Key Takeaways & Executive Findings
- •• • Carbon/iron-based heterogeneous Fenton catalysts increase active site density and accelerate Fe(III)/Fe(II) cycling, overcoming limitations of conventional iron catalysts (e.g., insufficient active sites, low recycling efficiency). • • Compositing iron with carbon materials (e.g., graphene, carbon nanotubes) enhances electron transfer and H2O2 activation, leading to improved degradation rates of organic pollutants. • • Physical field-assisted systems (e.g., photo-, electro-, ultrasound) can further enhance heterogeneous Fenton reaction efficiency by promoting radical generation and mass transfer. • • The review identifies that future development should focus on scalable synthesis, long-term stability, and mechanistic understanding to translate laboratory findings to industrial water treatment applications.
Abstract
Heterogeneous Fenton technology employs solid catalysts to activate H2O2, generating hydroxyl radicals (·OH) that oxidatively degrade organic pollutants. Among reported catalysts, iron-based materials are most prevalent but suffer from insufficient active sites and sluggish Fe(III)/Fe(II) cycling. Compositing iron with carbon materials increases active site density and accelerates Fe(II) regeneration, thereby enhancing catalytic efficiency. This review summarizes recent advances in carbon/iron-based heterogeneous Fenton catalysts, analyzing reaction mechanisms and characteristics for organic pollutant removal. It also discusses external energy field-assisted strategies (e.g., photo-, electro-, and ultrasound-assisted) that augment reaction kinetics. The paper concludes with perspectives on future development of carbon/iron-based Fenton-like materials, emphasizing the need for scalable synthesis and mechanistic elucidation. Key challenges include maintaining stability under continuous operation and achieving cost-effective production. The review highlights that carbon/iron composites with optimized interfacial properties can significantly improve H2O2 utilization and broaden pH applicability, addressing limitations of conventional Fenton processes. Future research directions include designing catalysts with tailored porosity and surface functionality, and integrating physical fields to synergistically enhance pollutant mineralization.
1. Introduction
Conventional homogeneous Fenton processes, relying on Fe2+ and H2O2, generate hydroxyl radicals but suffer from narrow pH range, iron sludge production, and low H2O2 utilization. These drawbacks limit large-scale application. Heterogeneous Fenton technology, employing solid catalysts, broadens pH applicability and avoids sludge, yet still faces challenges of insufficient active sites and slow Fe(III)/Fe(II) cycling.
Carbon/iron-based composites address these bottlenecks by providing abundant active sites and facilitating Fe(II) regeneration through enhanced electron transfer. This review systematically examines recent progress in carbon/iron-based heterogeneous Fenton catalysts, analyzing mechanisms and performance. Additionally, physical field-assisted strategies are explored as synergistic approaches to further boost reaction efficiency. The insights aim to guide rational catalyst design and process optimization for sustainable water treatment.
Loading authentic research manuscript (Pages 1–5)...
XIA Xiyuan, WANG Lan, CHENG Fei, WANG Bing, WANG Sen, WANG Chuanyi (2026). Research Progress on Heterogeneous Fenton Technology Based on Carbon/Iron-Based Catalysts and Physical Field-Assisted Systems. Environmental Chemistry. https://doi.org/10.7524/j.issn.0254-6108.2025010804
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What are the primary limitations of iron-based heterogeneous Fenton catalysts, and how do carbon/iron composites overcome them?
Iron-based catalysts suffer from insufficient active sites and low Fe(III)/Fe(II) cycling efficiency. Compositing with carbon materials increases surface area and active site density, while carbon's conductivity facilitates electron transfer, accelerating Fe(II) regeneration and enhancing H2O2 activation.
How do physical fields (e.g., photo, electro, ultrasound) enhance heterogeneous Fenton reactions?
Physical fields can promote radical generation, improve mass transfer, and regenerate Fe(II) via additional pathways. For instance, photo-irradiation can excite electrons in the catalyst, while electro-assistance provides continuous electron supply, and ultrasound enhances dispersion and surface renewal.
What are the key parameters to evaluate the performance of carbon/iron-based Fenton catalysts?
Key parameters include degradation rate constants (e.g., min⁻¹), mineralization efficiency (TOC removal %), H2O2 utilization efficiency, pH operating range, catalyst stability (reusability cycles), and iron leaching concentration. These metrics determine practical applicability and cost-effectiveness.
What are the scalability challenges for carbon/iron-based heterogeneous Fenton catalysts?
Scalability challenges include reproducible synthesis of uniform composites, maintaining catalytic activity in continuous flow reactors, managing iron leaching over extended operation, and achieving cost parity with conventional treatment methods. Addressing these requires optimization of synthesis conditions and reactor design.
How does the Fe(III)/Fe(II) cycling efficiency impact the overall Fenton reaction rate?
Fe(III)/Fe(II) cycling is rate-limiting in Fenton reactions. Slow reduction of Fe(III) to Fe(II) reduces ·OH production. Carbon supports accelerate this cycle by donating electrons, thus increasing steady-state Fe(II) concentration and enhancing pollutant degradation kinetics.
Related Chinese Research & Cross-Citations
Exploring the Potential Molecular Mechanisms of Eight Environmental Pollutants in Lung Adenocarcinoma through Network Toxicology, Machine Learning, and Multi-Omics Analysis
Epidemiological studies have established a significant association between exposure to environmental pollutants (EP) and the risk of lung adenocarcinoma (LUAD). This study integrates network toxicology and multi-omics analysis to elucidate the EP-LUAD molecular regulatory network and identify key regulatory genes, thereby revealing novel mechanisms of environmental carcinogenesis. Transcriptomic data from GEO and TCGA databases yielded 4,971 and 4,488 disease-related targets, respectively. Integration of toxicology databases (TargetNet, Swiss Target Prediction, CTD, SEA) identified 24,860 potential targets for eight common pollutants (SO2, NO, CO, NO2, O3, benzene, toluene, and polycyclic aromatic hydrocarbons). Intersection of these datasets produced 1,536 EP-LUAD common target genes. Protein-protein interaction network analysis identified 247 core targets. Machine learning selected five key genes: AGER, CAV1, CD44, CEP55, and GNB3, which demonstrated robust diagnostic and prognostic efficacy. Their expression correlated with immune cell infiltration, including CD4+ memory T cells and macrophages. Single-cell RNA sequencing revealed epithelial cell-specific expression patterns. Molecular docking confirmed stable pollutant-target binding, with PAH showing highest affinity for CD44 (binding energy −9.32 kcal·mol−1) and GNB3 (−8.32 kcal·mol−1). These findings establish AGER, CAV1, CD44, CEP55, and GNB3 as core molecular mediators of pollution-related LUAD. The high-affinity binding of PAH to CD44 and GNB3 underscores its carcinogenic potential. This study constructs a multi-level regulatory network for EP-LUAD, revealing underlying molecular mechanisms and providing novel potential targets and theoretical basis for early warning and intervention.
Effects of Different Functionalized Nanoplastics on the Transformation of Extracellular Antibiotic Resistance Genes in Aquatic Environments
The rapid dissemination of antibiotic resistance genes (ARGs) in aquatic environments poses serious threats to public health and environmental safety under the 'One Health' framework. Nanoplastics (NPs), as co-occurring pollutants, can exacerbate ARG risks by promoting horizontal gene transfer (HGT), yet the influence of different functional groups on extracellular ARG (eARG) transformation remains unclear. This study investigated the effects of carboxy-modified polystyrene NPs (PS-COOH) and amino-functionalized polystyrene NPs (PS-NH2) compared to unmodified polystyrene NPs (PS) on the transformation of the extracellular resistance plasmid IE-V1955 (carrying an ampicillin resistance gene) into Escherichia coli DH5α. Results showed that PS-COOH exposure promoted plasmid transformation similarly to PS, with effects increasing over 0.1–20 mg·L−1. Low concentrations (0.1–0.5 mg·L−1) of PS-NH2 also enhanced transformation, with stronger effects than PS-COOH at equal doses, whereas high concentrations (1–20 mg·L−1) inhibited it. Mechanistically, PS-COOH (0.1–20 mg·L−1) and low PS-NH2 induced intracellular reactive oxygen species (ROS), increased cell membrane permeability, elevated the protein-to-polysaccharide ratio in extracellular polymeric substances (EPS), and promoted biofilm formation, thereby facilitating transformation. High PS-NH2 concentrations caused excessive ROS leading to cell lysis and formed aggregates with plasmids larger than membrane pores, blocking uptake. These findings provide a theoretical basis for assessing the combined environmental health risks of NPs and ARGs.
Cardiovascular Toxicity Induced by Micro/Nano-Plastics and Its Mechanisms
Micro/nano-plastics (MNPs) are emerging contaminants widely detected in human circulatory systems, including blood, heart, and vascular endothelium, raising concerns about cardiovascular health risks. This systematic review analyzed 61 peer-reviewed studies (2008–2024) to elucidate the cardiotoxic effects and molecular mechanisms of MNPs. Evidence indicates that MNPs exposure elevates risks of atherosclerosis, thrombosis, and arrhythmias through oxidative stress, inflammatory cascades, endothelial dysfunction, and metabolic dysregulation. Notably, co-exposure with persistent organic pollutants (POPs) or heavy metals may produce synergistic or antagonistic effects. Current research relies predominantly on animal and cell models, with critical gaps in low-dose, long-term exposure data and epidemiological evidence. Future studies should optimize experimental designs, integrate metabolomics and epigenetics, and explore transgenerational effects and combined toxicity mechanisms to inform pollution control policies and mitigate cardiovascular risks.
Body Burden of Polybrominated Diphenyl Ethers and Joint Effects on Thyroid Function in a Physical Examination Population in Shenzhen
This study characterized the body burden of polybrominated diphenyl ethers (PBDEs) in a physical examination population in Shenzhen and evaluated its impact on thyroid function. Serum samples from 368 residents were analyzed for eight PBDE congeners using atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS). The median concentration of ∑8PBDEs was 10.2 ng·g⁻¹ lipid weight (lw), ranging from 0.13 to 2089.4 ng·g⁻¹ lw, with BDE-209 predominating (59.7% of total). Multiple linear regression revealed that a 1.7-fold increase in serum BDE-153 was associated with a 0.4% increase in free triiodothyronine (FT3) (P<0.05), while a 1.7-fold increase in BDE-183 was associated with a 0.9% decrease in total triiodothyronine (T3) and a 0.7% decrease in FT3 (P<0.05). Bayesian kernel machine regression (BKMR) indicated a negative correlation between mixed PBDE exposure and thyroid-stimulating hormone (TSH) at high exposure levels. Weighted quantile sum (WQS) regression showed that mixed exposure was associated with decreased T3 levels and T3/FT3 ratio, with BDE-153 and BDE-183 as the primary contributors. These findings suggest that PBDE exposure may adversely affect thyroid function and disrupt thyroid hormone homeostasis, with BDE-183 and BDE-153 playing key roles. This study provides a scientific basis for PBDE health risk assessment and thyroid protection.
Mechanisms of Natural Organic Matter in Regulating Microplastic Aggregation and Transport in Soil-Groundwater Systems: A Review
Microplastics (MPs) are persistent emerging contaminants ubiquitously distributed in soil-groundwater environments, where their aggregation and transport critically govern pollutant fate and ecological risks. Natural organic matter (NOM), a complex assemblage of organic compounds, interacts with MPs and porous media via hydrogen bonding, π-π interactions, hydrophobic effects, and electrostatic binding, thereby modulating MP surface properties and environmental behavior. This review systematically synthesizes the mechanisms by which NOM influences MP aggregation and transport, with emphasis on the distinct roles of humic substances, proteins, and extracellular polymeric substances (EPS), and their synergistic modulation with solution chemistry (pH, ionic strength, ion type). Additionally, NOM accelerates MP aging and alters surface characteristics, consequently impacting transport capacity. Current research limitations are identified, and future directions are proposed to inform MP pollution risk assessment and management strategies. Key findings indicate that NOM generally enhances MP stability and mobility at low ionic strengths, while high ionic strengths may induce aggregation depending on NOM type and ion valence. Humic substances predominantly increase electrostatic repulsion, whereas proteins and EPS can bridge particles, promoting aggregation. Aging processes, accelerated by NOM photochemical activity, increase surface oxygen functionality and hydrophilicity, further altering transport. The review underscores the need for systematic studies under environmentally relevant conditions to predict MP fate accurately.
Neurotoxicity of Carboxyl-Modified Polystyrene Microplastics on Zebrafish at Early Developmental Stage
Carboxyl-modified polystyrene microplastics (PS-COOH) are negatively charged particles formed by surface oxidation and functional group modification of polystyrene microplastics (PS), widely used in biomedical and analytical chemistry. However, studies on their neurotoxic effects on aquatic organisms are scarce. This study employed zebrafish (Danio rerio) as a model organism, exposing embryos to environmentally relevant concentrations (0.1, 1, 10, 100 μg·L−1) of PS and PS-COOH. Neurotoxic effects were assessed by measuring tail coiling frequency at 24 hpf and swimming velocity under alternating light/dark cycles at 120 hpf. Results demonstrated that both PS and PS-COOH induced neurotoxicity, with PS-COOH significantly reducing tail coiling frequency and average swimming speed compared to PS (P<0.05). Exposure to 10 μg·L−1 PS-COOH disrupted neurotransmitter homeostasis, altering levels of acetylcholine (ACh), serotonin (5-HT), and γ-aminobutyric acid (GABA). Transgenic zebrafish Tg(huc:EGFP) fluorescence assays revealed that PS-COOH (0.1–100 μg·L−1) caused damage to central neurons. These findings indicate that PS-COOH exposure impairs cholinergic, serotonergic, and GABAergic neurotransmission, induces neuronal damage, and exerts neurotoxic effects on zebrafish larvae. This study provides a theoretical basis for assessing the ecological and health risks of modified microplastics.