Method and apparatus for automated measurement of energy oxygen

Abstract

There is described herein a method and apparatus for determining the total consumption of dissolved oxygen in a liquid by organic materials contained therein in the presence of a biological growth culture. The invention includes providing a supply of liquid, preferably water, which is saturated with air. A liquid sample containing the organic material is supplied to the air saturated liquid. The combined mixture is then supplied, at a fixed volumetric rate, to a tube of predetermined length which contains the biological 'culture'. The biological growth, utilizing the oxygen dissolved in the liquid mixture, reacts with the organic material contained therein resulting in certain synthesized materials and other oxidation products. At the exit end of the tube oxygen detecting means is positioned which measures the oxygen contained in the liquid mixture after exposure to the biological growth. This measurement when plotted against time gives an indication of the total amount of oxygen consumed due to the assimilation of the organic material by the biological growth culture. Alternately, the readout of the oxygen detecting means can be supplied directly to an integrating amplifier or similar device, to which a set of system parameters can be supplied as constants. The output of such a device will represent the oxygen consumed.