The Role of Primary Clarifier in Biological Processes for Nutrient Removal

생물학적 질소·인제거 공정에서 일차 침전지의 영향

  • Whang, Gye-Dae (Department of Environment science and Engineering, Kyung Hee University) ;
  • Kim, Tae-Kyung (Department of Environment science and Engineering, Kyung Hee University)
  • 황규대 (경희대학교 환경응용화학대학 환경공학과) ;
  • 김태경 (경희대학교 환경응용화학대학 환경공학과)
  • Received : 2006.06.02
  • Accepted : 2006.11.20
  • Published : 2007.01.30


The lab-scale BNR processes fed with Municipal Wastewater Before or After Primary Clarifier (MWBPC or MWAPC) were operated to observe the behavior of particle organic matter in terms of nitrification and denitrification efficiency. As a result of the fractionation of the COD from MWBPC or MWAPC using an aerobic respirometric serum bottle reactor, the total mass of biodegradable organic matter from MWBPC is about 52% greater than the mass from MWAPC. Batch reactors were operated to observe the effect of the Particulate Organic Matter (POM) on substrate utilization for denitrification. Although the consumption of POM for denitrification was observed, the increment of the Specific Denitrification Rate (SDNR) was not great. In terms of the effect of POM on nitrification at different HRTs, activate sludge reactors were operated to determine the optimal HRT when MWBPC and MWAPC were fed relatively. All reactors showed a great organic matter removal efficiency. Reactors fed with MWAPC had obtained the nitrification efficiency above 90% when the HRT of 4 hr, at least, was maintained, while reactors fed with MWBPC had same efficiency when the HRT longer than 5 hr was kept. Three parallel $A^2/O$ systems fed with MWBPC or MWAPC relatively were operated to investigate the effects of POM on BNR processes with varying the HRT of an anoxic reactor. For all systems, the efficiency of organic matter removal and denitrification, respectively, was great and about the same. In case of denitrification efficiency, system with MWAPC had 1.5% lower than system with MWBPC at the same HRT of anoxic reactor of 2 hr, and the increasing the HRT of the anoxic reactor by 1 hr in systems fed with MWBPC resulted in a 3.5% increment. The denitrification rate was similar while the consumption of organic matter in systems fed with MWBPC was higher than system fed with MWBPC. It suggests that POM in MWBPC was not be used significantly as a substrate for denitrification in system with the HRT of 3 hr of an anoxic reactor.


  1. 유영수, 선단무산소조와 원수분배를 이용한 고도처리공정과 $A^2/O$공정의 영양염류 제거특성 비교, 연세대학교 대학원 도시공학과 석사학위 논문, pp. 43-56 (2000)
  2. 조남운, 임봉수, 어성욱, 간헐 포기를 결합한 MLE 공정과 $A^2/O$공정의 영양소 제거 특성 비교, 상하수도학회지, 15(4), pp. 325-333 (2001)
  3. Baeza, J. A., Gabriel, D. and Lafuente, J., Effect of Internal Recycle on the Nitrogen Removal Efficiency of an onaerobic/ anoxic/oxic($A^2/O$) Wastewater Treatment Plant(WWTP), Process Biochemistry, 39(2004), pp. 1615-1624 (2003)
  4. Benninger, R. W. and Sherrard, J. H., Nitrification and Alkalinity Relationships in Activated Sludge, J. Water Pollut. Control Fed., 50(9), pp. 2132-2142 (1978)
  5. Carley, B. N. , and Mavinic, D. S., The Effects of External Carbon Loading in Nitrification and Denitrification of a High-Amonia Landfill Leachate, J. Water Pollut. Control Fed., 63(1), pp. 51-59 (1991)
  6. Clarkson, R. A., Lau, P. J. and Krichten, D. J., Single-sludge Pure-oxygen Nitrification and Phosphorus Removal, J. Water Pollut. Control Fed., 52(4), pp. 770-779 (1980)
  7. Hanaki, K., Wantawin, C. and Ohgaki, S., Effects of the Activity of Heterotrophs on Nitrification in a Suspended-Growth Reactor, Wat. Res., 24(3), pp. 289-296 (1990)
  8. Henze, M., Grady Jr., C. P. L., Gujer, W., Marais, G. V. R. and Mastuo, T., Activated slugde model No. 1 : First Report by IAWPRC Task Group on Mathematical Modelling for Design and Operation of Biological Wastewater Treatment, IAWPRC Scientific and Technical Report Series 1, Elsevier Science, London (1987)
  9. Henze, M., The Influence of Raw Wastewater Biomass on Activated Sludge Oxygen Respiration Rates and Denitrification Rates, Wat. Sci. Technol., 21, pp. 603-607 (1989)
  10. Henze, M., Gujer, W. and Mino, T., Wastewater and Biomass Characterization for the Activated Sludge Model No. 2 : Biological phosphorus removal, Wat. Sci. Technol, 31(2), pp. 13-23 (1995)
  11. Lawrence, A. W. and Brown, C. G., Design and Control of Nitrifying Activated Sludge Systems, J. Water Pollut. Control Fed, 48(7), pp. 1779-1803 (1976)
  12. Marais, G. V. R., Loewenthal, R. E. and Siebritz, I. P., Review : Observations Supporting Phosphate Removal by Biological Excess Uptake, Wat. Sci. Technol, 15(3/4), pp. 15-41 (1988)
  13. Moser, E. R., Kuhni, M. K., Bemhard, C. and Siegrist, H., Fermentation of Raw Sludge on a Industrial Scale and Applications for Elutriating Its Dissolved Products and Non-sedimentable Solids, Wat. Res., 33(16), pp. 3503-3511 (1999)
  14. Orhon, D., Artan, N., Buyukmurat, M. and Gorgiin, E., The Effect of Residual COD on the Biological Treatability of Textile Wastewater, Wat. Sci. Technol, 26(3/4), pp. 815-825 (1992)
  15. Randall, C. W., Waltrip, D. and Wable, M. V., Upgrading a Municipal Activated Sludge Plant for High-rate Biological Nutrient Removal, Wat. Sci. Technol, 22(7/8), pp. 21-33 (1990)
  16. U. S. EPA, Process Design Manual Nitrogen Control, Office of Technology Transfer, Washington D. C. (1975)
  17. U. S. EPA, Manual : Nitrogen control, EPA 625/R-93/010, Office of Research and Development, Cincinnati, OH. (1993)
  18. Wentzel, M. C, Dold, P. L., Ekama, G. A. and Marais, G. V. R., Kinetics of Biological Phosphorus Release, Wat. Sci. Technol, 17, pp. 57-71 (1985)