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vary greatly for a given dye waste. With the acid treatment, some hydrogen sulfide evolved, but far less than with acid and aluminum sulfate treatments. Treatment of this particular waste would require about 33.5 pounds of acid and about 17.8 pounds (8.0 kg.) of ferric chloride, or its equivalent in ferrous sulfate, per 1000 gallons (3785.4 liters)
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Figure 2-Effect of Temperature on Sludge Concentration
of waste, or roughly a ratio of 1.9:1 by weight. This ratio does not correspond to the ferric chloride sold a t present, which contains acid, and part of the acidification would require some technical sulfuric acid. This can be added without deleterious effects. Discussion
The amount of chemicals and subsequently the cost of complete clarification accompanied by rapid settling is rather high. There are several ways of reducing the cost, by partial treatment of the waste for removal of most of the color, followed by subsequent treatment for complete clarification. It should be remembered that the experiments
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were made on w r y concentrated dyeing vat discharges, and that the wash water would require far smaller amounts of chemicals if its clarification is desired by chemical precipitation. Very good settling results with only a slight color in the supernatant can be obtained with half the quantity of chemicals. This blackish tinge, however, would be sufficient to produce an undesirable color in a stream which receives a heavy load of the treated waste water. Partial chemically treated waste discharged into a sewer would affect the sewage plant. I n case of an activated sludge plant, the color would be adsorbed by the floc, as would occur in a trickling flter, except that the adsorbed color would leave the bed together with the solids during sloughing, making the sloughing period worse. In case no sewage plant is available, the partially treated sewage could be run through pressure filters or the color absorbed on charcoal. This, however, would depend entirely upon the cost of complete chemical treatment as compared with partial treatment followed by absorption. Since cost of chemical treatment is comparatively high and the dye bath usually discharged does not give a deep enough color after immersion of the goods, but still contains considerable amounts of valuable salts and dye, it would be possible to have a pre-storage tank into which the dye waste is pumped, An analysis of the stored material would probably show a fairly constant composition and would have to be made only a t infrequent intervals. No field chemist would be required, since the occasional analyses could be made by an outside firm if no facilities were available. After chemical treatment of the waste, settling is required, producing a heavy, mostly inert, material which can be disposed of by using to fill in low land. Acknowledgment
The investigations reported were conducted with a general grant of the Chemical Foundation, Inc., for fundamental studies in sewage treatment and waste purification.
Composition of Kapok Seed' E. P. Griffing and C. L. Alsberg FOODRESEARCR INSTITUTE AND DEPARTMENT OF CHEMISTRY, STANFORD UNIVERSITY, CALIF.
HE oil and fiber seem to be the only constituents of kapok seed of which chemical examinations are reported in the literature. The statements concerning the composition of the oil are confusing, no doubt because the seeds of several quite different trees are marketed under the same or similar designations. Ceiba pentandra (L.) Fahlberg (synonyms: Eriodendron anfractuosum DC., Bombax pen.tandra L.) is the tree that furnishes most of the fiber and seed in world trade, for it is the species that is grown upon the island of Java, the most important producing region. While on a recent visit to that island, one of the writers had the opportunity to collect authentic samples of a pure strain of seed, the chemical examination of which is reported herein. The oil was analyzed by R. S. McKinney, of the Oil, Fat, and Wax Laboratory of the Bureau of Chemistry and Soils. The seeds were carefully hulled by hand, so that a clean separation was obtained with very little loss. The meats or kernels constituted 49 per cent of the seed. Since this is 7 to 8 per cent lower than the figures given in the literature,
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Received April 29, 1931.
another portion was similarly treated, still more care being taken that not a trace of the meats was left sticking to the hulls. With these precautions, a yield of 55 per cent of meats was obtained. Tests for Gossypol
Kapok belongs to the family Bombaceae, which has been considered a subfamily of the Malvaceae, to which cotton belongs, but is now generally recognized as worthy of family rank. Since kapok is related to cotton and since the chemical and physical constants of its seed oil resemble those of cottonseed oil, and since, like cottonseed oil, kapok-seed oil gives the Halphen reaction, it seemed desirable to test the seed for gossypol. Kapok press cake is certain to be used more and more as a feed, so that it is important to know whether or not it contains gossypol, the toxic principle of cottonseed. Both hulls and meats were tested according to the method of Caruth (1). The materials were extracted with petroleum ether for a day in a continuous extractor. The extracted material was then dried and extracted in the same way with ether. The ether extract was treated with one-third to one-half of its volume of glacial acetic acid.
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Upon standing several days, no gossypol acetate could be detected even with the microscope. There were present highly refractive substances, perhaps sterol, which were very bi-refringent under the polarizing microscope, but they had none of the characteristics of the yellow gossypol acetate crystals. A second preparation, when examined under t8he polarizing microscope, contained a few yellowish crystalline substances, but they were so limited in amount that positive identification of them as gossypol was impossible. There is apparently little or no gossypol in kapok seed. Analysis of Oil
Another portion of meats, containing 5.7 per cent of moisture, was extracted with petroleum ether, and the extract, after evaporation of the solvent, amounted to 39.9 per cent of the meats. It was a viscid, almost colorless oil of about the consistency of glycerol. No stearin separated from this oil a t room temperature in the course of 2 or 3 weeks. The test with Halphen’s reagent gave an intense ruby-red color, very much more striking than with ordinary refined commercial cottonseed oil. It may therefore be stated that reports that t’he seed oil of C . pentundra (E. anfracfrtosttm) does not give the Halphen reaction (4) are in error. The analysis of the oil extracted by petroleum ether gave the following results: Specific gravity a t 25’/25’ C . . . . . . . . . . . . . . . . 0,9225 1.4691 Refractive index at 25’ C . . . . . . . . . . . . . . . . . . . Saponification value.. . . . . . . . . . . . . . . . . . . . . . 191.6 Iodine number (Hanus).. . . . . . . . . . . . . . . . . . . 94.1 Unsaponifiable matter,’per cent. . . . . . . . . . . . . 0.94 Acid value.. .............................. 9.65 Saturated acids, per c e n t . , . . . . . . . . . . . . . . . . . 17.15 Unsaturated acids, per c e n t . . . . . . . . . . . . . . . . . 76.:32
With the exception of the specific gravity and acid value, all determinations were made in duplicate and closely agreeing results were obtained in each case. From the iodine number and the percentage of unsaturated acids, it was calculated that the oil contained 49.62 per cent of oleic acid and 26.70 per cent of linoleic acid. It will be observed that kapok-seed oil contains a much smaller quantity of saturated acids than cottonseed oil, which contains from 23 to more than 25 per cent. As is t o be expected from the lower iodine number, kapok-seed oil has much less linoleic acid than cottonseed oil. N a t u r e of Proteins in Seed
I n order t o determine the general character of the proteins of the seed, the meats, extracted first with petroleum ether and then with sulfuric ether, were dried a t room temperature, ground to pass a 60-mesh sieve, and then extracted successively three times with distilled water, three times with 5 per cent sodium chloride solution, three times with 10 per cent sodium chloride polution, once with 0.3 per cent sodium hydroxide solution, and once with 60 per cent alcohol, The amount of nitrogen extracted by these solvents was determined as well as the amount in the original meats and that left in the residue after extraction. The extracts were separated from the undissolved material by centrifugation. The decanted supernatant fluid was then filtered through hardened filter paper by suction; all the extracts, nevertheless, remained somewhat opalescent, undoubtedly a source of a slight error. The distribution of nitrogen, as determined by the Ter h,leulen-Heslinga method ( 2 ) , was found to be as follows: 7
Moisture content.. . . . . . . . . . . . . . Total nitrogen.. . . . . . . . . . . . . . . . Water-soluble.. . . . . . . . . . . . . 21 .O NaCl (5~o)-soluble... . . . . . . 45.0 NaCl (10%)-soluble. . . . . . . . 3.5 Alkali (0.2y0 Na0H)-soluble 3.9 0.9 Alcohol (60%)-soluble. . . . . . Undissolved. . . . . . . . . . . . . . . 28.0
0
% 8.90 9.05
The figure for nitrogen remaining unextracted in the residue is probably too high, because the residue was inevitably slightly contaminated with filter-paper fibers, which made sampling unsatisfactory. This is probably why the nitrogen of the table totals to more than 100 per cent. The determination of nitrogen distribution was repeated in the same manner, except that after removal of the oil the residue was heated for a short time a t 100” C. to dry it. This may have rendered some of the protein insoluble in water and salt solution, thus increasing the amount soluble in sodium hydroxide. Extraction with 60 per cent alcohol was omitted and extraction was made only with 15 per cent salt solution. The results were as follows: Moisture content., . . . . . . . . . . . . . Total nitrogen.. . . . . . . . . . . . . . . . Water-soluble.. . . . . . . . . . . . . NaCl (157,)-solubIe.. . . . . . . Alkali (0.2% Na0H)-soluble Undissolved., . . . . . . . . . . . . .
% 16.50 41.15 13.45 27.10
% 8.19 8.36
The figure for water-soluble nitrogen is probably too low owing to an error of manipulation. This is probably the reason why the total is less than 100 per cent. The water extract contains an appreciable amount of globulin, for it yields a precipitate when somewhat more than half saturated with ammonium sulfate. A precipitate also forms on dialysis. Whether it also contains albumin could not be determined with certainty; if present, it can only occur in slight amount, The salt extract contains an abundance of globulin which is completely removed by dialysis. The filtrate from the precipitated globulin contains no appreciable amount of protein. The globulin is also precipitated a t a little above half saturation with ammonium sulfate. Attempts to separate the globulin into two fractions, as was done by Jones and Csonka (a) for cottonseed, failed. Possibly with more material than was available such a separation might succeed. On heating, the salt extracts behaved somewhat in the manner described for cottonseed by Jones and Csonka (3). At about 55” C. the extract became cloudy. It was filtered and heated further. The filtrate became opalescent above 90” C. The glutelin extracted by alkali was not further studied. None of the proteins extracted were purified, nor was the non-protein nitrogen determined. Kevertheless, it may be said that the distribution of nitrogen in kapok seed is similar in a general way to that of cottonseed as determined by Jones and Csonka. The only apparent difference is that kapok seed probably contains more nitrogen in a form extracted neither by salt solution nor by dilute alkali. Like cotton seed, kapok seed contains principally a globulin or mixture of globulins, and a glutelin. It contains no prolamin and probably no albumin. Its globulins are difficult to coagulate by heat. Literature Cited (1) Caruth, F. E., J . Am. Chem. Soc., 40, 647 (1913). (2) Griffing, E. P., and Alsberg, C. L., Ibid., 63, 1037 (1931). (3) Jones, D. B., and Csonka, F. A.. J. Bioi. Chem., 64, 673 (1925). (4) Lewkowitsch, J., “Chemical Technology and Analysis of Oils, Fats, and Waxes,” 6th ed., Vol. 2, p. 185. Macmillan, 1921.
Correction-In the article on “Products of Corrosion of Steel,” by H. 0. Forrest, B. E. Roetheli, and R. H. Brown [IND.ENG. CHEM.,23, 650 (1931)] the authors state that the next to last sentence in the last paragraph of the synopsis should read “when the pH in the liquid film is allowed to build up because of slow diffusion of hydroxyl ions from the liquid film to the main body of the liquid (due to poor agitation), ferrous hydroxide will be precipitated and subsequently magnetic oxide of iron will be formed.”
