Cl^-、NH_3和H_20_2对COD测定的影响

Effects of Chloride, Ammonia and Hydrogen Peroxide on COD Measurement

在参阅国内外文献资料的基础上,讨论了采用重铬酸钾法测定水和工业废水中化学需氧量时,Cl^-、NH_3和H_2O_2等无机污染物对测定结果的影响及其干扰机理。结合实验资料,提出采用无汞盐测定化学需氧量的方法消除Cl^-的干扰,采用低浓度重铬酸钾溶液以消除NH_3的干扰;用预先测定水样中H_2O_2浓度而后加以扣除的方法消除H_2O_2的干扰。

Based on the literatures review, discussing the interference and mechanism of chloride, ammonia and hydrogen peroxide on measurement of COD in water and industrial wastewater. In combination with experimental data, the author put forward by using mercury-free salt, to eliminate chloride interference and low concentrated potassium dichrpmate solution to eliminate ammonia interference on COD measurement, and pre-determining the H2O2 concentration in water sample and then deducting of it in COD calculation.