T H E J O U R S A L O F I N D U S T R I A L A N D ENGIXEERILVG C H E M I S T R Y stable and containing nitrates equal t o 1:j parts per million. We have a t times studied filtration of these effluents, however. It is not m y purpose in the present paper to review all the Lawrence work along this line but to give some comparative results obtained during the past six or eight months by the two ways of working the process followed a t 1,awrence. The comparisons are made with two aerated slate tanks containing sludge and growths, Kos. 449 and 449B, and two activatedsludge tanks, so called, Kos. 46j and 482. These tanks hold only I I C to zoo gallons of sewage, each. The results appear in Table I. From Jan. I O t o bIarch 29 (3-cycle period with one-hour sedimentation a t the end of each period in Tank No. 4651, there were periods when a digestion of sludge occurred and the albuminoid ammonia in solution in the tank effluent averaged TABLE I-COMPARATIVE
h-0.
449 449B 465 482
(a) (b)
slightly greater than 40' F. and activated-sludge tanks were operated a t different temperatures, that of Tank 465 averaging O F. and of Tank 482 averaging j j F. Little difference in results T w s notqd a t first a t these temperatures, but a period of digestion of sludge occurred during a portion of the winter in activated-sludge Tank 465 and much organic matter wect into solution. On the whole, except for this period of several weeks when the organic matter of the sewage in Tank 4 6 j was going into solution, the effluents from these two activated-sludge tanks operated a t different temperatures were about equal, showing a general clearing ol the effluent, and 80 per cent of the samples stable. The work of the slate tanks during the winter period were much better, showing removals of j o to 60 per cent of the organic matter and practically every sample stable.
RESULTS:.kEKATED SLATE TANKS(NOS. 449
AKD
449B)
AXD
ACTIVATED-SLUDGE TAKKS ( N O S . 465
CUBIC FEETOF AIR USED Period of Per Per million Date of Treatment Aeration Hour aals. Treated July 1 to Oct. 6. 5 hrs. 50.000 250 000 Oct. 6 t o Feb. 15 6 hrs. 50,000 300:OOO Feh. l 5 to Mar. 29 3 hrs. 250,000 750,000 45OF. (a) 10 hrs. ( b ) 500,000 42' F. Oct. 6 to Jan. 10 (Period of settling, 1 hr.) 250,000 3-hr. Sample 750,000. 8-hr. Sample 2,000,000 55' F. Jan. 11 to Mar. 29 (Operated same as 465) Tank 449B receives effluent from Tank 449. Nitrification to 2.5 parts per 1,000,000. Total aeration period including aeration in Tank S o . 449.
TANK
AV.
Winter Temp. 41" F.
66 per cent greater than the albuminoid ammonia in solution in the sewage entering the tank and 1 2 per cent greater than the total albuminoid ammonia in the sewage entering the tank. This phenomenon was a t first a rather disquieting element in this investigation but its causes were easily contro!led. If these figures are compared it will be seen that a t Lawrence the results are about as follows: The slate process, as exemplified by Tanks 449 and 449B.gives considerably better purification in I O hrs., calculated upon removal of organic matter, than activated-sludge Tank 4 6 j in 3 hrs. and practically the same as Tank 465 in 8 hrs. By the slate tank method only 66 per cent as much air is used in I O hours as by the activated-sludge tank in 3 hrs. and only 37 per cent as much as is used by the activated-sludge tank in 8 hrs. Both methods give stable effluents, generally speaking, the slate-tank method requiring generally more time to accomplish this result but less air and the efRuent of the activated-sludge tank being the clearer in appearance. During the winter, as shown in the tables, the aerated slate tanks were operated a t temperatures
T-01. 8. NO. 7
AND
REDUCTION(IN PERCEKTAGES) ALBUMINOID .hlhlO~IA Oxygen susFree To- Dis- Con- pended "3 tal solved sumed Matter .. 40 46 57 65
..
..
..
..
59
88
86
80
80
49 63
$4
22
sx68
;;
48
49
..
74 63
STABILITY OF
EFFLUEXTS
Percentof SamDles Stable
..
11
."
482)
,
.
75
(3 cycles) (1 cycle) (3 cycles)
78 100 100
.. 86 100 100
At Lawrence the sludge from both methods has lost the offensive characteristics of sewage sludge; it is more dense, that is, more easily drained, and more or less granular when dried. It is of greater agricultural value, not only on account of the changes mentioned and increased nitrogenous contents, but also because a large percentage of the fatty matters present before treatment is destroyed. The governing factors in the success of this process of sewage treatment, as I have stated in previous articles, are: ( I ) The cost of power for supplying the large volume of air necessary; ( 2 ) a sewage that readily yields itself t o this method of treatment. It is not impossible to believe that certain selvages cannot be purified in this manner. In conclusion, I wish to state that we cannot a t Lawrence work out certain points in regard to such a method, these needing experiments upon a larger scale. It is probably true, however, that the method as first carried on by us a t Lawrence, without the use of slate, is the more practical. STATEDBPARTXENT O F HEALTH,BOSTON
CURRENT INDUSTRIAL NEWS HOT MECHANICAL PULP All attempts to make hot ground pulp with the aid of old or weakly constructed apparatus are futile, says the Paper-Maker. I n one mill experiments have been made in this direction but failed and were even dangerous t o life owing t o the bursting of the stones which, for want of axles thick enough, could not stand the increased pressure. Since, however, new machinery has been built for making hot pulp, the manufacture proceeds steadily and without trouble. The advantage of the hot grinding process compared with others may be recognized by the fact that four or five mills were hardly able to take care of the resultant coa.rse stuff, whereas nom- a single mill handles it easily. For tissue papers of less than 18 g. per sq. meter weight and which must contain 2 5 to 30 per cent of mechanical pulp, i t is advisable t o allow the pulp-wood logs that are to be converted into hot mechanical pulp to soak for some time before grinding in hot mater, The mechanical pulp thus obtained is exceedingly
feltable and like wadding, so that on open, as well as on automatic machines, steady working and a very strong product will result. For the production of cheap kinds of imitation parchment, such a previously warmed stuff is to be highly recommended. The pulp combines more intimately, is not so plainly visible and the sheet of paper possesses remarkable toughness.-hIcMILLAx. BEST OIL FOR DIESEL ENGlNES The best results with Diesel engines are obtained, says the Setional Petroleum A-ews, with an oil of between 20 and 40' Baume gravity. Oils with a higher gravity have a flash point too low for cheap storage and also do not furnish as many heat units per gallon, while an oil with a gravity below this is usually not fluid enough to be piped in cold weather without heating. Oils as heavy as 14' can be used if precautions be taken in heating, so that the oil can be readily handled and the lighter dis-
July, 1916
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
tillates not driven off. The oils used should have a fairly uniform distillation curve and practically all should distil a t from 7 0 0 to 9oo°F. The best fuel should be between 150 to 250°F. as regards flash point. An oil with a flash point less than 150’ has to be treated with great care in storage because of the pro.portion of light oil in it, while an oil with a flash point greater than 250’ causes trouble in starting or running with a variable load. Further, the oil should contain no water and the storage a t plant should be arranged so that water will drain off. Again, good Diesel engine oils should not contain over a very small percentage of sulfur as this burns to sulfur dioxide and, as sulfurous acid, attacks the metal. Fuel-oil should be free from solid matter although this can be removed by oil filters which should be used in conjunction with all heavy oil engines. Oils with a large percentage of asphalt can be used successfully, provided there is thorough preparation of the fuel before being injected into the cylinder. With the semi-Diesel or what is known as the hot bulb type of engine, there are some limitations t o the oils which may be used, as the tendency of most oils when brought into contact with the hot bulb or plate is t o “crack,” leaving a solid residue which clogs up the working chamber of the engine. This can, however, be obviated by carefully arranging the temperature of the hot plate to suit the particular oil being used.-M.
TILTING CRUCIBLE FURNACE A new crucible melting furnace of the tilting type has been introduced by the Monometer Manufacturing Company, of Aston, Birmingham, England. One of the features of the furnace is that the combustion chamber is made in the form of an annular chamber concentric with, but situated below the crucible and connected to the melting chamber by inclined ducts. The object of this arrangement is to delay the escape of the burnt gases and to distribute the heat evenly over the crucible so as to obtain simultaneous melting of the whole metal. The furnace takes standard crucibles without special spouts and the arrangement for pouring is such that the pouring lip does not deviate more than l / 8 in. from the vertical so that the contents can be poured into a r-in. hole until the furnace is emptied. The tilting mechanism consists of a transverse shaft a t the back of the furnace, a toothed wheel on the shaft and a high-speed silent chain which connects the wheel and the furnace body, and is accommodated in a quadrantal grooved runway on the bottom of the latter. By turning a handwheel the tilting shaft is rotated through reduction gearing, and the chain is wound on the toothed wheel, thus elevating or tilting the body about the axis of the trunnions. Two batteries of nearly 3 0 of these furnaces, intended to be fired with oil, are being constructed for use in melting copper, brass, nickel alloys and other metals a t some newly-erected works.-M.
THE UTILIZATION OF WASTE HEAT IN ENGLAND The growing attention that is being paid to methods of utilizing the large quantity of surplus heat which is everywhere a byproduct of British manufacturing is a hopeful sign. A public discussion on this question took place recently a t Sheffield, England, and attracted the attention of representatives of the iron and steel trades and scientific men, as well as those associated with gas, electricity and colliery undertakings. The suggestion that there should be established a Government Department to control the supply of power and electric current is’a somewhat drastic one and not likely to be accepted unless a very strong case were advanced in its favor. On the other hand, the proposal to harness all the energy of the South Yorkshire coal field, a t present running waste, and to employ it in the form of gas or electricity in the iron and steel trades of the district has certainly much to be said for it. This would mean that the individual manufacturer in the Sheffield district would
cease to provide his own power plant but would draw supplies from a large central station which would generate current from the waste energy available in the local coal field. If this plan were carried into operation, it has been calculated that manufacturers in the district could be supplied with current for power purposes a t one-half cent per unit.--M.
SUGGESTED SOURCES OF SULFATE OF AMMONIA A paper on “Kerogen and Kerogen Shales,” read recently before the Institute of Petroleum Technologists, London, by Mr. E. H. Cunningham Craig, contained suggestions as to fresh available sources of sulfate of ammonia. Vast masses of highly inspissated oil sands are known to exist in different parts of the Empire, the most important being the tar-sands of Athabasca. Large areas of material which could be worked from outcrop are also found a t Trinidad and Barbados. The recovery of oil from these deposits has been suggested often but the cost of extraction would be so great compared with the cost of drilling for petroleum that the exploitation of these dried up oil rocks has never been carried out on a commercial basis. If, however, such a valuable by-product as ammonium sulfate could be obtained in sufficient quantity, the working of these oil-sands might prove a commercial success. It has been shown that nitrogen compounds become concentrated in proportion to the state of inspissation, and it has been ascertained that the nitrogen content of such strata as Athabasca and La Brea oil-sands is not negligible. It was the production of ammonium sulfate which saved the Scottish oil shales from extinction through the competition of American oil; in the same way, a yield of this valuable product may be the means of these great oil-sand deposits being utilized and worked a t a profit.-M.
GAS PRODUCTION FROM WOOD IN AUSTRALIA Wood is regularly used, says Bas and Oil Power, in connection with gas production in many of the smaller Australian gas works.’ Only certain classes of timber are suitable, the best being those of the box and red gum varieties intermixed with coal to the extent of 25 per cent. The resulting gas is said to offer advantages over ordinary coal gas, chiefly owing t o the elimination of naphthalene, while there is a reduction of the scurf deposited on the retort walls. In Australia, the average yield of gas amounts to IZ,OOO cu. ft. per ton of wood carbonized. The charcoal is usually separated from the coke and made use of for heating the retort furnace. When employed for power purposes, wood gas is usually made from waste material such as sawdust, shavings, or even leaves, and, except for detarring and washing, is consumed in the crude form and.un.. mixed with any other gas. The presence of moisture in the wood has an important effect on the results and, if the water content exceeds 60 per cent, preliminary drying of the wood must be resorted to. Wood gas as obtained by distillation in gas works has a calorific value of about 400 B. t. u. per cu. ft., whereas that generated by &tion plant is approximately 160 B. t. u. A system known as the Brook’s dual method is stated in the Times Engineering Supplement to be successful for using wood waste. According to this method, the wood is primarily carbonized in retorts in the ordinary way when a gas equivalent to about 13,000 cu. f t . per ton and having a calorific value of from 375 to 390 B. t. u. is obtained. The resultant charcoal, which amounts t o ‘ / b of the original weight of wood, is then transferred to suction producers and the mixed gas used for power purposes.-M.
JAPANESE DYESTUFFS According to a report in the Chemical Trade Journal, a number of well-known dye merchants of Tokyo, Osaka, and Nagoya have formed a dyestuffs trust called the Kokuryu Kai with
6.56
T H E JOURNAL OF I N D U S T R I A L A N D EYGINEERING CHEMISTRY
offices a t Osaka, with the object of preventing speculative transactions by amateurs, and of regulating the market when the inevitable slump comes. The production of aniline dyes is still increasing but manufacturers still keep the monthly output secret. However, it is thought that the monthly production of aniline oil a t the different works exceeds 60,000 lbs. I n Tokyo alone, there arc four large works capable of producing about 24,000 lbs. per month. Of these, the largest is the Toshima Tokusan Kaisha, m-hich produces from 10,000 t o Ij,ooo lbs. per month. I n Osaka there are large works which devote the entire plant to the manufacture of aniline oil. These are the Sankyosha, the Osaka Chemical Works and the Yura Dye Company, which, between them, produce about 40,000 lbs. per month. I n addition, some small factories have been built a t Kobe and Kyoto, the combined output of which reaches 4,000 lbs. per month. As a result of the extraordinary rise in price, the demand has declined so that dyers’ requirements probably do not exceed zg,ooo lbs. per month, while military requirements absorb not more than 25,000 lbs. in addition. The output, therefore, exceeds the total demand by something like 10,000 lbs. a month. No further increase in the market price of aniline oil is anticipated unless the cost of benzole imported from the United States rises materially.-M. ~~
ANALYSlS OF PRUSSIAN BLUE Xr. James E. Heckel, in Drugs, Oils and Paints, points out the difficulty of estimating iron in Prussian blue by Penny’s method; i. e., by adding mercuric chloride to a solution of the material in acid containing stannous chloride and then titrating with potassium permanganate solution. The method recommended by the above author is to ignite the Prussian blue, dissolve the residue in concentrated hydrochloric acid with sufficient stannous chloride added to give an apple-green tint with chrome oxidized blues or to become colorless with chlorate oxidized blues. Mercuric chloride and manganous sulfate solutions are then added in definite proportions and the combined solution titrated with N/ro potassium permanganate.-M. RUSSIAN RESOURCES COMMISSION A series of monographs is a t present being published dealing with the natural resources of the Russian Empire, under the auspices of a Commission appointed by the Imperial Academy of Sciences of Petrograd. KO. 5 of the series (Petrograd, 1916) treats of natural sources of tungsten and tin ores. The author, P. P. SuSnskij, says that hitherto neither the mining nor the smelting of these ores has been organized on a regular basis in Russia, but that quite recently, in response to the requirements of Russian industry and of the Imperial Defence, Committee, an electro-metallurgical company has been formed in Petrograd for the preparation of special kinds of steel for the admiralty. The article concludes with an illustrated description of the Russian tungsten and tin mints.-M. ~
FERTILIZERS FROM MINERAL PHOSPHATE In the Journal of the Society of Chemical Industry (Vol. 35, No. 4), Ah-. G. S. Robertson brings forward the question of the possibility of procuring phosphate from basic slags and mineral phosphates. He puts forth the plea that these phosphatic bodies might become a fruitful source for fertilizers and does not place much reliance on the usual test for phosphates, i. e., z per cent citric acid test, on account of the low solubility of the phosphatic materials in this solvent. It is further shown that quite as much phosphoric acid can be dissolved out of the minerals as out of the slags if sufficient extractions are made and the mineral ground very finely. Results obtained a t English centers and also in the United States have shown the high value of rock phosphate as a fertilizer.-M.
Vol. 8, N o . 7
JAPANESE SULFUR AND ZINC
It is reported that the high price of sulfur will seriously affect the bleaching industry in Japan. The Hokkaido producers, says a contemporary, have announced the suspension of sales up to the end of June. While the supplies are running short, orders still pour in from Europe and Imerica, and a further advance in price is expected. The brisk export trade has kept the sulfur market on the up-grade since last October. The price of zinc on the Japanese market has also increased a t an alarming rate and several zinc-producing plants have been established to meet the demands as the imports of zinc have almost entirely ceased. By this means, it is hoped that, besides supplying home orders, some shipments abroad may be made. One company in Osaka is now able to turn out zoo tons per month and is preparing to enlarge the scope of its business.--M. ESTIMATION OF NAPHTHALENE IN AMMONIA The naphthalene present in ammonia liquor can be estimated by the picric acid method in the following manner: A known quantity of the solution is cooled in ice water and neutralized by gradual addition of sulfuric acid, cooling being maintained during the process. The liquid is then distilled and about 30 cc. of distillate collected. This is then extracted with ether and the condenser washed out with a little ether. The ethereal extracts are treated with a N / z o solution of picric acid. After being allowed to stand for z minutes, the ether is evaporated under reduced pressure and the residual solution cooled in icewater and titrated with N/IO caustic soda solution with litmus as indicator. Naphthalene is soluble in ammonia liquid containing j per cent NH3 t o the extent of 0 . 0 3 0 g. per 1000 g. of liquid, in a solution containing 100 per cent hTHsto the extent of 33 g. per 1000 g. solution. The solubility is increased if traces of pyridine are present. The distillation of ammonia liquor containing naphthalene results in blocking up the condenser tubes unless the temperature is kept above 303 C.-M.
BRITISH BOARD OF TRADE During the month of May the British Board of Trade received inquiries from firms in the United Kingdom and abroad regarding sources of supply of the following articles. Firms that may be able to give information regarding these things are asked to communicate with the Director of the Commercial Intelligence Branch, Board of Trade, 7 3 Basinghall Street, London, E. C.: Aluminum a n d other bronze powders Bags, p?.per. blue, for sugar Beads, insulating, glass or porcelain Boards, compressed leather, for boot manufacture Boxes. wood fiber, suitable for ointment Bottles, sample, 6 oz. and 8 oz., for oil
Buckles for clothing Buttons, boot, also pearl Cane-pith Celluloid eyelets for boot trade CHEMICALS: Cellulose acetate Ferric chloride Flowers of sulfur Paraphenylenediamine Selenium dioxide Sodium selenite Electric roof lamps for motor cars Frames, nickel, for tobacco pouches Frames, suitable for silk bags Glass t a p s Glass tubing for tubes for aerated water siphons Glassware suitable for mounting with electro-plate Glass chimneys for incandescent burners Handles for tea-trays Hangers chain. for coats Hoops chestnut ;or cask making, hazel or
Leather for football covers
hfACHINERY €+OR MAKING:
Pins, hair-pins, safety-pins Press buttons, all sizes Paper and cardboard Boot-lace braid Margarinb Paper tubes Asbestos roof slates Cardboard, mounts Cement tiles Tin boxes Wire of hexagonal section Wood-Qour Mirrors, small, for Kaffir t r a d e Moorings, rings and tackle, forged in iron or steel hTeedles Paper and cardboard Paper, felt, white Pins Press studs STATIOXBRY:
Rubber bands Envelopes
School books Account books Writing pads Straw-boards Tinder lighters Thermometers for incubators Wicks, lamp Vacuum Qasks
Yarn waste
M.
