Journal Published Online: 01 March 1984
Volume 12, Issue 2

Methods for Determination of -N, -N and Organic Forms of Nitrogen in Wastewaters



Methods of steam distillation for the determination of NH4+, NO3, NO2, and organic forms of nitrogen in wastewaters are described. Oil and grease derived from petroleum and coal processing must be removed by successive extraction with benzene and cyclohexane before distillation begins. To prevent biological nitrogen transformation and assimilation, preservation of water samples with a suitable preservant, such as chloroform, and subsequent analysis of samples within one week are recommended. In the procedure, NH4+ was steam distilled with a specified amount of magnesium oxide, NH4+ + NO3 + NO2 with magnesium oxide plus Devarda's alloy in 3 to 4 min. Nitrite was effectively destroyed with sulfamic acid, thus, allowing its quantitative measurement by difference before and after sulfamic acid treatment, which is before steam distillation. Organic forms of nitrogen in protein, oil brine, and coals were quantitatively converted as NH4+ by a micro-Kjeldahl method at 360°C on a temperature controlled block (Technicon BD-40) digester for 1 to 5 h after clearing. Ammonium recovered by steam distillation is measured either by titration or by a spectrophotometric method. The latter is favored because of its high sensitivity and because only a small amount of sample is required. The methods are applicable to waters of various types. Interference by organic and inorganic substances in water has rarely been encountered.

Author Information

Ho, CL
Bureau of Economic Geology, Mineral Studies Laboratory, The University of Texas, Austin, TX
Pages: 7
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Stock #: JTE10704J
ISSN: 0090-3973
DOI: 10.1520/JTE10704J