Denitrifying phosphorus removal for simultaneous nitrogen and phosphorus removal from wastewater with low C/N ratios and microbial community structure analysis

Abstract

AbstractSimultaneous nitrogen and phosphorus removal by denitrifying phosphorus accumulating organisms (DPAO) from domestic wastewater with a low C/N was studied in a pilot-scale A2N/BAF process. Through long-term investigation for more than 820 d, it was evidenced that the A2N/BAF performed well on COD, -N and TP removals with efficiencies averaged at 84, 97 and 90%, respectively. Phosphorus removal in the system was mainly attributed to the function of DPAO through the analysis of phosphorus uptake and nitrate consumption, and the relative phosphorus uptake activity of DPAO/PAO was approximately 70.3%. Moreover, the microbial diversity and dominant bacterial community in the A2N/BAF was investigated with high-throughput sequencing. It was revealed that the A2N/BAF sludge had comparatively less diversity than seed sludge and shared several common dominant taxonomic bacteria with seed sludge, while long-term operation also shifted the microbial community. The A2N/BAF system was feasible for the treatment ...