Technical assistance: COD in wastewater treatment
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This post was last edited by hesonchang214 on 2012-12-28 at 12:01. Today, I conducted a COD blank test, and the value obtained was 29.8; I think this deviation is too large. In the past, during summer, the values were usually between 23 and 24. Could you help me analyze what might be causing this issue?
I personally think it’s test error. . .
The first is caused by errors. Secondly, there are certain differences in water quality, especially that of natural water, between summer and winter.
What sample is the COD blank referred to by the poster? Is it pure water? Or what kind of water treatment sample was obtained? The blank should contain no substances that contribute to COD; with such a high detection value, there must be some oxidizable substances present in the sample.
This post was last edited by hesonchang214 on 2012-12-28 at 12:01. When deionized water is used as a blank sample, the COD value is below 10, or even below 5; of course, the condition of the water sample being tested also needs to be taken into account. For water samples with a COD value of several thousand or tens of thousands, dilution errors naturally lead to exaggerated values!