T h eC h e m i c a lN e w sP a r a d
R. H. Morris, Eastern Regional Β. Η. IS'issen, Anheuser-Busch; Corp.: J. J. Gilbert, Link-Belt
Research Laboratory; William Ehlen, Stolle Co.; L. F. Warrick,
A. C R O I T of S "work shop" symposia and Ι ό papers, including reviews of industrial problems, new processes for waste dis posal, ami its influence on public health and the conservation of natural resources made up the 2· day program of the Second Industrial Waste Conference at Purdue, Jan. 10 and 11. The conference, at which registered attendance was 275, was spon sored by the School of Civil engineering, Department of Sanitary Engineering, Purdue University, in cooperation with 8 trade associations and 3 departments of the State of Indiana. T h e sessions, held in Purdue's Memorial Union Building, Lafayette, Ind., were opened by R. B. Wiley, head of the School of Civil Engi neering. F . L. Hovde, Purdue's president, spoke at the dinner on Friday evening at which A. A. Potter, dean of the Schools of Engineering, presided. Donald K. Bloodgood, professor of sanitary engineering at Purdue, was general chairman. Municipal
Aid
T w o speakers urged the acceptance of waste treatment as a legitimate cost of production. Industry should n o t be com pelled t o absorb the cost of waste treat ment, stated M. M. Cohn, editor of Sewage Works Engineering, in a paper read by C. K. Calvert, of Indianapolis Water Co. T h e encouragement to industry to treat their wastes offered by the Indiana S t a t e Board of Health in pending legisla tion by extending tax leniencies on funds expended for such purposes was com mended because it recognizes this princi pleIndustry should also be prepared to p a y s. fair share of treatment cost if municipalities accept industrial waste, said George E . Symons, associate editor of Water Works and Sewerage. Reporting results of a survey of in dustrial wastes in the Ohio River Valley during 1939-41, M. LeBosquert, of the U. S. Public Health Service, Cincinnati, concluded that 4 5 % of the organic indus trial wastes produced in that region could be treated with sewage in municipal sys-
356
Wisconsin Board of Health sion of Water, Sewage, ACS); M. LeBosquert,
{former chairman of the Divi and Sanitation Chemistry, V. S. Public Health Service
WASTE CONFERENCE AT PURDUE ROBERT F. GOULD, Associate Editor
terns, compared with 12% that was being so treated at that time. Only 3 4 % of the Valley's sewage now receives treatment compared to 6 5 % for the country as a whole. Dominating the pollution problem in this region, according to Major LeBos quert, is acid mine drainage which can be reduced by sealing the mines to prevent the access of oxygen. In summarizing the waste disposal practices of 12 prin cipal industries, it was shown that the three industries with the highest sewage population equivalent in this area, some 200,000 square miles in 14 states, are chemical, distilling, and paper. The one fact that stands out in the dis posal of industrial waste waters, said Mr. Cohn, is that they are far more variable than sewage. And more than that, they are not germ-laden. This explains why a germ-conscious public has not become so concerned about them as about sewage. Their dangers stem from other causes— organic nature, suspended solids, color, poisonous character; these differences explain in part why industrial waste treatment has not kept pace with the construction progress which sewage treat ment works have enjoyed. Similarly, changes in the character of waste waters with variations in raw mate rial were cited as presenting the most per plexing problems in the treatment of wastes from the paper and pulp industry. In a paper by H. W . Oehm and D . E. Bloodgood, read by W. W. Hodge of Mellon Institute, it was pointed out that few by-products processes in the pulping industry eliminate discharge of polluted materials entirely; the majority remove
CHEMICAL
a portion of these polluting materials and leave residual substances similar to those originally present in the waste. Waste
Defined
Taking up the problem of defining the term industrial waste, Dr. Symons pointed out that neither the old industrial defi nition that waste is what goes down the sewer and has no value nor the old con servationist views that nothing should be discarded but that everything can be recovered—at a profit—are valid today. By defining wastes broadly as materials or energy that are discarded in the pro duction of some useful product or service regardless of receiver, point of discharge, potential value, or effect o n the receiving medium, they can be classified to assist in studying their disposal. Stating that by-product recovery is not the simple answer to the economics of waste treat ment, Dr. Symons cited many examples whore by-products are not profitable. Metal
Treating
Wastes
Discussing the composition of metal plating wastes, William Ehlen, of the Stolle Corp., Cincinnati, pointed o u t that much of the plating industry is made up of small plants which do not have waste treatment facilities. Leakage, mistakes, or bad baths which are more conveniently dumped than corrected, and obsolescence (such as wartime zinc baths now that cadmium is again available) for which storage facilities are not available, were listed as inevitable sources of pollution. T h e volume of these waste waters, how ever, is email.
AND ENGINEERING
NEWS
Speaking on developments in t h e dis posal of spent pickling liquors, Richard D . Hoak, of Mellon Institute, stated that in spite of t h e large amount of research and development that has been done on t h e problem, there is no process yet available for the profitable recovery of by-products from this source; all methods are considered temporary. But pickle liquor is not a significant stream pollutant. As ferrous sulfate oxidizes it exhibits a strong tendency to precipitate as basic sulfate, but recent studies at Mellon Institute have revealed that t h e amount of free acid liberated is substantially smaller than complete hy drolysis would indicate. Pickle
Liquor
Processes
Reviewing projects at Mellon Institute, D r . Hoak stated that a process is avail able for recovering free acid in pickle liquor b y t h e use of acetone as a differ ential solvent, but the by-product, cop peras, i s one of which a surplus is normally available. T h e demand for copperas was said to be less than 4 % of its potential production b y the steel industry. I t s use in portland cement t o replace gypsum as a setting agent would more than take care of this production, but even though technically practical, it would n o t be economically feasible. A surprisingly large amount of pickle liquor i s treated with lime, at a cost of about one cent a gallon, said Dr. Hoak. It has been shown that an initial treat ment with pulverized limestone can be used t o neutralize the free acid and pre cipitate part of the iron. The process, called t h e "split limestone-lime process'*', is in u s e in one plant and has shown attractive savings over the former practice. B e s t results are obtained with limestone containing less than 2 % magnesium oxide. Among other processes, the ferric chloride-salt cake process whereby pickle liquor is treated with salt and the ferrous chloride oxidized with chlorine, may have potentialities due to the large market for salt cake and the increasing usefulness of ferric chloride, but it is complex and re quires large capital outlay and close control. Processes have also been in vestigated for the recovery of magnesia from dolomitic lime and for the separation of a magnetic iron oxide. During t h e war a process was developed for concentrating low-grade manganese ores b y using waste pickle liquor as a reducing agent. I t also yielded a pure calcium sulfate and a hydrated ferrous oxide suitable for sintering. Preliminary study of stainless steel pickle liquors has shown that by treatment with lime, a pure calcium nitrate, which finds a market in fertilizer, and a sludge of metal oxides, which can b e sintered for recharging t o the furnace, are recovered. Vegetable
D. E. Blood good y Purdue, chairman, of the conference; F. W. Mohlman, director of laboratories. Sanitary District of Chicago; W. W. Hodge, Mellon Institute; C. C Ruchhaft, V. S. Public Health Service
developed at the Eastern Regional Re* search Laboratory was described b y R. Henry Morris, III, of t h e U. S. Depart ment of Agriculture, who spoke on canning wastes. By subjecting the material t o a high-velocity stream of air at 240° F., the tender leaf blades, which have a higher nutritive value, are quickly dried and embrittled and may b e separated from the still-moist stems and midribs by trommeling. A 3-belt dryer is used, and the separated stems are further dried on the second and third belts, each moving at twice the speed of the foregoing. T h e process was said to require less heat and was reported satisfactory for all wastes studied except pea vines for which s o m e modification is required. Costs ranged from $19.40 per ton (at α capacity of 7,450 lb. per hour) for carrot tops to $52.20 per ton (5,580 l b . per hour) for broccoli waste. Total cost of an installa tion of standard equipment was placed at $48,000. German
Developments
In his talk at the dinner, J. J. Gill>ert, of the Link Belt Co., Philadelphia, re ported on the status of industrial waste treatment in Germany between 1938 a>nd 1945. According to Mr. Gilbert, there were no new processes or major items of equipment for industrial waste treatment developed in Germany during the war years although about 70 plants were re modeled or built during this period, chiefly of the following types: phenol waste treatment and recovery, pickling liquor treatment, acid neutralization (in cluding T N T and dynamite plants), a n d coke wash water clarification. Con siderable progress was made, however, in
perfecting earlier techniques. Methods of treating a number of particular wastes were described. Other speakers on the program were: Ε . Ν. Mortenson, Swift and Co., "Grease Recovery in the Meat Packing Industry"; Β . Η. Nissen, Anheuser Busch, "Brewery Waste Utilization"; L. F. Warrick, Wis consin State Board of Health, "Milk Waste Treatment , , ; B. A. Poole, Indiana State Board of Health, "Economies in Industrial Waste Treatment Plant De sign", read by J. L. Quinn, Jr.; W. E. Howland, Purdue, "Conservation of N a tural Resources"; W. E. Ricker, Indiana University, "Industrial Wastes and Aquatic Life in Indiana Streams"; and L. E. Burney, State Health Commissioner of Indiana, "New Developments in Public Health". Subjects of the "work shops" symposia, held o n Thursday afternoon, were: milk wastes, wastes from food processing, fer mentation process wastes, paper manu facturing wastes, industrial and municipal water treatment and re-use, sewage treat ment and industrial wastes, metal plating and steel mill wastes, and oil refinery waste and recovery. Organizations cooperating in the confer ence were: Indiana Stream Pollution Control Board Indiana State Board of Health Indiana Conservation Department Indiana State Chamber of Commerce Indiana Manufacturers Association Indiana Dairy Products Association Indiana Canners Association Indiana Brewers Association Indiana Oil and Gas Association Indiana Sewage Works Association Indiana Section of the American Water Works Association
C . E. Synions, associate editor of Water Works and Setoage; BuswelL chief, Illinois State Water Survey; H. C. Feightner, tary, Indiana Brewers* Association; R. D. Hoak, Mellon
A, M. secre Institute
Wastes
A fractional drying procedure for treat ing leafy vegetable wastes that has been
VOLUME
2 4, N O .
3 . » FEBRUARY
10,
1946
357
