Possible causes of excess sludge reduction adding metabolic uncoupler, 3,3',4',5-tetrachlorosalicylanilide (TCS), in sequence batch reactors

• Published in: Bioresource technology Vol. 173; pp. 96 - 103
• Main Authors: FENG, Xiao-Chi, GUO, Wan-Qian, YANG, Shan-Shan, ZHENG, He-Shan, DU, Juan-Shan, WU, Qu-Li, REN, Nan-Qi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier 01.12.2014
• Subjects: Applied sciences; Bacteria, Anaerobic - metabolism; Batch Cell Culture Techniques - instrumentation; Biological and medical sciences; Bioreactors - microbiology; Effluents; Energy consumption; Equipment Contamination - prevention & control; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Excitation spectra; Fundamental and applied biological sciences. Psychology; Pollution; Reactors; Reduction; Resists; Salicylanilides - metabolism; Sewage - microbiology; Sludge; Spectra; Uncoupling Agents - metabolism; Wastes; Water Purification - instrumentation; Sludge reduction; Active transport; Waste treatment; TCS; Batch process; Electronics; EPS; Metabolic uncoupler; Uncoupler; Metabolism; Reactor; Electronic transport system activity
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.09.085

Two parallel sequence batch reactors (SBRs) were operated, with and without TCS addition, to research the causes of sludge reduction by uncouplers. Three possible mechanisms of sludge reduction by TCS were studied: (1) occurrence of metabolic uncoupling, (2) consumption of more energy to resist the infection of TCS, (3) promotion of lysis-cryptic growth by TCS addition. Results showed the remarkable reduction of electronic transport system (ETS) activity and specific cellular ATP (SATP) in TCS reactor, which proved the occurrence of metabolic uncoupling. The increasing amounts of extracellular polymeric substances (EPS), as measured by chemical methods and excitation-emission matrix (EEM) fluorescence spectra, implied microorganisms consumed more energy to resist TCS. The similar DNA concentrations of the effluents in two reactors indicated sludge lysis was not intensified by TCS. Therefore, uncoupler might not only cause metabolic uncoupling but also induce more energy consumption in the production of some substances to resist uncoupler.