Nitrification/denitrification shaped the mercury-oxidizing microbial community for simultaneous Hg0 and NO removal. (February 2019)

• Record Type: Journal Article
• Authors: Huang, Zhenshan; Wei, Zaishan; Xiao, Xiaoliang; Tang, Meiru; Li, Bolong; Zhang, Xiao
• Is Part Of: Bioresource technology. Volume 274(2019)
• Page Start: 18
• Page End: 24
• Publication Date: 2019-02
• Subjects: Hg0 bio-oxidation -- Nitrification/denitrification -- Membrane biofilm reactor -- Microbial community -- Mechanism; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2018.11.069
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: The Hg 0 -oxidizing microbial community was shaped by nitrification/denitrification. Dominant genera acted as Hg 0 oxidizers, nitrifiers and denitrifiers simultaneously. Characterization of biofilm confirmed the formation of Hg 2+ from mercury oxidation. Mechanism of mercury oxidation and nitrification/denitrification was proposed. Abstract: A denitrifying/nitrifying membrane biofilm reactor for simultaneous removal of Hg 0 and NO was investigated. Hg 0 and NO removal efficiency attained 94.5% and 86%, respectively. The mercury-oxidizing microbial community was significantly shaped by nitrification/denitrification after the supply of gaseous Hg 0 and NO continuously. Dominant genera Rhodanobacter and Nitrosomonas participated in Hg 0 oxidation, nitrification and denitrification simultaneously. Hg 0 oxidizing bacteria ( Gallionella, Rhodanobacter, Ottowia, Nitrosomonas and etc.), nitrifying bacteria ( Nitrosomonas, Rhodanobacter, Diaphorobacte and etc.) and denitrifying bacteria ( Nitrosomonas, Rhodanobacter, Castellaniella and etc.) co-existed in the MBfR, as shown by metagenomic sequencing. X-ray photoelectron spectroscopy (XPS) and high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) confirmed the formation of a mercuric species (Hg 2+ ) from mercury bio-oxidation. Mechanism of mercury oxidation can be described as the bacterial oxidation of Hg 0 in which Hg 0 serves as electron donor, NO serves as electron donor in nitrification and electron acceptor in denitrification, oxygen serves as electron acceptor.