Enhanced aerobic granulation by inoculating dewatered activated sludge under short settling time in a sequencing batch reactor

• Published in: Bioresource technology Vol. 286; p. 121386
• Main Authors: Wang, Lei, Zhan, Hanhui, Wang, Qingqing, Wu, Gang, Cui, Dabin
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2019
• Subjects: Aerobic granular sludge; Dewatered activated sludge; Microbial community; Short settling time; Dewatered activated sludge; Short settling time; Aerobic granular sludge; Microbial community
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121386

•A special method for fast aerobic granulation was proposed.•The special method shortened the granulation time to 5 days in a pilot scale SBR.•The aerobic granules had excellent physical property and pollutant removal ability on day 5.•The main mechanism of rapid granulation was the massive secretion of EPS in granules. The effect of dewatered activated sludge on aerobic granulation was investigated in a sequencing batch reactor (SBR) under short settling time. The results showed that dewatered sludge accelerated aerobic granulation and the granulation was completed within 5 days. On day 5, the aerobic granules were regular, compact, fast-settling and high granular strength and possessed excellent removal performance of carbon and nitrogen. The change trend of extracellular polymeric substances (EPS) was basically consistent with granular strength and granulation rate, indicating that EPS in granules played a vital function for granulation. Microbial community succession was investigated by pyrosequencing. In 5 days, microbial diversity was reduced and certain strains were rapidly enriched in the granules to become dominant species, serving on a crucial role in rapid granulation and pollutant removal as they could secrete excess EPS and possess the excellentability removing carbon and nitrogen pollutants.