化学需氧量测定方法研究

Research Progress on Determination of COD

原测定化学需氧量的方法操作过程冗长,测定成本高,紧急应变能力不够。为了改进以上不足,缩短分析时间,分析工作者在HJ/T399-2007基础上进行方法优化。通过对消解温度、消解时间、试剂选择及氯离子干扰问题等方面对比实验,可知在165℃下消解15 min较合适;硫酸汞的掩蔽效果较硝酸银好;应根据氯离子浓度选择合适的氧化剂的浓度。改良后的光度法测定COD结果精密度、准确度好,与国标测得结果一致。

The analysis method was originally taken during the laboratory lengthy , high measurement costs , inadequate emergency response capabilities.In order to improve these shortcomings and shorten analysis time , analysis of the workers , new method was studied on the basis of HJ/T399-2007.New analysis method optimized digestion temperature, digestion time, reagent, the elimination of chloride ion interference problems , and so on.The results showed that under the 165 ℃dissolve 15 min was relatively appropriate , mercury sulfate＇s masking effect was better than silver nitrate.Choosing suitable oxidant should be based on the concentration of chlorine ion concentration .Comparing the improved method of Spectrophotometry with the standard method , the results were consistent on the accuracy and precision with the results of the standard method.