低污染低成本COD快速测定方法的研究

文章探讨了一种无银快速测定废水COD的方法。该方法用CuSO4-MnSO4复合催化剂代替国标法中的Ag2SO4,采用H2SO4-H3PO4代替H2SO4,得到测定COD的最佳条件为:K2Cr2O7浓度为0.25 mol/L,催化剂CuSO4-MnSO4的配比为2:1,CuSO4和MnSO4总量为0.06 g,混酸比H2SO4:H3PO4为6:1,消解温度为160℃,消解时间为12 min。将实验得到的COD值与国标法COD测定结果相比较,准确度和精密度无显著性差异。此方法取样量少,消解速率快,操作简单省时,扩展了COD的测定范围,降低了污染,适用于大批量复杂水样的测定。

Determination of COD with Low Pollution and Low Cost

A method of rapid determination of COD in wastewater with no silver was discussed.CuSO4-MnSO4 was used as a composite catalyst instead of AgSO4 for standard determination of COD and H2SO4-H3PO4 instead of H2SO4.The optimum conditions for determining chemical oxygen demand(COD)were as amount of K2CrO7 0.25 mol/L,ratio of catalyst CuSO4MnSO42: 1,amount of CuSO4and MnSO40.06 g,volume ratio of mix acid H2SO4-H3PO46: 1,decomposition temperature 160 ℃ and decomposition time 12 min.Comparing the determination of COD with that by the national standard method,the accuracy and precision are all within allowable range.The method which is advantageous over small sample size,digestion rate,simple operation and time saving,extends the COD determination range and reduces water pollution,which is suitable for large quantities water samples determination.