新型紫外吸收光谱法测量化学需氧量的实验研究

采样系统在使用紫外吸收(UV)光谱法测量水质化学需氧量(COD)的仪器中是非常重要的组成部分。目前采样系统中普遍地使用样品池,但其窗片上附着的污染物难以完全去除,导致测量误差较大。介绍一种UV法检测COD的新型实验装置,该装置的取样系统中使用了一种新设计的喷嘴,它可以形成厚度为9 mm的稳定的水柱,克服样品池的缺点。在水质成分相对稳定的情况下,应用该装置检测实际废水并与标准方法比对,相对误差不超过10％,获得较好的一致性。

New-style Chemical Oxygen Demand Detection Research with UV Absorption Spectroscopy

Sampling system is an important part of the apparatus detecting water quality chemical oxygen demand (COD) with UV absorption spectroscopy. The sampling cell is widely used in the sampling system presently, but the contaminant deposited on the window is difficult to eliminate completely. This can result in quite large measurement errors. A new experimental equipment is introduced, in which a new designed nozzle is used and it can form a 9 mm steady water column. Thus the disadvantages of the sampling cell are overcome. This apparatus is used to detect the waste water, and a better coherence is obtained comparing with standard method. The relative error of experiment is less than 10% if the elements of water quality are relatively steady.