BOD types include carbonaceous BOD (cBOD), nitrogenous BOD (nBOD), and total BOD (tBOD). cBOD measures oxygen depletion from biological organisms breaking down carbonaceous pollutants. nBOD measures oxygen used by autotrophic bacteria to convert ammonia to nitrates through nutrient enrichment. tBOD is the total oxygen required to oxidize all organic compounds through microbial growth. Total organic carbon (TOC) has been standardized to assess organic pollution in water and can correlate to chemical oxygen demand (COD) measurements through dichromate oxidation correlations defined for different substances.

1. BOD TYPES
Biochemical Oxygen Demand

2. What is BOD
Amount of oxygen absorbed by a sewage sample during 5d of specific
time under 200c of specific temperature
Why is BOD
 To determine how much bacteria /organic matter present in the sewage
 To determine what effect dirty water
Some facts related to BOD
 Oxidant is microorganism
 For drinking water BOD
less than 1 mg/L
 Any to be discharged in
natural bodies of water
should have BOD less than
20 mg/L

3. c BOD
n BOD
t BOD
 TOC

4. c BOD
Carbonaceous Biochemical Oxygen Demand
 It is listed as a conventional pollutant
Measured by the depletion of dissolved oxygen by biological
organisms in a body of water in which the contribution from
nitrogenous bacteria has been suppressed
 It is a method defined parameter is widely used as an indication of
the pollutant removal from wastewater
 It has the widest application in measuring waste loadings to
treatment plants

5. n BOD
 Nitrogenous Biochemical Oxygen Demand
 The nitrogenous waste in municipal and industrial sewage is used
by autotrophic bacteria
 They use a significant amount of oxygen as an energy source and
convert ammonia to nitrates,
 This phenomenon is called n BOD.
 The nutrient enrichment ‘pollution’ contributes to the
eutrophication of lakes, rivers and water bodies when discharged
in a final effluent.

7. t BOD
 Total biochemical oxygen demand of a water sample
 It’s the amount of oxygen required to completely oxidize the
organic compounds to carbon dioxide and water through
generations of microbial growth, death & decay

8. TOC
 Total Organic Carbon
 It has been standardized as a
reference parameter for the
assessment of organic
pollution in water

10. Correlations between COD and TOC
 COD methods are based on the principle of the dichromate
oxidation
 Correlations between TOC and COD are defined in the German
waste water ordinance and can be determined for each substance
 correlation factors for unknown mixtures can also be detected