Simultaneous removal of organic matter and nitrogen by heterotrophic nitrification-aerobic denitrification bacteria in an air-lift multi-stage circulating integrated bioreactor.

This study aimed to propose a novel air-lift multi-stage circulating integrated bioreactor (AMCIB) to treat urban sewage. The AMCIB combined the reaction zone and sedimentation zone, the alternating circulation of activated sludge in separate aerobic and anaerobic environments facilitates the enrichment of HN-AD bacteria. The preliminary study showed that AMCIB had high removal efficiencies for COD, NH4+-N, TN and TP under high dissolved oxygen (DO) concentration conditions, with average removal rates of 93.21 %, 96.04 %, 75.06 % and 94.30 %, respectively. IlluminaMiSeq sequencing results showed that the system successfully cultured heterotrophic nitrification-aerobic denitrification (HN-AD) functional bacteria (Pseudomonas, Acinetobacter, Aeromonas) that played a crucial role in sewage treatment, and Tetrasphaera was the central phosphorus removing bacteria in the system. Functional gene predictions showed that the HN-AD played a dominant role in the system.

Pilot study on urban sewage treatment with micro pressure swirl reactor.

This study aimed to propose a new type of micro-pressure swirl reactor (MPSR) to treat urban sewage. The MPSR could form a stable swirl in the reactor, and realized the coexistence of anaerobic, anoxic, and aerobic zones in a single aeration tank. The pilot study showed that MPSR achieved high removal efficient of SS, COD, NH4+-N, TN, TP under the conditions of drastic fluctuation in influent quality and temperature, and the average removal rate were 88.58%, 93.32%, 94.47%, 73.19%, 96.16%. The relative high abundance of Thermomonas, Thaurea, and Dechloromonas, etc, guaranteed the denitrification efficiency of the MPSR, and Dechloromonas was the main phosphorus removal bacteria in the system. The study confirmed the rationality of the structural design of the MPSR, and it was excellent in sewage treatment and stability.