Simultaneous in Situ Determination of Dissolved Gases by Gas Chromatography: II. Oxygen and Nitrogen in Activated Sludge Process Streams

A simple, reliable and accurate means for dissolved gas analysis, hitherto used only in clean water, is shown to be suitable for all process streams encountered in activated sludge waste treatment plants. This technique consists of exposing samples of helium across a gas permeable membrane to the solution of interest and determining the amount of each species transferred by standard gas Chromatographic procedures. The technique appears to be the best available for the analysis of dissolved nitrogen and at least competitive to existing techniques for the measurement of dissolved oxygen. It should be possible to extend its use to any dissolved gas exerting a finite partial pressure.