A free nitrous acid (FNA)-based technology for reducing sludge production

Wang, Qilin, Ye, Liu, Jiang, Guangming and Yuan, Zhiguo (2013) A free nitrous acid (FNA)-based technology for reducing sludge production. Water Research, 47 11: 3663-3672. doi:10.1016/j.watres.2013.04.016

Author Wang, Qilin
Ye, Liu
Jiang, Guangming
Yuan, Zhiguo
Title A free nitrous acid (FNA)-based technology for reducing sludge production
Journal name Water Research   Check publisher's open access policy
ISSN 0043-1354
Publication date 2013-07-01
Year available 2013
Sub-type Article (original research)
DOI 10.1016/j.watres.2013.04.016
Volume 47
Issue 11
Start page 3663
End page 3672
Total pages 10
Place of publication London , United Kingdom
Publisher I W A Publishing
Language eng
Formatted abstract
Sludge treatment and disposal is one of the major challenges for biological wastewater treatment plants and can represent up to 60% of their total operating costs. This study presents a novel strategy based on free nitrous acid (FNA or HNO2) treatment to achieve sludge reduction. Two sequencing batch reactors treating synthetic domestic wastewater were used, with one serving as an experimental reactor and the other as a control. In the experimental system, 50% of the excess sludge was exposed to FNA at 2.0 mg N/L for 24–42 h in an FNA treatment unit and then returned to the parent reactor. The sludge wastage flow from the experimental reactor was adjusted to obtain a similar mixed liquor suspended solids concentration to that in the control reactor, which was operated at a sludge retention time of 15 days. It was found that sludge production in the experimental system was 28% lower in comparison to the control. The addition of the FNA-treated sludge did not negatively affect the treatment performance and sludge properties of the experimental reactor, namely the organic carbon and nitrogen removal, nitrous oxide (N2O) emission and sludge settleability. Endogenous denitrification batch tests indicate that FNA-treated sludge is available as a carbon source for denitrification.
Keyword Free nitrous acid
Sludge reduction
Excess sludge
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2014 Collection
Advanced Water Management Centre Publications
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Citation counts: TR Web of Science Citation Count  Cited 25 times in Thomson Reuters Web of Science Article | Citations
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Created: Sun, 11 Aug 2013, 10:28:09 EST by System User on behalf of Advanced Water Management Centre