污水处理厂水质检测中化学需氧量(COD)测定的手工分析法和仪器法对比

Comparison of Manual and Instrumental Methods for Measuring Chemical Oxygen Demand (COD) in Water Quality Testing of Sewage Treatment Plants

化学需氧量是污水处理厂进、出水水质检测中重要的常规参数之一,主要反映水体受有机物污染程度以及污水处理厂处理效果。随着有机物对水体的污染日益严重,污水中化学需氧量的测定也越来越受到重视,对测定结果的要求也越来越高。本文依据标准《HJ 828—2017水质化学需氧量的测定重铬酸盐法》要求,通过采用两种浓度范围4个有证标准物质对比了手工法和仪器法在化学需氧量测定中的准确度和精密度,并通过测定污水处理厂进、出水水样的化学需氧量而比较了两种测定方法的相对偏差。

Chemical oxygen demand is one of the important routine parameters in the water quality testing of sewage treatment plants,mainly reflecting the degree of organic pollution in water bodies and the treatment effect of sewage treatment plants.With the increasingly serious pollution of water bodies by organic matter,the determination of chemical oxygen demand in sewage is receiving more and more attention,and the requirements for the determination results are also increasing.This article compares the accuracy and precision of manual and instrumental methods for determining chemical oxygen demand in water quality using four certified standard substances in two concentration ranges,in accordance with the requirements of the standard HJ 828-2017 Determination of Chemical Oxygen Demand in Water Quality-Dichromate Method.The relative deviation of the two measurement methods is also compared by measuring the chemical oxygen demand of inlet and outlet water samples from sewage treatment plants.