Biofilm carrier type affects biogenic sulfur-driven denitrification performance and microbial community dynamics in moving-bed biofilm reactors.

Autotrophic denitrification with biosulfur (ADBIOS) provides a sustainable technological solution for biological nitrogen removal from wastewater driven by biogenic S, derived from biogas desulfurization. In this study, the effect of different biofilm carriers (conventional AnoxK™ 1 and Z-200 with a pre-defined maximum biofilm thickness) on ADBIOS performance and microbiomics was investigated in duplicate moving bed-biofilm reactors (MBBRs). The MBBRs were operated parallelly in continuous mode for 309 days, whilst gradually decreasing the hydraulic retention time (HRT) from 72 to 21 h, and biosulfur was either pumped in suspension (days 92-223) or supplied in powder form.