Triplet Photochemistry of Effluent Organic Matter in Degradation of Extracellular Antibiotic Resistance Genes.

Environ Sci Technol

School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.

Published: May 2023

Wastewater effluent is a major source of extracellular antibiotic resistance genes (eArGs) in the aquatic environment, a threat to human health and biosecurity. However, little is known about the extent to which organic matter in the wastewater effluent (EfOM) might contribute to photosensitized oxidation of eArGs. Triplet states of EfOM were found to dominate the degradation of eArGs (accounting for up to 85%). Photo-oxidation proceeded mainly via proton-coupled electron transfer reactions. They broke plasmid strands and damaged bases. O was also involved, and it coupled with the reactions' intermediate radicals of eArGs. The second-order reaction rates of and segments (209-216 bps) with the triplet state of 4-carboxybenzophenone were calculated to be (2.61-2.75) × 10 M s. Besides as photosensitizers, the antioxidant moieties in EfOM also acted as quenchers to revert intermediate radicals back to their original forms, reducing the rate of photodegradation. However, the terrestrial origin natural organic matter was unable to photosensitize because it formed less triplets, especially high-energy triplets, so its inhibitory effects predominated. This study advances our understanding of the role of EfOM in the photo-oxidation of eArGs and the difference between EfOM and terrestrial-origin natural organic matter.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.est.2c08036DOI Listing

Publication Analysis

Top Keywords

organic matter
16
extracellular antibiotic
8
antibiotic resistance
8
resistance genes
8
wastewater effluent
8
intermediate radicals
8
natural organic
8
eargs
5
efom
5
triplet photochemistry
4

Similar Publications

Sponge exhalent metabolites influence coral reef picoplankton dynamics.

Sci Rep

December 2024

Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Falmouth, USA.

Coral reef sponges efficiently take up particulate and dissolved organic matter (DOM) from the water column and release compounds such as nucleosides, amino acids, and other dissolved metabolites to the surrounding reef via their exhalent seawater, but the influence of this process on reef picoplankton and nutrient processing is relatively unexplored. Here we examined the impact of sponge exhalent on the reef picoplankon community and subsequent alterations to the reef dissolved metabolite pool. We exposed reef picoplankton communities to a sponge exhalent water mixture (Niphates digitalis and Xestospongia muta) or filtered reef seawater (control) in closed, container-based dark incubations.

View Article and Find Full Text PDF

Vegetation restoration can be effective in containing gully head advance. However, the effect of vegetation restoration type on soil aggregate stability and erosion resistance at the head of the gully is unclear. In this study, five types of vegetation restoration-Pinus tabulaeformis (PT), Prunus sibirica (PS), Caragana korshinskii (CKS), Hippophae rhamnoides (HR), and natural grassland (NG, the dominant species is Leymus chinensis)-in the gully head were studied.

View Article and Find Full Text PDF

Visible light photocatalysts hold great promise for water purification, yet research on highly efficient, non-toxic photocatalysts is limited. This study synthesized novel g-CN/AlOOH photocatalytic nanocomposites via thermal condensation, enhancing adsorption and visible light degradation by 36-fold and 11-fold, respectively, compared to g-CN alone. The nanocomposites achieved a 98% removal rate of methyl orange under xenon lamp irradiation (>400 nm) for 1 hour.

View Article and Find Full Text PDF

Enhanced coagulation of Microcystis aeruginosa using titanium xerogel coagulant.

Chemosphere

December 2024

Key Laboratory of Health Intelligent Perception and Ecological Restoration of River and Lake, Ministry of Education, Hubei University of Technology, Wuhan 430068, China; Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan 430068, China. Electronic address:

Cyanobacterial blooms are prevalent globally and present a significant threat to water security. Titanium salt coagulants have garnered considerable attention due to their superior coagulation properties and the absence of metal residue risks. This paper explored the influencing factors in the coagulation process of titanium xerogel coagulant (TXC), the alterations in cell activity during floc storage, and the release of cyanobacterial organic matters, thereby determining the application scope of TXC for cyanobacterial water treatment.

View Article and Find Full Text PDF

Biodegradable plastics (BPs) and lignite, both rich in organic matter, present significant challenges for efficient conversion into clean energy. This study examined the anaerobic co-digestion of BPs and lignite under controlled laboratory conditions. The results demonstrated that the co-digestion of polylactic acid (PLA) and lignite (at a 1:2 mass ratio, with 5 g PLA and 10 g lignite as the model system) rapidly acclimated to the anaerobic environment, enhancing cumulative biogas production by 57 % compared to the mono-digestion of lignite alone.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!