The activated sludge process generates a large amount of excess sludge as a byproduct, which is one of the most serious challenges in biological wastewater treatment. In the present study, the feasibility of 2,4,6-trichlorophenol (TCP) and malonic acid (MA) as metabolic uncouplers to reduce sludge generation in the sequence batch reactor (SBR) for treating organic wastewater for a long period was studied. The results showed that 2 mg/L TCP could reduce sludge generation by about 47%, while chemical oxygen demand (COD) removal efficiency and sludge settlability were not obviously influenced. Although 10 mg/L MA could also reduce excess sludge production by about 30% while slightly affecting COD removal, it seriously deteriorated sludge settlability. Accordingly, TCP is a better uncoupler for sludge reduction for a longer period in the SBR for treating organic wastewater, and MA can only be used as a short-term or transitional uncoupler. Microscopic and 16S ribosomal deoxyribonucleic acid analyses showed that the microbial population of sludge varied when uncouplers were fed to the activated sludge system. Occurrence of large amounts of filament and the disappearance of protozoa may be the main reason for the aggravation of sludge settlability under uncoupled metabolic conditions caused by MA.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Davis, R. D., & Hall, J. E. (1997). European Water Pollution Control, 7, 9–17.
Zhao, Q. L., & Kugel, G. (1996). Journal of Environmental Science and Health Part A, 31, 2211–2231.
Canales, A., Pareilleux, A., Rols, J. L., Goma, C., & Huyard, A. (1994). Water Science and Technology, 30, 96–106.
Lee, N. M., & Welander, T. (1996). Biotechnology Letters, 18, 429–434.
Low, E. W., & Chase, H. A. (1999). Water Research, 33, 1119–1132.
Tempest, W., & Neijssel, M. (1984). Annual Review of Microbiology, 38, 459–486.
Tempest, W., & Niejssel, M. (1992). FEMS Microbiology, 64, 91–99.
Tsai, S. P., & Lee, Y. H. (1990). Biotechnology and Bioengineering, 35, 138–145.
Okey, R. W., & Stensel, H. D. (1993). Toxicology and Environmental Chemistry, 40, 235–254.
Riveranevares, J. A., Wyman, J. F., Vonminden, D.L. (1995). Environmental Toxicology and Chemistry, 4, 251–256.
Chen, G. H., Mo, H. K., & Liu, Y. (2002). Water Research, 36, 2077–2083.
Chen, G. H., Mo, H. K., & Saby, S. (2001). Water Science and Technology, 42, 189–200.
Chen, Z. Y., Wang, L., & Zhou, Q. (2006). Environment Pollution and Control, 8, 34–39 (Chinese).
American Public Health Association (2000). Standard methods for the examination of water and wastewater (20th ed.). Washington, DC: American Public Health Association.
The authors thank the China Natural Science Foundation for supporting to this work (no. 40571145).
About this article
Cite this article
Zheng, G.H., Li, M.N., Wang, L. et al. Feasibility of 2,4,6-Trichlorophenol and Malonic Acid as Metabolic Uncoupler for Sludge Reduction in the Sequence Batch Reactor for Treating Organic Wastewater. Appl Biochem Biotechnol 144, 101–109 (2008). https://doi.org/10.1007/s12010-007-8101-3
- COD removal
- Microbial population
- Sludge reduction
- Sludge settling
- Uncoupling metabolism