February. 1927
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Chemical Treatment of Trade Waste‘ 11-Wastes from Silk Dyeing By Foster D. Snell and Donald S. Bruce PRATTINSTITUTE, BROOKLYN, N. Y.
Variation in Composition A plant dyeing both silk and silk-and-cotton goods HE plant supplying the has been investigated from the standpoint of waste Liter samples were taken data given is a relapurification. The wastes are dye liquors, two bleach a t half-hour intervals on two tively small piece-dye liquors, two boil-offs, a mercerizing liquor, and a sour. separate days, about 10 days works having a discharge of The chemical characteristics of each are discussed. apart, from a sump into 100,000 g a l l o n s of w a s t e A half-hour average of dye waste treated with 5 pounds which all the liquors were water per day, mainly withof copperas and 4 pounds of lime per thousand gallons discharged. These gave rein 10 hours. The plant dyes settles satisfactorily. Decolorization is better with sults which are summarized‘ silk a n d silk-and-cotton an hour average. One of the boil-offs goes to by-prodin the accompanying graphs. goods, principally with direct uct recovery and the other is diverted to the sewer. Figure 1 gives the total color dyes. About 300 pounds of Mercerizing liquors are neutralized and mixed with readings obtained on the first soap are used per day with the dye waste. The other miscellaneous liquors are day’s samples after I: 9 dilubleaching powder, silicate of mixed with the dye wastes without pretreatment. tion. Of the two peaks, one soda, hydrogen peroxide, and Sludge is settled in a 4-hour detention basin and diswas of blue and one of red. small amountsof other chemicharged to the sanitary sewer. The blue bath a t 10 A. M. was cals. found to be much less difficult This particular set of reto treat than the less intense sults was selected because it was in more complete form than that of several other plants. red one a t 6 P. M. Figure 2 shows the second day’s average Similar data have been collected from others with daily with no such extreme. Satisfactory color readings could discharge up to 4,500,000 gallons, and the same treatment not be obtained on the 11 o’clock sample on the first day because it contained a large amount of silk boil-off liquor. has been applied with equally satisfactory results. The plant is subject to the rulings of the Passaic Valley These graphs do not include the other miscellaneous disSewerage Commission and is or will soon be compelled to charges mentioned, as these are mainly discharged a t night treat the waste in such a way that 90 per cent will be sub- or in the early morning. They are not objectionable as to stantially colorless and harmless to fish or plant life when color. The data for solids are plotted in Figure 3, and show only discharged into the river. The discharge of the remaining 10 per cent of the waste into the Passaic Valley Trunk one high peak, at 11 A . M . This is due to the discharge Sewer is permitted provided it contains nothing which will of a boil-off a t 10:45 A . M . This liquor is to be diverted. The peaks of solids a t 4:30 and 5:30 P . M. are mainly inorbe injurious to the structure of the sewer. A preliminary study of the dye waste was made on three ganic and not objectionable. I n Figure 4 the oxygen consumed on the first set of samples samples so taken as to each represent an average day’s discharge. For the purpose, determinations of total solids, shows a peak a t 11 A . M . corresponding to discharge of the loss on ignition, oxygen consumed, and color readings are silk boil-off. Another peak a t 5:30 P.M. indicates dissufficient.2 Laboratory study indicated that treatment charge of a logwood bath which can be handled satisfactorily of these average dye wastes with 5 pounds of copperas and by Foagulat$n. At 4 pounds of lime per thousand gallons would give a satis- o t h e r t h a n t h e s e factory effluent. The data on these samples before and after times oxygen consumed is under 200 this treatment are giren in Table I. p. p. m., with most Table I-Analysis of Dye Wastes values between 100 and 150. While this EFFLUENT 1 EFFLUENT 2 EFFLUENT 3 Before After Before After Before After is not low, it is reasonP.0.m. P.9.m. P.0.m. P.g.m. P.0.m. P.p.m. ably u n i f o r m a n d Total solids 1896 1750 2894 3234 1618 1590 therefore treatment is Loss on ignition 768 288 372 710 4j2 260 Oxygen consumed 240 49 266 85 415 126 m u c h simplified. Lovibond Units per 50.8 mm. Layer The oxygen consumed Red 7.0 2.6 5.0 2.0 10.0 2.5 by the second set of Blue 3.5 0.0 6.0 0.0 11.0 0.0 Yellow 8.0 2.0 6.0 2.0 6.0 2.0 samples, also shown in Figure 4, shows I n addition to the dye wastes there are a number of others two peaks a t 1:30 and occurring a t more or less frequent intervals. These are a 2:30 P. M. running to mercerizing liquor, a sour, silk and silk-and-cotton boil- just over 400 p. p. m. 9 10 1 1 1 2 1 2 3 4 5 offs, a hypochlorite bleach, and a peroxide bleach. Typical Other than these the Time values fall mainly besamples of each of these were analyzed with the results Figure 1-Total Color in Lovibond Units tween 100 and 150 Per 50.8 M m . Layer on First Day’s indicated in Table 11. Samples p. p. m. Original color in 1:9 dilution -solid 1 Presented under the title “Chemical Purification of Wastes from The maximum al- line. Color after treatment of half-hour averSilk-Dyeing” before the Division of Water, Sewage, and Sanitation at the age (without dilution) - - - - dash line. Color kalinity to methyl 69th Meeting of the American Chemical Society, Baltimore, Md., April after treatment of hour average (without orange, eliminatnig dilution) , , . . . dot line. All values which in6 to 10. 1925. Received September 20, 1926. 11 o’clock sample omitted because of First article of this series. A m . Dresfuf R e p i r . , January 24, 1927. t h e boil-off, was clude boil-off
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0.015 N,and the single acid sample was 0.026 N . The observations on the second day were started earlier in order to see if the effluent showed acidity for any considerable time, and on that day the effluent was not acid a t any time.
and in the late afternoon. The results of treatment of the half-hour average effluent show sharply defined ups and downs, as might be expected. Averaging these effluents over a period of one hour results in a much more uniform line, generally lying much lower. The more complete data, of which only a summary is given in Figures 1 and 2, show Table 11-Analysis of Other Wastes SILK SILKAND COTTON HYPOCHLORITE that adjoining peaks are seldom of the same color. A given BOIL-OFF BOIL-OFF BLEACH quantity of coagulant appears to remove about the same amount of each color from a mixture of several differently P. p . m. P . p . m. P . p . m. Total solids 11,334 11 262 24,690 colored solutions as from each solution individually. We 6:522 4,210 Loss on ignition 1,326 hope to test this observation quantitatively on some synOxygen consumed 2.864 1,742 Alkalinity 0.0047 AT (phen.) 0.0141 N phen) thetically prepared wastes in the near future. The color 0.0600 N (m. 0 . ) 0.0473 N {m. 0;) of the treated hour-average waste from 1: 30 to 4: 30 was in Alkalinity of mercerizing liquor 0.293 n( (phen.) Acidity of sour liquor 0.023 i% (m. 0 . ) general less than half that of the treated half-hour average. Oxygen consumed by peroxide bleach, p. p. m. 48.8 This illustrates the need for careful mixing of the wastes before treatment, a factor of great importance when the P r e l i m i n a r y discharge from the plant is not homogeneous. With as4 work had indi- sumption of only a half-hour average the color of the second cated treatment set of treated effluents is not over 5 units. 3 of this waste with If, for a time, the b 5 pounds of cop- plant is operating on a p e r a s a n d 4 more highly colored e E pounds of lime waste, the amounts of 450. I per 1000 gallons. copperas and lime fed 1 The individual can be temporarily in- 400samples from the creased. The chemical first set were pre- feeds should be over- 350. cipitated in50-cc. size to allow for this Time p o r t i o n s a n d contingency. It was 300. Figure &Total Color in Lovlbond U n i t s per gave in 4 hours concluded t h a t the t; 50.8 M m . Layer on Second Day’s Samples Original color in 1: 9 dilution -solid line. from 10 to 15 per treatment could be ex- Ei 250 Color after treatment of half-hour average (mthout centof sludge by pected to give acceptdilution) - - - - dash line volume, varying able results in operain different samples. On standing 12 hours the sludge settled t i o n w i t h 1 h o u r further to 5 or 6 per cent by volume. This indicated that averaging and 4 hours’ 150. the above treatment would give satisfactory results so far as settling. the volume of sludge is concerned.
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Disposal of MiscellaneousLiquors Other Than Dye Liquors
Averaging
Samples taken from the sump at half-hour intervals are each believed to represent a fair average for the preceding half-hour. After treating these halfhour average samples the total color obtained from each is about one-tenth that of the original effluent, as shown in Figures 1and 2. In order to test out the advantage of takingaonehour average, samples were made up to repr e se n t a p p r o ximately such an average by mixing equal volumes of adjacent half-hour s a m p 1es. On treatment these Time Fiaure 3-Solids in First Set of Samules Pave the third series Total solids - - - -dash line. Loss on ignition of color values plotted -solid line in Figure 1. An effluent which gives a color reading-under 5 is not objectionable after dilution in a fair sized stream. Inspection of the graph indicates that the color of the treated effluent is mainly below this value, even for the half-hour average discharge. Striking exceptions are a t 10 A.M. 0
100
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The silk boil-off is 50rich in soaD and is I I I I I l l l l I 1 1 1 1 1 1 separately &charged 8 9101112 1 2 8 4 6 to a tank in which it is Time made acid to methyl Figure &Oxygen Consumed orange with sulfuric dad;:& saFTl_e-solid line. Second dash line. Value of 1270 acid. The sludge of is due to boil-off. 5.30 sample on second day, fatty acids and sericin data lacking which separates is skimmed and sold to a local plant, which works up such sludge for production of soap. Thus it furnishes a small source of revenue to offset the cost of chemicals and labor in the balance of the process. The silkand-cotton boil-off is so badly contaminated that it should be diverted to the sewer along with the sludge. The hypochlorite bleach liquor is so small in quantity as to be diluted nearly one hundred times in the averaging basin. Expen: ment has shown that it can be handled by the treatment recommended for dyes. The peroxide bleach bath can be treated with the dye waste in the dilution in which it reaches the averaging basin. Mercerizing liquors occur only at long intervals, and the tentative method is to neutralize with sulfuric acid and mix with the dye waste. If their volume were greater it would be economical to add them to the lime feed of the treating plant, but in this case the saving would not warrant the trouble. Volume of Sewage for Discharge to Trunk Sewer
Since there is an allotment of 10,000 gallons of trade waste per day, the estimated 6000 gallons of sludge from
February, 1927
INDUSTRIAL A N D ENGINEERING CHEMISTRY
this plant and the 1700 gallons of silk-and-cotton boil-off may be discharged directly to the sewer. If it were necessary to treat the sludge by filtration the settling would be made more efficient and it would run to filters, but there is no premium on efficiency in settling beyond a certain point, when a 10 per cent allotment is available. Effect of the Effluent on Fish Life The practical test on which the polluting or non-polluting character of waste is often judged is whether or not it prevents or destroys fish and plant life in the stream. The waste from this plant will flow through a park lake stocked with goldfish. A series of tests on goldfish showed that the undiluted waste after treatment was only slightly toxic. When diluted it should offer no hazard to fish life. Practicability and Cost
The method of treatment outlined has been studied in its application to several other plants, six of t>hemsimilar to but larger than the one under discussion. In all but one case the plants tvere so departmentalized that by simple changes in accessible drainage lines the desired separation of wastes could be obtained. This includes a large plant which has been in operation for only a few months. The cost of chemicals for treatment a t current prices
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is about $8 a day. A revenue of approximately $5 per day is derived from the boil-off, giving a net cost of about $3 per day. In a larger plant it is usually possible to separate some of the wash waters without treatment, so that the total cost of treatment for a large plant is somewhat less than a direct multiple according to size. English practice has shown separate treatment of soap and boil-off liquors to be more economical than their treatment as part of a mixed waste with dyes and other wastes. T r e a t m e n t Plant
The plant as designed has an averaging basin of 5000 gallons capacity to operate with continuous i d o w and overflow. The discharge from this will be a mixture containing varying amounts of the waste for several preceding hours. Not more than half of this will consist of inflow from the preceding half-hour, provided mixing is efficient. The settling basin has a capacity of 50,000 gallons, which allows for increase of plantiacilities. Acknowledgment
The results given in this paper were obtained in cooperation with Gerald W. Knight, Consulting Sanitary Engineer of Passaic, N. J. They are published by permission of the Passaic Piece Dye Works, Passaic, N. J.
Disposal of Trade Waste from a Plant Mercerizing, Bleaching, and Dyeing Cotton Materials’ By Walter E. Hadley CLARK T H R E ACo., D NEWARK N., J.
Efforts to Prevent Pollution in Passaic Valley
OR a number of years increasing legislation has been enacted by different states relative to the disposal of
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trade wastes into their waterways. Particularly noticeable in this respect has been the action of the State of New Jersey in its effort to clear the Passaic River and its tributaries between the Great Falls in the city of Paterson and the mouth of the river a t Newark Bay. Since the completion of the Passaic Valley Sewer a very real effort has been made to prevent the further pollution of the Passaic River, and it now shows the effect of the decreased discharge of polluting substances into the stream. The Passaic Valley Sewerage Commission has now entered suit against several concerns who they claim are still discharging polluting matter into the waterway, such action being based upon Chapter 10 of the Session Laws of 1907, which reads as follows: Every municipality, corporation and individual is hereby prohibited and forbidden to discharge, directly or indirectly, a n y sewage or other polluting matter into the waters of the Passaic River a t any point between the Great Falls, in the city of Paterson, and the mouth of the said river, at Newark Bay, or into any tributaries of the Passaic River which empty into the Passaic River between said points, after the twelfth day of December, in the year 1912; and the Passaic Valley Sewerage Commissioners a r e hereby authorized and empowered t o enforce the provisions of this act over and throughout all municipalities which may, or the inhabitants of which may, directly or indirectly discharge sewage or other polluting matter into the waters of the Passaic River between the points above designated, or into the tributaries aforesaid after the said twelfth day of December, 1912. 1
Presented under the title “Some Experiences in the Practical Dis-
posal of Trade Waste Produced in the Mercerizing, Bleaching, and Dyeing of
Cotton Material” before the Division of Water, Sewage, and Sanitation Chemistry a t the 72nd Meeting of the American Chemical Society, Philadelphia, Pa., September 5 to 11, 1926.
Each year the date was carried forward by the legislature, but the date now on the statute books has been fixed as December 31, 1923, when pollution should have ceased. The Passaic Valley Sewerage Commissioners are further authorized and empowered t o institute in their corporate name suits at law or in equity, as may be deemed necessary or appropriate to enforce the provisions of this section of the act after said twelfth day of December, in the year 1912; and the Court of Chancery of this State is hereby vested with special jurisdiction to enforce the provisions of this section of this act in a summary manner upon application of the Passaic Valley Sewerage Commissioners.
During the year 1924 the act was still further amended and now gives individuals the right to start suit, in the name of the commissioners, against anyone polluting the Passaic River or its tributaries. The interpretation given by the Passaic Valley Sewerage Commissioners of the term “polluting matter” has been outlined by them as follows: In a great industrial section such as ours, with a tidal river flowing through it, which probably will never again be used for potable purposes, this term of necessity must be interpreted to mean something different from t h a t which it would were i t applied t o a pure mountain stream being used for potable purposes. From a practical point of view, then, the determination of what constitutes “polluting matter” must be based on the broad ground of resulting effect upon the river rather than a literal definition of this expression. Also the physical impossibility of preventing certain forms of “polluting matter” from being discharged into the river, temporarily must be taken into account.
This would include street wash and discharge from combined sewers during a period of heavy storm.
