Enhancement of denitrification in biofilters by immobilized biochar under low-temperature stress. (March 2022)

• Record Type: Journal Article
• Authors: Guo, Fucheng; Xu, Fei; Cai, Ran; Li, Dexiang; Xu, Qinyuan; Yang, Xiangyu; Wu, Zhengsong; Wang, Yubo; He, Qiang; Ao, Lianggen; Vymazal, Jan; Chen, Yi
• Is Part Of: Bioresource technology. Volume 347(2022)
• Publication Date: 2022-03
• Subjects: Denitrification -- Biofilter -- Low temperature -- Immobilized biochar -- Enzyme activity -- Microbial community; 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.2021.126664
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Immobilized biochar promoted denitrification in biofilters under low temperature. Immobilized biochar inhibited toxic NO 2 - accumulation and N2 O emissions. HK, PFK, and PK activities in glycolysis were enhanced with immobilized biochar. Immobilized biochar improved the electron transport system activity. NAR, NIR, and NOS activities were significantly increased with immobilized biochar. Abstract: Efficient removal of nitrate under low temperature is challenging because of the reduction of the microbial activity. This study successfully explored the promotion on the performance of denitrification utilizing the immobilized biochar in biofilters under low temperature (6 ± 2 °C). The results showed that the immobilized biochar increased the denitrification rate by 76.8% and decreased the nitrous oxide emissions by 82.5%. Mechanistic studies revealed that the immobilized biochar increased the activities of the denitrifying enzymes and three enzymes involved in glycolysis. Furthermore, the immobilized biochar elevated the activity of the electron transport system by 31.8%. Finally, structural equation model explained that the increase of nitrate reductase activity was a crucial factor to enhance the total nitrogen removal efficiency in biofilters with immobilized biochar. Overall, the use of immobilized biochar can be a novel strategy to enhance nitrogen removal and reduce greenhouse gas emissions in biofilters under low temperature.