K_2Cr_2O_7法和紫外分光光度法测定污水COD的对比研究

分别利用重铬酸钾法、重铬酸钾紫外分光光度法和紫外分光光度法测定污水的COD极差分别为2.43mg/L、1.19 mg/L和4.72 mg/L,RE%分别为0.84%、0.53%和1.36%,重铬酸钾紫外分光光度法和紫外分光光度法的线性范围分别在0~280 mg/L和0~400 mg/L.结果表明:重铬酸钾紫外分光光度法测定的准确度和精密度最高,简化了用标准溶液进行标定的步骤,缩短了实验时间;紫外分光光度法测定的结果准确度和精密度相对差一些,但是快速、操作简单、节省试剂,为广大环境工作者提供借鉴参考的实例。

Comparative Study on COD Determination Using K2Cr2O7 and UV Spectrophotometry Method

K2Cr2O7, K2Cr2O7 -UV spectrophotometry and UV spectrophotometry methods were adopted to determine COD in sewage. The largest errors are 2. 43 mg/L,1.19 mg/L and 4.72mg/L, RE % are 0. 84%, 0. 53% and 1.36% respectively. The linear ranges of K2 Cr2O7 -UV spectrophotometry and UV spectrophotometry are 0 - 280 mg/L and 0 -400 mg/L. The results show that the method of K2Cr2O7 -UV spectrophotometry has the highest accuracy and precision, simple operations and decreasing the experiment time. The accuracy and precision of determination results using UV spectrophotometry is relatively low, but it has advantages of fast and simple operation and saving reagent. This study provides the reference example for environmental workers.