电位法测定化学耗氧量的研究

Study on the Determination of Chemical Oxygen Demand (COD) with the Potentiometry

本文分别试用PVC膜HCrO_4^-离子电极和铂电极作指示电极研究了直接电位法和自动电位滴定法测定COD的方法及实验条件,并测定了部分纯有机物和水样的COD,其结果与经典的重铬酸钾法基本一致。直接电位法由电子计算机输出结果,该法方进一步改进,用于连续自动监测是可供考虑的方案。自动电位滴定法具有简便、快速、便于推广等优点。

The method and the experimental conditions are reported for the determination of chemical oxygen demand (COD) with the direct potentiometry and the automatic potentiometric titration, in which a HCrO_4^- anion electrode is employed and a Pt electrode is used as a.n indicative electrode. The COD of different organic compounds and aquatic samples are also measured. The results agree with those obtained by the dichromate method. Together with a computer the direct potentiometry can be used continuously and automatically to detect the COD. The automatic potentiometric titration is found to be simple and efficient.