Basic Units of Measurement and Conversions - Basic Mathematics for Water and Wastewater Operators - page 64

TABLE 2.7 (continued)
Conversion Factors by Unit Category

Factor Metric (SI) or English Conversions

1 mCi (millicurie) 0.001 Ci (curie)

3.7 × 10 10 radioactive disintegrations/second
3.7 × 10 10 Bq (becquerels)

1 rad 100 ergs/g (ergs/gram)

0.01 Gy (gray)
1 rem, unless modified through division by an
appropriate factor, such as Q or N

1 rem 1 rad, unless modified through division by an

appropriate factor, such as Q or N

1 Sv (sievert) 1 Gy, unless modified through division by an

appropriate factor, such as Q or N

Problem: If 1850 gal of solids are removed from the primary settling tank, how
many pounds of solids are removed?

Solution:

Pounds = 1850 gal × 8.34 lb/gal = 15,429 lb

■ Example 2.114
Convert pounds to gallons.

Gallons (gal) = Pounds (lb) ÷ 8.34 lb/gal

Problem: How many gallons of water are required to fill a tank that holds 8500 lb
of water?

Solution:

Gallons = 8500 lb ÷ 8.34 lb/gal = 1019.18 gal

■ Example 2.115
Convert milligrams per liter to pounds.
Note: For plant operations, concentrations in milligrams per liter or parts per mil-
lion determined by laboratory testing must be converted to quantities of pounds,
kilograms, pounds per day, or kilograms per day.

Pounds (lb) = Concentration (mg/L) × Volume (MG) × 8.34 lb/MG/mg/L

Problem: The solids concentration in the aeration tank is 2500 mg/L. The aeration
tank volume is 0.90 MG. How many pounds of solids are in the tank?

Solution:

Pounds = 2500 mg/L × 0.90 MG × 8.34 lb/MG/mg/L = 18,765 lb