工业水处理 ›› 2022, Vol. 42 ›› Issue (12): 78-84. doi: 10.19965/j.cnki.iwt.2022-0174

• 试验研究 • 上一篇    下一篇

CASS工艺改进及对城镇污水含氮污染物的去除

郑丽丽1,2,3(),刘闯3,王倩3,李肖燕1,2,马莉萍1,2,梁文艳3   

  1. 1.北京中铁生态环境设计院有限公司,北京 102600
    2.中铁第五勘察设计院集团有限公司,北京 102600
    3.北京林业大学环境科学与工程学院,北京 100083
  • 收稿日期:2022-11-20 出版日期:2022-12-20 发布日期:2022-12-20
  • 作者简介:郑丽丽(1989— ),工程师。电话:15652937693,E-mail:zll890831@163.com
  • 基金资助:
    国家自然科学基金项目(51672028);中铁第五勘察设计院集团有限公司科技研究开发计划项目(T5Y2020-B09);北京中铁生态环境设计院有限公司科技研究开发计划项目(70052004)

Improvement of CASS process and enhanced removal of nitrogen-containing pollutants from urban wastewater

Lili ZHENG1,2,3(),Chuang LIU3,Qian WANG3,Xiaoyan LI1,2,Liping MA1,2,Wenyan LIANG3   

  1. 1.Beijing China Railway Ecology & Environment Design Institute Co. ,Ltd. ,Beijing 102600,China
    2.China Railway Fifth Survey and Design Institute Group Co. ,Ltd. ,Beijing 102600,China
    3.College of Environmental Science and Engineering,Beijing Forestry University,Beijing 100083,China
  • Received:2022-11-20 Online:2022-12-20 Published:2022-12-20

摘要:

含氮污染物的去除一直是污水处理领域的难题。传统的周期循环式活性污泥法(CASS)处理工艺在污水处理厂中广泛应用,但其普遍存在对总氮处理效果不佳的问题。分别通过增加硝化液回流、添加聚氨酯海绵填料2种方式,对传统周期循环式活性污泥法处理工艺进行改进,研究了循环周期、曝气时间、排水比和内硝化液回流比等运行参数对CASS改进工艺中总氮强化去除效果的影响,并通过高通量测序分析不同工艺中微生物群落的差异。研究结果表明,改进工艺的最佳操作参数:循环周期为8 h、曝气时间为4 h、排水比为50%、硝化液回流比为35%。与传统CASS工艺相比,CASS回流工艺(RCASS)和CASS复合生物膜工艺(IFAS-CASS)对TN的去除率分别增加10%~15%和15%~37%,出水TN质量浓度分别低至14.8、4.65 mg/L。在最优运行条件下,2种CASS改进工艺能够发挥最佳的处理作用,强化TN的去除。IFAS-CASS工艺内的Actinobacteria(放线菌门)和Proteobacteria(变形菌门)丰度较高,因此IFAS-CASS工艺可以更好地强化去除含氮污染物。

关键词: 城镇污水处理, 周期循环式活性污泥法, 回流工艺, 复合生物膜

Abstract:

The removal of nitrogen-containing pollutants has been a challenge in the field of wastewater treatment. The traditional cyclic activated sludge system(CASS) treatment process is widely used in wastewater treatment plants, but it generally has the problem of poor treatment effect on total nitrogen. The traditional CASS process was improved by adding nitrate liquid reflux and polyurethane sponge filler, respectively. The effects of operating parameters such as cycle time, aeration time, drainage ratio and internal nitrification fluid reflux ratio on the enhanced removal of total nitrogen in improved CASS process were investigated, and the differences of microbial communities in different processes were analyzed by high-throughput sequencing. The results showed that the optimal operating parameters for the improved process were: cycle time of 8 h, aeration time of 4 h, drainage ratio of 50%, and nitrification solution reflux ratio of 35%. Compared with the traditional CASS process, the removal rates of TN by CASS reflux process (RCASS) and CASS composite biofilm process(IFAS-CASS) increased by 10%-15% and 15%-37%, respectively, and the effluent TN mass concentrations were as low as 14.8 and 4.65 mg/L, respectively. Under the optimal operating conditions, two CASS improvement processes can play the best treatment role to enhance the TN removal. The abundance of Actinobacteria and Proteobacteria in the IFAS-CASS process was higher, resulted in better enhanced removal of nitrogen-containing pollutants by the IFAS-CASS process.

Key words: urban wastewater treatment, cyclic activated sludge system, reflux process, composite biofilm process

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