Abstract

The biofilms on pipe walls in water distribution systems are of interest since they can lead to chlorine demand, coliform growth, pipe corrosion, and water taste and odor problems. As such, the study described in this paper is part of an AWWARF and Tampa Bay Water tailored collaboration project to determine the effect of blending different source waters on the water quality in various distribution systems. The project was based on 18 independent pilot distribution systems (PDS), each being fed by a different water blend (7 finished waters blended in different proportions). The source waters compared were groundwater, surface water, and brackish water, which were treated in a variety of pilot distribution systems, including reverse osmosis (RO) (desalination), both membrane and chemical softening, and ozonation-biological activated carbon (BAC), resulting in a total of 7 different finished waters. The observations from this study consistently demonstrated that unlined ductile iron was more heavily colonized by a biomass than galvanized steel, lined ductile iron, and PVC (in that order) and that the fixed biomass accumulation was more influenced by the nature of the supporting material than by the water quality (including the secondary residual levels). However, although the bulk liquid water cultivable bacterial counts (i.e. heterotrophic plate counts or HPCs) did not increase with a greater biofilm accumulation, the results also suggested that high HPCs corresponded to a low disinfectant residual more than a high biofilm inventory. Furthermore, temperature was found to affect the biofilms, plus the AOC was important when the residual was between 0.6 and 2.0 mg $Cl_2/l$. An additional aspect of the current study was that the potential of the exoproteolytic activity (PEPA) technique was used along with a traditional so-called destructive technique in which the biofilm was scrapped off the coupon surface, resuspended, and cultivated on an R2A agar. Both techniques indicated similar trends and relative comparisons among the PDSs, yet the culturable biofilm values for the traditional method were several orders of magnitude lower than the PEPA values.

주제어

#Pipe material   #biofilm biomass quantification   #drinking water   #PEPA  

참고문헌 (19)

1. Rittman, B. E. and P. M. Huck. 1989. Biological treatment of public water supplies. CRC Crit. Rev. Environ. Control 19(2): 119 
2. Goshko, M. A., H. A. Minnigh, W. O. Pipes, and R. R. Christian. 1983. Relationships between standard plate counts and other parameters in water distribution systems. J. Am. Water Works Assoc. 75: 568-571 
3. Oh, B. K., Y. K. Kim, Y. M. Bae, W. H. Lee, and J. W. Choi. 2003. Detection of Escherichia coli 0157:H7 using immunosensor based on surface plasmon resonance. J. Microbiol. Biotechnol. 12: 780-786 
4. LeChevallier, M. W., C. D. Lowry, and R. G. Lee. 1990. Disinfecting biofilms in a model distribution system. J. Am. Water Works Assoc. 82(7): 87 
5. Somville, M. and G. Billén. 1983. A method for determining exoproteolytic activity in natural waters. Limnol. Oceanogr. 28: 190-193 
6. American Public Health Association. 1995. Standard Methods for the Examination of Water and Wastewater, 19th Ed. Washington, DC, U.S.A 
7. Holden, B., M. Greetham, B. T. Croll, and J. Scutt. 1995. The effect of changing inter-process and final disinfection reagents on corrosion and biofilm growth in distribution pipes. Water Sci. Technol. 32: 213-220 
8. Laurent, P. and P. Servais. 1995. Fixed bacterial biomass estimated by potential exoproteolytic activity. Can. J. Microbiol. 41(8): 749-752 
9. Kim, M. D., W. J. Lee, K. W. Park, K. H. Rhee, and J. H. Seo. 2003. Two-step fed-batch culture of recombinant Escherichia coli for production of Bacillus licheniformis maltogenic amylase. J. Microbiol. Biotechnol. 12: 273-278 
10. de Beer, D., R. Srinivasan, and P. S. Stewart. 1994. Direct measurement of chlorine penetration into biofilms. Appl. Environ. Microbiol. 60: 4339-4344 
11. Costerton, J. W., K. J. Cheng, G. G. Geesey, T. I. Ladd, J. C. Nickel, M. Dasgupta, and T. J. Marrie. 1987. Bacterial biofilms in nature and disease. Ann. Rev. Microbiol. 41: 435-464 
12. Quignon, F., M. Sardin, L. Kiene, and L. Schwartzbrod. 1997. Poliovirus-1 inactivation and interaction with biofilm: A pilot-scale study. Appl. Environ. Microbiol. 63: 978- 982 
13. Brown, M. R. W. and P. Gilbert. 1993. Sensivity of biofilms to antimicrobial agents. J. Applied Bact. 74: 87S-97S 
14. Van der Kooij, D. 1992. Assimiliable organic carbon as an indicator of bacterial regrowth. J. Am. Water Works Assoc. 84: 57-65 
15. LeChevallier, M. W., C. D. Lowry, R. G. Lee, and D. L. Gibbon. 1993. Examining the relationship between iron corrosion and the disinfection of biofilm bacteria. J. Am. Water Works Assoc. 85(7): 111 
16. Stewart, P. S. and J. B. Raquepas. 1995. Implications of reaction-diffusion theory for the disinfection of microbial biofilms by reactive antimicrobial agents. Chemical Engineering Science 50: 3099-3104 
17. Hahm, D. H., M. J. Yeom, W. M. Ko, E. H. Lee, H. J. Lee, I. S. Shim, and H. Y. Kim. 2003. Characterization of the nickel resistance gene from Legionella pneumophila: Attention of nickel resistance by ppk (polyphosphate kinase) distribution in Escherichia coli. J. Microbiol. Biotechnol. 12: 114-120 
18. Chen, X. and P. S. Stewart. 1996. Chlorine penetration into artificial biofilm is limited by a reaction-diffusion interaction. Environ. Sci. Technol. 30: 2078-2083 
19. Niquette, P., P. Servais, and R. Savoir. 2000. Impacts of pipe materials on densities of fixed bacterial biomass in a drinking water distribution system. Wat. Res. 34(6): 1952- 1956 

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