Response of denitrobacteria involved in nitrogen removal for treatment of simulated livestock wastewater using a novel bioreactor

A ceramic filter medium (CFM) and dewatered aluminum sludge (DAS) were used as a small-scale combined biofilter to treat synthetic livestock wastewater. The average removal efficiency of ammonia nitrogen (NH4+-N) and total nitrogen (TN) reached 95.75 and 75.11% respectively. Illumina sequencing indicated that, except for initial media, most beta diversities of napA, narG, nirS, qnorB, and nosZ in the CFM or DAS were in a steady-state condition regardless of space-time variation, while these genes showed discrepancy between the CFM and DAS. In addition, the dominant genera were principally influenced by the synergic environmental factors, namely NH4+-N, TN, chemical oxygen demand (COD), and pH of effluents. This research demonstrated that the elimination of TN for treating synthetic livestock wastewater could be achieved by increasing the relative abundance of Azoarcus, Rhodanobacter, and Burkholderia. Meanwhile, increasing these genera contributes to suppressing the genera disadvantageous to TN attenuation.