title: Aerobic sludge granulation in a full-scale sequencing batch reactor.
abstract: Aerobic granulation of activated sludge was successfully achieved in a full-scale sequencing batch reactor (SBR) with 50,000 m(3) d(-1) for treating a town's wastewater. After operation for 337 days, in this full-scale SBR, aerobic granules with an average SVI30 of 47.1 mL g(-1), diameter of 0.5 mm, and settling velocity of 42 m h(-1) were obtained. Compared to an anaerobic/oxic plug flow (A/O) reactor and an oxidation ditch (OD) being operated in this wastewater treatment plant, the sludge from full-scale SBR has more compact structure and excellent settling ability. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that Flavobacterium sp., uncultured beta proteobacterium, uncultured Aquabacterium sp., and uncultured Leptothrix sp. were just dominant in SBR, whereas uncultured bacteroidetes were only found in A/O and OD. Three kinds of sludge had a high content of protein in extracellular polymeric substances (EPS). X-ray fluorescence (XRF) analysis revealed that metal ions and some inorganics from raw wastewater precipitated in sludge acted as core to enhance granulation. Raw wastewater characteristics had a positive effect on the granule formation, but the SBR mode operating with periodic feast-famine, shorter settling time, and no return sludge pump played a crucial role in aerobic sludge granulation.
authors.affiliation: Department of Municipal Engineering, Zhejiang University of Technology, No. 18 Chao Wang Road, Hangzhou 310014, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Municipal Engineering, Zhejiang University of Technology, No. 18 Chao Wang Road, Hangzhou 310014, China.
authors.forename: Li-Bin
authors.initials: LB
authors.lastname: Ding
authors.affiliation: Department of Municipal Engineering, Zhejiang University of Technology, No. 18 Chao Wang Road, Hangzhou 310014, China.
authors.forename: Ang
authors.initials: A
authors.lastname: Cai
authors.affiliation: Yancang Wastewater Treatment Plant, Haining 314422, China.
authors.forename: Guo-Xian
authors.initials: GX
authors.lastname: Huang
authors.affiliation: Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, 76173 Karlsruhe, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Horn
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D012722:Sewage