水和废水中化学需氧量的测定方法比较与讨论

Comparison and Discussion on the Determination of Chemical Oxygen Demand in Water and Wastewater

化学需氧量是我国实施排放总量控制的指标之一, 反映了水中受还原性物质污染的程度, 也作为有机物相对含量的指标之一.通过测定标样和废水, 对重铬酸盐法和分光光度法进行比较, 得出两种方法在精密度和准确度检验方面均可以满足实验质控要求, 测定的结果相近.各实验室可根据自身情况和不同要求选用适当方法.

Chemical oxygen demand （COD） is one of the indicators of total emission control in our country.It reflects the degree of contamination by reducing substances in water as well as one of the indexes of the relative content of organic compounds. By comparing the standard sample with the wastewater, the dichromate method and the spectrophotometry are compared. The results show that the two methods can meet the quality control requirements of the experiment both in precision and accuracy, and the results are similar. The laboratories can choose the appropriate method according to their own situation and different requirements.