Hello everybody!
For the last 6 months, I run a COD and BOD test once a month for effluent wastewater sample and the result for BOD is always much greater than COD (about 3-4 times higher). Initial D.O value is always accepted, about 9 mg/L. Could this be due to nitrification? I have never added nitrification inhibitor, because total nitrogen isn't much high. What should I do? Thank you!
Honestly, I have not directly and experimentally worked on the subject.
Your question is excellent. By itself, it may constitute a PhD thesis!
I suggest you focus on the ratio of BOD/COD, and do not forget TOC (Total Organic Carbon).
You may find useful information here:
https://cgi.tu-harburg.de/~awwweb/wbt/emwater/lessons/lesson_a1/lm_pg_1068.html
Best wishes,
Djamel
@Ioanna Pantelaki : Theoretically the BOD = COD at maximum, it is in the case that all pollutants forming COD are 100 % degradable biologically. I agree with @{Joshua O. Ighalo about possibility of endogenic respiration.
REgards
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Ioanna Pantelaki
Aristotle University of Thessaloniki
Joshua O. Ighalo Thank you, I haven't heard about endogenic respiration before. I will search some info about it. What do you mean when you say to carry a blank with biomass? I always carry a BOD blank with distilled water and the value is less than 0.8 mg/L.
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