化学需氧量的三种测定方式对比分析

The Chemical Oxygen Demand was Measured in Three Different Ways

化学需氧量作为污水处理厂分析判断水质状况的重要检测项目之一,其数据大小能够直接反映水质情况,指导污水厂日常药剂投加量的确定。目前实验室主要采用的CODCr测定方法是重铬酸盐法(滴定法),该方法步骤多操作过程繁琐、耗时长且二次污染性大。本文通过采用快速消解分光光度法(HJ/T 399-2007)、重铬酸盐法(HJ 828-2017)(全自动分析仪和手工滴定法)三种测定方式分别对有证标准物质和污水厂实际进水水样进行化学需氧量检测,从检出限、结果的相对标准偏差、回收率等数据比较分析,结果表明污水厂日常COD检测运用快速消解分光光度法是最高效且环保的。

As one of the most important testing items in Sewage Treatment analysis,Chemical oxygen demand can directly reflect the water quality and direct the determination of daily dosage.At present,the main method for CODCr determination in laboratory is dichromate titration method,which has many steps,long time and heavy secondary pollution.In this study,certified reference materials and actual influent samples from sewage plants were Chemical oxygen demand by rapid digestion Spectrophotometer(HJ/T 399-2007),dichromate method(HJ 828-2017)(automatic analyzer and manual titration),based on the data of detection limit,relative standard deviation of results and recovery rate,the results show that the application of rapid digestion Spectrophotometer in daily COD detection in wastewater treatment plants is the most efficient and environmentally friendly.