Interfacial Electron Transfer Powers Synergistic Fenton-like Oxidation and Enhanced Microbial Metabolism for E2-3S...

Area of Science:

• Environmental Science
• Biotechnology
• Materials Science

Background:

• Conjugated estrogens, such as 17β-estradiol-3-sulfate (E2-3S), are prevalent in wastewater and pose ecological risks as potential endocrine disruptors.
• Conventional biological treatments show limited removal efficiency, while advanced oxidation processes are energy-intensive.
• A need exists for efficient and sustainable methods to mitigate estrogenic contaminants in wastewater.

Purpose of the Study:

• To develop and evaluate a novel biomaterial-coupled system (P.CE2S-Fe-Zn@NC) for mitigating the estrogenic risks of E2-3S.
• To investigate the synergistic integration of microbial metabolism and advanced oxidation via interfacial electron transfer.
• To provide a sustainable strategy for remediating estrogenic contaminants in wastewater.

Main Methods:

• Development of a biomaterial-coupled system integrating microbial metabolism with Fe-Zn@NC catalyst for interfacial electron transfer.
• Assessment of estrogenic activity reduction through biological, catalytic, and coupled treatments.
• Mechanistic investigations using gene transcriptional analysis and surface microelectric field characterization.
• Evaluation of Fenton-like reaction activation and oxidative transformation of E2-3S.

Main Results:

• The P.CE2S-Fe-Zn@NC system achieved a 92.4% reduction in estrogenic activity, significantly outperforming standalone biological (80.2%) and catalytic (38.6%) treatments.
• The Fe-Zn@NC catalyst facilitated interfacial electron transfer from bacteria, driving a self-sustained Fenton-like reaction to activate H2O2 into •OH.
• Upregulation of respiratory energy metabolism and extracellular electron-transfer genes in bacteria sustained E2-3S desulfation and steroid ring cleavage.

Conclusions:

• The coupled system synergistically combines material-driven oxidation with microbe-mediated metabolism to effectively reduce estrogenic activity in wastewater effluent.
• This study presents a transformative paradigm for integrating microbial bioenergetics with material catalysis for sustainable contaminant remediation.
• The developed system offers a promising and sustainable strategy for addressing latent estrogenic contaminants in the environment.