title: Enhanced system performance by dosing ferroferric oxide during the anaerobic treatment of tryptone-based high-strength wastewater.
abstract: Conductive materials can facilitate syntrophic methane (CH4) production by improving direct interspecies electron transfer. The effect of a conductive material, ferroferric oxide (Fe3O4), on the anaerobic treatment of tryptone-based high-strength wastewater was investigated in two anaerobic sequencing batch reactors (ASBRs). One was the control reactor without amendment of Fe3O4, and the other was the Fe3O4-amended reactor. In an ASBR reaction cycle, the dosage of Fe3O4increased the CH4production rate by 12.2%, shortened the methanogenic lag phase by 32.3%, and improved the COD removal rate by 8.1%. During anaerobic treatment, the dosage of Fe3O4not only enhanced the CH4production from acetate but also facilitated the hydrolysis/acidification process fed by tryptone. Maximum electron transport activities were increased by 40.4, 137.3, and 64.6% in the processes of the ASBR reaction cycle, the CH4production from acetate, and the hydrolysis/acidification of tryptone, respectively. Among all tested quorum sensing signal substances, N-octanoyl-L-homoserine lactone was dominant in both ASBRs, with the highest concentration in the biomass and the lowest concentration in the water phase. In addition, the concentration of signal substance was high in the ASBR cycle and low in the CH4production from acetate and the hydrolysis/acidification of tryptone. Proteiniclasticum and vadinCA02 were dominant acidogens, and their relative abundances increased during the long-term operation with Fe3O4dosing. Methanosarcina was the predominant methanogen, contributing to interspecies electron transfer.
authors.affiliation: Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, 518055, China.
authors.forename: Qidong
authors.initials: Q
authors.lastname: Yin
authors.affiliation: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Nishikyo, Kyoto, 615-8540, Japan.
authors.forename: Kai
authors.initials: K
authors.lastname: He
authors.affiliation: Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, 518055, China.
authors.forename: Aike
authors.initials: A
authors.lastname: Liu
authors.affiliation: Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen, Tsinghua University, Shenzhen, Guangdong, 518055, China. wu.guangxue@sz.tsinghua.edu.cn.
authors.forename: Guangxue
authors.initials: G
authors.lastname: Wu
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000693:Anaerobiosis; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D058448:Biota; D004579:Electron Transport; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D010461:Peptones / Q000378:metabolism*; D062065:Wastewater / Q000382:microbiology*
chemical_list: D000085:Acetates; D052203:Ferrosoferric Oxide; D008697:Methane; D010461:Peptones; D062065:Wastewater; C001830:tryptones
keywords: Anaerobic treatment; Direct interspecies electron transfer; Ferroferric oxide; Methane production; Quorum sensing