高浓度含盐废水COD测定中Cl^-的影响及消除

EFFECT AND ELIMINATION OF Cl^- TO COD DETERMINATION IN HIGH CONCENTRATION SALTY WASTEWATER

对于高氯离子质量浓度，低ＣＯＤ 值的水样，用国标法测定ＣＯＤ 值时会产生较大误差，且误差随着Ｃｌ－ 质量浓度的增加而增大。通过实验探讨了高氯离子质量浓度对水样ＣＯＤ 测定的影响及消除影响的方法。结果表明：采取不掩蔽Ｃｌ－ 测定水样的ＣＯＤ 总量，减去氯离子自身产生的ＣＯＤ 值，能较准确地反映水样的ＣＯＤ 值且结果重复性好。

Errors will appear when COD value is determined by GB11914-89 for high Cl - concentration water sample. In this paper the effect and eliminating effect method of high Cl - concentration to COD determination was investigated through experiment. The result show that determining the COD amount of water sample without sequestrating Cl - , and then minus the COD value produced by Cl - itself, with that amount can not only accurately inflect water sample COD value ,but also have good repeatability.