反硝化对于处理低C/N废水具有重要意义。在这项研究中,黄铁矿自养反硝化(PAD)与三维生物膜电极反应器(BER)耦合以增强反硝化。广泛研究了电流对反硝化的影响。与BER和PAD相比,PAD-BER的硝酸盐去除率分别提高了14.90%和74.64%,分别。此外,电子利用,胞外聚合物分泌,PAD-BER中的反硝化酶活性(NaR和NiR)增强。微生物群落研究表明,Dokdonella,Hydrogenophaga,硝基螺旋体,和Terrimonas成为反硝化的主要属。与PAD和BER相比,关键反硝化基因的丰度,nirk,nirs,和nosZ都在PAD-BER中增强。这项研究表明,增强的自养反硝化和反硝化基因负责改善PAD-BER中的反硝化。实践要点:PAD-BER显示出更高的硝酸盐去除率,EPS,NAR,和NIR活动。反硝化的三种类型(HD,HAD,和PAD)及其在PAD-BER中的贡献百分比进行了分析。在PAD-BER的三个反硝化过程中,HAD占主导地位。对微生物群落组成和关键反硝化基因进行了测试,以揭示反硝化机理。
Denitrification is of great significance for low C/N wastewater treatment. In this study, pyrite autotrophic denitrification (PAD) was coupled with a three-dimensional biofilm electrode reactor (BER) to enhance denitrification. The effect of current on denitrification was extensively studied. The nitrate removal of the PAD-BER increased by 14.90% and 74.64% compared to the BER and the PAD, respectively. In addition, the electron utilization, extracellular polymeric substances secretion, and denitrification enzyme activity (NaR and NiR) were enhanced in the PAD-BER. The microbial communities study displayed that Dokdonella, Hydrogenophaga, Nitrospira, and Terrimonas became the main genera for denitrification. Compared with the PAD and the BER, the abundance of the key denitrification genes narG, nirK, nirS, and nosZ were all boosted in the PAD-BER. This study indicated that the enhanced autotrophic denitrifiers and denitrification genes were responsible for the improved denitrification in the PAD-BER. PRACTITIONER POINTS: PAD-BER displayed higher nitrate removal, EPS, NAR, and NIR activity. The three types of denitrification (HD, HAD, and PAD) and their contribution percentage in the PAD-BER were analyzed. HAD was dominant among the three denitrification processes in PAD-BER. Microbial community composition and key denitrification genes were tested to reveal the denitrification mechanisms.