specific gravity of solid particles
size of particles
depth of tank
temperature of liquid
20°C - 1day
25°C- 3day
20°C - 5day
30°C- 5day
5 day BOD is the ultimate BOD.
5 day BOD is greater than 4 day BOD keeping other conditions same.
5 day BOD is less than 4 day BOD keeping other conditions same.
BOD does nof depend on time.
100000
1000
4000
400000
directly proportional to BOD satisfied
directly proportional to BOD remain-ing ,
inversely proportional to BOD satisfied
inversely proportional to BOD re-maining