Nocardia foaming control in activated sludge process treating domestic wastewater

Yiu Fai TSANG, S. N. SIN, H. CHUA

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18 Citations (Scopus)

Abstract

In this study, filamentous bacteria (Nocardia amarae) were identified as the major causal microorganism in foaming sludge. The results of growth kinetics study indicated that N. amarae had a relatively strong affinity for non-readily biodegradable fatty acids. N. amarae was able to consume various fatty acids at a constant growth yield from 0.413 to 0.487 g/gCOD. Under common F/M ratio (less than 0.5 gBOD/gMLSS/d) used in activated sludge processes, specific growth rate of N. amarae was found to be more significant than that of non-filamentous bacteria. Based on this feature, a novel technique feast–fast operation (FFO) was developed for the foaming control. The sludge volume index (SVI) rapidly decreased from 300 to 80 mL/g and further stabilized at about 70 mL/g and the system was free from stable foam, while the BOD removal efficiency was maintained above 95%. This control technology effectively suppressed the overgrowth of filaments and improved the settleability of activated sludge without adverse effects on the treatment performance and the process stability. Copyright © 2007 Elsevier Ltd. All rights reserved.
Original languageEnglish
Pages (from-to)3381-3388
JournalBioresource Technology
Volume99
Issue number9
DOIs
Publication statusPublished - Jun 2008

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Activated sludge process
Fatty acids
activated sludge
Bacteria
Wastewater
Fatty Acids
fatty acid
sludge
wastewater
bacterium
Biochemical oxygen demand
Growth kinetics
foam
Microorganisms
Foams
microorganism
kinetics
index
effect
removal

Citation

Tsang, Y. F., Sin, S. N., & Chua, H. (2008). Nocardia foaming control in activated sludge process treating domestic wastewater. Bioresource Technology, 99(9), 3381-3388. doi: 10.1016/j.biortech.2007.08.012

Keywords

  • Foaming control
  • Wastewater treatment
  • Filamentous bacteria
  • Long-chain fatty acids