INDUSTRIAL AND ENGINEERING CHEMISTRY
April 15, 1931
Table VI-Wastes
from Corn Products RefininQ - Comvanv - -
CARRON SAMPLE
Total
Organic
P. p . m.
123
TOTAL NITROGEN
Free COz plus carbonate
z;gfg, C.
ORGANICCARBOXORGANIC CARBON TOTAL NITROQEN TOTAL NITROGEN B. 0. D. B. 0. D.
~~~~
P. p . m.
P. 9. m.
P. fi. m.
1
310.2 301.4
P. p . m. 310.2 301.4
0.0
3.7
480
82.0
0 63
0.008
2
340.4 319.2
340.4 319.2
0.0
10.4
445
31.7
0.70
0.023
3
310.3 302.4
310.3 302.4
0.0
9.6
475
31.9
0.65
0.020
4
346.8 346.3
346.8 346.3
0.0
10.4
510
33.3
0.60
0.020
5
430.3 420.5
430.3 420.5
0.0
10.4
560
40.9
0.70
0.00s
6
383.3 406.2
383.3 406.2
0.0
14.0
620
2s.1
0.63
0.023
7
541.2 546.5
541.2 546.6
0.0
12.0
775
45.3
0.70
0.016
8
583.8 572.4
583.8 572.4
0.0
12.0
980
48.1
0.60
0.012
Av.
403.8
403.8
0.0
10.3
606
42.7
0.65
0.016
sludge effluent with a carbon-nitrogen ratio of 11.8 and a carbon-B. 0. D. ratio of 4.1 is in a different stage of oxidation and cannot be compared directly with the raw sewage or trade wastes. T a b l e VII-Comparison of Carbon-Nitrogen, Carbon-B. 0. D., a n d Nitrogen-B. 0. D. Ratios
Ratio organic carbon to nitrogen 42.7 Ratio organic carbon to 0.65 B. 0. D. Diff. fromaverage, % 6.6 RationitrogentoB. 0. D. 0.016 Diff. from average, 84.0
vo
6.9 0.64 5.0 0.094 6.9
4.0 0.55 10.0 0.143 41.5
3.96 0.59 3.2 0.151 49.5
14.4 0.61 6.1 0.101 45.5
As we would expect, we find no correlation between the values found for the nitrogen-oxygen demand ratios from
Effect of Light on Determination of Ethylene‘ J. Louis Oberseider and J. H. Boyd, Jr. THEATLANTIC REFINING COMPANY, 3144 PASSYUNK AvE.,PHILADELPHIA,PA.
THE course of the determination of ethylene in gaseous IatNatmospheric mixtures of paraffin and olefin hydrocarbons, separated pressure from cracked oils, inaccuracies may occur in the analysis because absorption in bromine water continues slowly after many passes if the apparatus is exposed to direct daylight or artificial light. To the knowledge of the authors, there is no mention of this phenomenon in standard texts (1, t?,3, 4) on gas analysis. The analyses were made in a modified Bureau of Mines Orsat apparatus. Acid gases and unsaturates, with the exception of ethylene, were absorbed in a 30 per cent caustic potash solution and an 87 per cent sulfuric acid, respectively. Ethylene was then determined by bubbling the gas three times through a Williams pipet containing a 33 per cent saturated solution of bromine water at an approximate 1 Received
November 29, 1930.
the sewage and trade wastes. These ratios vary from 0.016 to 0.151. The nitrogen-oxygen demand ratios for the different wastes seem to be similar only when the carbon-nitrogen ratios are similar. For instance, the nitrogen-B. 0. D. ratio for tannery waste is 0.151 and for raw sewage 0.143, whereas the carbon-nitrogen ratios are 3.96 and 4.0, respectively. The carbon-oxygen demand ratios are 0.59 and 0.55. When we compare corn products waste and raw sewage with carbonnitrogen ratios of 42.7 and 3.96, we find the nitrogen-oxygen demand ratios of 0.016 and 0.143, whereas the carbonoxygen demand ratios are 0.65 and 0.55. The total carbonoxygen demand ratios are not constant because of the variation in the free and combined carbon dioxide. Literature Cited (1) Bauer, O., and Deiss, E., “Sampling and Analysis of Iron and Steel,” p. 131, McGraw-Hill, 1915. (2) Friedemann, T. E., and Rendall, A. I., J . Biol. Chem., 81,45 (1929). (3) Schollenberger, C. J., J. IND. ENG.CHBM.,8, 1126 (1916). (4) White, J. W., and Holben, F. J., I b i d . , 17, 83 (1925).
rate 6f 15 cc. per minute, and subsequently through caustic potash solution to remove the bromine vapors. This should remove the ethylene from most gases, and repeating the operation should remove no more gas. With direct daylight shining on the apparatus, however, absorption continued even after making fifteen passes. By painting the Williams pipet black except for a narrow vertical strip, and shielding the buret from direct light, complete absorption was obtained after three or four passes. The cause of the continuous absorption in the presence of direct light is believed due to the well-known reaction between bromine and the heavier paraffin hydrocarbons. Some evidence in the support of this was obtained by passing a sample of n-butane through the bromine solution in the presence of direct light. Absorption was still taking place after ten passes. Using the shielded pipet no absorption took place. Literature Cited (1) Dennis, L. M., ”Gas Analysis,’’ MacMillan, 1920. (2) “Gas Chemist’s Handbook,” American Gas Assocn., 1922. (3) Parr, S. W., “The Analysis of Fuel, Gas, Water and Lubricants,” McGraw-Hill, 1922. (4) White, A. H., “Technical Gas and Fuel Analysis,” McGraw-Hill, 1920.
