title: A comparative study on the formation and characterization of aerobic 4-chloroaniline-degrading granules in SBR and SABR.
abstract: The formation and characterization of the aerobic 4-chloroaniline-degrading granules in the three column-type sequencing batch reactors were investigated in this paper. The granular sludge was observed since 15 days after start-up in R2 and R3 which had the high ratio of height to diameter (H/D). Since then and within the subsequent 75 days, the granulation of aerobic sludge was apparently developed by the decreased settling time and gradually increased 4-chloroaniline (4-ClA) concentration to above 400 mg.L(-1) in R1 to R3. The aerobic granules tended to be mature in all reactors continuously operated with 4-ClA loading rates of around 800 g.m(-3).d(-1), and the removal efficiencies of chemical oxygen demand, total nitrogen, and 4-ClA were maintained above 93%, 70%, and 99.9%, respectively. Mature aerobic granules in R1 to R3 featured with the average diameter of 0.78, 1.68, and 1.25 mm, minimal settling velocity of 20.5, 70.1 and 66.6 m.h(-1), specific 4-ClA degradation rates of 0.14, 0.21, and 0.27 g.gVSS(-1).d(-1), and the ratio of proteins to polysaccharides of 8.2, 10.8, and 13.7 mg.mg(-1), respectively. This study demonstrates that the reactor with a high H/D ratio and internal circulation favors the granulation and stabilization of aerobic sludge.
authors.affiliation: Department of Environmental Engineering, Zhejiang University, Hangzhou, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Xu
authors.forename: Weiguo
authors.initials: W
authors.lastname: Luo
authors.forename: Zhijuan
authors.initials: Z
authors.lastname: Tian
authors.forename: Haizhuan
authors.initials: H
authors.lastname: Lin
authors.forename: Nini
authors.initials: N
authors.lastname: Zhang
mesh_terms: D000332:Aerobiosis; D000814:Aniline Compounds / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D010316:Particle Size; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology
chemical_list: D000814:Aniline Compounds; D012722:Sewage; C004658:4-chloroaniline