Effect of organic loading on phosphorus forms transformation and microbial community in continuous-flow A2/O process

Abstract A continuous-flow Anaerobic/Anoxic/Oxic (A2/O) system was operated at different organic concentrations to systematically investigate the effect on nutrient removal, secretion characteristics of extracellular polymer, phosphorus forms transformation and changes in functional flora this system. The results showed that high loading more conducive promote polymeric substance (EPS), increase polysaccharide content obvious compared with protein, impact components loosely bound EPS (LB-EPS) higher than tight-bound (TB-EPS). Phosphorus sludge floc mainly existed form inorganic (IP), IP apatite (AP). High load storage EPS, positively correlated EPS. Non-apatite (NAIP) played an important role dephosphorization. abundance Nitrosomonas Nitrospira responsible for nitrification decreased loading. group denitrifiers large, Azospira most abundant genus among them. Dechloromonas, Acinetobacter, Povalibacter, Chryseolinea Pirellula were genera closely associated removal.