Coupled mechanism of enhanced and inhibitory effects of nanoscale zero-valent iron on methane production and antibiotic resistance genes in anaerobic digestion of swine manure. (September 2022)

• Record Type: Journal Article
• Authors: Lu, Tiedong; Zhang, Junya; Su, Tianming; Liang, Xuelian; Wei, Yuansong; He, Tieguang
• Is Part Of: Bioresource technology. Volume 360(2022)
• Publication Date: 2022-09
• Subjects: Swine manure -- Nanoscale zero-valent iron -- Anaerobic digestion -- High-throughput qPCR -- Antibiotic resistance genes; 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.2022.127635
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: NZVI could increase methane production by a maximum of 23.8%. Methane production increased due to the appropriate H2 and DIET induced by NZVI. Methane production decreased by 48.0% due to excessive ROS and H2 produced by NZVI. The ARGs reduction was enhanced due to steric hindrance produced by NZVI corrosion. Horizontal gene transfer induced by MGEs is the main factor of ARG change. Abstract: In this study, the turning point for nanoscale zero-valent iron's (NZVI) promotion and inhibition effects of methane production coupled with the reduction of antibiotic resistance genes (ARGs) was investigated. Adding 150 mmol/L NZVI increased methane production by maximum of 23.8 %, which was due to the chemical reaction producing H2 and enhancement of direct interspecies electron transfer (DIET) by NZVI. NZVI350 dramatically repressed methane generation by 48.0 %, which might be associated with the large quantity of reactive oxygen species (ROS) and excessive H2 inhibiting the functioning of microorganisms. The fate of ARGs was significantly related to daily methane production, indicating that the more methane production finally generated, the less the abundance of ARGs at last left. The reduction of ARGs was enhanced by maximum of 61.0 %, which was attributed to the inhibition of vertical gene transfer (VGT) and horizontal gene transfer (HGT) caused by steric hindrance associated with NZVI corrosion.