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Associate Professor
Supervisor of Master's Candidates

Alma Mater:日本国立爱媛大学
Degree:Doctoral Degree
Business Address:大连理工大学综合实验4号楼412室
Contact Information:0411-84708619
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Spatial and daily variations of nitrous oxide emissions from biological reactors in a full-scale activated sludge anoxic/oxic process

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Indexed by:Journal Papers

First Author:Jia Sijing

Co-author:Chen Xiaoqiang,Suenaga Toshikazu,Terada Akihiko,Ishikawa Susumu,Nishimura Fumitake,Ding Shaolan,Fujiwara Taku

Date of Publication:2019-03-01

Journal:Journal of bioscience and bioengineering

Included Journals:PubMed、Scopus



Page Number:333-339

ISSN No.:1347-4421

Key Words:Affecting factors,Anoxic/oxic process,Daily variation,Emission factors,Nitrous oxide,Production mechanism,Spatial variation

Abstract:Nitrous oxide (N2O) is an important greenhouse gas that can be emitted from wastewater treatment plants (WWTPs). Such emissions are reportedly process specific and related to operational parameters. This study was conducted to clarify spatial and daily variations of N2O in a full-scale activated sludge anoxic/oxic process that consisted of an anoxic tank and three oxic tanks (oxic-1, oxic-2 and oxic-3), all of which except the final sedimentation tank were fully covered. Higher dissolved N2O (D-N2O) loading and gaseous N2O (G-N2O) emissions were observed for oxic-3 than for the anoxic, oxic-1, and oxic-2 tanks, implying that there was higher N2O production potential via nitrification in the latter stage of the oxic tank. Moreover, the sudden decrease in dissolved oxygen concentration after the peak was found to lead to abrupt production of D-N2O at oxic-3 in the anoxic/oxic process. The increases in AOB amoA, AOB nirK and the following AOB norB gene transcripts at the end of the oxic-2 tank suggested that nitrifier denitrification occurred to produce N2O under low dissolved oxygen conditions when the N2O peak was observed. Additionally, the much lower transcription levels of the two nosZ genes suggested lower N2O consumption. The N2O emission factors ranged from 0.087% to 0.302%, and lower N2O emission factors were observed during summer.Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.