▎ 摘　　要

NOVELTY - Use of nitrogen-doped graphene is claimed in promoting the enrichment of anammox bacteria and denitrification of wastewater. USE - Nitrogen-doped graphene used in promoting the enrichment of anammox bacteria, Candidatus Kuenenia, Candidatus Brocadia, Candidatus Jettenia and Candidatus Scalindua and denitrification of wastewater and in improving the abundance of genes encoding anammox key enzymes Hzs and Hdh, improve the abundance of nitrogen metabolism-related genes NirS, NirK, NorB, NosZ and NrfA in anammox wastewater denitrification, and improve the abundance of cyclic diguanylate gene DgcB, PLeC, PLeD and quinolone signal molecule gene TrpE, TrpG (all claimed). ADVANTAGE - The nitrogen-doped graphene promotes the growth of the anaerobic ammonia oxidation specific microorganism and reactor higher denitrification efficiency, and improves the abundance of the anaerobic ammonia oxidation flora key function gene. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: 1. method for promoting the enrichment of anammox bacteria and the denitrification of wastewater by nitrogen-doped graphene, involving: inoculating sludge and nitrogen-doped graphene in wastewater, cultivating anammox sludge, and denitrifying wastewater by controlling operating conditions; 2. nitrogen-doped graphene, which comprises C-N and C=N, contains two forms of nitrogen, pyridine and pyrrole, and having shrunken and porous morphology structure; and 3. method for preparing nitrogen-doped graphene, involving: a. dissolving urea in graphene oxide suspension, the concentration of described graphene oxide suspension is 2-2.5mg/mL, and the mass ratio of urea and graphene oxide is (2-3):(1-2), and ultrasonically mixing uniformly after stirring to obtain a mixture; b. reacting mixture at 160-200℃ for 14-18 hours, cooling to room temperature, washing with deionized water until neutral, and freeze-drying to obtain a dried product; and c grinding dried product and then calcining at 480-520℃ for 0.5-1.5 hours under the protection of argon to obtain product.