title: Activated sludge filterability improvement by nitrifying bacteria abundance regulation in an adsorption membrane bioreactor (Ad-MBR).
abstract: Autotrophic nitrifying bacteria have its intrinsic properties including low EPS production, dense colonial structure and slow-growth rate, favoring the sludge filterability improvement. An adsorption-MBR (Ad-MBR) was developed to enrich nitrifier abundance in the MBR chamber by inlet C/N regulation, and its possible positive effect on sludge filterability and underlying mechanisms were investigated. By DNA extraction, PCR amplification and Illumina high-throughput pyrosequencing, the abundance of nitrifying bacteria was accurately quantified. More than 8.29% nitrifier abundance was achieved in Ad-MBR sludge, which was above three times of that in conventional MBR. Regulated C/N ratio and thereafter nitrifier abundance enrichment improved sludge filterability by altering sludge mixture and its supernatant properties, reflected by a good sludge settleability, a low supernatant viscosity and turbidity, a low supernatant organic substances concentration, and a small amount of strong hydrophobic fractional components, thus to profoundly improve sludge filterability and decelerate membrane fouling.
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China.
authors.forename: Fei-Yun
authors.initials: FY
authors.lastname: Sun
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Lv
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China. Electronic address: sunfeiyun1982@gmail.com.
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China.
authors.forename: Zhong-Yi
authors.initials: ZY
authors.lastname: Peng
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China.
authors.forename: Pu
authors.initials: P
authors.lastname: Li
authors.affiliation: Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, China.
authors.forename: Ming-Fei
authors.initials: MF
authors.lastname: Shao
mesh_terms: D000327:Adsorption; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors; D002244:Carbon / Q000032:analysis; D017931:DNA Primers / Q000235:genetics; D005374:Filtration; D059014:High-Throughput Nucleotide Sequencing; D008567:Membranes, Artificial; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology
chemical_list: D017931:DNA Primers; D008567:Membranes, Artificial; D012722:Sewage; D002244:Carbon; D009584:Nitrogen
keywords: Activated sludge filterability; Adsorption membrane bioreactor; Fouling alleviation; Membrane fouling; Nitrifying bacteria