Thank you so much for the kind attention and reply, I know it before but i wish to clarify twice myself, because of the pristine nature without any disturbances.

BOD as it is a measure of " the amount of oxygen required for aerobic decomposition, stabilization or oxidation of **carbonaceous organic** matter by aerobic microbes at 27 degrees for 3 days or 20 degrees C for 5 days".

Now when we talk about COD, it's a measure of the amount of oxygen required to oxidize such chemical waste (using strong oxidizers _ in appropriate conditions) that can not be biologically be decomposed (or oxidized in other words).

In this case, all the organic matter that can be decomposed biologically will obviously be decomposed when we use strong oxidizing agents. but in the other case, the BOD is only a measure of biological requirement of oxygen for the carbonaceous organic waste.

So in this case, BOD will always be LESS THAN OR EQUAL TO COD, what so ever the case is.

Hope this will be helpful to you.

Regards,

Manthan Tailor

Thank you so much for the sharing Mr.Manthan Tailor and for your kind notice with more information.

You're most welcome sir.....

I generally agree with the above mentioned theoretical consideration that BOD is the part of COD that can be oxidized biologically by microorganisms.

However in practice the two parameters are defined by analytic procedures. If one uses standard methods with an inocloum for the BOD test of activated sludge and the COD is determined by the oxidation of chromate it happens in both wastewater and polluted streams that the measured BOD is higher than the COD because chromic acid does not oxidise ammonia while a bacteria community with nitrifiers does this quite efficiently.

For natural stream, COD>BOD, however, when high quantity of Nicotinic acid is mixed in water the result may be otherwise. Reported recovery of Nicotinic acid is only 14% in standard method of COD, whereas it is highly biodegradable. Input solicited on the submission.

Thank you so much both of you Mr.Henrik Andersen &Mr.Sundeep Singh for your valuable notes on my question.