CIESC Journal ›› 2021, Vol. 72 ›› Issue (3): 1675-1683.DOI: 10.11949/0438-1157.20200829

• Energy and environmental engineering • Previous Articles     Next Articles

The competitive relationship between PAOs-GAOs and N2O emission in An/A/O-SBR under different NO3- cultivation

GONG Youkui1(),LI Meiling1,SUN Hongwei2   

  1. 1.Department of Architecture Engineering, Yantai Vocational College, Yantai 264670, Shandong, China
    2.School of Environmental and Material Engineering, Yantai University, Yantai 264005, Shandong, China
  • Received:2020-06-24 Revised:2020-07-26 Online:2021-03-05 Published:2021-03-05
  • Contact: GONG Youkui

不同NO3-浓度An/A/O-SBR系统PAOs-GAOs竞争及N2O释放特性

巩有奎1(),李美玲1,孙洪伟2   

  1. 1.烟台职业学院建筑工程系,山东 烟台 264670
    2.烟台大学环境与材料工程学院,山东 烟台 264005
  • 通讯作者: 巩有奎
  • 作者简介:巩有奎(1977—),男,博士,副教授,260943813@qq.com
  • 基金资助:
    国家自然科学基金项目(51668031);烟职博士基金2018002号;烟台职业学院横向课题(HX2020018)

Abstract:

Using anaerobic/anoxic/aerobic sequencing batch reactors (An/A/O-SBRs), the long-term impact of the NO3- cultivation on denitrification phosphorus removal performance and N2O emission characteristics was investigated in four SBRs of 10(R10), 20(R20), 30(R30) and 40 mg N/L(R40). The anaerobic and anoxic stoichiometric parameters related to various NO3- concentrations were monitored over time. The results showed that with the increasing of NO3- concentration, the total nitrogen (TN) removal efficiency decreased from more than 90% to 41.3%, and the N2O emission ratio (N2O emission/ NOx-removal) were 1.68%, 4.17%, 8.92% and 14.28% respectively, while the total phosphorus removal (TP) efficiency increased at first and then decreased. NO2- accumulates in the process of high-concentration NO3- anoxic phosphorus absorption, which inhibits the activity of DPAOs, and the carbon source competition ability of GAOs is enhanced. The ratio of DPAOs/COD consumption in anaerobic process decreased from 33.5% to 25.1%, while that of GAOs increased from 59.3% to 74.1% as the NO3- increased from 10 to 40 mg N/L. The NO2- /HNO2 accumulation coupled with the increase of GAOs, was the main reason for the reduction of nitrogen and phosphorus efficiencies and higher N2O yields under higher NO3- concentration.

Key words: denitrifying phosphorus accumulating organisms, glycogen accumulating organisms, NO3-, N2O, competitive mechanism

摘要:

采用厌氧/缺氧/好氧运行的序批式生物反应器(An/A/O-SBR),经不同NO3-浓度(10,20,30和40 mg/L,以氮计)长期驯化,考察了不同NO3-条件下An/A/O-SBR脱氮除磷及N2O释放特性,基于不同微生物降解特性分析,确定了不同NO3-浓度下SBR系统内反硝化聚磷菌(denitrifying phosphorus accumulating organisms,DPAOs)和聚糖菌(glycogen-accumulating organisms, GAOs)竞争关系。结果表明:随NO3-浓度增加,总氮(TN)去除率由90%以上降至41.3%,TP去除率呈先增高后降低的趋势,N2O产率(N2Oemission/NOx-removal)分别为1.68%、4.17%、8.92%和14.28%。An/A/O-SBR内微生物呈PAOs和GAOs共存的污染物降解特性,高浓度NO3-缺氧吸磷过程出现NO2-积累,抑制DPAOs活性,GAOs碳源竞争能力增强,NO3--N由10 mg/L增至40 mg/L,厌氧阶段PAOs的COD耗量比例由33.5%降至25.1%,相应GAOs的COD耗量由59.3%增至74.1%。DPAOs-GAOs共生体系内,反硝化过程NO2-/HNO2积累耦合反硝化聚糖菌比例增加,加剧了高NO3-下An/A/O-SBR内N2O释放。

关键词: 反硝化聚磷菌, 聚糖菌, 硝态氮, 氧化亚氮, 竞争机制

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