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.