Reaction mechanisms and toxicity evolution of Sulfamethoxazole degradation by CoFe-N doped C as Electro-Fenton cathode

Lewis acid sites-regulated microscopic interface on graphite felt surface for enhanced heterogeneous electro-Fenton process: Formation of confinement effect and generation of singlet oxygen

The short lifetime and limited diffusion capability of hydroxyl radicals (•OH) restrict the further development of heterogeneous electro-Fenton (Hetero-EF) technology. In contrast, singlet oxygen (1O2) demonstrates many advantages over •OH. In the present work, a porous confined graphite felt (PCGF) was prepared through in-situ etching of nickel oxide (NiOx) and used as the cathode for Hetero-EF, aiming at constructing a 1O2-dominated Hetero-EF system to enhance its degradation performance for various antibiotic pollutants in wastewater. The in-situ etching of NiOx introduced abundant Lewis acid sites within the porous architecture of PCGF, enabling the modulation of electrode's interfacial properties and selective adsorption of Lewis basic substances, thereby generating a characteristic "confinement effect". This enhanced interfacial interaction achieved 50.23 % adsorptive removal of oxytetracycline within 30 min without external power supply, facilitating the enrichment of pollutants at the cathode interface. Meanwhile, the "confinement effect" significantly enhanced the utilization efficiency of reactive oxygen species and the selectivity of 1O2. The PCGF electrode demonstrated excellent degradation performance across a wide range of pH and exhibited strong anti-interference capability. The results from radical quenching experiments and density functional theory calculations revealed that the generation of 1O2 proceeded through multiple routes involving hydrogen peroxide, •OH, and superoxide anions. The present study presents a novel strategy for advancing the development of 1O2-dominated Hetero-EF systems for treating antibiotic-containing wastewaters.

Novel CoFe-supported UiO-66-derived ZrO2 for rapid activation of peracetic acid for sulfamethoxazole degradation

The leaching of toxic metals is still problematic for heterogeneous metal catalysts in activating peracetic acid (PAA). Herein, CoFe/U-ZrO2 was synthesized by loading CoFe onto the metal-organic framework (UiO-66) derived ZrO2 (U-ZrO2) for PAA activation. The high porosity and specific surface area of UiO-66 enable efficient embedding and uniform dispersion of CoFe particles into pore channels. The supported material effectively activates PAA and significantly reduces Co leaching. CoFe/U-ZrO2-PAA system shows a removal efficiency of sulfamethoxazole reaching 98.9% within 10 min with Co leaching concentrations as low as 0.005 mg/L (equivalent to 1.4% of CoFe-PAA system). Quenching experiments, probe experiments and electron paramagnetic resonance tests identify CH3C(O)OO· as the dominant radical species. The CoFe/U-ZrO2-PAA system maintains high activity in actual water bodies and can resist the interference of HPO42-, Cl-, SO42-, NO3- and humic acid except for the inhibitory effect of HCO3-. The system also displays good stability and high degradability to different pollutants, maintaining consistently outstanding degradation efficiency in the flow-through experiment. Overall, the environmentally friendly, good efficiency, and high stability of the CoFe/U-ZrO2-PAA system makes it potential for broad applications in wastewater treatment.

Magnetic activated carbon for improving the removal of antibiotics by heterogeneous solar photo-Fenton at circumneutral pH

A pulp and paper industry waste-based powder activated carbon combined with Fe nanoparticles (PAC-Fe) was obtained through a simple one-step synthesis for application in heterogeneous photo-Fenton treatment. PAC-Fe was characterized and applied for the removal of sulfamethoxazole (SMX) and trimethoprim (TMP) from water at circumneutral pH and under simulated solar irradiation. The contribution of the different processes involved in the overall removal of the contaminants (adsorption, Fenton and photo-Fenton) was evaluated. Degradation in both Fenton and photo-Fenton processes were fitted to the pseudo first-order and BMG kinetic models. Photo-Fenton resulted in the complete removal of SMX and TMP from water within 20 min. In contrast, in the absence of the material (H2O2 + UV), only 49 % and 59 % of SMX and TMP were removed, respectively, after the same time. The synthesis procedure allowed to obtain a PAC-Fe with a satisfactory saturation magnetization (21.14 emu g-1) and stability without any detectable leaching of iron during its application. The magnetic properties of PAC-Fe allowed for easy separation from the treated water, with degradation percentage above 50 % and 70 %, for SMX and TMP, respectively, after five consecutive cycles. The removal mechanisms involved a combination of different processes, with heterogeneous photo-Fenton and Fenton proving to be the most significant, followed by adsorption and photo-assisted peroxidation to a smaller extent. Eight transformation products of SMX were identified and fourteen for TMP, which were formed mainly by hydroxylation. The results achieved at pH close to neutral show that the PAC-Fe can be relevant for application in wastewater treatment.

Construction of a microalgal-fungal spore co-culture system for the treatment of wastewater containing Zn(II) and estrone: Pollutant removal and microbial biochemical reactions

The co-culture system of Chlorella sorokiniana and Aspergillus oryzae has demonstrated exceptional tolerance and efficiency in the removal of pollutants from swine manure. This study evaluates the ability of the co-culture system to remove Zn(II) and estrone, while assessing the impact of these pollutants on the system's overall functionality. Results indicated that co-cultivation achieved higher biomass accumulation, peaking at 0.88 g/L after 96 h. Increasing estrone exposure concentration reduced photosynthetic activity and chlorophyll content, whereas Zn(II) exposure initially enhanced and later inhibited chlorophyll synthesis. Co-cultivation secreted extracellular polymeric substances, including protein-like and humus-like substances, to alleviate environmental stress and form algal-fungal community. After 96 h of cultivation, the removal efficiencies reached 86.44% for 1.5 mg/L Zn(II) and 84.55% for 20 mg/L estrone. The Quantitative Structure Activity Relationship model revealed a reduction in the ecotoxicity of estrone intermediate products to varying degrees. Metabolomics analysis showed that exposure to estrone and Zn(II) significantly boosted the production of Gibberellic acid, Indole-3-acetic acid, and Zeatin riboside in Chlorella sorokiniana, while reducing Abscisic Acid levels. Furthermore, the exposure led to an increase in various metabolites in the Tricarboxylic acid cycle of the co-cultivation system, influencing the synthesis and metabolism of key biochemical components like carbohydrates, lipids, and proteins. These findings elucidate the biochemical responses of Chlorella sorokiniana-Aspergillus oryzae co-culture system to pollutants and provide insights into its potential application in the treatment of wastewater containing endocrine disrupting chemicals and heavy metals.

Electrochemical Degradation of Sulfamethoxazole Enhanced by Bio-Inspired Iron-Nickel Encapsulated Biochar Particle Electrode

In the electrocatalytic (EC) degradation process, challenges such as inefficient mass transfer, suboptimal mineralization rates, and limited current efficiency have restricted its broader application. To overcome these obstacles, this study synthesized spherical particle electrodes (FeNi@BC) with superior electrocatalytic performance using a bio-inspired preparation method. A three-dimensional electrocatalytic oxidation system based on FeNi@BC electrode, EC/FeNi@BC, showed excellent degradation efficiency of sulfamethoxazole (SMX), reaching 0.0456 min-1. Quenching experiments and electron paramagnetic resonance experiments showed that the excellent SMX degradation efficiency in the EC/FeNi@BC system was attributed to the synergistic effect of multiple reactive oxygen species (ROS) and revealed their evolution path. Characterization results showed that FeNi3 generated in the FeNi@BC electrode was a key bimetallic active site for improving electrocatalytic activity and repolarization ability. More importantly, the degradation pathway and reaction mechanism of SMX in the EC/FeNi@BC system were proposed. In addition, the influencing factors of the reaction system (voltage, pH, initial SMX concentration, electrode dosage, and sodium sulfate concentration, etc.) and the stability of the catalyst (maintained more than 81% after 5 cycles) were systematically evaluated. This study may provide help for the construction of environmentally friendly catalytic and efficient degradation of organic pollutants.

Citric acid modulated strong magnetic CoFe-LDH/CoFe2O4 coupled dielectric barrier discharge plasma for efficient levofloxacin degradation: Enhanced internal electric field and accelerated electron migration

A novel citric acid (CA) modulation strategy was developed to prepare strong magnetic CoFe-LDH/CoFe2O4-C composites, which were combined with dielectric barrier discharge (DBD) to effectively degrade levofloxacin (LEV) in wastewater. Kelvin probe force microscopy (KPFM) test showed that CA modulation facilitated a more powerful internal electric field to drive rapid charge migration. The addition of CoFe-LDH/CoFe2O4-C increased LEV degradation from 78.2 % to 98.6 % and reduced energy efficiency from 24.77 to 8.93 kWh m-3. Quenching experiments and electron paramagnetic resonance (EPR) spectra showed the CoFe-LDH/CoFe2O4-C could take full advantage of the active substances originating from DBD plasma and highlighted the role of 1O2 and ·O2-. Density functional theory (DFT) calculation revealed that the heterojunction can not only drive faster electron migration but also reduce the energy barrier of O3 decomposition. Possible degradation pathways for LEV were proposed. This study opened up a new avenue for the synthesis of applicable catalysts for plasma systems in water treatment areas.

In situ grown petal-like La-doped FeCo-layered double hydroxide on carbon felt for enhanced moxifloxacin hydrochloride removal via heterogeneous electro-Fenton process

In this study, a petal-like ternary metal-layered double hydroxide (FeCoLa-LDH) was synthesized through a facile one-step hydrothermal method and in situ grown on carbon felt (CF). The FeCoLa-LDH/CF composite electrode was applied in a heterogeneous electro-Fenton (HEF) system for the degradation of moxifloxacin hydrochloride (MOX). Characterization revealed that La-doped FeCo-LDH/CF exhibited petal-like layered structure rather than particle's structure, with higher surface defect degree and an increased electroactive surface area (ESA) compared to FeCo-LDH/CF. The composite electrode effectively degraded MOX across a pH range of 3-9. Under optimal conditions, it achieved a degradation efficiency of 92.2% within 45 min and 96.8% within 120 min. After 120 min, 82.4% of the chemical oxygen demand (COD) was removed. The superior degradation performance was primarily attributed to La doping, which enhanced electron transfer between Co2+/Co3+ and Fe2+/Fe3+, promoting in situ H2O2 generation and causing rapid conversion of H2O2 to hydroxyl radical(•OH) on the electrode surface. Radical quenching experiments confirmed that •OH was the primary reactive species. The possible MOX degradation pathways were elucidated through liquid chromatography-mass spectrometry (LC-MS) analysis and density functional theory (DFT) calculations, and a catalytic mechanism of HEF process was proposed. Moreover, the electrode maintained 82.8% efficiency after five cycles, with lower ion leaching and broader pollutant applicability. Moreover, good degradation efficiencies of MOX were still observed in actual water bodies. Toxicity tests confirmed that MOX degradation intermediate products had low plant toxicity. This study provides a promising high-performance cathode for antibiotic removal from wastewater.

Iron metal-organic framework nanofiber membrane for the integration of electro-Fenton and effective continuous treatment of pharmaceuticals in water

In this study, an iron metal-organic framework (Fe-MOF) was synthesized and immobilized by electrospinning technique with the objective of obtaining a membrane composed of nanofibers of this material (Fe-MOF nanofiber membrane). The characterization performed by XRD, TEM, SEM, EDS mapping and FTIR confirmed the correct synthesis of Fe-MOF as well as its correct retention in the elaborated membranes. The usefulness and effectiveness of the Fe-MOF nanofiber membrane as a catalyst for the electro-Fenton process was evaluated by performing sulfamethoxazole degradation tests. Different parameters such as the effect of intensity (25 and 100 mA), the effect of the drug initial concentration (10-50 mg/L) and the reusability of membranes were studied. Then, the degradation of a drug mixture formed by sulfamethoxazole and antipyrine was evaluated, reaching a degradation of 92.10 % and 87.43 % respectively for each drug in 4 h at 25 mA. In addition, the identification of reactive oxygen species was ascertained by scavenger assays. The study of degradation products was also carried out and their toxicity was predicted by ECOSAR program, concluding that the environmental toxicity would disappear with mineralization. Finally, given the good results obtained in batch tests, the behavior of the process was studied in a system that works continuously, achieving a stable degradation of 83.10 % in the case of treatment with a mixture of drugs. This confirmed the stability of the Fe-MOF nanofiber membrane, as well as, its catalytic activity, making it suitable for long-term treatments.

Distributions and transformation of polyhalogenated carbazoles in environmental matrices contaminated by printing and dyeing plants

As emerging organic contaminants, Polyhalogenated carbazoles (PHCZs) have caused wide concerns due to their wide distribution in the environment and dioxin-like toxicity. Nevertheless, research on the distribution and formation mechanisms of PHCZs in polluted environment of printing and dyeing plants is lacking. Here, 11 PHCZs were detected in samples from the Cao'e River, China, a typical river heavily polluted by printing and dyeing. The PHCZs concentrations in the soil, sediment, and water samples were 8.3-134.5 ng/g (median: 26.3 ng/g), 17.7-348.8 ng/g (median: 64.2 ng/g), and 1.2-41.4 μg/L (median: 4.8 μg/L), respectively. 3,6-dichlorocarbazole was the dominant congener, proved by both analysis results and formation mechanisms. PHCZ migration patterns in water-sediment systems indicated that highly halogenated PHCZs tend to be transferred to sediment. Furthermore, PHCZs are persistent, can undergo long-range transport, and pose high risks to aquatic organisms by models. PHCZs released from dye production into environment can be form through halogenation of carbazole or PHCZs formed during the dye synthesis, heating of halogenated indigo dyes, and photolysis of highly halogenated PHCZs. This is the first comprehensive study to reveal the impact of printing and dyeing plant activities on PHCZs in the environment.

Antibiotic Degradation via Fenton Process Assisted by a 3-Electron Oxygen Reduction Reaction Pathway Catalyzed by Bio-Carbon-Manganese Composites

Bio-carbon-manganese composites obtained from olive mill wastewater were successfully prepared using manganese acetate as the manganese source and olive wastewater as the carbon precursor. The samples were characterized chemically and texturally by N2 and CO2 adsorption at 77 K and 273 K, respectively, by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction. Electrochemical characterization was carried out by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The samples were evaluated in the electro-Fenton degradation of tetracycline in a typical three-electrode system under natural conditions of pH and temperature (6.5 and 25 °C). The results show that the catalysts have a high catalytic power capable of degrading tetracycline (about 70%) by a three-electron oxygen reduction pathway in which hydroxyl radicals are generated in situ, thus eliminating the need for two catalysts (ORR and Fenton).

Enhanced aerobic granular sludge with micro-electric field for sulfamethoxazole degradation: Efficiency, mechanism, and microbial community

In this study, an aerobic granular sludge electrochemical system (AGES) was established by applying the micro-electric field to an aerobic granular sludge (AGS) reactor for the degradation of sulfamethoxazole (SMZ). Under the stimulation of the micro-electric field, the granulation of sludge was improved and the degradation rate of SMZ was enhanced. The features of granular sludge were characterized by scanning electron microscopy and X-ray diffraction. The optimal degradation rate of SMZ (88%) was obtained at the voltage of 3 V and the effective electrode area of 800 mm2. The results of kinetics analyses revealed that the degradation of SMZ by AGES can be fitted with the second-order kinetic equation, showing a degradation rate constant (k) of 0.001 L mol-1·min-1. The degradation products of SMZ in the AGES system were detected by LC-MS and their possible degradation routes were elucidated. The micro-electric field in the AGES system played a selective role in microbes' enrichment and growth, changing the diversity of the microbial community. Pseudomonas, Tolumonas, and Acidovorax were the dominant bacteria in the AGES system, which is accountable for the abatement of SMZ and nutrients. This work provides a green means for improving AGS and paves the way for applying the AGS process to real-world wastewater treatment.

Iron hydroxyphosphate electro-Fenton catalyst for efficient removal of sulfamethoxazole and resource recycling into slow-release fertiliser ammonium ferrous phosphate

Although the electro-Fenton (EF) process is effective for wastewater treatment, recycling spent catalysts remain a major challenge. Therefore, we introduce a reuse strategy for spent catalysts where an iron hydroxyphosphate [Fe5(PO4)4(OH)3·2H2O] catalyst is utilized. Fe5(PO4)4(OH)3·2H2O obtained •OH and •O2- by activating in-situ produced H2O2, and the degradation rate of sulfamethoxazole reached 94.5% after 120 min and showed excellent stability (maintained above 90%) for 10 cycles. Finally, the used catalyst was converted into slow-release ammonium ferrous phosphate (NH4FePO4·H2O) fertiliser at a conversion rate of 85.6%. NH4FePO4·H2O significantly promoted plant and seed growth within 6 days, highlighting the contribution of the resource recycling of the spent catalyst. This study serves as a valuable reference for the efficient utilization of spent catalysts. This study successfully applied EF catalysts and explored the recycling of spent catalysts.

Facile Synthesis of Carbon-Based Inks to Develop Metal-Free ORR Electrocatalysts for Electro-Fenton Removal of Amoxicillin

The electro-Fenton process is based on the generation of hydroxyl radicals (OH•) from hydroxide peroxide (H2O2) generated in situ by an oxygen reduction reaction (ORR). Catalysts based on carbon gels have aroused the interest of researchers as ORR catalysts due to their textural, chemical and even electrical properties. In this work, we synthesized metal-free electrocatalysts based on carbon gels doped with graphene oxide, which were conformed to a working electrode. The catalysts were prepared from organic-gel-based inks using painted (brush) and screen-printed methods free of binders. These new methods of electrode preparation were compared with the conventional pasted method on graphite supports using a binder. All these materials were tested for the electro-Fenton degradation of amoxicillin using a homemade magnetite coated with carbon (Fe3O4/C) as a Fenton catalyst. All catalysts showed very good behavior, but the one prepared by ink painting (brush) was the best one. The degradation of amoxicillin was close to 90% under optimal conditions ([Fe3O4/C] = 100 mg L-1, -0.55 V) with the catalyst prepared using the painted method with a brush, which had 14.59 mA cm-2 as JK and a H2O2 electrogeneration close to 100% at the optimal voltage. These results show that carbon-gel-based electrocatalysts are not only very good at this type of application but can be adhered to graphite free of binders, thus enhancing all their catalytic properties.

Rational design of animal-derived biochar composite for peroxymonosulfate activation: Understanding the mechanism of singlet oxygen-mediated degradation of sulfamethoxazole

Animal-derived biochar are identified as a promising candidate for peroxymonosulfate (PMS) activation due to the abundant aromatics and oxygen-containing functional groups. The current investigation focuses on pig carcass-derived biochar (800-BA-PBC) by ball milling-assisted alkali activation. The results showed that 800-BA-PBC could effectively activate PMS and degraded 94.2% sulfamethoxazole (SMX, 10 mg/L) within 40 min. The reaction rate constant was found to be 47 times higher than that observed with PBC. The enhanced catalytic activity is mainly attributed to the increase in specific surface area, the increase content of oxygen-containing groups on the surface, and the formation of graphitic nitrogen. The quenching tests and electron paramagnetic resonance (EPR) analysis demonstrated that 1O2 is the main active species in the degradation of SMX. Moreover, the 800-BA-PBC + PMS system can maintain excellent degradation rate under different water quality, wide pH range, and the presence of different anions. The degradation pathways of SMX in the optimal system are also evaluated through intermediate identification and DFT calculation. These results indicate that the catalytic system has high anti-interference ability and practical application potential. This investigation provides new insight into the rational design of animal-derived biochar and develops a low-cost technology for the treatment of antibiotic containing wastewater.

pH adjustable MgAl@LDH-coated MOFs-derived Co2.25Mn0.75O4 for SMX degradation in PMS activated system

Sulfate radical-based advanced oxidation processes (SR-AOPs) is considered as one of the most promising technologies for antibiotic pollution. In this study, a core-shell catalyst of cobalt-manganese oxide derived from CoMn-MOFs coating by MgAl-LDH (Co/Mn@LDH) was synthesized for peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX). Degradation efficiency of nearly 100% and a mineralization efficiency of 68.3% for SMX were achieved in Co/Mn@LDH/PMS system. Mn species and out shell MgAl-LDH greatly suppressed the cobalt ions leaching, which only 23 μg/L Co ions were detected by ICP after the reaction. SO4·- was identified as dominant reactive species in the system. Furthermore, the possible reactive sites of SMX were predicted by the density functional theory (DFT) calculations. And the intermediates of SMX were detected by LC-MS and the degradation pathway was proposed based on the results above. The ECOSAR results suggested the intermediates of SMX showed a relatively low toxicity compared to SMX, indicating huge potential of utilization of Co/Mn@LDH in SR-AOPs system.

Heterogeneous Fenton system driven by iron-loaded sludge biochar for sulfamethoxazole-containing wastewater treatment

In this study, the treatment performance of a heterogeneous Fenton system (Fe-BC + H₂O₂) driven by iron-loaded sludge biochar (Fe-BC) on wastewater containing sulfamethoxazole (SMX) was investigated using the CODcr removal efficiency (φ) as an indicator. The batch experimental results showed that the optimal operating conditions were as follow: initial pH 3, H₂O₂ concentration 20 mmol L^-1, Fe-BC dose 1.2 g L^-1, temperature 298 K. The corresponding φ was as high as 83.43%. The removal of CODcr was better described by BMG model and revised BMG (BMGL) model. According to the BMGL model, the φ_max could be 98.37% (298 K). Moreover, the removal of CODcr was a diffusion-controlled process, while liquid film diffusion and intraparticle diffusion together determined its removal rate. The removal of CODcr should be a synergistic effect of adsorption and Fenton oxidation (real heterogeneous Fenton and homogeneous Fenton) and other pathways. Their contributions were 42.79%, 54.01% and 3.20%, respectively. For homogeneous Fenton, there seemed to be two simultaneous SMX degradation pathways: SMX→4-(pyrrolidine-11-sulfonyl)-aniline→N-(4-aminobenzenesulfonyl) acetamide/4-amino-N-ethyl benzene sulfonamides→4-amino-N-hydroxy benzene sulfonamides; SMX→N-ethyl-3-amino benzene sulfonamides→4-methanesulfonylaniline. In summary, Fe-BC had potential for practical application as a heterogeneous Fenton catalyst.

Two-dimensional manganese-iron bimetallic MOF-74 for electro-Fenton degradation of sulfamethoxazole

This study reported a novel application of Mn_0.67Fe_0.33-MOF-74 with two-dimensional (2D) morphology grown on carbon felt as a cathode for efficiently removing antibiotic sulfamethoxazole in the heterogeneous electro-Fenton system. Characterization demonstrated the successful synthesis of bimetallic MOF-74 by a simple one-step method. Electrochemical detection showed that the second metal addition and morphological change improved the electrochemical activity of the electrode and contributed to pollutant degradation. At pH 3 and 30 mA of current, the degradation efficiency of SMX reached 96% with 12.09 mg L^-1 H₂O₂ and 0.21 mM ·OH detected in the system after 90 min. During the reaction, electron transfer between ≡Fe^II/III and ≡Mn^II/III promoted divalent metal ions regeneration, which ensured the continuation of the Fenton reaction. Two-dimensional structures exposed more active sites favoring ·OH production. The pathway of sulfamethoxazole degradation and the reaction mechanisms were proposed based on the intermediates identification by LC-MS and radical capture results. High degradation rates were still observed in tap and river water, revealing the potential of Mn_0.67Fe_0.33-MOF-74@CF for practical applications. This study provides a simple MOF-based cathode synthesis method, which enhances our understanding of constructing efficient electrocatalytic cathodes based on morphological design and multi-metal strategies.

Flow-through heterogeneous electro-Fenton system using a bifunctional FeOCl/carbon cloth/activated carbon fiber cathode for efficient degradation of trimethoprim at neutral pH

The synthesis of multifunctional cathode with high-efficiency and stable catalytic activity for simultaneously producing and activating H₂O₂ is an effective way for promoting the performance of heterogeneous electro-Fenton process (HEF). In addition, accelerating mass transfer by adopting a flow-through reactor is also great importance because of its better utilization of catalysts and adequate contact of the contaminant with the oxidants generated on the electrode surface. Herein, a novel flow-through HEF (FHEF) system was designed for the degradation of trimethoprim (TMP) using bifunctional cathode with a sandwich structure FeOCl nanosheets loaded onto carbon cloth (CC) and activated carbon fiber (ACF) (FeOCl/CC/ACF). The cathode exhibited excellent performance in activating H₂O₂ for the in-situ generation of hydroxyl radicals (^•OH). The electron spin resonance (ESR) measurements and radical quenching tests proved that the high production of ^•OH in the FHEF process was favorable to the high catalytic efficiency. 25 mg L^-1 TMP was entirely degraded after 60 min, with the TOC removal of 62.6% (180 min) at pH 6.8, 9.0 mA cm^-2, and flux rate 210 mL min^-1. Moreover, the degradation rate still could reach 83% (60 min) after 10 cycles without obvious valence and crystal phase changes. Simultaneously, the current utilization rate has also been greatly enhanced, with an average current efficiency of 69.9% and a low energy consumption of 0.28 kWh kg^-1. The reasonable degradation pathways for TMP were proposed based on the UPLC-QTOF-MS/MS results. Finally, the results of toxicological simulation showed a declining trend in the toxicity of the samples during TMP degradation. These results claim that the FeOCl/CC/ACF-FHEF system is an efficient and economical technology for the treatment of organic contaminants in effluents.