Abstract:

We employed different concentrations of dichromate to determine low concentration water from different areas of Shandong Province for the bad precision of the determination of CODCr with low concentration water by GB 11914. This is to analyze the impact of concentration gradient on CODCr. Results indicate that CODCr increases with the increase of dichromate concentration. Determination result is significantly affected by quality of blank water, determination of endpoints, etc. We should completely collect the relative information about water samples when analyzing low concentration water. We should also fully consider system errors, oxidizability and detection range and choose suitable dichromate concentration in order to improve the accuracy of data detection.

Key words: dichromate concentration, low-concentration water, CODCr