[michel]

Hye..
Can anyone explain about BOD calculation(with seeding)?This is based on APHA method (5210 B).
BOD5 mg/L = (D1 – D2) – (B1-B2)
            P
Where;
D1 = DO of diluted sample immediately after preparation, mg/L
D2 = DO of diluted sample after 5 d incubation at 20°C, mg/L
P   = Decimal volumetric fraction of sample used
B1 = DO of seed control before incubation, mg/L
B2 = DO of seed control after incubation, mg/L
f    = ratio of seed in diluted sample to seed in seed control = (% seed in diluted sample)
                         (% seed in seed control)