摘要
该文以厌氧/缺氧/好氧方式(An/A/O)运行序批式生物反应器(SBR),采用NO_(3)^(-)驯化缺氧反硝化聚磷菌,利用pH值调控An/A/O-SBR内各菌群间的竞争优势,通过考察脱氮除磷过程的化学计量学参数变化,确定了不同pH下SBR内聚磷菌-聚糖菌(PAOs-GAOs)间竞争关系及N_(2)O释放特性。结果表明,An/A/O-SBR内存在PAOs和GAOs对碳源的竞争,高pH有利于反硝化聚磷菌增殖、提升SBR内同步脱氮除磷效率并降低N_(2)O产率。pH由6.5增至8.0,PAOs转化外碳源比例由24.1%增至55.6%。pH=8.0,SBR内脱氮和除磷效率均达90%以上,平均N_(2)O产率为2.8%。不同pH值下,An/A/O-SBR内厌氧阶段ΔGly/ΔPHA、ΔGly/COD_(in)、PRA/COD_(in)以及缺氧阶段PUA/NaRA、ΔGly/ΔPHA均表现出PAOs-GAOs共存特性,微碱性条件促进SBR内微生物趋向富集反硝化聚磷菌的生化反应动力学。pH=6.5,N_(2)O产率达11.2%。低pH值耦合高NO_(2)^(-)形成高浓度游离亚硝酸,对反硝化聚磷菌的毒性及对亚硝态氮还原酶、氧化亚氮还原酶的活性抑制作用,是导致低pH值下SBR脱氮除磷性能降低和N_(2)O产率增加的重要因素,以N_(2)O作为终产物的GAOs反硝化比例增加,加剧了低pH条件下N_(2)O释放。
The regulation of competition between phosphorous accumulating bacteria(PAOs)and glycogen accumulating organisms(GAOs),as well as the N_(2)O emissions was studied with an anaerobic/anoxic/aerobic sequencing batch reactor(An/A/O-SBR).The denitrifying phosphorus bacteria(DPBs)was acclimated with NO_(3)^(-)addition at the beginning of anoxic stage.Results showed that there existed competition between PAOs and GAOs for external carbon sources.Higher pH was proved to be effective to improve the efficiency of simultaneous nitrogen and phosphorus removal in An/A/O-SBR,which reduced the N_(2)O yield as well.The conversion of external carbon source by PAOs increased from 24.1%to 55.6%with the pH increasing from 6.5 to 8.0.The denitrification and phosphorus removal efficiency were both more than 90%,with the N_(2)O yield of 2.8%at the pH of 8.0.Both theΔGly/ΔPHA,ΔGly/COD_(in),PRA/COD_(in)in anaerobic stage and the PUA/NaRA,ΔGly/ΔPHA in anoxic stage showed the coexistence characteristics of DPBs-GAOs no matter which pH was applied.The slightly alkaline conditions promoted the accumulation of DPBs.The N_(2)O yield was 11.2%at the p H value of 6.5.The lower pH value,coupled with the higher NO_(2)^(-)accumulation,resulted in high FNA concentration,which definitely inhibited the activities of Nir and Nos.Meanwhile,the proportion of denitrification by GAOs with N_(2)O as the final product increased,which intensified the release of N_(2)O.
作者
巩有奎
冯华
任丽芳
李美玲
孙洪伟
GONG Youkui;FENG Hua;REN Lifang;LI Meiling;SUN Hongwei(Department of Architecture Engineering,Yantai Vocational College,Yantai 264670,China;Yantai Engineering&Technology College,Yantai 264006,China;School of Environmental and Material Engineering,Yantai University,Yantai 264005,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2021年第7期145-153,共9页
Environmental Science & Technology
基金
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)
关键词
pH
反硝化聚磷菌
聚糖菌
同步脱氮除磷
氧化亚氮
pH
denitrifying phosphorus bacteria
glycogen accumulating organisms
denitrification phosphorus removal
N2O
