Basic Units of Measurement and Conversions - Basic Mathematics for Water and Wastewater Operators - page 18

Problem: If 9640 lb of solids must be removed per day from an activated biosolids
process, and the waste activated biosolids concentration is 7699 mg/L, how many
million gallons per day of waste activated biosolids must be removed?

Solution:

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

Flow =

× 8.34 lb/MG/mg/L

9640 lb/day
7699 mg/L

= = 0.15 MGD

× 8.34 lb/MG /mg/L

■ Example 2.16
Convert million gallons per day to gallons per minute.

Flow (MGD) × 1,000,000 gal/MG

Flow (gpm) =

1440 min/day

Problem: The current flow rate is 5.55 MGD. What is the flow rate in gallons per
m inute?

Solution:

Flow (MGD) 1,000,000 gal/MG
1440 min/da

×

Flow =

y
5.55 MGD 1,000,000 gal/MG
1440 min/day

×

= = 3854 gpm

■ Example 2.17
Convert million gallons per day to gallons per day.

Flow (gpd) = Flow (MGD) × 1,000,000 gal/MG

Problem: The influent meter reads 28.8 MGD. What is the current flow rate in gal-
lons per day?

Solution:

Flow = 28.8 MGD × 1,000,000 gal/MG = 28,800,000 gpd

■ Example 2.18
Convert million gallons per day to cubic feet per second (cfs).

Flow (cfs) = Flow (MGD) × 1.55 cfs/MGD