Page 381 - Water and wastewater engineering

9-20 WATER AND WASTEWATER ENGINEERING

Alkalinity 284.0 mg/L as CaCO 3
pH 7.6 units
9-10. Estimate the permeate recovery rate for a groundwater with the following characteristics:

Calcium 96.8 mg/L
Carbonate 1.67 mg/L
Bicarbonate 318.0 mg/L as CaCO 3
pH 8.0

9-11. Estimate the dose of sulfuric acid required to achieve a product water recovery rate
of 75% for the water in Problem 9-9 . Assume the acid is a 100% solution.
9-12. Estimate the dose of sulfuric acid required to achieve a product water recovery rate of
75% for the water in Problem 9-10 . Assume the acid is a 100% solution.

9-8 DISCUSSION QUESTION

9-1. For the following water analysis select one of the following options for softening:
lime-soda, ion exchange, NF.

Water A
2
Ca 111 mg/L as CaCO 3
2
Mg 56 mg/L as CaCO 3

Na 63 mg/L as CaCO 3

HCO 3 110 mg/L as CaCO 3
Turbidity 4 NTU
pH 7.0
3
Q design 85 m /d
Water B
2
Ca 152 mg/L as CaCO 3
2
Mg 114 mg/L as CaCO 3

Na 438 mg/L as CaCO 3

HCO 3 460 mg/L as CaCO 3
Turbidity 1 NTU
pH 7.7
3
Q design 850 m /d
9-9 REFERENCES
AWWA (1999) Reverse Osmosis and Nanofiltration, American Water Works Association Manual M46,
Denver, Colorado.
Bergman, R. A. (2005) “Membrane Processes,” in E. E Baruth (ed.), Water Treatment Plant Design,
McGraw-Hill, New York, pp. 13.1–13.49.
Davis, M. L. and D. A. Cornwell (2008) Introduction to Environmental Engineering, McGraw-Hill,
New York, p. 876.