| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus for measuring chemical oxygen demand and a method therefor which generate no measurement errors by halide ions simpler and easy to process without using mercury nitrate, silver nitrate, and the like. SOLUTION: According to the method for measuring chemical oxygen demand and the apparatus for carrying out the measurement method, a fixed amount of a sample whose chemical oxygen demand is to be measured is collected. A predetermined amount of sulfuric acid is added to the sample, which is heated under an inert ambience to remove dissolved chloride ions present in the sample as a hydrogen chloride. Then, a fixed amount of an oxidation reagent for oxidizing the sample is added and heated, whereby a substance to be oxidized in the sample is oxidized. The residual oxidation reagent is coulometric titrated by a reagent solution for reduction. An amount of the residual excessive oxidation reagent is measured. An amount of the oxidation reagent consumed for oxidizing the substance to be oxidized of the sample is measured from the fixed amount of the oxidation reagent added beforehand. The chemical oxygen demand is calculated from the volume of the sample, and the measured value of the oxidation reagent consumed for oxidizing the substance to be oxidized in the sample. |
