This study proposed a novel approach of cultivating aerobic granular sludge (AGS) using intertidal wetland sediment (IWS) as inoculant in MBR for saline wastewater treatment. Granulation was observed in IWS-MBR during start-up, with increased sludge particle size (3.1-3.3 mm) and improved settling property (23.8 ml/g). The abundant inorganic particulates (acted as nuclei) and distinctive microbial community in IWS contributed to the granules formation. With the help of AGS, IWS-MBR system exhibited excellent TOC reduction of 90.3 ± 6.1% and significant TN reduction of 31.2 ± 5.0%, while the control MBR (Co-MBR) only showed 58.9 ± 7.2% and 10.4 ± 2.7%, respectively. Meanwhile, membrane fouling was mitigated in IWS-MBR, with a longer filtration cycle of 21.5 d, as compared with that of 8.9 d for Co-MBR. Microbial community analysis revealed that abundant functional bacteria associated with granulation and pollutants removal were enriched from IWS and set the basis for AGS formation and the superior treatment performance.
Keywords: Aerobic granular sludge; Intertidal wetland sediment; Membrane bioreactor; Saline wastewater.
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