title: Effect of zero-valent iron on the start-up performance of anaerobic ammonium oxidation (anammox) process.
abstract: The long start-up time of anaerobic ammonium oxidation (anammox) process hinders the widespread application of anammox technology in practical wastewater treatment when anammox seed sludge is not available. Meanwhile, the production of nitrate cannot meet the increasingly more strict discharge standards. To combine the chemical nitrate reduction to ammonium with biological nitrogen removal, two anammox upflow anaerobic sludge blanket reactors packed with different types of zero-valent iron (ZVI), microscale ZVI (mZVI) and nanoscale ZVI (nZVI), were developed to accelerate the start-up of anammox process. The results revealed that anammox start-up time shortened from 126 to 105 and 84 days with the addition of mZVI and nZVI. The nitrogen removal performance was also improved remarkably by adding ZVI, especially in the start-up stage. The value of dissolved oxygen showed that ZVI could be regarded as a useful deoxidant to create anaerobic condition for the proliferation of anammox bacteria. ZVI was favorable for the secretion of EPS, which would represent the activity of anammox bacteria. The result of real-time quantitative PCR (qPCR) further confirmed that the proliferation of anammox bacteria was enhanced by ZVI.
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 ShandaNanlu, Jinan, 250100, Shandong, People's Republic of China.
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Ren
authors.forename: Shou-Qing
authors.initials: SQ
authors.lastname: Ni
authors.forename: Cui
authors.initials: C
authors.lastname: Liu
authors.forename: Shuang
authors.initials: S
authors.lastname: Liang
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Kong
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism; D001704:Biopolymers / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology; D007501:Iron / Q000032:analysis / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D064751:Ammonium Compounds; D001704:Biopolymers; D012722:Sewage; D007501:Iron; D009584:Nitrogen; D010100:Oxygen