Impact of Particle Aggregated Microbes on UV Disinfection. I: Evaluation of Spore–Clay Aggregates and Suspended Spores
This article is a reply.
VIEW THE ORIGINAL ARTICLEThis article has a reply.
VIEW THE REPLYPublication: Journal of Environmental Engineering
Volume 132, Issue 6
Abstract
Aggregation of microbes with particles can reduce the effectiveness of ultraviolet (UV) disinfection. This study evaluated the comparative impact of dispersed spores, dispersed spores mixed with clay particles (nonaggregated), spore–spore aggregates, and spore–clay aggregates on UV disinfection performance in simulated drinking waters. Aggregates were induced by flocculation with alum and characterized by particle size analysis (count, volume, and surface area) of dispersed and aggregated systems, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. It was concluded that spores within aggregates of the spore–clay system were protected from UV irradiation compared to nonaggregated spores and the difference between these systems was found to be statistically significant throughout the UV range tested. In addition SEM-EDX analysis suggested that aggregate composition is nonhomogeneous with respect to the ratio of spores and clay particles among aggregates. It was estimated that 30–50% of the spores in the aggregates tested were protected from UV irradiation.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The writers gratefully acknowledge Professor Regina Sommer, Institute of Hygiene, University of Vienna, Vienna, Austria, for providing Bacillus subtilis spores for this research, and Professor Robert Bagnell, the University of North Carolina at Chapel Hill, who provided microscopic facilities and advice for aggregate imaging. They also thank the Ultraviolet Research Group at Duke University including Dr. Sharpless and Dr. Ormeci who assisted in this project. This research was funded by the USEPA Science to Achieve Results (STAR) Program, Grant No. UNSPECIFIEDR82-9012. At the time of this research, Dr. Mamane was a doctoral candidate in the Department of Civil and Environmental Engineering at Duke University.
References
Adin, A. (1999). “Particle characteristics: A key factor in effluent treatment and reuse.” Water Res., 40, 67–74.
American Public Health Association, American Water Works Association, Water Environment Federation (APHA, AWWA, WEF). (1995). Standard methods for the examination of water and wastewater, 19th Ed., Washington, D.C.
Averett, R. C., Leenheer, J. A., McKnight, D. M., and Thorn, K. A. (1994). “Humic substances in the Suwannee River, Georgia: Interactions, properties, and proposed structures.” USGS water-supply paper. ⟨http://www.ihss.gatech.edu⟩
Bell-Ajy, K., Abbaszadegan, M., Ibrahim, E., Verges, D., and LeChevallier, M. (2000). “Conventional and optimized coagulation for NOM removal.” J. Am. Water Works Assoc., 92(10), 44–58.
Cairns, W., Sakamoto, G., Comair, C., and Gehr, R. (1993). “Assessing UV disinfection of a physico-chemical effluent by medium pressure lamps using a collimated beam and pilot plant.” Proc., Planning, Design and Operation of Effluent Disinfection Systems, Water Environment Federation Specialty Conf., WEF, Whippany, N.J.
Doyle, R. J., Nedjat-Haiem, F., and Singh, J. S. (1984). “Hydrophobic characteristics of Bacillus spores.” Curr. Microbiol., 10, 329–332.
Edzwald, J. K., and Kelley, M. B. (1998). “Control of Cryptosporidium: From reservoirs to clarifiers to filters.” Water Sci. Technol., 37(2), 1–8.
Emerick, R. W., Loge, F. J., Ginn, T., and Darby, J. L. (2000). “Modeling the inactivation of particle-associated coliform bacteria.” Water Environ. Res., 72(4), 432–438.
Emerick, R. W., Loge, F. J., Thompson, D., and Darby, J. L. (1999). “Factors influencing ultraviolet disinfection performance. II: Association of coliform bacteria with wastewater particles.” Water Environ. Res., 71(6), 1178–1187.
Krasner, S. W., and Amy, G. (1995). “Jar-test evaluations of enhanced coagulation.” J. Am. Water Works Assoc.87(10), 93–107.
LeChevallier, M. W., Evans, T. M., and Seidler, R. J. (1981). “Effect of turbidity on chlorination efficiency and bacterial persistence in drinking water.” Appl. Environ. Microbiol., 42(1), 159–167.
Loge, F. J., Emerick, R. W., Thompson, D. E., Nelson, D. C., and Darby, J. L. (1999). “Factors influencing ultraviolet disinfection performance. I: Light penetration to wastewater particles.” Water Environ. Res., 71(3), 377–381.
Malley, J. P. (2000). “Engineering of UV disinfection systems for drinking water.” International Ultraviolet Association News, 2(3), 8–12.
Morowitz, H. J. (1950). “Absorption effects in volume irradiation of microorganisms.” Science, 111, 229–230.
Parker, J. A., and Darby, J. L. (1995). “Particle-associated coliform in secondary effluents: Shielding from ultraviolet light disinfection.” Water Environ. Res., 67(7), 1065–1075.
Passantino, L., Malley, J., Knudson, M., Ward, R., and Kim, J. (2004). “Effect of low turbidity and algae on UV disinfection performance.” J. Am. Water Works Assoc., 96(6), 128–137.
Qualls, R. G., Flynn, M. P., and Johnson, D. (1983). “The role of suspended particles in ultraviolet disinfection.” J. Water Pollut. Control Fed., 55(10), 1280–1285.
Rice, E. W., Fox, K. R., Miltner, R. J., Lytle, D. A., and Johnson, C. H. (1996). “Evaluating plant performance with endospores.” J. Am. Water Works Assoc., 88(9), 122–130.
Sall, J., Lehman, A., and Creighton, L. (2001). “Fitting linear models.” JMP start statistics, 2nd Ed., Duxbury Thompson Learning, Pacific Grove, Calif., 305–328.
Sharpless, C. M., Page, M. A., and Linden, K. G. (2003). “Impact of hydrogen peroxide on nitrite formation during UV disinfection.” Water Res., 37(19), 4730–4736.
Sobsey, M. D., Fuji, T., and Hall, R. W. (1991). “Inactivation of cell associated and dispersed Hepatitis-A virus in water.” J. Am. Water Works Assoc., 83(11), 64–67.
Sommer, R., and Cabaj, A. (1993). “Evaluation of the efficiency of a UV plant for drinking water disinfection.” Water Sci. Technol., 27, 357–362.
Stagg, C. H. (1976). “Inactivation of solids associated virus by hypochlorous acid.” Ph.D. dissertation, Rice Univ., Houston.
States, S., and Tomko, R. J. (2002). “Enhanced coagulation and removal of Cryptosporidium.” J. Am. Water Works Assoc., 94(11), 67–77.
Stewart, M. H., and Olson, B. H. (1996). “Bacterial resistance to potable water disinfectants.” Modeling disease transmission and its prevention by disinfection, C. J. Hurst, ed., Cambridge University Press, Cambridge, U.K., 140–192.
Stumm, W., and Morgan, J. M. (1962). “Chemical aspects of coagulation.” J. Am. Water Works Assoc., 54(8), 971–994.
Templeton, M. R., Andrews, R. C., Hofmann, R., and Whitby, G. E. (2003). “UV inactivation of floc-associated MS2 coliphage.” Proc., 76th Annual Water Environment Federation Technical Exhibition and Conf. (WEFTEC), WEF, Los Angeles.
Tombacz, E., Filipcsei, G., Szekeres, M., and Gingl, Z. (1999). “Particle aggregation in complex aquatic systems.” Colloids Surf., A, 151, 233–244.
U.S. Environmental Protection Agency (USEPA). (2003). “Draft ultraviolet disinfection guidance manual.” EPA 815-D-03-007, Office of Water, Washington, D.C.
Van Olphen, H.and Fripiat, J. J. (1979). Data handbook for clay minerals and other non-metallic materials, Pergamon, New York, ⟨http://www.clays.org⟩
Wen, H. J., Liu, C. I., and Lee, D. J. (1997). “Size and density of flocculated sludge flocs.” J. Environ. Sci. Health [C], 32(4), 1125–1137.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 132 • Issue 6 • June 2006
Pages: 596 - 606
Copyright
© 2006 ASCE.
History
Received: Aug 13, 2004
Accepted: Oct 12, 2005
Published online: Jun 1, 2006
Published in print: Jun 2006
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.