Page 324 - Water and wastewater engineering

LIME–SODA SOFTENING 7-41

Well No. 1, Lab No. 02694, November 9, 1971

Iron 0.2 Silica (SiO 2 ) 20.0
Manganese 0.0 Fluoride 0.35
Ammonium 0.5 Boron 0.1
Sodium 4.7 Nitrate 0.0
Potassium 0.9 Chloride 4.5
Calcium 67.2 Sulfate 29.0
Magnesium 40.0 Alkalinity 284.0 as CaCO 3
Barium 0.5 pH 7.6 units

NOTE: All reported as “mg/L as the ion” unless stated otherwise.
7-6. Determine the total, carbonate, and noncarbonate hardness in mg/L as CaCO 3 and in
meq/L for the water analysis in Problem 7-5 using the predominant polyvalent cations.
7-7. Calculate the total, carbonate, and noncarbonate hardness for the water analysis in
Problem 7-5 in mg/L as CaCO 3 using all of the polyvalent cations. What is the
percent error in using only the predominant cations as in Problem 7-6?
7-8. The following mineral analysis was reported for a water sample taken from Well No. 1
at Magnolia, Illinois (Woller and Sanderson, 1976b). Determine the total, carbonate and
noncarbonate hardness in mg/L as CaCO 3 and in meq/L using the predominant polyva-
lent cation definition of hardness.

Well No. 1, Lab No. B109535, April 23, 1973
Iron 0.42 Zinc 0.01
Manganese 0.04 Silica (SiO 2 ) 20.0
Ammonium 11.0 Fluoride 0.3
Sodium 78.0 Boron 0.3
Potassium 2.6 Nitrate 0.0
Calcium 78.0 Chloride 9.0
Magnesium 32.0 Sulfate 0.0
Barium 0.5 Alkalinity 494.0 as CaCO 3
Copper 0.01 pH 7.7 units

NOTE: All reported as “mg/L as the ion” unless stated otherwise.

7-9. The following mineral analysis was reported for Michigan State University well water
(MDEQ, 1979). Determine the total, carbonate, and noncarbonate hardness in mg/L as
CaCO 3 and in meq/L using the predominant polyvalent cation definition of hardness.
Michigan State University Well Water

Fluoride 1.1 Silica (SiO 2 ) 3.4
Chloride 4.0 Bicarbonate 318.0 mg/L as CaCO 3
Nitrate 0.0 Sulfate 52.0
Sodium 14.0 Iron 0.5
(continued)