Biochemical Oxygen Demand (BOD)

For details visit WaterontheWeb Module 9 – Laboratory Methods

  • Usually the BOD test measures the amount of oxygen consumed during 5 days in the dark in a sealed bottle with no air space at 20 °C.
  • The oxygen is typically consumed mostly by microorganisms as they decompose carbonaceous organic matter. However, some of the BOD may be due to microorganisms that can oxidize ammonium to nitrate to generate energy and some comes from the chemical oxidation of inorganic matter. Additional tests can separate these sources.
O2 meter apparatus lab tech

References:

EPA Stream Monitoring Manual
http://www.epa.gov/volunteer/stream/vms52.html

USGS Field Manual
http://water.usgs.gov/owq/FieldManual/Chapter7/7.0.html