Biochemical Oxygen Demand And Chemical Oxygen Demand
- required for oxidation of inorganic and organic matter.
- essential for the livelihood of micro organisms.
- can be measured by
- BOD – Biochemical oxygen demand
- COD – Chemical oxygen demand
Biochemical Oxygen Demand
- DO Is measured prior to incubation.
- allowed to stand for five days at a controlled temperature of 20 °C (68 °F).
- At the end of the five-day period, the remaining dissolved oxygen is measured.
- BODt = (DOi – DOf) × D.F.
BODt = Biochemical oxygen demand at t days.
DOi = initial dissolved oxygen before incubation.
DOf = final dissolved oxygen.
D.F.= dilution factor= volume of the bottle/volume of the sample.