不同COD/N对主流同步短程硝化反硝化的影响  

Effects of COD/N ratios on mainstream simultaneous nitritation and denitritation process

作　　者：张群 张郅昊 于婷 徐湖淳 易鑫 徐光景 ZHANG Qun;ZHANG Zhi-hao;YU Ting;XU Hu-chun;YI Xin;XU Guang-jing(School of Marine Science and Environment Engineering,Dalian Ocean University,Dalian 116023,China;Jingzhou Agricultural Technology Extension Center,Jingzhou 434000,China)

机构地区：[1]大连海洋大学海洋科技与环境学院,辽宁大连116023 [2]荆州市农业技术推广中心,湖北荆州434000

出　　处：《环境生态学》2023年第4期68-73,共6页Environmental Ecology

基　　金：国家自然科学基金青年项目(31800104)资助。

摘　　要：为了解决农村生活污水生物脱氮过程中碳源不足的问题,利用混合悬浮污泥和生物膜的多循环序批式反应器(Sequencing Batch Reactor,SBR)建立了同步短程硝化反硝化工艺,并详细分析了COD/N比例对该工艺的影响。当COD/N比例为4∶1时,总氮去除率和亚硝化率分别达到85.0%和95.6%;当COD/N比例为2∶1时,总氮去除率和亚硝化率分别为76.1%和83.8%;当COD/N比例降至1∶1时,总氮去除率降至31.0%,而亚硝化率仅1.2%,说明COD/N比例对同步短程硝化反硝化影响明显。当碳源充足时,NO^(-)_(2)-N可在缺氧段被全部去除,导致亚硝酸氮氧化菌(Nitrite Oxidizing Bacteria,NOB)的可利用底物(NO-2-N)远远低于氨氧化菌(Ammonium Oxidizing Bacteria,AOB)的可利用底物(NH^(+)_(4)-N),且生物膜内缺氧反硝化菌也能在好氧段进行反硝化,进一步减少了NOB的可利用底物。加上短污泥龄控制,悬浮NOB被持续冲刷排出。因此,多循环SBR内NOB抑制的核心点是高COD/N情况下反硝化菌与NOB竞争NO-2-N,通过强化反硝化抑制NOB的策略可在工程应用中予以借鉴。In order to solve limitation of organic carbon sources for biological nitrogen removal from rural domestic wastewater,a novel simultaneous nitritation and denitritation process was developed in a multi-cycle sequencing batch reactor(SBR)with integrated fixed biofilm and suspended sludge.Effect of COD/N ratios on this process was detailly investigated.Results showed that the total nitrogen(TN)removal efficiency and nitrite accumulation rate(NAR)reached 85.0%and 95.6%at an influent COD/N ratio of 4∶1.As the influent COD/N ratio decreased to 2∶1,TN removal efficiency and NAR decreased to 76.1%and 83.8%,respectively.As COD/N decreased to 1∶1,TN removal rate and NAR decreased as low as 31.0%and 1.2%,respectively,indicating that COD/N ratio significantly affected both TN removal efficiencies and NOB suppression.In the presence of sufficient organic carbons,nitrite could be consumed by denitrifiers in the anoxic phases,so nitrite available for nitrite oxidizing bacteria(NOB)was far less than ammonium available for ammonium oxidizing bacteria(AOB).Besides,some nitrite produced by AOB could simultaneously be removed by NOB in the biofilm,aggravating the serious nitrite shortage of NOB,so NOB was easily suppressed and washed out from SBR.Therefore,the key control strategy of NOB suppression in a multi-cycle SBR is the nitrite competition between denitrifiers and NOB with enough organics,which can be used for reference in related engineering applications of nitritation and denitritation through enhancing denitritation.

关 键 词：农村污水处理 序批式反应器 亚硝酸氮短缺 分步进水 短污泥龄 亚硝酸氮氧化菌 

分 类 号：X703[环境科学与工程—环境工程]