三种COD检测方法的比对研究

Contrast Research on Three COD Detection Methods

以标准水样和实际废水为检测对象,分别采用重铬酸盐法、HACH比色法及在线分析法进行COD比对试验。结果表明:三种方法对标准溶液、进水水样(高浓度)进行测定,均具有较高的精密度和准确度;重铬酸盐法、在线分析法对出水水样(低浓度)进行测定,具有较高的精密度;HACH比色法对出水水样(低浓度)进行测定,精密度低,方法不可取。

By taking the standard water samples and actual wastewater as test objects, the paper adopts dichromate method, HACH colorimetric method and on-line analytic method respectively to carry out COD contrast tests, The results show that all the three methods have high precision and accuracy in the determination of standard solution and influent water sample （high concentration）. When the dichromate method and on-line analysis method are used to determine the water sample （low concentration）, a high precision is shown; and by using the HACH colorimetric method to measure the water sample （low con- centration）, a low precision is shown, The method is not desirable.