CIESC Journal ›› 2021, Vol. 72 ›› Issue (8): 4381-4390.DOI: 10.11949/0438-1157.20201916

• Energy and environmental engineering • Previous Articles     Next Articles

The characteristics of SNDPR and N2O emission in anaerobic-oxygen limited SBR treating low C/N domestic sewage

Youkui GONG1(),Peiyun LUO1,Hongwei SUN2   

  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:2020-12-25 Revised:2021-04-07 Online:2021-08-05 Published:2021-08-05
  • Contact: Youkui GONG

厌氧-限氧SBR处理低C/N生活污水SNDPR启动及N2O释放

巩有奎1(),罗佩云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,教授,260943813@qq.com
  • 基金资助:
    国家自然科学基金项目(51668031);烟台职业学院2020年校本科研项目(2020XBZD001)

Abstract:

By gradually reducing the carbon to nitrogen (C/N) ratio, the phosphorus accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were acclimated in a sequencing batch with anaerobic-limited oxygen operation mode. The simultaneous nitrification-denitrification and phosphorus removal(SNDPR) process of low C/N ratio domestic wastewater was accomplished. The competition between PAOs and GAOs, as well as the N2O release at different C/N ratio, was studied. The results showed that the simultaneous nitrification and denitrification (SND) nitrogen removal and phosphorus removal efficiency of SNDPR were 83.5% and over 90% respectively at the C/N ratio of 7.0. The N2O emission was 0.54 mg/L. The SND and phosphorus removal efficiency decreased to 60.1% and 80.5% respectively at C/N ratio of 3.0—3.5. Meanwhile, the N2O emission reached 1.09 mg/L and the N2O yield was 7.68%. The decrease of PHA accumulation, coupled with the increase of denitrification by GAOs, resulted in the higher N2O emission at the lower C/N ratio of domestic wastewater. The variation of endogenous substance in different stage of SBR showed that PAOs-GAOs coexisted at each C/N ratio. GAOs tended to be enriched in SNDPR with the decreasing of C/N ratio. The extracellular polymer (EPS) increased from 43.4 mg/g VSS to 50.5mg/g VSS and the sludge volume index(SVI) increased from 99 ml/g to 127 ml/g with the decrease of C/N ratio. In loose EPS (LB-EPS), the ratio of protein (PN) to polysaccharide (PS) (PN/PS) decreases as C/N increases, and the hydrophilicity of sludge increases, which is not conducive to sludge dewatering.

Key words: carbon to nitrogen ratio, phosphorous accumulating organisms (PAOs), glycogen accumulating organisms (GAOs), simultaneous nitrification and denitrification phosphorous removal process(SNDPR), N2O

摘要:

以厌氧-限氧方式运行序批式生物反应器(SBR),采用逐步降低进水碳氮比(C/N)方式驯化聚磷菌(PAOs)和聚糖菌(GAOs),启动了低C/N生活污水同步脱氮除磷过程(SNDPR),并考察了SNDPR内PAOs、GAOs间竞争关系及系统脱氮除磷性能过程N2O释放特性。结果表明,C/N=7.0,SBR限氧段脱氮和除磷效率分别为83.5%和90%以上,N2O产量为0.54 mg/L;C/N=3.0~3.5,脱氮和除磷效率分别降至60.1%和80.5%,N2O产量达1.09 mg/L。SBR内不同反应阶段内源物质变化均表现出PAOs-GAOs共存特性。高C/N有利于微生物合成聚-β-羟基烷酸酯(PHA)并促进N2O还原。C/N降低,SBR内污泥内源物质转化倾向于富集GAOs的降解特性。氨氧化菌(AOB)好氧反硝化过程及GAOs以PHA作为电子供体的内源反硝化过程促进了N2O的释放。随C/N降低,SBR内污泥平均胞外聚合物(EPS)由43.4 mg/g VSS增至50.5 mg/g VSS,污泥容积指数(SVI)由99 ml/g增至127 ml/g。疏松型EPS(LB-EPS)内,蛋白质(PN)与多糖(PS)之比(PN/PS)随C/N增加而降低,污泥亲水性增加,不利于污泥脱水。

关键词: 碳氮比, 聚磷菌, 聚糖菌, 同步脱氮除磷, N2O

CLC Number: