重铬酸钾法测特定化学需氧量几种屏蔽氯离子干扰方法比较  

Comparison of Several Methods for the Removal of Chloride Ion When Measuring COD with Potassium Dichromate Method

作　　者：陈超 钱玉亭 

机构地区：[1]江阴市环境监测站,江苏江阴214431

出　　处：《环境科学导刊》2014年第1期99-100,共2页Environmental Science Survey

摘　　要：探讨了COD为60mg/L的情况下,氯离子对测定值的影响。氯离子浓度在100mg/L时,固态硫酸汞可完全屏蔽其干扰;氯离子浓度在500 mg/L时,液态硫酸汞可完全屏蔽其干扰;绘制COD-氯离子标准曲线,屏蔽氯离子浓度可达2000mg/L,但操作较为繁琐;在水样环境单纯的情况下,用低浓度重铬酸钾法,可忽略氯离子的干扰。This paper,presented the influence of chloride ion on COD when it was 60mg/L.When chloride ion concentration was about 100mg/L,solid mercury sulfate could be used to screen the interference of chloride ion.It is the same case when chloride ion concentration was about 500mg/L.By drawing the standard curve with COD as the y-coordinate and chloride ion concentration as the x-coordinate,we could see that the maximum chloride ion concentration was about 2000mg/L without interference.But the operation was complicated.The influence of chlo-ride ion might be negligible in water with low COD measuring by 0.025 mol/L potassium dichromate.

关 键 词：重铬酸钾法 化学需氧量 氯离子 干扰 屏蔽 

分 类 号：X83[环境科学与工程—环境工程]