title: Effects of step-feed on granulation processes and nitrogen removal performances of partial nitrifying granules.
abstract: Two anoxic/oxic sequencing batch reactors (A/O SBRs) were operated to investigate the effects of step-feed on granulation processes and performances of partial nitrifying granules (PNG). R1 was operated in a traditional single-feed mode, while a two-step-feed strategy was used in R2. Results showed that R1 had a faster granulation process and better performance in maintaining partial nitrification compared with R2, indicating that the step-feed mode had a negative effect of on formation of PNG. However, after full granulation, PNG in both reactors had similar properties in terms of suspended solids (MLSS), sludge volume index (SVI) and granule size. Moreover, mature granules in R2 had a higher nitrite accumulation rate than that in R1. Step-feed strategy was also observed to enhance denitrification and TN removal, as well as ammonia oxidation. It can be concluded that step-feed was unfavorable for cultivating PNG, but it significantly improved the nitrogen removal performance of PNG.
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China. xinhuawang@sdu.edu.cn
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Wang
authors.forename: Li-Xiu
authors.initials: LX
authors.lastname: Jiang
authors.forename: Yi-Jing
authors.initials: YJ
authors.lastname: Shi
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Gao
authors.forename: Sen
authors.initials: S
authors.lastname: Yang
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Wang
mesh_terms: D000641:Ammonia / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000379:methods*; D058465:Nitrification; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification*; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors
chemical_list: D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D000641:Ammonia; D009584:Nitrogen