重铬酸盐法测定生活污水中化学需氧量时消解时间的探究

Exploration of Dissolution Time in the Determination of Chemical Oxygen Demand in Domestic Wastewater by Dichromate Method

依据《水质化学需氧量的测定重铬酸盐法》(HJ 828—2017)测定COD_(Cr)时存在消解时间过长导致工作效率低的问题,本文通过对有证标准样品以及太原市污水处理厂进水水样在不同消解时间下COD_(Cr)的测定,得出将消解时间由120 min缩短为60 min时测得的COD_(Cr)也满足方法准确度和精密度要求。因此,将消解时间适当缩短也可以满足太原市生活污水中化学需氧量的检测要求。

According to the Determination of Chemical Oxygen Demand in Water Quality-Dichromate Method(HJ 828-2017),there is a problem of low work efficiency caused by long digestion time when measuring CODCr.This article determines the CODCr of certified standard samples and influent water samples from Taiyuan sewage treatment plant at different digestion times,and concludes that the CODCr measured when the digestion time is shortened from 120 min to 60 min also meets the accuracy and precision requirements of the method.Therefore,shortening the digestion time appropriately can also meet the detection requirements of chemical oxygen demand in domestic sewage in Taiyuan City.