Enumeration and Comparison of Fecal Indicator Bacteria in a Sewage Treatment Plant Using Activated Sludge Process

활성슬러지공정 하수종말처리장의 분원성 지표세균의 농도 및 비교

  • Received : 2010.02.15
  • Accepted : 2010.03.26
  • Published : 2010.04.30


Indicator bacteria of fecal pollution were enumerated and compared by various detection methods for influent and final effluent of a sewage treatment plant. Total coliforms were enumerated by four methods including most probable numbers, chromogenic enzyme substrate test, membrane filtration, and plate counts and were about $10^4$ for influent and $10^2{\sim}10^3\;CFU/ml$ for final effluent. Fecal coliforms ranged between $10^3$ and $10^4$ for influent and $10^2\;CFU/ml$ for effluent by chromogenic enzyme substrate test and membrane filtration. Fecal streptococci counts were 1-log less than fecal coliforms counts, $10^2{\sim}10^3$ for influent and $10^1\;CFU/ml$ for effluent. Total coliforms numbers by plate count both in influent and in effluent showed 1-log higher than by the other three methods. Statistical analysis revealed that numbers of total coliforms by plate count in final effluent had the highest average of correlation (r=0.778, p<0.01) compared with those by the other three methods. In addition, total coliforms numbers by plate count showed most significant correlation (r=0.835, p<0.01) with those by chromogenic test which is well-known as its highest recovery efficiency. These results suggest that the plate count would be the optimum detection method for total coliforms in wastewater treatment plants which are the only microbiological standard of final effluent from wastewater treatment plants in the Republic of Korea, considering economic aspects and difficulties in laboratories.


fecal indicator bacteria;total coliforms;fecal coliforms;fecal streptococci;sewage treatment plant


  1. Ministry of Enviornment Republic of Korea : 2008 White paper on Environment. Seoul, 362-364, 2009.
  2. Lee, G. C. and Lee, H. S. : Total coliforms and fecal coliforms as microbial indicators of waterborne enteric viruses in korean surface water. Journal of the Korean Society of Water and Wastewater, 20, 885-892, 2006.
  3. Jung, H. M., Im, Y. T. and Ryu, J. G. : Interpretation of coliform data in natural water by statistical analysis of frequency and seasonal distribution. Proceedings of Korean Society on Water Quality, Seoul, 39-42, 1999.
  4. Ministry of Environment Republic of Korea : Water and Wastewater Technology, 2008.
  5. Lee, M. A. and Lee, S. H. : Comparative study on detecting methods for total coliform in sewage effluent. Korean Journal of Environmental Health, 33, 422-427. 2007.
  6. Jang, H. J., Lee, M. Y., Choi, S. Y., Lee, E. K., Oh, S. J. and Park, S. W. : Comparison chromogenic enzyme substrate test with the standard multiple tube fermentation method and membrane filtration method for detection of coliforms in drinking water. Journal of Korean Society on Water Quality, 18, 501-508.2002.
  7. Ministry of Environment Republic of Korea : Drinking Water Technology, 2008.
  8. Harwood, V. J., Levine, A. D., Scott, T. M., Chivukula, V., Lukasik, J., Farrah, S. R. and Rose, J. B. : Validity of the indicator organism paradigm for pathogen reduction in reclaimed water and public health protection. Applied and Environmental Microbiology, 71, 3163-3170, 2005.
  9. Beck, Y. S. and Sohn, J. S. : Studies on chlorine demand and its decay kinetics in chlorinated sewage effluents. Journal of Korean Society on Water Quality, 21, 176-183, 2005.
  10. Lee, O. M., Kim, T. H., Nam, Y. K., Lee, M. J. and Yu, S. H. : Reactivation study and comparison of disinfection efficiency of coliform bacteria in municipal wastewater treatment using UV and gamma ray. Applied Chemistry, 12, 221-224, 2008.
  11. American Water Works Association Research Foundation : Colilert system for Total Coliform and Escherichia coli. 1991.
  12. Chao, K. K., Chao, C. C. and Chao, W. L. : Evaluation of Colilert-18 for detection of coliforms and Escherichia coli in subtropical freshwater. Applied and Environmental Microbiology, 70, 1242-1244, 2004.
  13. Jang, H. J. and Lee, Y. O. : A study on investigation of fecal contamination indicator bacteria for management of source water quality. Korean Journal of Environmental Health, 29, 19-27, 2003.
  14. Kim, S. D., Cho, J. R., Kim, S. H., Lee, H. J. and Lee, Y. O. : Comparative studies on detecting methods of fecal indicators (coliforms) in surface water. Journal of Korean Society on Water Quality, 22, 1052-1059, 2006.


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