DO : Dissolve oxygen (FWQ)

Dissolve oxygen ( FWQ )

Parameter of DO : Dissolve oxygen

• Temperature increase = Dissolve oxygen decrease.
• Partial pressure increase = Dissolve oxygen increase
• Solved concentration increase = Dissolve oxygen decrease.

Ability of water to dissolve atmospheric oxygen is depend on the following parameters :

1. Temperature
2. Partial pressure
3. Salt concentration
4. Rate of mixing ( Minor parameter )

Note	1 to 3 all these parameter is Major parameter

DO : less soluble in water

Temperature (°C )	Dissolve oxygen concentration
0	14.6
20	9.4
25	8.1

Temperature effect on Dissolve oxygen concentration

Freshwater / Good water should have at least 4 Milligram per litre Dissolve oxygen at all the time.

Physical, chemical, biological process are going on in Dissolve oxygen.

Most important figure for Exam ! Fig DO concentration ( if any question asked in exam related to this Dissolve oxygen ( FWQ ) draw it )

Environmental signification of Dissolve oxygen Determination

• Maintain aquatic system alive in the water Dissolve oxygen determination important.

• Determination of domestic and industrial wastewater strength.

NOTE	• Strength of pollutant = concentration of pollutants × flow of pollutants • it's unit is kilogram per day (mass)

What is strength ?

• Deo is required to control aerobic biological process in natural water and wastewater treatment.

• To control corrosion for power industry Dissolve oxygen determination is required.