Page 504 - Water and wastewater engineering

MEMBRANE FILTRATION 12-21

12-8. Determine the number of racks for the Spartanburg membrane filtration system for
the “worst case scenario” of one rack off-line for CIP plus one rack off-line for back-
wash given the following design requirements:
3
Q max 30,300 m /d
3
2
J 0.127 m /h · m
2
3
J max allowable 0.170 m /h · m
Cleaning cycle 30 min
Time off-line to clean 150 s
2
Membrane area per module 15 m
Modules per rack 90
12-9. Determine the number of racks for the town of Agate’s membrane filtration system
for the worst case scenario of one rack off-line for CIP plus one rack off-line for
backwash given the following design requirements:
3
Q winter 7,600 m /d
3
Q summer 10,200 m /d
Winter water temperature 1 C
Summer water temperature 15 C
2
3
J 0.159 m /h · m for winter temperature
3
2
J max allowable 0.267 m /h · m for winter temperature
Cleaning cycle 30 min
Time off-line to clean 150 s
2
Membrane area per module 15 m
Modules per rack 40
12-7 DISCUSSION QUESTIONS

12-1. Because of the change in viscosity of water, a membrane design for cold water will
have a higher flux and be able to treat a greater flow rate at a higher temperature.
True or false?

12-2. What is the difference between irreversible and reversible transmembrane membrane
pressure?
12-3. Describe the parameter values you would need to compare membranes from different
manufacturers.

12-8 REFERENCES
AWWA (2005) Microfiltration and Ultrafiltration Membranes for Drinking Water, AWWA Manual
M53, American Water Works Association, 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.
Carmen, P. C. (1937) “Fluid Flow through Granular Beds,” Transactions of Institute of Chemical
Engineers, London, vol. 15, p. 150.
Chellam, S. and J. G. Jacangelo (1998) “Existence of Critical Recovery and Impacts of Operational Mode
on Portable Water Microfiltration,” Journal of Environmental Engineering, vol. 124, no. 12,
pp. 1211–1219.