Data on the treatment of nitrate contaminated wastewater using a continuous upflow palm fiber biofilm electrode reactor (PBER)

The infiltration of residual nitrate nitrogen fertilizer carried by runoff is the primary cause of this pollution. As a potential means to improve bioremediation performance and overcome these limitations, electrode biofilm technology has attracted widespread attention.This study constructed a continuously upflow PBER to investigate the effects of C/N ratio, HRT, and inflow method on the denitrification performance of PBER, and analyzed the microbial community structure of the reactor under different inflow methods. The continuous upflow palm fiber biofilm electrode reactor (PBER) constructed in this study achieved a nitrate removal efficiency of 97.9% ± 0.6% and a nitrate removal rate of 6.15 ± 0.08 mg-N/(L·h) under optimal operating conditions (current density of 250 mA/m2, C/N ratio of 1.5, HRT of 8 hours, and vertical inflow). The accumulation of nitrite and ammonium nitrogen in the effluent was relatively low. Microbial analysis showed that the inflow method influenced the community composition and abundance of dominant denitrifying bacteria in the two systems, with lower microbial diversity observed in the vertical inflow PBER. Both vertical and parallel inflow PBER systems showed enrichment of the hydrogen autotrophic denitrifying bacterium Thauera. Additionally, vertical inflow PBER exhibited enrichment of Azonexus, a bacterium capable of extracellular electron transfer. The PBER demonstrated high efficiency and low energy consumption, achieving efficient and stable nitrate removal while also facilitating the resource utilization of agricultural and forestry waste.

径流携带的残留硝态氮肥下渗是该类污染的主要成因。作为一种有望提升生物修复性能并克服上述局限的技术，电极生物膜技术受到了广泛关注。本研究构建了连续上流式棕榈纤维生物膜电极反应器（PBER），以探究碳氮比（Carbon/Nitrogen ratio, C/N）、水力停留时间（Hydraulic Retention Time, HRT）及进水方式对PBER反硝化性能的影响，并分析了不同进水方式下反应器内的微生物群落结构。本研究构建的连续上流式棕榈纤维生物膜电极反应器（PBER）在最优运行工况（电流密度250 mA/m²、碳氮比1.5、水力停留时间8 h、垂直进水）下，硝态氮去除率可达97.9% ± 0.6%，硝态氮去除速率为6.15 ± 0.08 mg-N/(L·h)，出水中亚硝态氮与氨氮的积累量均处于较低水平。微生物分析结果表明，进水方式会影响两种系统内的群落组成与优势反硝化菌的丰度，垂直进水式PBER的微生物多样性更低。垂直进水与平行进水式PBER系统均富集了氢自养反硝化细菌陶厄氏菌属（Thauera）。此外，垂直进水式PBER还富集了具备胞外电子转移能力的阿佐氏菌属（Azonexus）。该PBER兼具高效低耗的特点，可实现硝态氮的高效稳定去除，同时还能助力农林废弃物的资源化利用。