5 Day Biochemical Oxygen Demand Formula

Equation for calculate 5 day biochemical oxygen demand is,

BOD ₅ = [D₁ - D₅] / P

where,
D₁ = initial sample dissolved-oxygen (DO) concentration,
D₅ = sample DO after 5 days,
P = Dilution factor (decimal volumetric fraction of sample used),
BOD ₅ = 5 day biochemical oxygen demand