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This study aimed to evaluate the performances of sequencing batch biofilm reactors (SBBRs) in removing nitrogen and phosphorus from synthetic municipal wastewater with different carbon to total nitrogen (C/ N) ratios. The effect of control systems, including an intelligent control system (ICS) and conventional timer control system (TCS) on the performance of SBBRs was also investigated. When C/N ratios were 10.0, 5.0 and 3.3, the average COD removal efficiencies in the ICS-SBBR reached 87.7%, 92.3% and 97.6%, while total phosphorous (TP) removals reached 95.0%, 97.0% and 97.2%. When the C/N ratio was 5.0, the TN removal efficiency was 81.0% under ICS and 65.4% under TCS. Moreover, compared with TCS-SBBR, both reaction time and aeration time were shortened by 180 min and 157 min, respectively, in the ICS-SBBR. Therefore, the ICS-SBBR has potential in practical applications for significant nitrogen and phosphorus removal and energy savings.

article i nfo This study was conducted to evaluate domestic sewage treatment using a special sequencing batch biofilm reactor (SBBR). To optimize the operation of traditional SBBRs and reduce the aeration phase, a newly developed intelligent controlling system (ICS) was adopted to control the SBBR. Stable performance was achieved in the SBBR at a hydraulic retention time (HRT) of 7 h, at which point the removal efficiencies of NH3-N, TP and COD reached 99%, 100% and 96%, respectively. When compared with conventional SBBRs, the SBBR controlled by the ICS reduced the HRT and total aeration time by 56% and 50%, respectively, and achieved better performance at removing the COD. In addition, the optimal carbon nitrogen (COD/N) ratio for the simultaneous removal of nitrogen and COD in the SBBR was found to be 12.5, and no accumulation of NO3 � -N or NO2 � -N was detected at this ratio, indicating that efficient simultaneous nitrification and denitrification (SND) was occurring in the reactor. The SND efficiency reached 98%.

The behavior of total phosphorus removal was investigated in present study in sequencing batch biofilm reactor (SBBR) controlled by an intelligent control system (ICS) with less energy consumption for municipal wastewater treatment. Stable total phosphorus (TP) removal efficiency of 93.9 ± 2.2% was achieved in comparison to that of 93.3 ± 2.5% in a conventional timer control system (TCS-SBBR). Significant anaerobic phosphorus release was not observed in ICS-SBBR, which was unlike the conventional TCS-SBBR. Moreover, lower accumulations/transformations of polyhydroxyalkanoates (PHAs) and higher transformation of glycogen occurred in the ICS-SBBR, indicating that PHAs was the main energy source while glycogen played a supporting role when PHAs were inadequate, which was different from the traditional mechanism of biological phosphorus removal in TCS-SBBR. The possible biochemical metabolism of phosphorus removal in ICS-SBBR was also elucidated.