Abstract: To analyze the oxidizable substances, for example the chemical oxygen demand (COD), contained in an aqueous sample liquid, for example sewage water, the aqueous sample liquid is diluted with dilution water and fed into a reaction container where it is mixed with ozone from an ozone generating device. After passing through a second reaction container, for example a tubular reactor, the sample liquid reaches an ozonometer appliance. Ozone being added continuously, the ratio of sample liquid to dilution water of the mixture is regulated in such a manner that the residual ozone content measured by the ozonometer appliance remains constant at a predetermined level. The ratio of sample liquid to dilution water of the mixture required to maintain the reading on the ozonometer at the predetermined level is used to determine oxidizable substances contained in the water, in particular COD.

Abstract: A process and apparatus for measuring the degree of pollution, the degradableness, and the level of toxicity of aqueous liquids, for example, effluent. A partial stream is withdrawn from the liquid undergoing examination and diluted with biologically neutral water. The diluted partial stream is oxygenated and continuously flows through a biological bath in a reaction vessel having a constant living mass. The dilution of the partial stream is regulated in such a manner through measurement of the oxygen content upstream and downstream of the reaction vessel, that with constant volume flow through the reaction vessel, the difference between the measurement values obtained remains essentially constant at a predetermined value, so that the amount of dilution serves for the indication of the level of pollution. Additional reaction vessels connected in parallel or in series with the first reaction vessel and having associated oxygen electrodes allows measurement of the toxicity and degradableness of the pollution.

Abstract: A process and apparatus for measuring the degree of pollution, the degradableness, and the level of toxicity of aqueous liquids such as effluent. A partial stream is withdrawn from the liquid undergoing examination and diluted with biologically neutral water. The diluted partial stream is oxygenated and continuously flows through a biological bath in a reaction vessel having a constant living mass. The dilution of the partial stream is regulated in such a manner through measurement of the oxygen content upstream and downstream of the reaction vessel, that with constant volume flow through the reaction vessel, the difference between the measurement values obtained remains essentially constant at a predetermined value, so that the amount of dilution serves for the indication of the level of pollution. Additional reaction vessels connected in parallel or in series with the first reaction vessel and having associated oxygen electrodes allows measurement of the toxicity and degradableness of the pollution.