Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2011-4-19
pubmed:abstractText
New Activated Sludge (NAS(®)) is a hybrid, floc-based nitrogen removal process without carbon addition, based on the control of sludge retention times (SRT) and dissolved oxygen (DO) levels. The aim of this study was to examine the performance of a retrofitted four-stage NAS(®) plant, including on-line measurements of greenhouse gas emissions (N(2)O and CH(4)). The plant treated anaerobically digested industrial wastewater, containing 264 mg N L(-1), 1154 mg chemical oxygen demand (COD) L(-1) and an inorganic carbon alkalinity of 34 meq L(-1). The batch-fed partial nitritation step received an overall nitrogen loading rate of 0.18-0.22 kg N m(-3) d(-1), thereby oxidized nitrogen to nitrite (45-47%) and some nitrate (13-15%), but also to N(2)O (5.1-6.6%). This was achieved at a SRT of 1.7 d and DO around 1.0 mg O(2) L(-1). Subsequently, anammox, denitrification and nitrification compartments were followed by a final settler, at an overall SRT of 46 d. None of the latter three reactors emitted N(2)O. In the anammox step, 0.26 kg N m(-3) d(-1) was removed, with an estimated contribution of 71% by the genus Kuenenia, which constituted 3.1% of the biomass. Overall, a nitrogen removal efficiency of 95% was obtained, yielding a dischargeable effluent. Retrofitting floc-based nitrification/denitrification with carbon addition to NAS(®) allowed to save 40% of the operational wastewater treatment costs. Yet, a decrease of the N(2)O emissions by about 50% is necessary in order to obtain a CO(2) neutral footprint. The impact of emitted CH(4) was 20 times lower.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1879-2448
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2811-21
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Floc-based sequential partial nitritation and anammox at full scale with contrasting N2O emissions.
pubmed:affiliation
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Gent, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't