Question

Question: What does the NA stand for or what does it mean?

Table 2-1 Oxygen Requirements Based on Supplied Form of Oxygen Oxygen Concentration in H2O Volume to Degrade 1 lb Hydrocarbon 8 to 10 mg/L Oxygen Form Air-saturated 1, 0 Oxygen-saturated H2O Hydrogen peroxide 40 to 50 mg/L Up to 500 mg/L 47,000 gallons (180,000 L) 11,000 gallons (42,000 L) 1,600 gallons (6,100 L) 170 ft (4,800 L) Air NA (21% vol/vol in air)

Answer 1

Oxygen in form of air contains Oxygen concentration in water equal to 21% vol/vol in air.

NA refers to Normal amount .