Effect of Biogas Feeding Mode on the Performance of Anammox Reactor

This study proposes an innovative process that aims to achieve the synergy of biogas purification and efficient nitrogen removal by introducing biogas into an Anammox reactor. In this process, high-purity methane (with a purity of up to 97.6%) is selectively extracted from biogas. Concurrently, the invigorating impact of biogas substantially diminishes the average size of sludge particles (from 0.73 to 0.65 mm), enhances mass transfer efficiency, and refines its physical and chemical characteristics, thereby augmenting the efficiency of nitrogen removal. When the nitrogen loading rate of the system reached 4880 mg N L^-1 day^-1, the total nitrogen removal amount reached 3200 mg N L^-1 day^-1. Microbial community analysis showed that Planctomycota was continuously enriched and dominated and Methylosarcina proliferated, confirming the promoting effect of biogas on changes in the anammox microbial system. This process offers an efficient and feasible technical pathway for mainstream anammox engineering by integrating biogas recycling and denitrification.