Key Takeaways & Executive Findings
- •• • Under optimized conditions, various Fenton-like methods achieve tetracycline removal rates exceeding 90%, demonstrating their efficacy for treating high-strength pharmaceutical wastewater. • • Heterogeneous Fenton methods significantly widen the applicable pH range and reduce iron sludge production, addressing two major bottlenecks of conventional Fenton processes and enhancing industrial feasibility. • • Catalyst recyclability in heterogeneous systems enables repeated use, lowering operational costs and minimizing secondary pollution, which is critical for scale-up. • • Integration of bio-electro-Fenton systems with carbon-modified Fe, Co dual-metal cathodes achieves simultaneous tetracycline degradation and bioelectricity generation, offering a sustainable hybrid approach.
Abstract
Tetracycline, a poorly biodegradable organic pollutant, poses a serious threat to aquatic environments. Fenton-like methods have attracted attention for their high efficiency in treating tetracycline-containing wastewater by generating hydroxyl radicals (·OH) via H2O2 activation, thereby improving wastewater biodegradability. This review systematically summarizes recent advances in improved Fenton methods (electro-, photo-, and sono-Fenton) and heterogeneous Fenton systems, detailing reaction mechanisms, treatment efficiencies, and technical features. Under optimized conditions, tetracycline removal rates exceed 90% for various methods. Heterogeneous Fenton methods demonstrate superior applicability over a wider pH range, reduced iron sludge production, and excellent catalyst recyclability, representing the most promising strategy for practical implementation. Future perspectives emphasize developing novel catalysts, optimizing reactor design, controlling toxic by-products, and integrating hybrid technologies to facilitate practical application.
1. Introduction
Tetracycline, a widely used antibiotic, enters water bodies through wastewater, posing a serious threat to ecosystems due to its poor biodegradability and biological toxicity. Conventional wastewater treatment processes are inadequate for removing tetracycline effectively, necessitating advanced oxidation processes (AOPs). Among AOPs, Fenton oxidation is favored for its technical and cost advantages, generating hydroxyl radicals (·OH) from Fe2+ and H2O2 to degrade organic pollutants. However, traditional Fenton processes suffer from narrow pH range (2-4), low H2O2 utilization, and significant iron sludge production, limiting their practical application.
To overcome these bottlenecks, Fenton-like methods have been developed, either by introducing external fields (electric, light, ultrasound) or by employing heterogeneous catalysts to replace dissolved Fe2+. These strategies aim to expand the pH range, reduce iron sludge, and enhance catalyst recyclability. This review systematically evaluates recent progress in improved Fenton methods and heterogeneous Fenton systems for tetracycline degradation, focusing on reaction mechanisms, treatment efficiencies, and technical features, and outlines future directions for practical implementation.
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BAN Fuchen, ZHAO Jianghao (2026). Progress and Prospects in Fenton-like Methods for Tetracycline-Containing Wastewater Treatment. Journal of Environmental Engineering Technology. https://doi.org/10.13205/j.hjgc.202608011
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Frequently Asked Questions
What are the main limitations of conventional Fenton processes that Fenton-like methods aim to overcome?
Conventional Fenton processes suffer from a narrow pH range (typically 2-4), low H2O2 utilization efficiency, and significant iron sludge production. Fenton-like methods address these by introducing external fields or heterogeneous catalysts to widen the pH range, reduce sludge, and improve catalyst recyclability.
How do heterogeneous Fenton methods achieve higher tetracycline removal rates compared to homogeneous systems?
Heterogeneous Fenton methods utilize solid catalysts that can be easily recovered and reused, often exhibiting higher activity and stability over a wider pH range. Under optimized conditions, they achieve tetracycline removal rates exceeding 90%, while minimizing iron sludge production and enhancing operational feasibility.
What are the key factors influencing the efficiency of electro-Fenton processes for tetracycline degradation?
Key factors include electrode materials (e.g., DSA anodes, gas diffusion electrodes), current efficiency, pH, and Fe2+ concentration. Optimizing these parameters can enhance H2O2 production and ·OH generation, leading to higher degradation rates. For instance, gas diffusion electrodes improve H2O2 yield and catalytic performance.
What is the role of catalyst recyclability in the economic viability of Fenton-like processes?
Catalyst recyclability is crucial for reducing operational costs and minimizing secondary pollution. Heterogeneous catalysts can be recovered and reused multiple times without significant loss of activity, making the process more sustainable and economically attractive for large-scale applications.
How can bio-electro-Fenton systems integrate tetracycline degradation with energy recovery?
Bio-electro-Fenton systems combine biological and electrochemical processes, using carbon-modified Fe, Co dual-metal cathodes to degrade tetracycline while simultaneously generating bioelectricity. This dual-functionality offers a sustainable approach, achieving high removal rates and energy recovery, as demonstrated in recent studies.
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