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过程工程学报 ›› 2020, Vol. 20 ›› Issue (8): 970-978.DOI: 10.12034/j.issn.1009-606X.219325

• 生化工程 • 上一篇    下一篇

盐度对缺氧–好氧SBBR微生物活性及N2O释放的影响

巩有奎1,2*， 岳英龙1， 彭永臻2   

  1. 1. 烟台职业学院建筑工程系，山东 烟台 264670 2. 北京工业大学城镇污水深度处理与资源化利用技术国家工程实验室，北京 100124
  • 收稿日期:2019-10-22 修回日期:2019-12-08 出版日期:2020-08-24 发布日期:2020-08-24
  • 通讯作者: 巩有奎 260943813@qq.com
  • 基金资助:
    国家自然科学基金

The effects of salinity on microbial activity and N2O release in anoxic–aerobic sequencing batch biofilm reactor

Youkui GONG1,2*, Yinglong YUE1, Yongzhen PENG2   

  1. 1. Department of Architecture Engineering, Yantai Vocational College, Yantai, Shandong 264670, China 2. National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
  • Received:2019-10-22 Revised:2019-12-08 Online:2020-08-24 Published:2020-08-24

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摘要： 含盐废水硝化过程常常出现亚硝酸盐积累，从而导致强温室气体N2O的产生。利用序批式生物膜反应器(SBBR)，考察了含盐生活污水同步脱氮过程不同菌群活性变化及N2O释放过程。结果表明，盐度增加，各菌群活性受抑制程度依次为亚硝酸盐氧化菌(Nitrite Oxidizing Bacteria, NOB)?氨氧化菌(Ammonia Oxidizing Bacteria, AOB)?碳氧化菌。实验盐度范围内(0~20 g NaCl/L)，COD出水约稳定在50.0 mg/L，平均NH4+去除率由98%以上降至约70.5%，TN去除率由42.4%降至16.9%，N2O平均产率由3.9%增至13.3%。与SND变化类似，微生物体内聚-β-羟基脂肪酸酯(PHA)和糖原(Gly)积累随盐度增加呈先增加后减少趋势。N2O主要产生于AOB好氧反硝化过程和硝化后期内源反硝化过程。低盐度(≤10 g NaCl/L)下，SBBR内缺氧区有助于减少N2O释放；盐度增加，高盐度耦合低内碳源合成，加剧了内源反硝化阶段各还原酶之间电子竞争。高盐度导致微生物胞外聚合物(EPS)分泌增加，多聚糖(PS)比例上升，膜内缺氧区域减少，抑制N2O还原过程。

关键词: SBBR, 盐度, N2O, 好氧反硝化, 内源反硝化

Abstract: Accumulation of nitrites is frequently observed in saline wastewater nitrification processes, which often results in the release of the strong greenhouse gas, nitrous oxide (N2O). This study investigated the effect of salinity on microbial activity and N2O release characteristics during the simultaneous nitrification and denitrification processes in a sequencing batch biofilm reactor (SBBR). The result showed that salinity inhibited the microbial activities of each bacterial group in increasing, sequential order as follows: nitrite oxidizing bacteria (NOB)>ammonia oxidizing bacteria (AOB)>carbon oxidizing bacteria. The effluent COD was stable at about 50.0 mg/L in the range of salinity from 0 to 20 g NaCl/L. The average NH4+ removal efficiency reduced from more than 98% to 70.5%, and TN removal efficiency reduced from 42.4% to 16.9% respectively, while the N2O yield increased from 3.9% to 13.3%. Similar to SND efficiency, the internal concentration of carbon sources (PHA and Gly) first increased and then decreased with increase in salinity. The N2O release was mainly produced in AOB aerobic and endogenous denitrification processes. The low N2O release could be ascribed to the anoxic zone deep in the SBBR at low salinity (≤10 g NaCl/L). As the salinity was increased to more than 10 g NaCl/L, there was a decrease in internal carbon source synthesis, which aggravated the electron competition between each bacterial reductases in the denitrification process. Further increase in salinity led to an increase in extracellular polymer substances (EPS) synthesis and the proportion of polysaccharides (PS) in the EPS. A decrease in the anoxic area deep in the membrane led to the inhibition of the N2O reduction.

Key words: SBBR, salinity, N2O, aerobic denitrification, endogenous denitrification