Naslov
Supersaturated-oxygen aeration effects on a high-loaded membrane bioreactor (HL-MBR): Biological performance and microbial population dynamics

Autori
Kim, Sang Yeob ; Lopez-Vazquez, Carlos M. ; Ćurko, Josip ; Matošić, Marin ; Svetec, Ivan K. ; Štafa, Anamarija ; Milligan, Chris ; Herrera, Aridai ; Maestre, Juan Pedro ; Kinney, Kerry A. ; Brdjanovic, Damir ; Garcia, Hector A.

Izvornik
Science of the Total Environment (0048-9697) 771 (2021); 144847, 12

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Oxygen transfer, Supersaturated dissolved oxygen, High mixed liquor suspended solids, Biological wastewater treatment, High-loaded membrane bioreactor

Sažetak
Conventional diffused aeration systems (such as fine-bubble diffusers) exhibit a poor oxygen transfer in wastewater treatment plants (WWTPs), particularly when operating at sludge concentrations higher than 15 g L-1. The supersaturated dissolved oxygen (SDOX) system has been proposed as an alternative for supplying dissolved oxygen (DO) at high mixed liquor suspended solids (MLSS) concentrations. The advantages introduced by such technology include the possibility of operating WWTPs at much higher than usual MLSS concentrations, increasing the treatment capacity of WWTPs. Recent studies have demonstrated that the SDOX system has higher oxygen transfer rates (OTRs) and oxygen transfer efficiencies (OTEs) relative to fine-bubble diffusers. However, it is unknown if the high-pressure conditions introduced by SDOX may possibly impact the biological performance of WWTPs. In this study, the effects of SDOX technology on the biological performance of a membrane bioreactor (MBR) were evaluated. The MBR was operated at a MLSS concentration of approximately 15 g L-1 in four phases as follows: (P1) with bubble diffusers, (P2) with an SDOX unit, (P3) with the bubble diffusers, and (P4) with the SDOX unit. The performance of the MBR was assessed by monitoring the sludge concentration, as well as changes in the particle size distribution (PSD), sludge activity, organic matter removal and nitrification performance, and changes in the microbial community within the MBR. The operational conditions exerted by the SDOX technology did not affect the concentration of active biomass during the study period. The biological performance of the MBR was not affected by the introduction of the SDOX technology. Finally, the microbial community was relatively stable although some variations at the family and genus level were evident during each of the study phases. Therefore, the SDOX system can be proposed as an alternative technology for DO supply in WWTPs increasing the overall treatment capacity.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo, Biotehnologija, Prehrambena tehnologija

POVEZANOST RADA