Effect of modified biochar on nitrogen removal performance and population structure of anaerobic ammonium oxidation system

High-throughput sequencing analysis revealed the effects of the two modified biochars on the microbial community structure of the anaerobic ammonia oxidation system: the species of anaerobic ammonia oxidizing bacteria in all three reactors were Candidatus-Kuenenia, and the addition of magnetic ferromanganese oxide modified biochar could increase the abundance of anaerobic ammonia oxidizing bacteria and related denitrifying bacteria, as well as the microbial species richness in the whole reactor. The alkali-modified biochar reduced the abundance of anaerobic ammonia-oxidizing bacteria in the first stage and also reduced the species richness in the reactor, but gradually returned to the abundance level of the blank control group in the subsequent experimental stages.