Basic Units of Measurement and Conversions - Basic Mathematics for Water and Wastewater Operators - page 17

■ Example 2.13
Convert pounds to milligrams per liter.

Quantity (lb)
Volume (M

Concentration(mg/L) =

G) × 8.34 lb/MG/mg/L

Problem: An aeration tank contains 89,990 lb of solids. The volume of the aeration
tank is 4.45 MG. What is the concentration of solids in the aeration tank in milli-
grams per liter?

Solution:

Quantity (lb)
Volume (MG)

Concentration =

× 8.34 lb/MG/mg/L

89,990 lb

= = 2425 mg/L

4.45 MG × 8.34 lb/MG/mg /L

■ Example 2.14
Convert pounds per day to milligrams per liter.

Quantity (lb/day)

Concentration(mg/L) =

Volum ee(MGD) × 8.34 lb/MG/mg/L

Problem: The disinfection process uses 4820 pounds per day of chlorine to disinfect
a flow of 25.2 MGD. What is the concentration of chlorine applied to the effluent?

Solution:

Quantity (lb/day)
Volume (MGD)

Concentration =

8.34 lb/MG/mg/L
4820 lb/day
25.2 MGD

×

= = 22 . mg/L

× 8.34 lb/MG/mg/L

■ Example 2.15
Convert pounds to flow in million gallons per day.

Quantity (lb/day)
Quantity (mg/L)

Flow (MGD) =

× 8.34 lb/MG/mg/L