聚氨酯填料孔径对反硝化滤池运行及微生物群落的影响

宋家骏; 杨继富; 于娜; 吕育锋; 赵翠

doi:10.13928/j.cnki.wrahe.2026.07.007

水利水电技术（中英文） ›› 2026, Vol. 57 ›› Issue (7) : 87 -103. DOI: 10.13928/j.cnki.wrahe.2026.07.007

城市水循环过程解析与水质安全保障专栏

聚氨酯填料孔径对反硝化滤池运行及微生物群落的影响

宋家骏 ¹ ,
杨继富 ¹ ,
于娜 ² ,
吕育锋 ¹ ,
赵翠 ¹

作者信息 +

Effects of polyurethane medium pore size on operation and microbial community of denitrification biofilters

Jiajun SONG ¹ ,
Jifu YANG ¹ ,
Na YU ² ,
Yufeng LYU ¹ ,
Cui ZHAO ¹

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文章历史 +

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摘要

【目的】探究了不同孔径聚氨酯(PU)填料在反硝化生物滤池(DNBFs)中的脱氮性能及微生物机制，明确填料孔径与运行参数，揭示孔径对生物膜特性及氮代谢功能基因的调控规律，为地下水硝酸盐污染治理提供技术支撑。【方法】选取15 ppi(大孔径)、30 ppi(中孔径)和40 ppi(小孔径)3种PU填料构建DNBFs,设置空床水力停留时间(EBHRT)为3、2、1.5、1 h,监测各系统硝态氮(NO^-₃-N)去除率、体积反硝化速率(R_vd)等脱氮指标；测定不同填料表面生物量及胞外聚合物(EPS)含量与组成；通过高通量测序分析微生物群落结构，并结合PICRUSt2预测氮代谢功能基因(nirKS、norBC、nosZ)丰度。【结果】在EBHRT=1.5 h时，30 ppi PU填料的DNBF实现了更高的NO^-₃-N去除率(93.15%)和R_vd(0.89 kg N·m^-3·d^-1),优于40 ppi PU(0.83 kg N·m^-3·d^-1)和15 ppi PU(0.75 kg N·m^-3·d^-1)。该填料表面生物量为93.6 mg·cm^-3,胞外聚合物(EPS)产量为49.61 mg·g^-1,均高于其余两种填料。微生物群落分析表明，30 ppi PU富集了相对丰度更高的Proteobacteria门(63.93%)和反硝化菌群，如Simplicispira(15.87%),Cloacibacterium(14.24%)等。PICRUSt2氮功能预测进一步显示，其反硝化基因(nirKS、norBC和nosZ)的丰度较15 ppi PU和40 ppi PU分别高出1.6倍和1.5倍。【结论】30 ppi的PU通过提升生物量与EPS产量、富集反硝化功能菌群及关键基因丰度，显著提高DNBFs脱氮效率。为构建高效、稳定的地下水硝酸盐去除系统提供可靠支撑，也为工业与市政废水处理中推广经济可行的反硝化工艺提供理论基础与技术参考。

Abstract

[Objective] The denitrification performance and microbial mechanisms of polyurethane(PU) media with different pore sizes in denitrification biofilters(DNBFs) are investigated to clarify the relationship between medium pore size and operating parameters, to reveal the regulatory effects of pore size on biofilm characteristics and nitrogen metabolism functional genes, thereby providing technical support for groundwater nitrate pollution control.[Methods] Three DNBFs were constructed using 15 ppi(large pore), 30 ppi(medium pore), and 40 ppi(small pore) PU media. The empty bed hydraulic retention time(EBHRT) was set to 3, 2, 1.5, and 1 h. The nitrate nitrogen(NO^-₃-N) removal rate and volumetric denitrification rate(R_vd) were monitored. The biomass on the medium surface and the content and composition of extracellular polymeric substances(EPS) were determined. The microbial community structure was analyzed via high-throughput sequencing, and the abundance of nitrogen metabolism functional genes(nirKS, norBC, nosZ) was predicted using PICRUSt2.[Results] At EBHRT=1.5 h, the DNBF with 30 ppi PU medium achieved a higher NO^-₃-N removal rate(93.15%) and R_vd(0.89 kg N·m^-3·d^-1), outperforming those with the 40 ppi(0.83 kg N·m^-3·d^-1) and 15 ppi(0.75 kg N·m^-3·d^-1) media. The biomass on this medium surface was 93.6 mg·cm^-3, and the extracellular polymeric substances(EPS) production was 49.61 mg·g^-1, both of which were higher than those of the other two media. Microbial community analysis showed that the 30 ppi medium enriched a higher relative abundance of the phylum Proteobacteria(63.93%) and denitrifying bacterial groups(e.g., Simplicispira: 15.87%; Cloacibacterium: 14.24%). PICRUSt2-based prediction of nitrogen function further revealed that the abundance of denitrification genes(nirKS, norBC, nosZ) in the 30 ppi medium was 1.6 times and 1.5 times higher than that of the 15 ppi and 40 ppi media, respectively.[Conclusion] The 30 ppi PU significantly improves the denitrification efficiency of DNBFs by increasing biomass and EPS production, enriching denitrifying functional bacterial groups, and enhancing the abundance of key genes. These findings provide reliable support for constructing efficient and stable groundwater nitrate removal systems, and also provide a theoretical basis and technical reference for promoting economically feasible denitrification processes in industrial and municipal wastewater treatment.