individualities and must not attempt to handle them like a platoon of soldiers. The success of the laboratory is the bum of the quccesseq of the individual men. To get the maximum of succeSs in a man, he must be given the necessary working toolq, he must feel the confidence and support of his superior., he must be permitted to confine his personal efforts to revarch itself, and the resulti: of his work qhould be well known. To quote again froin John E. Teeple, he tee1niillq, paper mills: slaughter houses, etc. Sewage pollution, heing an entirely separate problem, is also not condered. There are several dams across the river around which canals n-ere built for the purpose of navigation. In later years, howel-er, the lockage through them has been practically nothing. An estimate made by the State Deparhient of Healt,h, in 1928, gires the following comparison between the sewage and industrial pollution loads on the river from Ileading to Sorridon-n:
T
Recei\.ed .4pril 2 6 , 1930. Presented before the Division of Water, Sewage, and Sanitation Chemistry a t the 79th Meeting of the American Chemical Society, Atlanta. Ga., .4pril 7 t o 11, 1930.
Raw Sewage P o p u l a t i o n E q u i v a l e n t , R e a d i n g Seware load: Past... , . . , , . . . Present, . . . . . Near f u t u r e . . , , Ultimate. . . . . , . Pollution l o a d . . . , ~~
~0~
~
.. ,. .. ..,.. .. .. . ... .. . . ... . . .. .. ... . ... .. .
t o Norristowri
. . . , 1S3,000 . . . . . 132,000 . , . 67,000 . . . . 37,000
~007,nnn
The corresponding sewage load to the city line woiilcl be slightly more, so that in general ternis t’he sewage and intiustrial pollution loads are of a similar order of magnitude. Survey of I n d u s t r i a l Pollution
The present, study of the pollution of the Schuylkill River started in 1920, when a representative of the city Departmelit of Health and the writer representing the Department of Public Works were delegated to ascertain, if possible, the source or sources of certain tastes noticed at times during the winter season in the Philadelphia mater supply. This ta;te was variously described by the public as iodoform, niedicinnl, chlorine, tar, carbolic acid, and otherwise. Different plants along the river were visited and samples of their effluents 01)tained. The writer then tested these samples for their ta+producing properties, both by straight dilution and dilution plus chlorination. Some of these effluents were found to give a taste whet] diluted and chlorinated 1part in 10 million. This taste is a peculiar one which develops after a few seconds on the back of the tongue. The writer designated this taste in 1920 as the “X’taste because lie did not know its cause, nor could it be accurately described. This designation has been continued and now forms our regular symbol for this type of taste.
578
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
The matter was then brought to the attention of the Pennsylvania Department of Health, which established a patrol of the river during several months of 1920, and an immense amount of cleaning up was accomplished with the cooperation of the different gas plants along the river, which had been the offenders in discharging these taste-producing effluents. This applied particularly to the gas plants at Reading, Pottstown, Phoenixville, and West Conshohocken. Some of these have been, or in the near future will he, discontinued.
T’ol. 22, S o . 6
T h k phase of the work continued until March, 1928, and dealt primarily with the prevention of the “X” ta-te in the city’s water supply from this river. It was essentially a survey and constant inspection of the plants potentially able by accident to discharge, or allow to be washed, into the water courses materials causing the production of this “X” taste in the river. A few pears after this study started an interesting situation developed in the water wpplv of Chester, a city twelve miles 1
I n the early part of 1921 this patrol and survey of the watershed was taken over by the city of Philadelphia. Inspection trips were made by one of the laboratory force under the supervision of the writer, and continued along these lines until 1923, when an appropriation was made for a patrol consisting of two men. This patrol has continued up to the present time, with, however, changes in its personnel. I n 1923 a systematic survey of the watershed was inaugurated in which it was planned to investigate and note every outlet to the river and its tributaries. This was carried out in detail for the lower portion of the watershed. This period from 1920 to 1928 might be considered the first phase of the pollution investigation and consisted mainly of a survey and general patrolling of the watershed with special reference to such plants that discharged waste which had potential taste-producing possibilities. Some of these plants had very inadequate tar separators or none a t all; tar drippings from the gas holders were allowed to accumulate on the ground, tarry matters w r e allowed t o trickle into the canals, and in general very little attention was paid to the matter of river pollution. Consequently, every hard rain washed these accumulated matters into the river and flushed them down past the city’s intakes. This generally caused the appearance in the water supply of the “X” taste. This clean-up campaign greatly reduced the frequency of the appearance of this taste. To prevent the storing up of any tarry run-off in the canals, the writer suggested to the State Department of Health that they request the navigation company to operate the wickets at each canal outlet for a few hours a t regular intervals. This was done and is now a matter of routine operation. I n general, the plants cooperated with the city’s patrol in a very satisfactory manner. I n many cases considerable sums of money were spent to keep the wastes out of the river or to purify them. One company spent over ten thousand dollars installing a tar separator and filter; another put in a pipe line and pumped its waste to an abandoned quarry a mile and a half inland, while others adopted various other improvements.
below Philadelphia, which takes its supply from the Delaware, a few miles below the mouth of the Schuylliill. A peculiar taste, accompanied by a similar odor, was noticed in the water. This odor was noticed on the boats passing up and down the river. Some of the officials of the State Department of Health came down to investigate it and the writer went down with them. While going through the filter plant the writer suggested warming a sample of the water with a little permanganate. This caused the odor to disappear. It was suggested that the pre-chlorination of the water be increased. This solved the problem as far as the water plant was concerned. Pre-chlorination has been practiced at Chester almost continuously since that time. The Department of Health finally traced this odor to a plant on the lower Schuylkill, below the Philadelphia intakes. This “X” taste is not removed by any of the ordinary methods of treatment, and is not always absorbed by the slow sand filters. Its appearance was, however, most generally noted in the rapid sand water. Ammonia-chlorine treatment will reduce the taste, but its removal is not so thorough as t h a t of the true phenol taste. Legal Cooperation
The second phase of the work started in March, 1928, when G. C. Ladner was appointed a special counsel in the Department of Law to take up the subject of stream pollution. -4pollution board was formed, consisting of the river patrol and other representatives from the Bureau of Water, Sewage Disposal Division of the Bureau of Engineering, and the Law Department. The scope of the work was broadened, and has been carried out under his general direction since that time. The first step was to write a letter to each plant which the water survey showed was polluting the river or its tributaries, asking them what steps they proposed taking to abate their pollution, and also when and how. Each plant has been dealt with in accordance with the spirit of cooperation manifested. Most of the plants promised full cooperation in the
June, 1930
INDUSTRIAL A N D ENGINEERING CHEMISTRY
campaign to clean up the river. A few, however, had to be threatened with a suit in equity before t.hey manifested any real intention of adopting remedial measures. Therc art? many acts of assembly defining the right of the city (if Philadelphia to tlic waters of t h e Schnylkill, and to control its pollution. One act, in particular gives the city power to inspect thc watershed. This is the Act of May 2, 1905, P.L. 350, which provides: BE IT ENACTED, ETC., T h a t any city owning and operating a water works system is hereby authorized and empowered to enter, by any of its employers, upon private lands through which may pass any stream or streams of water supplying such city, for the purposc of patrolling the drainage area of such streams, and making investigations or inquiries pertaining to the conditioii of the stream or streams, sanitary or otherwise; PROVIDED nowF.vEn, that any injury or damage done to thc property so entered upon shall be paid by such city.
One of the first Icgal activit,ics of this phase of the work vas to file a suit, in equity against a plant rvliicb had longheoir polluting the river ainl had not. slrow-TIso uiiich coiipcration with the state or city as some of the other plants. The Corninonwealt,li of I'cnnsylranin joiiird with the cit,y in this suit:. This matter will lie fmtlrer described uuder plant, Xo. 1 , The character of the mnrk aceomplislied to (late is indicated hy the followirig drscrijrtion of about twenty individual inilustrial plants. 'These plants will he drscrilxd by a mimher, which has no sigrrifioancc other than being the nuoibcr (if t,he filing envelope of that# plant ut tire Law Dejtartnimt office. Typical ~IIBIVSIT are given of effluents of S O I I I ~of these plants. The key iiurnher shown under such plants refers bo the accompanying table of analyses.
579
scheme has yet been deviscd for taking care of this wastc. This waste is really more of a nuisance than real pollution. Plant No. 3 formerly did some wool scouring but is now only engaged in the manufacture of cotton yarns and rugs of t h r chenille type. It dischargcs'into Saw Mill Run, a tributary of the Schuylkill River, ahout 2000 gallons per day of liquid wmte containing dye liquors and wash water. The organic content of these wastes is slight. Thcreasonahle and simple method of treatment will be to discharge into the borough WWCT which can be done as soon as the sewer reachrs the mill. Plant No. 4 has three general types of waste. Thc company formerly purchased resinous substances, such as Bakelite and impregnated canvas and paper with it, which w r r ~then pressed and molded into gears, panels, and radio parts. For the past two and one-half years i t has hpeii making its own condcnsite. The attrntion of the city was first focused on this plant following
condensite plant. a i d also from the iu>-off from thc-dust from
heeninstalled to collect the dust, which i? now demxitcd on tlw
andfollectcd ir; a sump and bill he disposed of by evaporation and
..
allr." which were later'kbandoned Eeccntlv tI& have been installed inside-flow rotary screens, which remove the major portion of the suspended matter, consisting of fine paper pulp. This discharge amount5 to several million gallons per day. (Analysis 4-A)
Results of Pollution Investigation
Plant No. 1 manufactures motor fuels, roofing compounds, and wood preservatives. This was one of the first plants under ohservation by t h e city because it discharged an effluent into the Schuylkill River having a strong taste-producing powcr. During the war period this plant manufactured phenol. A sma!l stream runs through the plant and across a flat into the river. The first improvement was to build a dike along the river to confine this material. Heavy storms broke through this dike at various times so it was found impracticable to confine this waste and attention was directed to the cleaning up of conditions at the plant. At the time of our first inspection in February, 1920, this plant was making a motor fuel by cracking the tar oils from near-by gas plants into benzene fractions which were mixed with gasoline. Although the plant ceased making phenol before the patrol started in 1920 there was for a while some waste Dhenol scattered ahout the plant The investigation of this plant may be briefly summarized by stating there have been a number of spills and leaks contributing taste-producing matFrials to the river. One hundred and forty different tests had been made on this effluent up to October 8, 1928. These have shown a taste-producing power at times as high s s 1 part in 500,000 giving the characteristic "X" taste. A suit in eauitv was brounht in the name of the Commonwealth of Pcndsy1;ania and ti% City of Philadelphia in the April term of 1928 in the Court of Common Pleas of Montgomery County. This resulted in a decree being issued by thc Court which was dictated bv the citv soecifvine what work should be done about the p l a n t t o safegtiard t h e w & supply. One paragraph of the decree is of particular interest, which is as follows: The defendants s l d l not permit any tarry or other medicinal taste- pro^ dvcing substances to Row or escape from their plant into the Schuylkill River or its tributaries, which eivr the elRuent from t h e plant. when diluted one part ( 0 one hundred md chlorinated. /L medicinal tnsie and odor.
This company has carried out the terms of the dccrec in a very satisfactory manner and the management is now very much interested in the prevention of stream pollution. ieeling that all industries can and should be free from gross pollution of the river. (Figure 2 ) Plant No. 2 is a rolling mill discharging into the river 3 million gallons per day of cooling water carrying grease from the rolls equivalent to about 035 pounds per day. This forma an oil slick on the river which a t times carries down stream for a mile or more. There is no mom for a sedimentation basin or other installation between the plant and the river and no satisfactory
fiikure 2-Leak.
Tarry Master from Plant No. I
The third waste is from the rag washer
This company imports
iiig water. Thc wastr then has an oxy& demmd of ahout 103 and ao oxygen-consuming power of about 68. The digeiicr water is soda ash and caustic wash, being similar to 8 strong laundry waste. (Analysis 4-8) This problem has yet to he solved. as it present3 many engineering dificulties. Them is a minor oil slick from hydraulic presses. There is also a weak zinc chloridc waste from the sizing depaitment, which is not considered important at this time. Plan! No. 5 formerly manufactured a thin parchment-like paper by treating paper with sulfuric acid and glycerol, which was dyed various colors. This has heen abandoned, and the present system is to manufacture glassinc yaper from papcr pulp, which is received at the plant and fed to the beaters and bleachpd. Liquid chlorine is used to make hypochlorite and small qiiantities of alum and rosin are used for sizing. The beaten pulp is processcd, dried. and rolled. The water from thc process Is passed
testing with starch Todide paper.. The company states t h a t recently i t began recirculating some of the p m c e s ~water and found it advantageous, a s it saved considerable pulp. There are two effluents, totaling about 1,500,000 gallons per day. One is a
I N D U S T R I A L A S D E S G I S E E R I S G CHE;TfISTRY
580
Vol. 22, s o . 6 Analyses of Industrial Wastes
Sample Date
PH
4-A 4-B 3-A 5-B 6-10- 6-10- 10-25-9-1229 29 29 29 7 6 8 2 7.5 7.4
Alkalinity 16 88 Acidity Chlorides 14 110 109 79 Sulfates 603) Ether-soluble 24 28 Oxygen: Dissolved 31 68 Consumed 30 rnin 105 O+ Demand, 10 days 2120 1100 Total solids 790 1800 Tntal volatile 272 272 &iended solidsa 176 142 Suspended volatile 828 1848 Dissolved solids 614 1658 Dissolved vDlatile a Gooch crucible method.
5-C 10-2529 8.0
6-A 5-129 9.3
6-B 6-C 9-27- 9-2729 29
13-A 13-B 9-18- 12-2029 28 7 3 8.0
14-h 6-i29 1-
40
34
56
320
2000
1950
90
84
262
12 40 8
13 13 1
38 76 135
185 250 3728
230 163 1780
10 90 35
25 63 11
29,100
358 300 2480 1215 1330 580 1150 635
1004 2900 12,900 6925 6240 2800 6660 4125
700 1250 6600 3680 1340 960 5260 2720
148 300 810 355 467 230 343 125
8.8 53 7 575 275 214 130 361 145
7500 950 81,875 69,812 100 48 81.775 69,812
'i
8.9 78 4 1 920 380 80 76 840 304
9.8
16 280 145 106
io
174 75
i
3.6 130
io
12 10 118 60
combination OF the save-all and chlorine mixer, amounting to about 1 million gallons per day. (Analysis 5-A) The other is the cellar drain, amounting to about 1 million gallons per day. (Analysis 5-B) This was cut down by recirculation to about 300,000 gallons per day. (Analysis 5-C) Plant No. 6 manufactures woolen yarns and discharges 500,000 to 600,000 gallons per day into the Bridgeport Canal, the sewage from the plant also formerly went into the canal. The waste consisted of three kinds-condensing water, dye water, and woolscouring liquor. The sanitary waste now goes into the borough sewer, and the storm water and condenser water now go into the canal. The wool-scouring and dye wastes were combined for treatment. The company built an experimental tank, 40 by 4 by 3 feet deep, and found that by passing the uncooled mixed liquor through this tank plain sedimentation gave about 60 per cent purification, based on the oxygen demand. It then constructed a tank 40 by 40 by 16 feet to the water line, which is equipped with a clarifier of the Archimedes screw type. About 30 tons of sludge per week are formed, or about one carload, which is hauled away to a fertilizer plant. This sludge contains about 39 per cent moisture, and is being sold for one dollar a ton. The company intends to pass the scouring liquor through highspeed centrifuges and re-use it, which will cut down the discharge to the tank 90 per cent. Analysis 6-A (grabbed sample) represents the combined waste of about 600,000 gallons per day before separated, 6-B represents the present discharge into the tank, and 6-C the present final effluent. Plant No. 7 manufactures woolen goods and discharges waste, 50,000 to 100,000 gallons per day containing wash water, dye, and wool-scouring liquors directly into the river. About 95 per cent of the wool used is received in the scoured condition. The wool is sponged, dyed, and woven into cloth. The cloth is scoured and rinsed before being shipped. The scouring liquor consists of 10 ounces of hard soap and 2 ounces of soda ash per gallon of water. Six bucketfuls of this soft soap are added to each scouring machine, which contains 100 gallons of water. The machine is run for 10 minutes, then emptied and refilled with the same mixture. After the second scouring, water containing a slight amount of ammonia is run through the goods until they are free from soap. This plant plans to discharge into the borough sewer, and has installed the necessary pumps and piping to do so, awaiting the construction of the borough sewage-purification plant This will end the direct pollution from this plant. Plant A'o 9 manufactures cement and formerly created quite a nuisance through its pulverized coal. Sprays throughout the coal-pulverizing plant washed a large amount of coal dust into the neighboring stream. It was found by experiment that this coal dust settled out in 20 minutes by plain sedimentation. The coaldust spray is now conducted to a natural settling basin. The influent of this basin contains 300 p. p. m. suspended matter and the effluent 3 p. p. m. Plant Are. 10 manufactures woolen goods from scoured wool and dyes them This plant discharges 15,000 to 20,000 gallons per day, consisting of fulling water, rinsing water, and dye liquor. The company expects to connect to the borough sewer, when, and if, it reaches them, but there is no possibility of this in the near future. The woolen cloth is fulled and washed, soap, soda ash, and water being used. Dye liquor consists of spent aniline dyes. There are about 6000 gallons of dye liquor and 10,000 to 15,000 gallons of fulling and rinse water. It is planned to install a fine-mesh rotary screen to filter this waste. Plant No. 13 manufactures high-grade paper. It formerly manufactured its own pulp from logs by the black-ash process, but this was discontinued in April, 1928, and prepared pulp is now
20,500
14-B 15-.4 6-7- 9-2529 28 9.8
15-B 15-12 11-12- 11-1229 29 7.0 9.1
15-D 11-1229 8.5
16-h 4-129 9.2
60
270
22
200
190
i30
140 9300
3 6 75 39
12 74 8
80 176 24
80 242 29
22 38 218
8000 405 26,195 3685 19,015
100 135 1275 840 44 36 1231 804
193 17; 990 285 100 85 895 200
176 162 1140 330 116 72 1024 258
740 250 2680 1860 610 485 2070 137j
3665 I180
20
10.2 4.6 3.9 220 70 Trace
purchased. The regular paper pulp is shredded and fed to the beaters, where small quantities of alum, rosin, and clay are added for sizing and filling. When colored paper is run, the dye is added in the beaters. The beaten pulp passes to the paper machines, where it is processed, dried, and rolled. It is then cut and prepared for the market. All the waste, about 2 million gallons per day, formerly went into the river. Part of the water from the paper machines is now recirculated. The excess goes to four save-alls, where it trickles through porous brick, the pulp being retained. The discharge is now about one million gallons per day and contains about 1600 pounds of pulp and 500 pounds of clay. The capacity of the plant is 50 tons of paper per 24 hours. (The water comes from a spring.) A t present sodium aluminate is being used as a coagulant in the save-alls, and white water is being recirculated. This company has recently installed a rotary screen save-all on the paper machine which makes colored paper. 18-il is a typical analysis before the installation of save-alls and recirculation; 13-B is typical of the effluent afterward. Plant No. 1 4 makes hot-water boilers, ice-cream cans, and such material. Its wastes consisted essentially of pickling and carbide liquors. Pickling liquors ran 4.5 to 5.5 per cent acid. These were discharged directly into the stream. It was suggested that these two wastes be combined, as the lime of the carbide waste was sufficient to neutralize the acid in the pickling liquor. A concrete pit, 3 by 21 and 5 feet deep was built. The use OF carbide was greatly reduced, so lump lime was added to the pickling liquor. This proved to be a failure as proper mixing did not occur, so milk of lime is now being used. The c:ment pit is coated with asphalt pitch for protection against the acid wastes. This is not satisfactory because of the large amount of sludge formed. This is being held in abeyance, awaiting results of a method being developed elsewhere. Analyses 14-A and 14-B are typical of the influent and effluent of the tank. Plant No. 15 manufactures heavy cotton goods. They dye cotton and weave heavy piece goods, using sulfur black and salt dyes (aniline). The total water consumption is 75,000 gallons per day. Spent dye liquors were discharged into an old open well about 15 feet in diameter, and about 15 to 20 feet deep. This waste consisted of two to five 350-gallon kettlefuls per day. The spent sulfur-black liquor had a small dye content, and was discharged through a drain into the canal. A similar well was dug to care for this sulfur-black waste. The cotton fiber in the sulfur-black waste soon clogged the lower part of this well, the waste then finding its way to the canal. The company suggested drilling through the bottom of the well, allowing escape to lower water courses. The city maintains that this is bad practice, and recommended studies of other treatment, as this might pollute water-supply wells in this district. The purification of this waste is now being studied. The condition of the main effluent before separation of the sulfur-black dye is shown in analysis l 5 A , taken a t a time when it was rather strong. 15-B represents the effluent after separation; 15-C is the sulfur-black dye discharged to well, and 15-D is the present seepage into the canal. Plant No. 16 is a laundry, which discharged its waste into a small swamp, then into Plymouth Creek. The waste consists of about 5000 gallons per day of soapy wash water and has a high oxygen demand. The swamp was filled up with cinders, which caused the water to go directly into the creek. The solution of this problem is pending, as i t is stated that it will eventually be taken to the borough sewage-purification plant when erected. An analysis of this discharge is shown in 16-A. Plant No. 17 manufactures ranges, boilers, and tanks. Acetylene gas used for welding is made in the plant from calcium car-
I-YDCSTRI.4L d.1-D ENGI;VEERISG CHEMISTRY
June, 1930
581
Expressed in P a r t s per Million l7-.4 3-i29
20-.4 10-1728
20-B 10-28 29
-, . I
800
i 15 0 1070 260 580 100 490 160
1400 81 4073
20-C 21-A 10-26- 7-1229 2s 8 6
190
300
2i
50 9s i180
95 632
25i0 260 1650 200 28,970 1600 16,325 1090 22.800 485 13,530 453 6170 1115 635 2i95
13S0 900
330
4800
iS
100
31
108
27i
4213 7000 20.140 13.605 13.560 9634 6380
700 1105 635 10,820 325 6900 295 Si05 780 100
l!;;.;
21-B i-122s
21-C 22-.4 22-B 7-24- 9-24- 8-232s 2s 29 7 3 7.6 400
TO
40
637 3Si
9 70 16
11 96 12
254 50 770 590 523 478 24i 112
36 0 3.50 170 80 74 270 96
6600 9000 4500 1408 914 3092
28-.4 12-132s
31-.4 44-.4 44-B 4 7 - 4 47-B 9-18- 12-20- 5 2 4 - 5-244-229 28 29 29 29 6.2 6.07 8 10.0 9 S
-_
160 7000
11.290 3400 119,290 65.070 1050 370 118,240 64.iOO
bide. The finished product is pickled before being galvanized and shipped out. There are three pickling tanks, 1200 to 1500 gallons each, making a total capacity of 4000 to 4300 gallons. Three hundred and fifty pounds of 66" BC. sulfuric acid are added t o each 1200 t o 1500 gallons of water. This is strengthened daily with an additional 175 pounds. At the end of each week the tanks are drained and cleaned, the liquor being siphoned from them through a 2-inch hose. About 4000 pounds per week of calcium carbide are used. These two wastes pass from the plant through a common 10-inch terra cotta drain about 200 feet long. This empties into a ditch about the same length, which leads to the river. Most of the carbide waste is deposited in the ditch and i t is necessary to remove it occasionally. Samples show that pickling liquor is neutralized by the carbide waste in its passage to the river, and that the discharge into the river is alkaline. No delta is forming a t the outlet of the ditch where i t empties into the river. An analysis of this discharge is shown in 17-A. Plant No. 19 manufactures woolen goods and discharges a waste of about 30,000 gallons per day, containing cloth washings and spent dye liquors, directly into the river. Scoured wool is received a t the plant, where it is dyed and made into woolen cloths. The woolen cloth is fulled, using soap, soda ash, and water. The dyes consist of alizarin dyes, cut with acetic acid, 10 pounds of acid per 1000 gallons of water. The waste consists of about 6000 gallons of dye liquor and 15,000 to 20,000 gallons fulling liquor a day. The plant expects t o connect into the h-orristown sewer. As the plant is not now in operation, no treatment was recommended. Plant No. 20 manufactures worsted yarns and uses 50,000 gallons of water per day. The wastes consisted of about 10,000 gallons of wool-scouring liquor and 40,000 gallons of boiler water per day. I n May, 1928, it was decided to install centrifuges and recirculate the water. This system is now in operation. The main feature of the process is a centrifuge system for the continuous purification of the scouring liquor in the first bowl of the scouring treatment. Dirt is removed from the scouring liquor and wool grease is recovered. This can be sold under favorable market conditions. The consumption of the soap is reduced about 60 per cent, and of sodium carbonate 50 per cent. The quantity of discharge is between 10 and 20 per cent of that formerly thrown into the stream. The action of the scouring liquor in the first bowl is kept a t a satisfactory value by the use of soap and soda. The action is tempered by the organic compounds removed from the wool and the wool grease itself, giving a final product which is softer and easier to handle. The entire process is a closed one. In the first scouring bowl, instead of being discharged into the river, the water is now pumped into a tank and fed to a bulk centrifuge, where the grease and insoluble dirt are removed. The liquor is continuously thrown from the bowl by a nozzle dipping into the surface of the rotating liquid. This carries it t o a supply tank, where it goes to the supercentrifuge. I n this centrifuge more grease and fine dirt are separated, which are continuously discharged into buckets. This purified scouring liquor flows to a sump and is pumped back to the first scouring bowl. The bulk centrifuge pumps a t a higher rate than the supercentrifuges, and the excess dirt-free liquor flows through the overflow line to the sump, where it is pumped to the first scouring bowl, thus forming a continuous closed process. This does not remove the soluble impurities, and i t is necessary periodically or continuously to discard a portion of this liquor to prevent an excessive accumulation of these compounds. This is discarded from a point of the process containing the least amount of grease and insoluble dirt, and it is therefore least objectionable from the standpoint of stream polIution. Fresh water is added t o make up these losses. The dirt is removed from the bulk centrifuge by a hydraulic
2700
2600
1.50
60
10
20 86 30
91 240
240 13 357 66
14 33 6
1622
8S2
43
600 22,750 8060 22.560 8040 190 20
294 300 1230 924 785 750 44.5 174
i 4 7 2 3 260 130 38 11 222 119
2610 in50 9420 6400 1Oi2 886 8348 5514
1133 1150 9835 6895 92 6.5 743 6820
24 430 335 4 3 426 332
(a
2270
44
54-A 56-A 56-E 47-C 53-.4 5-24- 12-2@ 12-27-11-27-11-2729 29 29 28 28 5.7? 7.1 6.3 0
0
6.0 1460 279 135 5000 1100 37,740 7735 700 400 20,990 303 3385 700 16.750 4330 397
+
510
850
20 40 0
20
12 0 780 435 164 139 616 296
3 0 950 605 18 16 932 399
unloader in a putty-like cake. This cake is very obnoxious, and was responsible for a large percentage of the pollution load on the stream. The grease collected in the supercentrifuge is washed to remove soap and produce a dry grease, which is barreled for shipment. This wash water is discarded into a cesspool and leaches its way out. The bulk centrifuge has to be cleaned about once a n hour when using a very dirty wool, and about once in 4 hours for clean wool. The bowl of this centrifuge holds about 200 pounds of dirt. I n scouring an average grade of wool there are now added for replenishment about 25 pounds of soap and 5 pounds of soda per 1000 pounds of wool. I n the supercentrifuge about 400 gallons per day are discharged to prevent the accumulation of the soluble material in the bowl, and about every 4 weeks the entire contents of the first bowl are purified and discarded. About 30 pounds of commercial wool grease are recovered for each 1000 pounds of wool scoured. This has a present value of from 4 to 6 cents a pound. About 93 gallons of liquor are discharged per 1000 pounds of wool scoured or about 550 gnllons per day, compared with the former discharge of 10,000 gallons per day. The company installing this equipment estimated it would save about $6000 per year. This was based on a short run so is merely an indication of its possibilities. This process gives promise of success in this operation. I t is not, however, a t present entirely free from polluting discharges. The sludge in time will accumulate so that it will have t o be discharged in some manner, and the small amount of liquor discharged into the cesspool has a very high oxygen demand. A typical analys's of wool-scouring liquor formerly discharged direct into the canal is shown in 20-A. An analysis of the discharge of the high-speed centrifuge is shown in 20-B. The character of the seepage from the cesspool into the river is shown by 20-c. Plant N o . 21 is engaged in the general pork slaughterhouse, and packing business, and discharged into the canal about 8000 gallons per day of liquid wastes, containing slaughterhouse wash water and fats. I t also emptied pieces of the intestines directly into the canal. The water discharged into the canal consisted of that used to wash the slaughtering floor and hog pens, that used in curing the meats, and scrub water used in cleaning meats. Sal soda is used in cleaning the floors. Most of this water passed through a catch basin, 21/2 by 5 feet, before entering the canal. This basin is too small for the amount of liquid passing through it, and only retains part of the small fleshy pieces. One hundred and fifty to three hundred hogs were slaughtered and dressed every Monday, Wednesday, and Saturday. The canal during the slaughtering and cleaning was in a very bad condition. The blood washed from the floors gave a decided reddish tinge to the canal and the soda created a nasty scum, which could be followed down the canal to the locks. Some of the scraps of flesh were caught in the catch-all, as they tried to retain these and the major portion of the blood for converting into fertilizer. This plant was refused admission into the borough sewer. No satisfactory method of disposal was attempted and a suit in equity was instituted; thereupon, they ceased slaughtering and continued packing, purchasing the dressed hogs from a company in Philadelphia. Coincidently with this an increase of grease and fleshings was noted in the tanks a t the Northeast Sewage U'orks, which receives the waste from the Philadelphia packing company. This is the present method of operation, and removes the major portion of their pollution from the canal, but transfers it to the Delaware River through the Northeast Sewage IVorks. The present curing water consists of saltpeter, sugar, and salt, and is dropped into the sewer outlet. -4nalyses 21-A, B, and C are typical examples of this waste.
INDUSTRIAL A N D ENGIiVEERIiVG CHEMISTRY
are manufactured
screen type, Znd the oth& half is beina recirculated.
Figure 3-No.
.
..
Thirty thbusaLd racons of water are use2
This has
31 Cannl Sfarf of Slauahterhoure Discharm: Plant No. 21
Plolrt h'o. 23 manufactures airplane tubing, metal tcnnis racquets, fishing poles, etc. I n the process of manufacture they are immersed in a oickline bath and finallv in limewater. which coatinn arrests & m o s p k c action. Pickline tanks are dumped twice wrrk, and contain 2 to 3 per cent of free acid, the total quantity being 3000 gallons weekly. This was dumped into a small stream dischareine into the Brideeoort Canal. The company first attemptid io neutralize thc li&& in the tanks by throwing in lump lime. This was not a succcss. Thcy are now working on an acid recovery process. This is the only company which has w e r refused permission to the River Patrol to inspect their plant during the allcged erection of their recovery plant, as they said they nere crrmplying with the requirement3 of thc Sanitary Water Board. They estimate the cost of this recovery plant a t about S4.11100. T o date this plant has not heen completed, hut they say it will be iti operation in the near future. This waste is discharged with the water from their cooling and other general plant operations. Analysis 28-A repmsents a sa.mPlc of this wastc while disclrarging a tub of pickling liquor. This comhined waste was about 35,0(!l!aallons per day.
a
plant No. ti outlpt; di&harging &uring-wool liquor, spent dye liquors; No. 4, one hundrrd outlets, consisting of wartcs from boiler houses, dye vats, paper-mill, condensite fiber dust, small amounts of phenolic wastes; No. 21, twenty-five outlcts, discharging boiler-house wastes, curing liquoxs, offal, wash water from slauehterine floors: one nrivate sewer; No. 22, two outlets ite: and a small stream enters the canal. upon which & situated t h e N o . 28, which discharges spent pidrling liquors, and No. 10, which discharges scouring liquor and spent dye wastes.
Vol. 22, No. 6
of 79 per cent; oxygen demand 15,000 p. p. m. (wet); solid matter 21 pcr cent, of which 44 per cent was volatile. On the dried sample the nitrogen content as ammonia was 1.1 per cent; ether-soluble, 8.7 per cent. Analysis 31-A represents the outflow from this canal while i t was being drained. Plant No. 44 manufactures ruhher tires and tubes, and also operates a small rubber-recovery process, using sulfuric acid. T h e total discharg? equals 250,000 gallons per 8-hour working day, consisting mainly of cooling water with 2000 and 3000 gallons of acid waste. When the recovery plant was installed, it was planned to pass the acid waste over a limestone trickling filter. This was not effective. This recovery plant digested the scrap rubber with 12 per cent sulfuric acid t o remove the fabric. The rubber was then washcd frcc of acid. This pracess has reccntlv becii abandoned so the waste is now only the cooling water. Analysis 44-A is rcprcsentatve of thc combined effluent with thc recovery plant in operation, while 44-B is an analysis of thc present discharge. Plant No. 47 reclaims rubber from rubber tires, inner tubes, galoshes, etc., by the use of sodium hydroxide solution. This solution is recirculated and restrengthened until it is unht for iurthcr use; then it is discharged into B large lagoon or pit, together with the water used in washing the digested material. This pit is an acrc 01 more in area, and serves as an excellent sedimentation basin. Thc outlct is dammed with a bed of cinders 8 to 10 feet thick and 10 feet high The discharge seeps throunh this bed of cinders bcforc enterine the idant drain lint.
factory tr&tmcnt has yct been worked out. The company i s now vorking on a dry process, which will be the reverse of the present method~---thatis, take out the rubber by solvents, leaving thc fabric. The quantity of discharge and its oxygen demand have been cut down. This plant is earnestly endeavoring to solve the prohlrm. The deposited material in the lagoon is recovered and reworked, and is greatly in demand hy a certain customer. This waste is diluted with cooling water to about 3 million gallons per day and discharged into a creek. Analysis 41-A represents the discharge into the pit; 47-B, that leaving pit; and 4i-C, thc combined effluents entering the Stream. Plant No. 53 consists o< an upper and lower mill, making corrugated and solid fiber containers and box hoards from waste paper, newspapers, paper stack clipping, etc., to the extent OF 500 tons per day. This is mostly plain stock, but some is colored. ' pounds of pulp per The rffluent to the rivm carried I l l ? to 2!2 1000 g?llons of water. About 230 g~llonsper minute werc discharged from the lower mill and 870 gallons from the upper mill. This plant has installed a closed system in the lower mill, which has heretofore proved unsoccessfnl bccanse of the accumulation of a fungous growth or slime. This has b ~ e i lovercome by using chlorine and maintaining a residual content of 0.75 to I p. p. m. A small amount of lime is added to prPcipitatc some of the soluble matwial The upper mill is still discharging its waste into the rivcr aftor parsing it through a rotary save-all. Experiments on chlorination of this waste showed this not t o he worth while. Thc comnanv is nlannine to erect a new huildine. when this waite will I> r&ircuiated ; as-in the loner mill. Thys plant is in the City, but above two of the city intakes. Analysis 53-A shows the character of thc ijresent discharge. Plml No. 54 manufactures special electrical conduits and fittings. Steel is rolled, welded, squared, pickled, and enameled. Soda ash, acid-pickling. and lime baths a~ used in the process. All wastes, amounting to about 5!)011 galloils per neck, were run inLo a pit, which was stated to havc no direct outlct to tlic river, but seeped away into the ground. The introduction of "ranine into the pit showed that it had an underground passagr to the rivcr, as the dye appearcd in the river 35 or 20 feet away i n about 10 minutes. I t was finally ascertained this was an old ditch. which had bcm filled with stones and covered with earth. T o neutrulizc this waste the company constructed a concrete tank. lining linine it with acid-resisting acid-resistine brick covered with pitch. Ditch. .4n tank, abundoned"Dicklmr
