title: Improving nitrogen removal in an ANAMMOX reactor using a permeable reactive biobarrier.
abstract: A novel ANAMMOX biofilm reactor that combines the advantages of conventional biofilm reactors and membrane bioreactors (MBRs) was developed in an attempt to decrease the levels of nitrogen in the reactor filtrate. In this reactor, nonwoven fabric modules served as both biofilm carriers and membrane-like separators, and the biofilm acted as a permeable reactive barrier for the removal of nitrogen species from the bulk liquid. Long-term monitoring suggests that the nitrogen removal rates (NRR) of the reactor reached ca. 1.6 kg-N/(m(3) d). Interestingly, large fractions of the ammonium (ca. 27%) and nitrite (ca. 48%) remaining in the bulk liquid were removed during their transport through the biofilm; thus, the reactive barrier process of the biofilm contributed ca. 11% to the total NRR. With an increase in the imposed flux, the contribution of the reactive barrier process to the removal of nitrogen from the reactor bulk liquid increased significantly, e.g., it contributed 26% to the NRR at 17.4 L/(m(2) h). Additionally, the nonwoven modules could retain free bacteria effectively; they maintained a non-fouling state during the entire operation period of approximately 400 days. Sequence analysis shows that Candidatus Kuenenia-like species dominated the ANAMMOX bacteria in the reactor. These results clearly demonstrate that this innovative reactor holds great promise for improving the ANAMMOX process, thus decreasing nitrogen levels in the effluent.
authors.affiliation: SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China. Electronic address: mengfg@mail.sysu.edu.cn.
authors.forename: Fangang
authors.initials: F
authors.lastname: Meng
authors.affiliation: SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China.
authors.forename: Guangyi
authors.initials: G
authors.lastname: Su
authors.affiliation: SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China.
authors.forename: Yifang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Lu
authors.affiliation: School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PR China.
authors.forename: Li-Nan
authors.initials: LN
authors.lastname: Huang
authors.affiliation: SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Guang-Hao
authors.initials: GH
authors.lastname: Chen
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology; D004867:Equipment Design; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods
chemical_list: D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D000641:Ammonia; D009584:Nitrogen
keywords: ANAMMOX; Biofilm reactors; Mass transport; Membrane fouling; Nitrogen removal