CIESC Journal ›› 2022, Vol. 73 ›› Issue (11): 5098-5105.DOI: 10.11949/0438-1157.20221008

• Energy and environmental engineering • Previous Articles     Next Articles

Enhance nitrogen removal via endogenous denitrification in a sludge double recirculation-anaerobic/aerobic/anoxic process

Xinjie GAO1(), Zaizhou XU1, Yongzhen PENG1(), Yuwei HUANG1, Jing DING1, Zeming AN1, Chuanxin WANG2   

  1. 1.National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China
    2.Guangdong Shouhui Lantian Engineering and Technology Co. Ltd. , Guangzhou 510075, Guangdong, China
  • Received:2022-07-19 Revised:2022-08-30 Online:2022-12-06 Published:2022-11-05
  • Contact: Yongzhen PENG

污泥双回流-厌氧/好氧/缺氧强化内源反硝化深度脱氮

高歆婕1(), 许载周1, 彭永臻1(), 黄雨薇1, 丁静1, 安泽铭1, 汪传新2   

  1. 1.北京工业大学城镇污水深度处理与资源化利用国家工程实验室,北京市污水脱氮除磷处理与过程控制工程技术 研究中心,北京 100124
    2.广东首汇蓝天工程科技有限公司,广东 广州 510075
  • 通讯作者: 彭永臻
  • 作者简介:高歆婕(1995-),女,博士研究生,907562469@qq.com
  • 基金资助:
    国家重点研发计划课题项目(2021YFC3200605);广州市产业领军人才集聚工程项目(CYLJTD-201607);高等学校学科创新引智计划(111计划)项目(基地编号D16003)

Abstract:

At present, how to economically and effectively realize the deep denitrification of low C/N domestic sewage is still a major challenge faced by sewage treatment plants. Theoretically, the endogenous denitrification in post anoxic zone can achieve advanced nitrogen removal. However,due to lacking external carbon source, it was often difficult to meet the discharge standard and saving-energy at the same time. In this study, a novel sludge double recirculation-anaerobic/aerobic/anoxic (AOA) process was set up. This process was conducive to the enrichment and cultivation of denitrifying glycogen accumulating organisms (DGAOs) and dominated by Candidatus Competibacte, which could develop and utilize of intracellular carbon sources. The TIN removal efficiency of 91.81% and the TIN concentration in effluent was 4.36mg·L-1 in the long-term treatment of low C/N ratio (3.2) real municipal wastewater. In addition, the specific endogenous denitrification rate was increased with a higher MLSS in the anoxic zone after setting secondary sludge recirculation. This was the mainly reason for achieving advanced nitrogen removal. With the improvement of the nitrogen removal efficiency, the sufficient intracellular carbon sources storage in anaerobic zone was increase, and the endogenous denitrification enhanced. The nitrogen removal performance showed a positive cycle. Finally, the additional carbon source generation, which was from the bottom of the secondary sedimentation tank and introduced to the system through the secondary sludge recirculation, further enhanced the nitrogen removal. This study clarified the mechanisms and key factors for advanced nitrogen removal in sludge double recirculation-AOA system, and provided feasibility for the increased nitrogen removal efficiency in low C/N municipal wastewater treatment.

Key words: anaerobic, aeration, waste water, endogenous denitrification, low C/N ratio, enhanced nitrogen removal

摘要:

目前,如何经济有效地实现低C/N生活污水深度脱氮仍是污水处理厂面临的一个重大挑战。理论上后置反硝化可以实现深度脱氮效果,但往往由于缺乏外碳源难以同时满足经济高效脱氮。本研究建立的新型污泥双回流-厌氧/好氧/缺氧(AOA)工艺有利于富集培养以Candidatus Competibacter为主的反硝化聚糖菌(DGAOs),能够开发与利用内碳源脱氮。该系统长期处理低C/N (3.2)实际城市生活污水,TIN去除率达91.81%,出水TIN浓度为4.36 mg·L-1。此外,提高第二污泥回流量增加了缺氧区的MLSS同时提升了比内源反硝化速率,是深度氮去除的主要原因。随着去除效果的提升,充分的厌氧环境使得内碳源贮存量升高,脱氮效果呈现正向循环。二沉池底部产生的额外碳源随第二回流引入系统进一步强化脱氮。本研究阐明了污泥双回流-AOA系统节碳脱氮的原理与关键,为低C/N城市污水的脱氮效率提供了一种可行性。

关键词: 厌氧, 曝气, 污水, 内源反硝化, 低C/N, 强化脱氮

CLC Number: