Measurements of oxygen consumed in a 5-d test period (5-d
BOD or BOD5, 5210B), oxygen consumed after 60 to 90 d of
incubation (ultimate BOD or UBOD, 5210C), and continuous
oxygen uptake (respirometric method, 5210D) are described
here. Many other variations of oxygen demand measurements
exist, including using shorter and longer incubation periods and
tests to determine rates of oxygen uptake. Alternative seeding,
dilution, and incubation conditions can be chosen to mimic
receiving-water conditions, thereby providing an estimate of the
environmental effects of wastewaters and effluents.