railway RRB JE (CBT I + CBT II) Mock Test 2024 Environmental Engineering Quality and Characteristics of Sewage
The correct relationship between theoretical oxygen demand (TOD), biochemical oxygen demand (BOD) and, chemical oxygen demand (COD) is given by
1
TOD > BOD > COD
2
TOD > COD > BOD
3
COD > BOD > TOD
4
BOD > COD > TOD