Tang Xinhua, Huang Yu, Tan Shenyu, Yang Heng
School of Civil Engineering and Architecture, Wuhan University of Technology Wuhan 430070 China
RSC Adv. 2024 May 13;14(22):15431-15440. doi: 10.1039/d4ra02260b. eCollection 2024 May 10.
In this study, a denitrification biofilter coupled with water electrolysis (DNBF-WE) was developed as a novel heterotrophic-hydrogen autotrophic denitrification system, which could enhance denitrification with limited organic carbon in the secondary effluent. The volumetric denitrification rate of DNBF-WE reached 152.16 g N m d (C/N = 2, = 60 mA, and HRT = 5 h). Besides, the vertical spatial denitrification of DNBF-WE was explored, with the nitrate removal rate being 49.5%, 16.3%, and 29.3% in the top, middle, and bottom, respectively. The concentration of extracellular polymeric substances (EPSs) was consistent with the denitrification performance vertically. The high-throughput sequencing analysis results revealed that autotrophic denitrification bacteria () gradually enriched along DNBF-WE from top to bottom. The functional gene prediction results illustrated the vertical stratification mechanisms of the denitrification. Both dissimilatory nitrate reduction and denitrification contributed to nitrate removal, and denitrification became more advantageous with an increase in the filter depth. The research on both the performance of DNBF-WE and the characteristics of microbial communities in the vertical zones of the biofilter may lay a foundation for the biofilter denitrification process in practice.
在本研究中，开发了一种结合水电解的反硝化生物滤池（DNBF-WE）作为新型异养-氢自养反硝化系统，该系统可利用二级出水中有限的有机碳强化反硝化作用。DNBF-WE的容积反硝化速率达到152.16 g N m⁻³ d⁻¹（C/N = 2，I = 60 mA，HRT = 5 h）。此外，还探究了DNBF-WE的垂直空间反硝化情况，其顶部、中部和底部的硝酸盐去除率分别为49.5%、16.3%和29.3%。胞外聚合物（EPSs）的浓度在垂直方向上与反硝化性能一致。高通量测序分析结果表明，自养反硝化细菌沿DNBF-WE从顶部到底部逐渐富集。功能基因预测结果阐明了反硝化的垂直分层机制。异化硝酸盐还原和反硝化作用均有助于硝酸盐去除，且随着滤池深度增加，反硝化作用更具优势。对DNBF-WE性能以及生物滤池垂直区域微生物群落特征的研究可为实际中的生物滤池反硝化过程奠定基础。
