缺氧分段式UCT工艺的脱氮除磷效能

Performance of Anoxic Step-Wise UCT Process for Nitrogen and Phosphorus Removal

在UCT工艺的基础上,提出一种新型缺氧分段式UCT工艺用于高效脱氮除磷。试验考察了新工艺对模拟生活污水的处理效果,并对各个功能单元的氮磷去除能力和微生物群落进行分析。工艺运行结果表明,CODCr、氨氮、TN和TP的平均去除率分别为95.85%、99.37%、83.12%和87.13%。通过氮磷质量平衡发现,前段缺氧池和后段缺氧池均呈现出明显的脱氮能力。同时分段式进水模式有利于系统脱氮能力的提升,从而有效降低回流至厌氧池的NO-3-N浓度,减小NO-3-N对厌氧释磷的不利影响。高通量测序结果揭示了变形菌门(Proteobacteria)和拟杆菌门(Bacteroidota)为优势菌门。在新型UCT工艺中,Candidatus_Competibacter(18.75%~26.43%)、OLB8(7.81%~12.52%)等反硝化菌为优势菌属,Tetrasphaera和Dechloromonas是主要的聚磷菌,有利于实现高效的脱氮除磷。

Based on the UCT process,a novel anoxic step-wise UCT process was developed to nitrogen and phosphorus removal efficiently.The performance of novel UCT process during synthetic domestic wastewater treatment was evaluated in this paper.Meanwhile,the nitrogen and phosphorus removal ability and the microbial community characteristics of each functional tank were also studied.The operation results showed that average removal efficiencies of CODCr,ammonia nitrogen,TN and TP were 95.85%,99.37%,83.12%and 87.13%,respectively.The analysis of nitrogen and phosphorus mass balance demonstrated that the nitrogen removal capacity of both front-anoxic tank and back-anoxic tank were apparent.The step feed mode was beneficial for improving the performance of nitrogen removal,decreasing the concentration of NO-3-N returned to anaerobic tank and reducing the adverse effect of NO-3-N on anaerobic phosphorus release.High-throughput sequencing results revealed that Proteobacteria and Bacteroidota were the dominant phyla.Denitrifying bacteria such as Candidatus_Competbacter(18.75%~26.43%)and OLB8(7.81%~12.52%)were the dominant genus,and Tetrasphaera and Dechromonas were the main phosphorus accumulating bacteria in the novel UCT process,which were conducive to efficient nitrogen and phosphorus removal.