Performance and recovery of a completely separated partial nitritation and anammox process treating phenol-containing wastewater

Abstract

Anammox process is considered as a promising technology for removing total nitrogen from low-strength ammonium and phenol-containing wastewater. However, it is still a challenge for the anammox process to treat high-strength ammonium and phenol-containing wastewater. A completely separated partial nitritation and anammox (CSPN/A) process was developed to remove total nitrogen from high-strength phenol-containing wastewater. About 92% of COD, 100% of phenol, and 82.4% of total nitrogen were successfully removed at a NH-N concentration of 200 mg L with a phenol/NH-N mass ratio of 0.5 in the CSPN/A process. Furthermore, a shock loading of 300 mg phenol L with a phenol/NH-N mass ratio of 1.5 led to a complete failure of partial nitritation, but the performance was rapidly recovered by the increase of NH-N concentration. Although the activities of ammonium-oxidizing bacteria and anammox bacteria were severely inhibited at a phenol/NH-N mass ratio of 1.5, the enrichment of efficient phenol degraders in the CSPN stage could strengthen the performance robustness of partial nitritation and anammox process. Therefore, this study presented a new insight on the feasibility of the anammox process for treating high-strength ammonium and phenol-containing wastewater.

Performance of single‐stage partial nitritation and anammox reactor treating low‐phenol/ammonia ratio wastewater and analysis of microbial community structure

“…The activity of NOB was 80.2 ± 3.1, 79.2 ± 8.4, 75.1 ± 1.3, 65.0 ± 2.8, and 47.8 ± 2.5 mgN g −1 MLVSS d −1 under the phenol–nitrogen ratio of 0, 0.1, 0.3, 0.5, and 1.0, respectively. When phenol–nitrogen ratio was less than 0.3, the ratio had slight effect on activity of NOB (Wang et al, 2018). For initial phenol/N ratio of 0.050 and 0.067, the recoveries of nitrate productivity could reach 77% and 67% of the control group, respectively (Liu et al, 2005).…”

“…As observed in Figure 2, the activity of AOB was most affected by the phenol–nitrogen ratio. In fact, phenol inhibited the activity of AOB and NOB which caused the ammonia oxidation rate decreased and nitrite accumulation (Wang et al, 2018). It was conducive to regulate low DO to reach the proper ratio of residual NH 4 + ‐N to the accumulated NO 2 − ‐N.…”

“…On the contrary, the SAA of sludge increased at low‐phenol–ammonia ratio condition. The anammox bacteria had a stronger tolerance to phenol and could still remain high activity under low‐phenol concentration (Pereira et al, 2014; Wang et al, 2018). According to the results of Figure 2, the anammox bacteria had the best activity and the other bacteria also kept relative good activities at the phenol–nitrogen ratio of 0.3.…”

“…The corresponding phenol/N ratio was controlled at 0, 0.1, 0.3, 0.5, and 1.0, respectively. The activities of AOB, NOB, and denitrifying bacteria, and the SAA of sludge were analyzed according to previous experiments (Wang et al, 2018; Zhang et al, 2019).…”

“…The SOUR was the ratio of OUR to the sludge concentration (MLVSS) in the triangular conical flask. The measuring way of the activities of AOB, NOB and denitrifying bacteria, and SAA of sludge were carried out according to previous experiments (Wang et al, 2018; Zhang et al, 2019).…”