Activated-Sludge Yield Reduction Using Chemical Uncouplers

• Published in: Water environment research Vol. 71; no. 4; pp. 454 - 458
• Main Authors: Strand, Stuart E., Harem, Greg N., Stensel, H. David
• Format: Journal Article
• Language: English
• Published: Alexandria, VA Water Environment Federation 01.07.1999; Blackwell Publishing Ltd
• Subjects: 320604 - Energy Conservation, Consumption, & Utilization- Municipalities & Community Systems- Municipal Waste Management- (1980-); ACCLIMATION; ACTIVATED SLUDGE; ACTIVATED SLUDGE PROCESS; Aeration; Applied sciences; AROMATICS; BIODEGRADATION; Biological and medical sciences; Biological treatment of waters; Biomass; Biotechnology; Bottles; Chemical oxygen demand; CHEMICAL REACTIONS; CHLORINATED AROMATIC HYDROCARBONS; DECOMPOSITION; ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General purification processes; HALOGENATED AROMATIC HYDROCARBONS; HYDROGEN COMPOUNDS; Industrial applications and implications. Economical aspects; LIQUID WASTES; MANAGEMENT; MUNICIPAL WASTES; ORGANIC CHLORINE COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; Oxygen; OXYGEN COMPOUNDS; Phenols; Pollution; PROCESSING; Research Papers; RESPIRATION; Sludge; SLUDGE REDUCTION; Sludge treatment; TRICHLOROPHENOL; UNCOUPLERS; WASTE MANAGEMENT; WASTE PROCESSING; WASTE WATER; WASTES; Wastewater treatment; Wastewaters; WATER; WATER TREATMENT; Water treatment and pollution; YIELDS; USA; Activated sludge; Decrease; Yield; Uncoupler; Waste water purification; Experimental study; Biological purification
• ISSN: 1061-4303; 1554-7531
• DOI: 10.2175/106143097X122013

To determine whether chemical additions can be used to reduce sludge production in biological wastewater treatment, uncouplers of respiratory adenosine triphosphate production were added to activated-sludge cultures. Effects of 12 uncoupling chemicals on cell yields in batch cultures were compared. The most effective of these chemicals, 2,4,5-trichlorophenol (TCP), was tested in a continuous-flow, bench-scale, completely mixed activated-sludge system treating simulated municipal wastewater. Initially, TCP addition reduced average yield by approximately 50%. After 80 days, sludge yield increased as TCP levels in the reactor decreased. Specific oxygen use rates were good indicators of sludge yields, increasing from 8 g${\rm O}_{2}$/g volatile suspended solids (VSS)·d without TCP addition to approximately 20 g${\rm O}_{2}$/g VSS·d, when sludge yield was lowest. These results suggest that addition of chemical uncouplers to biological wastewater treatment systems can significantly reduce sludge production, but long-term bioacclimation can eventually negate the effects of uncoupler addition.