A SNAD(simultaneous partial nitrification,ANAMMOX,and denitrification) process initiated in a submerged biological aerated filter (SBAF) was started up by seeding nitrification sludge and an ANAMMOX filter to investigate the operating characteristics and the succession of functional bacteria. The results showed that when the autotrophic nitrogen removal and denitrification were operated stably for 67 days at an initial COD concentration of 60 mg·L-1, the maximum nitrogen removal efficiency, the COD removal rate, and the nitrogen removal rate were 92.0%, 82.9%, and 2.3 kg·(m3·d)-1, respectively. Moreover, the total nitrogen removal rate of the SNAD process in this study was 12.6% higher than that of CANON process. The results of quantitative PCR showed that the abundance of AOB slightly increased, while the abundance of ANAMMOX was one order higher than that before the start-up of SNAD. In comparison, the abundances of denitrifiers and NOB remained at a relatively low level (107 copies·g-1). Taken together, these results suggested that the SBAF process with volcanic filter was beneficial for the accumulation of ANAMMOX and AOB.
Keywords: CANON process; SNAD process; filter; quantitative PCR; volcanic rock.