Application of a Rapid Chemical Oxygen Demand Test for Determining Organic Pollutions'*
,*+
JANET   B.   PEPINSKY,   NANDOR   PORGES   AND   SAM   R.   HOOVER
;   ' U. S. Department of Agriculture      '•
Eastern Regional Research Laboratory** Philadelphia, Pennsylvania.
A rapid chemical oxygen demand method for determining the strength of organic wastes has been proposed by Porges, Pepinsky, Hendler and Hoover for use in the dairy industry*. Other chemical oxygen consumed tests are available, but they require more time than is desirable for empirical procedures. Dichromate methods similar to those first used by Adeney and Dawson^ and von Fellenberg^ have been developed by Rhame^ and Ingols and Murray*. A further modification has been devised by Moore, Kroner, and Ruchhoft*. The Standard Method approved by the American Public Health Association and the American Water Works Association is based on oxygen consumed from permanganate^. Also available is the Johnson, Halvorson and Tsuchiya modification^ of the iodic acid method. Previous reports give the use of a modification of Rhame's procedure which was developed by Eldridge*. This report constitutes a study of the accuracy of the method and its sensitivity to variations in experimental procedure. The extent of oxi¬ dation of some organic materials has been determined.
• METHOD '
Reagents '
1. Dichromate oxidizing agent is prepared by dissolving 2.5 grams of potassium dichromate in a mixture of 500 ml. each of concentrated H2SO4 and 85 per cent ortho H3PO4.
2. Potassium iodide solution is made by dissolving 55.3 grams of KI in 200 ml. of distilled water. -
• Report of a study made under the Research and Marketing Act of 1946. + Presented  at the  American  Chemical  Society  Meeting-in-Miniature, Phila¬ delphia, Pa., January 1951. ** One of the laboratories of the Bureau of Agricultural and Industrial Chemis¬ try,   Agricultural   Research   Administration,   United   States   Department   of Agriculture.
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