Effect of gaseous mercury on nitric oxide removal performance and microbial community of a hybrid catalytic membrane biofilm reactor

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 316; pp. 584 - 591
• Main Authors: Wei, Z.S., Wang, J.B., Huang, Z.S., He, Y.M., Pei, J.L., Xiao, X.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-05-2017
• Subjects: Gaseous elemental mercury; Mercury metabolism; Microbial community; Nitric oxide; Nitrogen metabolism; Gaseous elemental mercury; Nitrogen metabolism; Mercury metabolism; Nitric oxide; Microbial community
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2017.01.085

•NO and Hg0 removal efficiency achieved 68.8 and 81.7%, respectively.•Mercury affected microbial structure, but not changed nitrogen metabolic pathways.•Hg0 could be transported by merT, and then be oxidized into Hg2+ by KatG or KatE.•Mechanism of simultaneous denitration and demercuration in HCMBRHg was proposed.
The effect of gaseous elemental mercury on nitric oxide removal performance, microbial community and microbial nitrogen metabolism of a hybrid catalytic membrane biofilm reactor (HCMBR) were evaluated. A gaseous Hg0 concentration of 25±5μg·m−3 reduced the NO removal efficiency of HCMBR from 86.4% to 41.9%. In 80days of operation, NO removal efficiency was up to 68.8%, and Hg0 removal efficiency achieved 81.7%, respectively. The addition of gaseous elemental mercury affected the microbial community structure and changed microbial nitrogen metabolism, as shown by metagenomics sequencing method. Some phyla, such as Azospirillum, and Delftia, increased in abundance, whereas others, such as Weeksella, decreased. Hg0 could combine with merP and be transported by merT, and then be oxidized into Hg2+ by KatG or KatE. The nitrogen metabolism related processes such as catalysis, nitrification and denitrification, ammoniation and biological nitrogen fixation processes, exists in HCMBR and HCMBRHg.