Document 2qbpRyEzkz2O4dXNLQddbVQwR

INDUSTRIAL WASTES' Water Pollution ROBERT SPERR WESTON Weston & Sampson, Boston, Mass. In one state the pollution load due to industrial wastes is two thirds of that due to sewage. Difficult conditions exist in all industrial regions, and much study has been given to the problem in various countries. Important has been the work of the U. S. Public Health Service, and before the de pression the movement towards cleaner streams was well under way. With the depression, progress was retarded but inter est is being revived. Streams must be used but not abused. This may require the classification of streams for various uses. While the study of waste treatment is im- portant and each waste presents an indi vidual problem, the first consideration is the load that the stream can carry--that is, its capacity for self-purification. Treat ment must then follow to enable it to meet this load and must be carried far enough to maintain about 4 p. p. m. of dissolved oxy gen in streams used for water supply and 2 p. p. m. in others. Certain wastes, because of their effects upon odor, taste, or aquatic life, require special treatment, but in any event the necessities of the stream should receive first consideration. ITH the concentration of industries on both navigable Wand unnavigable waters, there necessarily follows the use of water for processes and the discharge of waste In succeeding years the Massachusetts Board of Health extended the investigation to cover most of the polluted rivers of the state and studied methods for the treatment of into these waters. The result is one of the problems of civmilia ny wastes, as described by Clark in 1909 (7). zation and one absent from the concept of the hunter and the Other valuable studies have been made by various state trapper. boards and commissions--for example, those in Rhode Is That the problem is attracting public attention is shown by land (16), Connecticut (31), New Jersey (14, 18), Penn the criticisms of conditions on such rivers as the Merrimac, sylvania (SO, SI), Michigan (IS), Wisconsin (SO), Minnesota the Connecticut, the Blackstone, the Naugatuck, the Passaio, (4), and Illinois (SS). the Delaware, the Illinois, the Ohio, and many others, and by In the last decade and prior to the industrial depression, the conditions in New York, Boston, and other harbors. Similar widespread studies of the United States Public Health Service, conditions exist in Europe, notably in England, France, particularly at the experiment station on the Ohio at Cin Belgium, and Germany. cinnati, described by Streeter, Theriault, Hoskins, and others; As early as 1872, the Massachusetts Legislature sent Wil the problems of the Sanitary District of Chicago with its large liam Ripley Nichols to Europe to study the matters of stream load of industrial waste; the studies of the international waters pollution and methods of water analysis. Later he assisted of the Great Lakes; the work of the Pennsylvania Sanitary in the studies of the pollution of the Merrimac at Lowell Water Board, led by W. L. Stevenson; the work on the and of the Blaokstone at Worcester. Emscher and the Ruhr Rivers in Germany; and in England the work of the Water Pollution Research Board and of the i The group of papers op pages 1311 to 1380 were presented before the Division of Industrial and Engineering Chemistry at the 93th Meeting of the iizneriean Chemical Society, Boston, Mass. administrative boards controlling the West Riding, Mersey, Irwell, and other drainage areass'--all have indicated the strong movement toward the cleaning of rivers and harbors. 1311 1312 INDUSTRIAL AND ENGINEERING CHEMISTRY VOL. 31, NO. 11 But with the financial depression and the concurrent dis abilities of industry, the pressure applied by the sanitary authorities was greatly lessened, and progress towards im provement was retarded in spite of an increasing demand for cleaner streams by the general public and by such organiza tions as the Izaak Walton League. But curtailed production was accompanied by curtailed discharge of waste. Now, because industry is reviving, the insistence upon action is becoming more urgent, not only by the recreationists and nature lovers but also by the sanitary authorities. Clean rivers are being classed more and more with beautiful public buildings and parks as goals for munici pal striving. The problem is not easy, since it involves the use of streams, on the one hand, and the avoidance of the abuse of them, on the other. Twenty-one years ago, the writer expressed his idea of the problem as follows (28): Rivers attract population and population demands disposal of sewage, as well as water supply. On some industrial rivers the prohibition of pollution would so hamper industry that manu facturers would be forced to go out of business or move away; consequently, many rivers must necessarily be used for manu facturing, drainage and water supply. Others may become unfit for water supply and be relegated to drainage and manufactur ing uses only. Each stream, in other words, must be used for the best interests of all riparian owners and with due regard for the right and convenience of all. On handing down the opinion of the United States Supreme Court on the Delaware River Case (New Jersey t>. New York), Justice Oliver Wendell Holmes stated that "a rivex is more than an amenity, it is a treasure. It offers necessities of life that must be rationed among those who have power over it." In no place has the principle of designating streams for particular uses been applied better than in Pennsylvania, where three classes of streams were recognized. In brief, they were: I. Those preserved in nearly their natural condition and re served for water supply. II. Those used for sewage disposal after treatment of the sewage, and for water supply after purification of the water. III. Those used for sewage disposal after such treatment of sewage and industrial wastes as is neoessary to prevent nuisance. The upper Delaware River is in class I, the middle Delaware in class II, and the lower Delaware in class III. However, on June 22,1937, the Commonwealth of Pennsyl vania enacted a new law which forbade the discharge of any industrial waste into stream or sewer which ``is or may prove injurious to public health or to animal or aquatic life or pre vent the use of the waters for domestic, industrial or recrea tional purposes". Acid mine drainage and silt from coal mines were exempted from the requirements of this law until ``in the opinion of the Sanitary Water Board practical means for the removal of the polluting properties of such drainage shall become known". Obviously this law would go far beyond preventing the abuse of streams and would destroy their use for many. It seems unenforceable because, if taken literally, treatment of a reservoir water with copper sulfate to kill algae would be "injurious to aquatic life" and incidentally might kill a few perch or pickerel and therefore be "injurious to animal life". Therefore, great need exists for care and judgment, for study by state and federal departments for the control of interstate drainage areas by interstate compacts (which is a better method than control by a federal commission), and for con structive programs not too burdensome for industry. The United States National Resources Committee has well stated the situation as follows (27): The essential approach to the problem of ridding stream waters of undesirable industrial wastes lies in the active cooperation of the industries involved, always assuming, however, flexible and reasonably administered water pollution legislation. The prob lem cannot be settled by abstract studies on the part of govern ment nor by inflexible and arbitrary state or federal legislation. Waste materials are so diverse and so complex that each industry, and possibly each plant, presents a special problem. Instead of "industries involved", one might well substitute "all parties involved". . Other papers in this symposium are emphasizing the diversity of the problem, the need for research, the importance of recovery of by-products and utilization of waste, and the fact that each case presents a new problem requiring pre liminary study before design and involving modifications in standard sewage devices to fit the various wastes. But in any case the necessities of the body of water or the sewerage system receiving industrial wastes are controlling factors. From a practical standpoint, the questions to be asked re garding a stream are: What pollution load can it carry? What is its capacity for self-purification? Then, and not be fore, may follow the consideration of wastes to be disposed of and the methods of treating them prior to disposal. Pollution Load Here is presented a problem widely different from that of the disposal of domestic sewage because of the high bio chemical oxygen demand of some industrial wastes and the character of their ingredients. Wisely and Klassen (82) showed that in the Peoria-Pekin metropolitan area of Illinois the combined human population contributing sewage is 130,000, whereas the industries con tribute a pollution load equivalent to more than 1,000,000 people, largely in the form of distillery wastes. Calvert and Parks (5) compared the industrial wastes of Indianapolis: Table I is taken from their figures. Table I. Waste Laundry Creamery Dairy Canning Starch Five meatpaokers Paperboard Garbage Population Equivalents op Wastes Volume of Work Done 2,800 lb. dirty clothing 8,000 lb. butter made 166,000 lb. raw milk reeeived 306,700 lb. pork and beans 21,674 bu. corn 20,280 equivalent hogs 102.1 tons produced 72.9 tons green garbage Total Population Equivalent 668 736 11,782 8,429 90,665 267,728 6,978 12,271 The ordinary oxygen demand (B. O. D.) of sewage from American residential communities will average less than 150 parts per million, or 57 grams per capita, whereas the oxygen demand of the industrial waste in an American manufacturing city with separate sewers will usually exceed that of the sewage. The oxygen demand as well as the suspended resi due and the oxygen consumed of certain wastes are given in Table II. Table II. Oxygen Demand op Wastes Kind of Waste Mixed oaustio and peroxide kier liquor Wool securing waste, plant A Wool soouring waste, plant C Tannery waste Paper sizing waste Sulfite pulp liquor Paper maonine waste Slaughterhouse Creamery waste B. O. D. Suspended - Oxygen (6-day) Residue Consumed Parts per million 1241 4464 216 6000 610 9000 70 600 1200 1,685 15.000 700 5,160 120 600 1,160 3,600 2,842 7,900 230 2,000 236 60,000 260 366 600 While the biochemical oxygen demand of the waste, the suspended matter in it, and the oxygen consumed by it are all NOVEMBER, 1939 INDUSTRIAL AND ENGINEERING CHEMISTRY 1313 1314 INDUSTRIAL AND ENGINEERING CHEMISTRY VOL. 31, NO. 11 Above. Unpolluted Stream BeUno. Deposits or Paper Waste important, certain wastes demand consideration because of their individual characteristics: Ligneous and Resinous Wastes. These wastes, both alkaline and acid, from the digestion of wood, paper stock, cotton cloth, and vegetable fibers, are often low in settleable solids; but they are usually highly concentrated and anti septic, and therefore resist the natural biological purification of stream waters. Kier and sulfite liquors are among the most difficult of these wastes. Greasy Wastes. Wool-scouring, cloth-washing, tanning, and meat packing wastes, with their high solids, fats, and organic contents, are potent for pollution and befoul many streams. Highly Nitrogenous Wastes from the animal industries include tanning wastes, high in suspended matter and oxygen demand, and slaughterhouse and packinghouse wastes. Highly Carbonaceous Wastes. Industries such as starch, sugar, and glucose factories, breweries, and distilleries discharge wastes which undergo acid fermentation; when concentrated, they halt self-purification and consequently place a great burden upon waters receiving them. Soapy Wastes from laundries and textile mills are ob jectionable to sight and oxidize with difficulty. Acid Wastes. When acid wastes from mines and metal works are discharged into streams, they may act as coagulants and not only acidify but precipitate the suspended matter from the waters into which they are discharged. Rivers in western Pennsylvania and in West Vir ginia illustrate this effect. Wastes from Gas and Coke Works may contain ammonia and tar deriva tives; even when largely diluted they may impart tastes and odors difficult to remove and thus affect the animal life of the stream. They are particularly poison ous to fish life (S, 13) and the biological units in its food chain. Wastes High in Suspended Matter. These may vary in their effect, as a com parison of sand or silt, on the one hand, with parts of hides or beet sugar factory wastes, on the other, will show. Oily Wastes are unsightly, sometimes poisonous. Miscellaneous Wastes may contain arsenic or cyanide. Then there are the highly colored dyehouse wastes which are unsightly although frequently low in oxy gen demand. Many objectionable conditions are due to batch discharges, as from wool-scouring bowls or from dyehouse or tannery vats. In many cases these discharges would be innocuous if they were distributed through out the twenty-four hours. Fish are sensitive to alkali and often succumb when exposed to the discharges of calcium hydroxide from tanneries, am monia liquors, or laundry wastes. Species ol fish vary greatly in their resistance to pollution. The introduction of silt into a nonsilt-bearing stream is often disas trous to fish life. This discharge, how ever, is rarely prohibited by statute, for law makers evidently assume that what a Mississippi catfish can stand a state-ofMaine trout ought to. Suspended matter, like paper fiber (8), is not only injurious to fish but may af fect oysters also (10). Self-Purification From the classic studies of Adeney (i) in Great Britain and Phelps (IS) in this country, followed by those of Theriault (Zd), Frost (9), Streeter (ZZ-S5), and others, the laws regard ing the oxygen demand factor, the reaeration factor, and the oxygen balance (the main factors of self-purification in rivers and harbors) have been not only elucidated but mathe matically expressed. The progressive changes in the biochemical oxygen demand of polluted stream waters are becoming well known. They are modified, however, by additional pollution, inflow or dilution, sedimentation and absorption, channel scouring, and the presence of an "immediate" or "enzymic" oxygen demand. They are modified by the characters of polluting discharges. Because self-purification is a combined biological, chemical, and physical process, it is evident that discharges of hot akaline antiseptic wastes, like kier liquor, or those high in suspended matter, like wool-scouring waste, may delay self purification, first, by inhibitng or destroying the growth of stream-purifying bacteria, and secondly, by forming sludge NOVEMBER, 1939 INDUSTRIAL AND ENGINEERING CHEMISTRY 1315 banks and introducing resistant fats. This delay may last until the dilution of the waste is large. The significance of sludge beds was suggested by Rudolfs (17) in the case of Connecticut v. Massachusetts (Connecticut River Case); their purification requirements have been esti mated by several investigators, notably by the Public Health Service group, and their requirements under aerobic conditions have been calculated by the experiments of Baity (8). Standards for Polluted Waters In establishing standards for waters polluted by industrial wastes, it is generally customary to use certain values, such as minimal dissolved oxygen, freedom from accumulating sludge deposits, or limiting bacterial content, all dependent upon the uses of the stream. These standards range from those of freedom from nuisance to those of suitability for the supply of water purification plants. When industrial wastes are discharged, the physical and chemical loading is more important than the bacterial contents. In the case of domestic sewage, the opposite is often the case. The oxygen demand of normal sewage in a residential town is about 55 grams per capita, in large individual cities, as high as 150 grams per capita. This means that the dis charge of sewage by 1000 people would be equivalent to from 55 to 150 kg. a day. In 24 hours a fair sized woolen mill will discharge about 70,000 gallons of waste having a B. O. D. of about 9000 p. p. m. This is 2363 kg. daily or the equivalent of the sewage of an ordinary city having a population of twenty-one thou sand people. In some wastes the settleable solids are excessive and may amount to 20 per cent of the volume of waste. Furthermore, the diluting power of streams receiving wastes with high amounts of settleable solids is less thaii that of those receiving wastes with low amounts. The effect of sludge deposits on fish life is often disastrous, as Hubbs pointed out (11). Because few industrial wastes are of human origin, although 6ome are of animal origin, and because some of the most troublesome ones are sterile when discharged, the chemical criteria are generally more important than the bacterial. However, studies by the United States Public Health Service have indicated that the limit of tolerance for water purifica tion plants employing chemioal treatment and chlorination is about five thousand B. coli per milliliter. That our Analytical mathnd,a era nnt, nlI-rWp-rmining is wellknown. In studying the biology of stream pollution, Claassen (6) used schools of minnows for tests, but even these, valuable as they are, show the condition at the time of ex posure only, just as chemical tests show the condition at the time of sampling only. This constitutes an argument for integrated rather than for catch chemical samples. It naturally follows that a study of the plankton of a stream, which is a perfectly integrated index, is of great as sistance in the study of pollution and self-purification. For example, the finding of the larvae of caddis flies is an index of tolerable condition, while the presence of blood worms (Chiromonidae) or a fungus such as Leptomitus indicates the opposite. " The amount of self-purification performed by the plants and animals in a stream is not generally recognized, although these factors are substantial. Studies by the M. I. T. Sanitary Research Laboratory (89) of the Coweeset River receiving treated Brockton, Mass., sewage showed that the river re ceiving the effluent lays down a "pollution oarpet" containing an abnormal number of organisms, beginning with the lowest forms and ending with the highest; each group appears along with a definite food material. When the Coweeset River was discharging less than 5,000,000 and was receiving about 2,000,000 gallons per day of sand bed effluent, the most important changes occurred in the first mile of flow. However, the return of this stream to its normal chemical condition was not so rapid as its return to its normal biological condition. Here, as in Europe (19), where fish ponds are used for the treatment of sewage, the value of shallow storage in the course of the stream was shown. In many polluted streams the dissolved oxygen tends to decrease until the excessive growth of animal life which is favored by pollution ceases. The rate of this decrease is usually higher than the normal rate of reaeration of the stream by absorption from the atmosphere, by plant growth, or by both. Conclusion The foregoing may serve to introduce the problem of in dustrial waste disposal. Again we must emphasize the ca pacity for self-purification of the stream or other body of water and the volumes and characteristics (chemical and biological) of the wastes contributed. Then follows in logical order the treatment necessary to preserve the stream or other body of water for its most useful purpose, whether that be for sewage or waste disposal, angling, shellfish culture, recrea tion, or water supply. In every case the capacity of the diluting water is the most important factor. Editor's Noth. In the discussion which followed the presenta tion of this paper, reference was made to a recent publication of Mohlman (18A). Literature Gted (1) Adeney, W. E., "Principles and Practices of Dilution Method of Sewage Disposal", 1928. (2) Baity, H. G., Sewage Works J., 10, 539 (1938). (3) Belding, D. L., Trans. Am. Fisheries Soc., 57, 100-19 (1927). (4) Black, A. G., and Vail, R. S., Metropolitan Drainage Commis sion of Minneapolis and St. Paul, 2nd Ann. Rept., 1928. (5) Calvert, C. K., and Parks, E. H., Sewage Works J., 6, 1159 (1934). (6) Claassen, P. W., Ibid., 4, 195 (1932). (7) Clark, H. W., Kept, of Mass. Board of Health, 1909. (8) Cole, A. E., Sewage Works J., 7, 280-302 (1936). (9) Frost, W. H., and Streeter, H. W., TJ. S. Publio Health Servioe, Bull. 143 (1924). (10) Hopkins, Galtsoff, and McMillin, U. S. Bur. Fisheries, Bull, 6 (1931). (11) Hubbs, C. M., Sewage Works J., 5,1033 (1933). (12) Mich. Stream Control Commission, Repts. (12A) Mohlman, F. W., Sewage Works J., 11, 646 (1939). (13) Moore, Emmeline, Ibid., 4, 159 (1932). (14) N. J. State Water Policy Commision, Repts. (15) Phelps, E. B., Orig. Com. 8th Intern. Cong. Appl. Chem. {Ap pendix), 26, 251 (1912); Sewage Works J., 6, 998 (1934). (16) R. I. Div. of Purification of Waters, Repts. (17) Rudolfs, Willem, Sewage Works J., 4, 316 (1932). (18) Rudolfs, Willem, Trans. Am. Inst. Chem. Engrs., 27, 31 (1931). (19) Schilling, A., Gesundh.-lng., 58, 192-3 (1935). (20) Stevenson, W. L,, Sewage Works J., 2, 142 (1930). (21) Stevenson, W. L., Trans. Am. Inst. Chem. Engrs., 27, 9 (1931). (22) Streeter, H. W., Sewage Works J., 3, 713 (1931). (23) Ibid., 7, 251 (1935). (24) Ibid., 7, 534 (1935). . (25) Streeter, Wright, and Kehr, Ibid., 8, 282 (1936). (26) Theriault, E. J., U. S. Publio Health Service, Bull. 173 (1927). (27) U. S. Natl. Resources Committee, Rept. of Special Advisory Commission on Water Pollution, 48, July, 1935). (28) Weston, R. S., Munic. Eng., 54, 59-60 (1918). (29) Weston, R. S., and Turner, C. E., Contrib. Sanitary Res. Lob. & Sewage Expt. Sta., Mass. Inst. Tech., 10, 1-96 (1918). (30) Wis. State Commission on Water Pollution, Repts. (31) Wise, W. 8., Trans. Am. Inst. Chem. Engrs., 27, 91 (1931); Biennial Repts. of Conn. State Water Commission. (32) Wisely, W. T., and Klassen, C. W., Sewage Works J., 10, 439 (1938).