Enhanced nitrogen removal from low C/N wastewater using biodegradable and inert carriers: performance and microbial shift

Abstract This work aims at investigating the enhancing effect of biodegradable and inert carriers on nitrogen removal from low C/N wastewater and revealing temporal changes in community succession. Natural corncobs and commercial fibers were used as biodegradable and inert carriers, respectively. Results showed that the TN removal efficiency was enhanced by 24% and 8.98% using biodegradable and inert carriers, respectively. For corncob carriers, denitrifiers achieved an obvious enrichment and reached a peak on the 30th day. On contrast, inert carriers were more favorable for the enrichment of nitirifiers. Additionally, the dominant denitrifying genus in the corncob system had changed to Dechloromonas, while it remained as Thauera at inert carriers. Finally, the potential coupling pattern of corncob conversion with denitrification in the corncob system was proposed based on the relevant functional enzymes. This work promotes a comprehensive understanding about carrier-enhanced nitrogen removal systems.