Granule size informs the characteristics and performance of microalgal-bacterial granular sludge for wastewater treatment

• Published in: Bioresource technology Vol. 346; p. 126649
• Main Authors: Zhang, Meng, Ji, Bin, Wang, Shulian, Gu, Jun, Liu, Yu
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2022
• Subjects: ammonium; Bacteria; Bioreactors; Granule characteristics; Granule size; Microalgae; Microalgal-bacterial granular sludge; Microbial community; Nitrogen; phosphorus; polymers; Process performance; Sewage; sludge; Waste Water; wastewater; wastewater treatment; Water Purification; Microalgal-bacterial granular sludge; Process performance; Granule characteristics; Microbial community; Granule size
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2021.126649

[Display omitted] •A close correlation between EPS content and the granule size was observed.•Granule size had a positive effect on removal of COD while negative for nutrients.•Granule size could determine synergy between microalgae and bacteria in granules.•Abundance and distribution of microalgae and bacteria were granule size dependent. In this study, four groups of microalgal-bacterial granules with averaged diameters of about 356, 760, 951 and 1,444 µm were used to investigate their characteristics and performance in treating wastewater. A strong correlation between extracellular polymeric substances of microalgal-bacterial granules and the granule size was observed. Moreover, granule size showed a positive effect on the specific organics removal rate, but being negative for ammonium and phosphorus removal. It appeared that granule size could be used as a useful index to reflect the synergistic interactions between microalgae and bacteria in terms of the abundances, distributions and functional species in the microalgal-bacterial granules. This study is expected to offer new insights into the size-dependent performances of microalgal-bacterial granules for wastewater treatment.