NEWS EDITION Vol. 1 4 , No. 2 2
INDUSTRIAL andENGINEERING CHEMISTRY
NOVEMBER 20, 1936
Vol. 28, C o n s e c u t i v e N o . 39
Published by t h e American Chemical Society Harrison E . Howe, Editor Publication Offices: Easton, P a . Cable: Jiechem (Washington)
Editorial Office: Room 706. Mills Building. Washington, D. C . Advertising Department: 332 West 42nd Street, New York, N. Y .
Telephone: Telephone:
National 0848 Bryant 9-4490
T h e Economic Importance of Waste Treatment to the Industries 1 this title, Michael J. Blew, UNDER research engineer, Bureau of Engineering and Surveys, City of Philadelphia, presented an interesting discussion. "Pollution," h e said, "has been defined as the admission of deleterious substances to a stream in excess of its natural ability properly t o dispose of them. These substances may be of natural origin, such as the washings from the soil, or they may be the result of the encroachment of civilization." After discussing various factors in waste treatment, the types of effluents, and the alternatives in disposing of waste from many industries, he presented the following cases where industry has directly benefited b y measures to alleviate stream pollution:
by this process at a profit. Similar wastes could be treated in a like manner with a saving of chemicals and tremendous benefit to the rivers.
plants to warrant conducting sales. These losses are largely from hotels and restaurants. DISTILLERY SLOP.
Pollution
from
this
source may be almost entirely avoided by evaporating the slop. The entire solid conCURLED HAIR. This company simply installed a screen and settling tank and re- tent can be recovered for cattle food and the water vapor from the evaporators returned covered sufficient hair to be profitable. to the mash tanks. A CHEMICAL PLANT located in the basin CARBONIZING PLANT. This wool scouring of an old quarry had considerable spring water seeping from the rock at the rear of the plant added a carbonization process. The effluents from the two processes were complant. This water ran through the company's grounds picking up in its travel some con- bined and trapped. The traps were skimmed centrated chemical compounds. The latter and screened, recovering sufficient wool to eventually produced a taste in the city's make it profitable. The effluent was alkawater supply many miles down stream. By line, and sufficiently clean to mix with collecting this water and storing it behind a domestic sewage in the sewerage system. ADVERSE EFFECTS. A plant using a large simple, earthen dam, the company utilized this water supply for boiler and cooling volume of water from the river was forced to water at a saving of about $3000 annually. change its source of pumping to a new point The excess water was conducted around the about 20 feet lower in elevation and considerably farther away, because of excessive chemical-saturated premises with no further PAPER INDUSTRY. By installing save-alls pollution of its original supply. This complaint. and recirculating the white water, paper necessitated pumping farther and under an industries have been able to reduce the pulp WOOL SCOURING. This plant installed a loss to practically nothing. The higher the semi-closed system to utilize the water from increased head. The added cost amounted, grade of paper stock being produced, the the end of the scouring train after treatment in this case, to from $10,000 to $12,000 per greater the loss that may be encountered by centrifugals. The effluent was reduced year. The new supply, once instituted, in the process when only a few parts per 90 per cent in volume and also in pollution was soon polluted by a neighboring industry, million of pulp are permitted to escape. The load. The water consumption was reduced which caused consternation and embarrassvalue ranges from $20 to $65 per ton of to about 10 to 15 per cent of the original, ment for both parties. PLANT COOPERATION. Another interestpulp, practically all of which can be rethis being necessary to compensate for loss covered by recirculating the white water. by steam, spillage, and as make-up water to ing case is that of two meat packers working In this instance, success was achieved by maintain the dissolved solids in proper bal- in harmony with another industry. The chlorine or chlorine-ammonia treatment of ance. The sludge was treated to recover the packers dry the blood and grease together the white water to prevent the development grease. With grease worth 6 to 7 cents per and sell it for about 2 cents per pound to the of fungus growths. This process can be pound, this process was self-supporting. In third industry, which is profitably engaged operated on practically a closed basis with a Germany, this sludge is filtered and the in making glycerol and stearic acid. saving of pulp and power and reducing the A storage battery plant with a strong acid cake extracted with benzine. Savings conpollution load about 70 to 90 per cent. sisted in fuel for heating the scouring water, waste is located near a silk dyeing plant with soap, and detergents, water pumping charges, an alkaline waste. Both effluents are delePHOTOGRAPHIC CHEMICALS. The waste from the manufacture of films contains as and stock losses through the effluent. The terious to the sewer structure and to sewage much as 3 ounces of silver per ton of waste product scoured in this way is said to have treatment. They are combined and mixed a softer, finer texture than wool scoured in with domestic sewage with no ill effects. water. This can be recovered by sine oxide the usual manner. This fact is corroborated HEAT RECOVERY. Another plant has inand lime, making the process profitable. by findings in Scotland nearly a century ago stalled copper coils in its settling tank and One instance on record shows a bathing that "wool scoured at the end of a run was recovers sufficient heat to cover the cost of beach contaminated with such a waste, treatment. There are many instances where while the river mud near the outlet from the finer, softer, and not so harsh as that at the heat recovery can be used advantageously. plant assayed $170 worth of silver per ton. beginning." This is a richer deposit than many silver GREASE RENDERING. This plant cooled Sufficient importance is rarely attached ores. A settling tank with baffles can recover its waste liquids, skimmed them, and remost of the silver residues. covered sufficient grease to pay for the to the composition of water used in industreatment. It recovers from 60 to 75 per trial plants. If the supply is abundant MERCERIZING. A process is in effect recovering 97 per cent of the caustic soda from cent of the grease and renders its effluent to and reasonably economical, it generally satisfies the engineer. The possibilities of a mercerizing plant. This is one of the the sewer unobjectionable. meanest of trade effluents, and can be treated LAUNDRY. This laundry installed a trap deleterious and destructive chemicals in and screen and recovered enough linen to the water are often entirely overlooked. Canneries have had their products renpay for the process. The effluent was then * Abstract of a paper presented before the Division of Water, Sewage, and Sanitation dered unmarketable by chemical tastes in treated with domestic sewage without diffiChemistry at the 92nd Meeting of the AMEBICA* their water supply. Dyeing, textiles, culty. There are instances where sufficient CHBMICAL SOCISTT, Pittsburgh, Pa., September laundries, and wool-scouring plants require linens are recovered on the screens of disposal 7 to 11. 1936. 445
446
INDUSTRIAL A N D ENGINEERING CHEMISTRY
water free from iron, manganese, acids, and alkalies. Excessive hardness gives rise to wastage of soap and increased cost for water-softening. The precipitate of calcium and magnesium soaps forms a greasy curd that sticks to the cloth, increases the labor of cleaning, and shortens the life of the fabric. Excessive hardness causes wastage of tanning material, and uneven shades in the leather. Waste matter in water can cause priming, foaming, and scale in boilers, and possibly corrosion—all aggravated by waste in river water. Apparently, the plan of attack should be: to increase the development and installation of closed systems, which can be used by many places that at present decry the idea; to develop new and better processes; to' institute intelligent research on the utilization of by-products; to separate
waste from drainage and storm water to reduce the cost of effluent treatment: to combine wastes, taking advantage of their differences in chemical character to render them innocuous or less harmful, and t o minimize their deleterious and destructive effects; to utilize heat in effluents by heat exchangers; to develop better machinery: t o utilize cheaper construction in plant design. There is probably no reason for the construction of elaborate concrete tanks when steel can be employed to better advantage and at a much lower cost. Steel has been used in water works for years, and undoubtedly can be used in sewage and trade-waste work with equal success. The present method of construction, erection, and welding in place makes steel a desirable material for treatment tanks.
VOL. 14, NO. 22
Many industries in the past had the wrong attitude toward stream pollution, but are slowly changing from the defensive t o the aggressive for the protection of their own interests. It is inevitable that eventually they will force each other and also municipalities to adopt stream protective measures. Every other consideration for stream recovery follows as secondary, since every worth-while project develops from individual initiative, which works out for the common good of all. This problem is a direct challenge to the chemists and engineers of America. Sufficient studies have been made to warrant far more activity than is in evidence. Concentrated study of individual requirements should soon break down those few cases where treatment might be found inadequate.
Improvements in Impregnating Textiles with Synthetic Resins C. H . S. TUPHOLME, R u n c t o n Cottage, Lower B o u r n e , F a r n h a m , Surrey, E n g l a n d MONG the British textile operators who A have taken a prominent part in the use of synthetic resins in the textile industry is the Calico Printers' Association, an influential group of textile printers. Chemists of that group claim to have perfected two processes—one for avoiding high temperatures in insolubility, and the other for improving the fastness of textiles to washing after treatment with synthetic resins. The first process is claimed t o be an improvement on previous ones involving the treatment of textiles with synthetic resins of the amido aldehyde group for the purpose of fixing certain desirable finishes (such as mechanically produced effects), or for improving fixation of dyestuffs in that it ensures insolubility or fixation of the synthetic resin in the fabric without the necessity of using relatively high temperatures which might injure the fibers or which require special equipment not usually available in textile plants. The process consists in the impregnation of the textile material with a solution of an early intermediate condensation product of an amidic component with formaldehyde, or with a solution of the amidic component itself, or of the amidic component and formaldehyde, followed by treatment of the textile in a steam atmosphere in the presence of gaseous formaldehyde, the impregnation and steaming preferably being effected in the presence of acid. Suitable amidic components are urea and its derivatives, thiourea and its derivatives, and dicyanodiamide. T o obtain the best fixation of dyestuffs or mechanically produced effects, the steam must contain a certain minimum proportion of formaldehyde vapor, such as is obtained when boiling a 10 per cent formaldehyde solution. The resin is insoluble o n the fabric o r fibers at temperatures slightly above 100° C , such as prevail in the steaming machines ordinarily used for the fixation o f dyestuffs on textile fibers. Examples of the new process follow: A viscose rayon fabric is dyed with Diamine Rose FFB, impregnated with a solution prepared b y dissolving 5 parts by weight of salicylic acid and 10 parts by weight of urea in water and making up to 100 parts b y volume, dried, and treated for 20 minutes in the vapor from boiling 15
per cent formaldehyde solution. The color is made fast to washing and soaping at the boil. Secondly, a cotton fabric is padded through a solution prepared b y dissolving 10 parts by weight of urea and 5 parts by weight of 80 per cent lactic acid and making up to 100 parts by volume, dried, conditioned, embossed, and treated for 20 minutes in the vapor from a boiling 15 per cent formaldehyde solution. The embossing is made fast to water and soaping at the boil. In the second process, the fastness to washing of dyeings on regenerated cellulose rayon, cotton, other vegetable fibers, natural silk, or mixtures of these materials is improved, or the fixation of dyes normally having little or no affinity for these dyes is made possible by dyeing the fibers with acid or direct dyestuffs, simultaneously or subsequently impregnating the dyed fibers with an aqueous solution of substances leading to the formation of a synthetic resin of the urea-, thiourea-, or dicyanodiamide formaldehyde type in acid medium, drying the fibers, and afterwards making the resin insoluble by heating the treated fibers to a temperature of 180° to 210° C. for 30 to 60 seconds. The amount of formaldehyde used is in excess of the molecular proportion required for the formation of dimethylol urea or analogous dimethylol compound. The chemists draw attention to the fact that, with the exception of the vat colors, none of the various dyestuff groups permits of the production of a comprehensive range of shades fast both to light and to severe washing treatment. Among the substantive colors used for dyeing and rinting vegetable fibers are many fast-toght dyes fulfilling most of the requirements as to shade and dischargeability but of very poor to moderate fastness to washing. On the other hand, direct dyestuffs giving shades which can be made fast to washing b y diazotizing and developing or by coupling with a diazotized compound are, with a few exceptions, of only poor to moderate fastness to light. Among the acid dyestuffs used for dyeing and printing silk are many possessing good fastness to light and other desirable properties, but which are very fugitive t o washing. The degree of improvement in washing fastness brought about by the present proc-
E
ess is stated to vary somewhat from dyestuff t o dyestuff, but to be, on the whole, more marked and obviously of greater value the lower the initial fastness to washing of a dyestuff. Thus, a substantive dyestuff which, if dyed or printed on cotton, viscose, or cuprammonium rayon, would not stand even the mildest soaping treatment without appreciable fading, becomes in many cases as fast to washing as dyeings produced with diazotized and developed or coupled substantive coloring matters. It is even possible, it is claimed, to achieve the fixation on vegetable fibers of dyestuffs which normally have no affinity for these fibers—for example, acid dyestuffs. Another feature of the process is the application of the amidic component and of the aldehydic component separately after the dyeing or printing, or the amidic component may be applied along with the dyestuff, and together with, if desired, a catalyst or condensing agent, the aldehydic component being applied afterwards, either in aqueous solution or in gaseous form in an atmosphere of steam. The resin is then made insoluble b y heat. Two examples of the new process follow: Twenty-five parts by weight of urea and 10 parts by weight of ammonium acetate are dissolved in 115 parts of water, and 100 parts by volume of 40 per cent formaldehyde solution are added. The mixture is allowed to react for 30 minutes a t room temperature. A cuprammonium rayon fabric dyed with 2 per cent Chlorazol Fast Scarlet 4BS is impregnated with this solution, dried, and heated at 200° C . for 30 seconds. The color withstands washing in boiling soap solution. Secondly, 10 parts by weight of urea, 4 parts b y weight of ammonium acetate, and 2 parts by weight of Chlorazol Fast Red K are dissolved in water and the solution is bulked to 100 parts by volume. A cotton fabric is impregnated with this solution, dried, and treated in an atmosphere of steam and an excess of formaldehyde vapor for 15 minutes. A heat treatment of 3 0 seconds at 200° C. completes the fixation of the color, which is then fast to hot soaping. EDITORIAL NOTE.
At leaat one U. S. patent
has been issued in this field. This is No. 1,734,516 (November 5, 1029) t o Tootal Broadhurst Lee Co., Ltd., the patentees being R. P. Foulds. J. T. Marsh, and F. C. Wood.
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