American process drier.

travels to the lower end on account of the slope of the machine and the high draft created 

by the blower. All hot gases pass through the drier on their way to the chimney, and as the 

material is showered from top to bottom of the shell it is brought in direct contact with the 

gases, thus accomplishing a rapid and thorough drying.

This drying process is the final preparation for sacking and shipment.

Table 11 shows the probable amount of the various slops and slop products (in pounds and 

gallons) and the amount of recoverable solids therein (in pounds), arranged by quantity per 

day, quantity per hour, and quantity per bushel of grain mashed. The figures shown are 

based upon measurements of quantities at the distillery, laboratory experiments, and general 

knowledge of the efficiency and capacity of the machinery described. Although these figures 

are unsubstantiated by practice, no such plant havii^ yet been placed in operation, it is 

believed that they are fairly accurate and suitable for use in estimating costs and values.
STREAM POLLUTION BY DISTILLERY REFUSE.

11. Probable amount of classified slops and slop products and recoverable matter under 

proposed system of disposal by evaporation.

Source.

Corn. 

From still................

Over screen............. .

Through screen ........... 

Pressed feed. .............

Slop from presses .........

Distillate from evaporaEye.

For first drier 6 ...........

Distillate from evaporaSlops and slop products. .

Gallons.

Per 

day.

77,000 

19,500 

57,500

15,800 

37,500 

2,600

OA Qfln

61,500 

13,900

47,600

11,400 

59,000 

4,000

55,000

Per 

hour.

7,000 

1,770 

5,230

1,440 

3,410 

290

3,170

3,420 

770 

2,640

630 

3,280 

220

3,060

Per 

bushel 

of grain 

mashed.

44.0 

11.1 

- 32.9

9.0 

21.4 

1.5

20.0

44.2 

10.0 

34.2

Q 0

8.2 

42.4 

2 9

39.5

Pounds.

Per

day.

651,600 

171,300 

480,300 

39,000 

132,300 

313,900 

28,400 

67,400 

35,300 

29,000

524,200 

124,200 

400,000 

28,800 

95,400 

495, 400 

44,000 

72,800 

33,800 

27,500

Per 

hour.

59,200 

15,600 

43,700 

3,500 

12,000 

28,500 

2,600 

6,100 

3,200 

2,600

29,100 

6,900 

22,200 

1,600 

5,300 

27,500 

2,400 

4,000 

1,880 

1,500

Per 

bushel 

of grain 

mashed.

372 

98 

274 

22 

76 

179 

16 

38 

20 

17

377 

. 89 

288 

21 

68 

356 

31 

52 

24 

20

Recoverable solids.

Pounds, i

Per

day.

33,300 

22,500 

10,800 

19,500 

3,000 

7,100 

7,100 

-26,600 

26,500 

26,300

25,400 

16,400 

9,000 

14,400 

2,000 

11,000 

11,000 

25,400 

25,300 

25,100

Per 

hour.

3,030 

2,050 

980 

1,770 

270 

650 

650 

2,420 

2,410 

2,390

1,410 

910

500 

800

no

610 

610 

1,410 

1,400 

1,390

Per 

bushel 

of grain 

mashed.

19.0 

12.9 

6.2 

11.1 

1.7 

4.1 

4.1 

15.2 

15.1 

15.0

18.2 

11.8 

6.5 

10.4 

1.4 

7.9 

7.9 

18.2 

18.2 

18.0

a Slco through screen, from presses, and waste A, less 35,800 gallons.

6 iSufh of pressed feed and evaporated slop.

c Slop through screen, from presses, and waste A.

As in the present system at Lynchburg, the thick slop from the screens should be filterpressed to reduce the moisture content to about 50 per cent.

COST OP PLANT.

From the foregoing statement regarding the processes involved it will be inferred that 

recovery by evaporation involves the installation of costly machinery and the erection of an 

extensive plant. Chief in the list of machinery is the evaporating apparatus. Manufacturers were consulted and estimates secured on three different machines, as follows:

No. 1. Capacity, 3,250 gallons per hour. Price, $21,555. Triple effect, cast iron with 

copper heating surfaces. Three and four-tenths pounds of steam required to evaporate 1 

gallon. Space required, 16 feet by 48 feet by 26 feet in height.

No. 2. Capacity, 3,500 gallons per hour. Price, $31,850. Quadruple effect, cast iron 

with brass heating surfaces. Two and eight-tenths pounds of steam required to evaporate 1 

gallon. Space required, 18 feet by 24 feet by 27 feet in height.

No. 3. Capacity, 4,150 gallons per hour. Price, $25,000. Quadruple effect, cast iron 

^throughout. Two and eight-tenths pounds of steam required to evaporate 1 gallon.
COST OF PLANT. 27

If we assume that 30 pounds of steam are equivalent to 1 horsepower hour, that 1 pound of 

coal will produce 7 pounds of steam, and that such coal can be procured for $2 per ton, the 

following data for the three machines are easily calculated from the figures in table 11:

TABLE 12. Cost of operating evaporators. '

Number.

1.... ............... .

2............... .. .

3........... .

Hours 

per day.

11 

10

8+

Corn.

Pounds 

coal per 

day.

17,000

14,000

14 000

Cost per 

day.

i $17.00

14.00

14.80

Hours 

per day.

17 

10 1

Rye.

Pounds 

coal 

per day.

26,700

99 nnn

Cost per 

day.

$26.70

22.00

23.25

Horsecapacity 

of boilers 

required.

369

327

387

Cost per 

season.

$3,890

3,200

3,380

The average number of hours per day for corn distillation is 11, for rye distillation 18. 

Any one of these evaporators would therefore answer the purpose so far as time is concerned. 

In fact, there is little to choose between them. In about fifteen years the greater cost of 

operation on No. 1 would offset the greater first cost on No. 2, while in about seven years it 

would offset the greater first cost on No. 3. To state the comparison in another way, the 

additional capital invested in No. 2 will pay 7 per cent interest in decreased fuel bill, while 

the increased capital invested in No. 3 would similarly pay 15 per cent interest. In the 

daily cost of operating No. 3 is included 80 cents on corn and $1.25 on rye for lime to neutralize 

the acidity of the slop before passing it into a cast-iron machine.

Other considerations such as floor space, labor, etc. also enter into the problem. It is 

not the object of this paper to choose the best machine, and the foregoing discussion is 

merely intended to show that different types of evaporators manufactured by different 

firms will give results that are about equal viewed from an economic standpoint. In the 

estimates which are given later the foregoing have been averaged approximately, a theoretical 

machine costing $26,000 and operating at a daily cost of $15.50 for corn and $24 for rye 

being used as a basis of calculations.

Some additional expense would be incurred, including boilers of 400 horsepower capacity, 

costing about $2,000; a drier, $5,000; an addition to the slop house, $2,000, and installation, 

engineering, and incidentals not to exceed $5,000. These, it must be understood, are additions requisite to adapt the present plant to the manufacture of cattle feed by screening, 

filter-pressing, and drying, including the evaporation of thin slop previously wasted or fed to 

cattle in liquid form.

The estimated cost of present plant and additions is as follows:

TABLE 13. Estimated cost of food-stuff recovery plant at Lynchlurg.

Old plant.

Building................................... $2,000

Filter presses.............................. 2,000

Drier....................................... 6,000

Miscellaneous........................ ..... 2,000

Total................................ 12,000

Additions.

Building.................................... $2,000

Boilers..................................... 2,000

Drier............ .......................... 5,000

Evaporator. ,. ............................ 26,000

Miscellaneous.............................. 5,000

Total................................. 40,000

The costs of the additions will apply to any distillerv with a capacity of 1,750 bushels of 

corn or 1,392 bushels of lye per day. The total cost of installing a new plant throughout will 

be seen to be estimated at $52J000.

:-; /tY
28 STREAM POLLUTION BY DISTILLERY EEFUSE.

COST OF PROCESS.

The installation of an evaporating plant, with consequent increase in amount of feed 

grains, will increase the greater daily cost of production. Two firemen at $1.50 per day will 

be required for the additional boilers; two men, one at $2.50 and one at $1.50, will beTequired 

for the evaporator; two additional men at $1.£0 will be required for pressing and drying; 

two additional men at $1.50 for sacking and loading. For rye one-half should be added to 

the above, except sacking and loading, because of the extra hours, or for the average daily 

cost during the season one and one-eighth times the above should be taken. Fuel costs will 

also be increased. In the following table the seasonal average costs per day and total costs 

per season are shown.

TABLE 14. Cost of present and proposed feed grains.

Labor:

Fuel:

Total...............................

Proposed 

grain.

dfr oo

9.87

8.57

17.38

10.01

53.71

Per day.

Present 

grain.

$6.50

5.57

5.56

17.63

Increase.

fl»7 oo

3.37

3.00

17.38

4.45

36.08

]

Proposed 

grain.

$1,576

1,974

1,714

3,476

2,002

10,742

'er season

Present 

grain.

$1,300

1,114

1,112

3,526

Increase.

$1,576

674

600

"3,476

890

7,216

VALUE OP PRODUCTS.

The value of the product depends of course upon its quality. The present corn grains 

have an average value of $18.25 per ton, or $20.16 per ton of dry substance. This is very 

nearly at the rate of 2| cents per pound of protein and fat, a ton of dry substance at that rate 

being worth $20.45. The present rye grains have an average value of-$13.25 per ton, or 

$14.40 per ton of dry substance. At 2| cents per pound of protein and fat the value would 

be $14.08 per ton of dry substance.

To find the comparative value of the grains obtained by evaporation three rye and three 

corn grains were prepared and sent to A. Lasche, Milwaukee, Wis., for analysis, a number of 

similar analyses made by Mr. Lasche" being at hand for comparison. The results of these 

analyses appear in table 15.

Proposed rye grain No. 1 was obtained by evaporating the slop rye 1. It represents the 

total product which we would expect under the evaporation scheme. Proposed corn grain 

No. 3 is a similar product obtained by evaporating slop corn Ib. It is with these two grains 

that our estimates will be concerned.

The other proposed grains were prepared with a view to maintaining the present grains as 

they are and making separate grains of the product of the evaporator. In preparing proposed rye grain No. 2 thin rye slops were evaporated to a sirup, the excess moisture being 

taken up with finely chopped wheat straw in the ratio of 0.37 part of straw to 1 part of dry 

substance in- slop. Proposed rye grain No. 3 is merely the fine material of No. 2 after passing 

through a sieve. Proposed corn grain No. 2 was prepared in the same manner as the similarly numbered rye grain, the ratio of straw to evaporated dry substance being 0.73 to 1. 

Proposed corn grain No. 1 was prepared by evaporating thin corn slops to a sirup, taking up 

the excess moisture with damp feed from the filter presses, and drying. The ratio of dry substance in sirup to dry substance in damp feed was 1 to 1. The values of these grains, as 

shown at the bottom of table 15, indicate that such a method of preparing grains is feasible 

and would be attended with profit.
VALUE OF PRODUCTS. 29

TABLE 15. Percentage composition of cattle-feed grains.

Fat. .................

Ash.................

Total..........

Protein and fat in 

dry substance ..... 

Value per ton ol dry 

substance per Ib. 

of protein and fat . .

Present 

rye 

grain, 

average 

of three

analyses.

7.28

21.00

6.48

8.11

6.24

49 61

1.58

100.30

29.64 

$14.08

Proposed 

rye 

grain 

No. 1.

7.85

24.50

7.60

36.55

19.10

o 4.40

100.00

34.83 

$16.54

Proposed 

rye 

grain 

No. 2.

10.00

16.62

7.70

45.38

on Oft

27.02 

$12.84

Proposed 

rye 

grain 

No. 3.

8.65

21.44

6.50

38.75

24.66

100.00

30.57 

$14.52

Present 

corn 

grain, 

average 

of seven

analyses.

10.15

27.15

11.54

8.10

At CO

1.57

100.03

43.06 

$20.45

Proposed 

corn 

grain

9.60

22.75

9.00

36.60

100.00

35.11

$16.68

Pn> 

posed 

corn 

frain 

0.2.

8.75

1 14.81

9.40

38.75

28.29

100.00

26.53 

$12.60

Proposed 

corn 

grain 

No. 3.

8.70

21.44

12.00

26.92

25.44

«5.50

100.00

40.93 

$19.44

a. Determined at laboratory of Ohio State board of health.

Returning to the value of the total product of grains obtained by the evaporation scheme, 

proposed rye grain No. 1 and proposed corn grain No. 3, we find that the rye has a much 

higher protein and fat content than the present rye grain. This is accounted for by the 

greater solubility of the proteids of rye. The same holds true of the free extract. It 

will be noted that ash, free extract, and fat have increased in amount in the new corn 

grain, while the protein has decreased. Rated at 2| cents per pound of fat and protein, 

the new rye grain is worth $2.46 more per dry ton than the old, while new corn grain is worth 

SI.01 less per dry ton than the old. This does not, however, fully represent the true feed 

value of the new grains. Since the added part is almost all soluble, the digestibility of the 

new grains must be much higher than that of the old. As no data were available to determine 

the value of increased digestible nutritive material, the present rate paid for feed grains 

and the price of 2| cents per pound of protein and fat were taken as the sole bases of value. 

Calculations based upon them are shown below.

TABLE 16. Amount and value of present and proposed feed grains.

Proposed grain. . . 

Present grain .....

Gain........

Dry tons 

per day.

Corn.

13.15 

7.90

5.25

Rye.

12.55 

5.35

7.20

Value: Rye, $14.40; corn, $20.16 

per ton.

Per day.

Corn.

$265.10 

159.26

105.84

Rye.

$180.72 

77.04

103.68

Per season.

Corn.

$39,765 

23,889

15,876

Rye.

$9,036 

3,852

5,184

Total.

$48,801 

27,741

21,060

Value: 2| cents per pound protein and fat.

Per day.

Corn.

$255.64 

161.56

94.08

Rye.

$207.58 

75.33

132.25

Per season.

Corn.

$38, 346 

24,234

14,112

Rye.

$10,379 

3,766

6,613

Total.

$48,725 

28,000

20,725

From the foregoing it will be observed that the gain in value is nearly the same whether 

calculated upon price of present grains or upon content of protein and fat, being 1.6 per 

cent less upon the latter basis.

As a secondary product of evaporation, on corn there will be 34,900 gallons and on 

rye 55,000 gallons of distillate, which may be utilized at the cost of condensing the vapor 

from the slop. Tests made by G. L. Bering at Lynchburg showed that this distillate 

will convert starch into dextrose ten minutes quicker than the best water now available at 

the distillery. It can be used in the mashing and cooking process, therefore, to excellent
30 STREAM POLLUTION BY DISTILLERY REFUSE.

advantage, and it will be more than sufficient in quantity to answer this purpose. Under 

the multiple system of evaporation this product will be exhaust water and steam and 

will doubtless be suitable to discharge into the cookers without condensation. This is 

an asset that can not well be calculated in money value, but is well worthy of consideration 

as an economy resulting from the evaporation process.

Having obtained approximate figures upon the cost of plant, cost of operation, and 

value of product, we are in a position to consider both amount and per cent of profits 

obtainable from the proposed methods of slop treatment.

From tables 14 and 16 the following is deduced:

TABLE 17. Seasonal value, cost, and profit for present and proposed feed grains.

Value based on price of present grains.

Value.

$48,801 

27,741

21,060

Cost.

$10,742 

3,526

7,216

Profit.

$38,059 

24,215

13,844

Value based on protein and 

fat content.

Value.

$48,725 

28,000

20,725

Cost.

$10,742 

3,526

7,216

Profit.

$37,983 

24,474

13,509

A profit of approximately $38,000 per season is therefore obtainable upon an investment 

of $52,000 in a complete plant, including evaporation. This represents a return of 73 

per cent per annum. An increased profit of about $13,600 is obtained by adding a $40,000 

plant for evaporation to the old plant, as described; this is at the rate of 34 per cent per 

annum. It must be remembered, also, that the foregoing estimates are based upon figures 

showing less than the true food value of the grains. A practical test demonstrating their 

greater nutritive properties should result in higher prices and increased profits. Furthermore, a considerable margin of safety is afforded by the calculation of the chief cost (fuel 

for evaporation) at 7 pounds of steam from 1 pound of coal. One pound of good coal 

should, in practice, produce between 8 and 9 pounds of steam.

The following tables show the value, cost, and profit per ton of dried product (9| per cent 

for corn grains and 8 per cent for rye grains being assumed moisture content), and the 

value, cost, and profit per bushel of grain mashed. It will be observed that while the profit 

per ton is decreased 12 or 15 per cent the profit per bushel of grain mashed is increased 

55 per cent because of the greater volume of the product.

TABLE 18. Value, cost, and profit per ton of feed-grain product.

Value based on price of present grains.

Value.

$17.04 

17.34

0.30

Cost.

$3.81 

2.20

1.61

Profit.

$13.23 

15.14

1.91

Value based on protein and 

fat content.

Value.

$16,85 

17.50

.65

Cost.

$3.81 

2.20

1.61

Profit.

$13.04 

15.30

2.26
RESULT AT LYNCHBUEG DISTILLEEY. 

TABLE 19. Value, cost, and profit in cents per lushel of grain mashed.

31

Value based on price of present grains.

Value.

14.5 

8.4

6.1

Cost.

3.2 

1.1

2.1

Profit.

11.3

7.3

4.0

Value based on protein and 

fat content.

Value.

14.5

8.4

6.1

Cost.

3.2 

1.1

2.1

Profit.

11.3

7.3

4.0

Table 17 shows that the cost of production is only two-ninths the value of the product 

under the proposed method of disposal. This method could obviously be applied, therefore, to a distillery two-ninths as large (capacity abc^t 400 bushels of grain per day) with 

a very considerable degree of profit. In fact, there does not seem to be a minimum limit 

to the size of the distillery to which it could be economically applied, except the limit for 

economic operation of a multiple evaporator.

RESULT AT LYNCIIBURG DISTILLERY.

A plant for the evaporation of slop was installed at the Lynchburg distillery late in the 

autumn of 1905. This plant was inspected by the writer while it was in process of construction, early in December, 1905, and again when in operation, on March 8 and May 1, 1906.

The slop is first passed over a brass screen containing 576 perforations to the square inch. 

This screen has an area of 21 square feet and a slope of about 9 inches in a length of 2 feet 

8 inches. The slop passing over this screen is conducted to a second screen of similar 

area and somewhat greater slope.

The thick slop from the second screen is received in a wooden vat and pumped thence 

to be filtered in two 40-plate presses. Each press is 20 feet in length and 3 feet in diameter 

and has a net filtering area of 230 square feet.

The thin slop from both screens is received in large wooden tanks, from which it is pumped 

to the evaporator.

The evaporating apparatus is of chief importance and will therefore be described in some 

detail. The machine used is the Hoffman-Ahlers triple-effect vacuum evaporator, a view 

of which is shown in fig. 5. Each effect consists, essentially, of two chambers, A and B, A' 

and B', A" and £", connected by four large pipes, C, C', and C", and also by a great number 

of tubes, placed within the steam chamber, E, E', and E". The slop is introduced at F, 

into one of the pipes, C, of the first effect, and by the internal conditions is forced to circulate 

through the tubes (not visible in the cut) in the steam chamber E. These tubes are heated 

by steam under pressure^ and the slop in passing through them is largely vaporized. The 

vapor passes out at the top of chamber A, through the large pipe G, which leads to the 

chamber E' of the second effect. The concentrated slop passes out at H, enters the second 

effect at F, and is further concentrated at a reduced pressure in the tubes D'. The vapor 

from the second effect is carried by the pipe 0' to the steam chamber E" of the third effect. 

The concentrated slop enters the third effect through one of the pipes C" and is still furtherconcentrated under a greatly reduced pressure. The vapor from the third effect is exhausted 

through the pipe G", by the vacuum pump K, which serves to reduce the pressures as desired 

in the successive effects. The concentrated sirup from the third effect is pumped away to 

a convenient place by the magma pump L.

After several months of experimentation this apparatus is now in good working order. 

It is capable of treating more than 40,000 gallons of the thin slop in twenty hours (guaranteed capacity 2,700 gallons per hour) and reducing it 88 to 90 per cent in volume. It 

is now operated with 40 pounds of steam pressure in the first effect, a 3 or 4 inch vacuum 

in the second effect, and a 26-inch vacuum in the third effect. This apparatus costs, in 

place, $16,000. While this machine will dispose of all the waste corn slop at Lynchburg,
32 STREAM POLLUTION BY DISTILLERY REFUSE.

Fie. 5. Hoffman-Alilers triple-eflect vacuum evaporator.
RESULT AT LYNCHBUEG DISTILLERY. 33

it may prove too small to evaporate all the rye slop. A small vacuum pan has been 

installed for further slop reduction when desired.

The magma from the evaporator is added to the feed from the filter presses, and the two 

are thoroughly mixed by passing through a screw conveyor 1 foot in diameter and 40 feet 

in length. It is then dried by passing through a direct-heat rotary drier, 40 feet in length 

and 6 feet in diameter, and a steam rotary drier, 20 feet in length and 6 feet in diameter. 

The product of these machines is placed in sacks for shipment.

The new apparatus consists of screens; evaporator and vacuum pan with accessory liquor, 

magma, and vacuum pumps; steam drier; addition to building; and a considerable amount 

of piping and a few minor pieces of apparatus.

Owing to difficulty experienced in the use of the new steam drier with the moist feed a 

machine has been specially designed to replace it.

The plant is so constructed that almost unlimited variations in operation can be secured. 

It will take a considerable length of time to develop the most economical plan of operation, 

as must necessarily be the case in any pioneer plant. Many possible economies have already 

suggested themselves, and others may be expected to develop with longer operation.

The evaporation system as installed at Lynchburg is an unqualified success, and even 

under present imperfect conditions a substantial, profit upon the investment is being made. 

Although it is too early to figure definite profits, the indications are that the estimates in 

the body of this report will be realized and probably exceeded. In making these estimates 

a large factor of safety was used and the cost of plant and operation were purposely placed 

at a maximum figure. The installation at Lynchburg proves that the cost figures can be 

reduced in the main by about 25 per cent. The predicted increase in amount of manufactured food stuff has not yet been realized because all the slop has not been evaporated. 

The plant installed is apparently too small to evaporate all the slop at all times, but greater 

amounts will be handled when the mode of operation is perfected.

The predicted change in quality of manufactured feed has been realized. The new feed 

is sweeter and has a more attractive odor. It has a higher specific gravity. According to 

chemical analysis the protein and fat content for corn and the fat content for rye are slightly 

decreased, but this, decrease is more than made up by the increased digestibility of these and 

the other constituents. Analyses of concentrated slop liquors made by A. Lasche, Milwaukee, Wis., are shown below.

TABLE 20. Analyses of concentrated rye and corn slop.

Protein ........................................................

Fat............................................................

Free extract ...................................................

Ash...........................................................

Total....................................................

Rye.

Per cent.

86.40

3.025 

.63 

8.7 

.3 

.883 

.062

100.000

Per cent 

in dry 

substance.

22.17 

4.63 

63.95 

2.20 

6.49 

.56

100.00

Corn.

Percent.

75.31

6.497 

2.2 

13.6 - 

.8 

.293 

1.3

100.000

Per cent 

in dry 

substance.

26.32 

8.91 

55.08 

3.2 

1.22 

5.27

100.00

The great per cent of moisture in the rye sample is to be accounted for by the fact that the 

evaporator had just been placed in operation. The 75 per cent moisture content of the 

corn sirup corresponds exactly with the predicted value, but it seems probable that both rye 

and corn sirups can profitably be concentrated in the evaporator to contain about 70 per 

cent of moisture. By comparing table 20 with table 15, it will be seen that the chief 

IKE 179 06 3
34 STREAM POLLUTION BY DISTILLERY REFUSE.

result in quality obtained by adding this sirup to the old grains is a large increase in free 

extract, a lesser increase in ash, and decrease in starch and crude fiber. The new grains 

will make the better cattle food.

With regard to stream pollution little can be said at present. Of course stream pollution 

can bt entirely prevented by evaporating all the slop. The new plant at Lynchburg is not 

at present evaporating all the slop all the time, so that stream pollution still continues. 

By the end of the present distilling season better conditions will undoubtedly prevail, and 

probably all pollution will be obviated. The difficulties incident to the perfection of any 

entirely new system of manufacture are the cause of the present continuance of pollution.

SUMMARY.

The results of the investigation may be summed up as follows:

1. From the still and rectifier of a distillery about 45 gallons of waste slop liquor are discharged for each bushel of grain mashed. This liquor contains approximately 5 per cent 

(by weight) of solid matter, nearly half of which is held in solution. All the elementary 

compounds of the grain are represented in full quantity, starch excepted, the greater part 

of this substance being separated in the manufacture of the spirituous product.

2. One part of distillery refuse discharged into a stream of moderate fall having an average 

flow of 150 parts of water will produce a serious pollution for a long distance below the point 

of its introduction and may at times render the stream waters unfit for any use.

3. By screening out most of the suspended solids, nearly 10 per cent (by volume) of the slop 

may be converted into a dry cattle feed at a high rate of profit; an additional 50 per cent may 

be utilized as a liquid cattle food, generally with a slight profit; in the manufacture of some 

liquors a considerable quantity may be used instead of water in certain processes. From 

10 to 40 per cent can not be profitably used and is run to waste.

4. Stream pollution by such refuse may be wholly avoided by means of evaporation 

recovery of cattle feed grains from the slops. By this method of disposal the entire slop 

product of a distillery may be utilized, the solid matter as a feed stuff and the distillate 

from evaporation as water for mashing. -

5. As applied to a distillery using daily 1,750 bushels of corn for a season of 150 days and 

1,392 bushels of rye for a season of 50 days, the following data regarding the process may be 

accepted as approximate:

a. Cost of complete recovery plant............................................................. $52,000

6. Annual profit over operating expenses on investment in complete plant for evaporation recovery, per cent........................................................................... 73

c. Cost of additional plant to add evaporation to recovery by screening....................... $40,000

d. Annual profit over operating expenses afforded by increased product, based on investment in

additional plant to add evaporation to recovery by screening, per cent................... 34

6. A practical trial of the evaporation method at Lynchburg, Ohio, substantiates all the 

claims made for it and indicates that it will prove to be a rather greater source of profit than 

had been expected.

7. This system of economical disposal of slops can probably be applied successfully to any 

distillery large enough to create a serious nuisance by the discharge of its waste liquors into 

any but the smallest of streams.
CLASSIFICATION OF THE PUBLICATIONS OF THE UNITED STATES GEOLOGICAL

SURVEY.

[Water-Supply Paper No. 179.]

The serial publications of the United States Geological Survey consist of (1) 

Annual Reports, (2) Monographs, (3) Professional Papers, (4) Bulletins, (5) Mineral 

Resources, (6) Water-Supply and Irrigation Papers, (7) Topographic Atlas of United 

States folios and separate sheets thereof, (8) Geologic Atlas of the United States 

folios thereof. The classes numbered 2, 7, and 8 are sold at cost of publication; the 

others are distributed free. A circular giving complete lists may be had on application.

Most of the above publications maybe obtained or consulted in the following ways:

1. A limited number are delivered to the Director of the Survey, from whom they 

may be obtained, free of charge (except classes 2, 7, and 8), on application.

2. A certain number are delivered to Senators and Representatives in Congress, 

for distribution.

3. Other copies are deposited with the Superintendent of Documents, Washington, 

D. C., from whom they may be had at practically cost.

4. Copies of all Government publications are furnished to the principal public 

libraries in the large cities throughout the United States, where they may be consulted by those interested.

The Professional Papers, Bulletins, and Water-Supply Papers treat of a variety of 

subjects, and the total number issued is large. They have therefore been classified 

into the following series: A, Economic geology; B, Descriptive geology; C, Systematic geology and paleontology; D, Petrography and mineralogy; E, Chemistry and 

physics; F, Geography; G, Miscellaneous; H, Forestry; I, Irrigation; J, Water storage; K, Pumping water; L, Quality of water; M, General hydrographic investigations; N, Water power; O, Underground waters; P, Hydrographic progress reports. 

This paper is the fourteenth in Series L, the complete list of which follows (PP= 

Professional Paper; B=Bulletin; WS=Water-Supply Paper):

SERIES L, QUALITY OF WATER.

WS 3. Sewage irrigation, by G. W. Rafter. 1897. 100 pp., 4 pis. (Out of stock.)

WS 22. Sewage irrigation, Pt. II, by G. W. Rafter. 1899. 100 pp., 7 pis. (Out of stock.)

WS 72. Sewage pollution near New York City, by M. O. Leighton. 1902. 75 pp., 8 pis.

WS 76. Flow of rivers near New York City, by H. A. Pressey. 1903. 108 pp., 13 pis.

WS 79. Normal and polluted waters in northeastern United States, by M. O. Leighton. 1903. 192pp.,

15 pis. 

WS 103. Review of the laws forbidding pollution of inland waters in the United States, by E. B.

Goodell. 1904. 120 pp. 

WS 108. Quality of water in the Susquehanna River drainage basin, by M. O. Leighton, with an

introductory chapter on physiographic features, by G. B. Hollister. 1904. 76pp., 4 pis. 

WS 113. Strawboard and oil wastes, by R. L. Sackett and Isaiah Bowman. 1905. 52 pp., 4 pis. 

WS 121. Preliminary report on the pollution of Lake Champlain, by M. O. Leighton. 1905. 119pp.,

13 pis. 

WS 144. The normal distribution of chlorine in the natural waters of New York and New England,

by D. D. Jackson. 1905. 31 pp., 5 pis.

WS 151. Field assay of water, by M. O. Leighton. 1905. 77 pp., 4 pis. 

WS 152. A review of the laws forbidding pollution of inland waters in the United States, second

edition, by E. B. Goodell. 1905. 149 pp. 

WS 161. Quality of water in upper Ohio River basin and at Erie, Pa., by S. J. Lewis. 1906. pp.,

6 pis. 

WS 179. Prevention of stream pollution by distillery refuse, based on investigations at Lynchburg,

Ohio, by Herman Stabler. 1906. 34 pp., 1 pi.

Correspondence should be addressed to

THE DIRECTOR,

UNITED STATES GEOLOGICAL SURVEY,

WASHINGTON, D. C. 

SEPTEMBER, 1906.

O