Review on the formation of Anammox granular sludge

As a new nitrogen removal technology, Anammox has the advantages of energy conservation, emission reduction and no additional carbon source. The Anammox technology has great application value in the treatment of wastewater with low C/N. However, Anammox can not be quickly started up due to sludge loss in the practical application. Adding mature Anammox granular sludge (AnGS) is an effective way to overcome the above-mentioned challenges. The formation process, mechanism and influencing factors of AnGS were introduced, and the technical issues related to the rapid cultivation of AnGS were summarized. The models of AnGS formation and related researches based on various models were explored. The structural characteristics and microbial community characteristics of AnGS were introduced. The relationship between anaerobic ammonia oxidizing bacteria(AnAOB) and AnGS was elucidated. The effects of inoculation sludge type, reactor type, nitrogen loading rate, organic concentration, quorum sensing, and external forces on the formation of AnGS were analyzed. The phenomenon of AnGS floating was introduced. The relationship between AnGS floating and nitrogen loading rate, bubble was analyzed and discussed. The current issues with AnGS technology were summarized and the research direction on AnGS was prospected. The purpose was to provide reference for the formation of AnGS in full-scale industrialization.