The first thing to look at ...
Published by Waymon Hofheins
The first thing to look at is a BOD vs the COD; they do not necessarily follow each other. It depends upon what the waste is composed of. For example a high BOD with a low COD with a food produce vs a lower BOD and an high COD for a product from tannins from a lumber operation. COD may have to be broken with an oxidizer such as Hydrogen peroxide, or chlorine. A high BOD can be easily broken with bacteria cultures - such as strains of Bacillus - along with air injection.
However, the pH of 8.1 is OK, but on the high side of 8.2 for the best bacteria digestion. Slightly lowered pH with a little acid can greatly improve bacteria digestion; a 7.5 would be a great point to shoot for.