Search Results (353)

Modification of zeolitic structures through the incorporation of transition metal oxides has proven to be a promising approach for heterogeneous catalysis. In the present study, *BEA zeolite was modified using the incipient wetness impregnation method with varying amounts (10, 20, and 40 wt.%) of iron(III) oxide to investigate its structural and physicochemical properties. Characterization techniques such as XRD, UV–Vis DRS, FT–IR, Raman spectroscopy, SEM/EDS, TEM/EDS, and SAED, as well as textural and thermal analyses, were employed to assess the main changes. Different iron species were detected, including isolated iron(III) and well-dispersed Fe₂O₃ nanoparticles coating the zeolite surface. Under the synthesis conditions, increased Fe₂O₃ loading promoted hematite nanocrystal growth and the formation of the α-Fe₂O₃ phase, as demonstrated by XRD, Raman, and SAED analyses. Key observations included the preservation of the zeolite framework, high relative crystallinity (ranging from 70% to 85%), and a band gap of approximately 2.0 eV. Furthermore, a general increase in mesoporosity and external surface area was observed, along with a reduction in the number of acidic sites. This decrease may be attributed to restricted accessibility of the probe molecule (pyridine) to Brønsted sites due to micropore blockage in *BEA. These results demonstrate that the adopted synthesis method effectively produced α-Fe₂O₃/BEA catalysts, with no other crystalline phases of iron(III) oxide detected. Full article

To address the technical challenges involved in the resource utilization of hot metal containing high levels of vanadium (V: 2–5%) and chromium (Cr: 1–5%), this study proposes a novel method based on pyrometallurgical selective oxidation for simultaneously extracting vanadium and retaining chromium. Through thermodynamic analysis and high-temperature smelting experiments, the competitive oxidation behaviors of carbon, vanadium, and chromium were revealed, and the synergistic control mechanism of temperature and oxygen partial pressure was clarified. The results indicate that within a temperature range of 1693–1753 K, adjusted over 1 h, vanadium preferentially oxidizes over carbon and chromium, while carbon effectively suppresses chromium oxidation. By optimizing ω(FeO) (10.0–15.7%), we achieved a vanadium oxidation efficiency (η_V) of 72.5–82.2% and maintained a chromium retention efficiency (100−η_Cr) exceeding 57.1%. Compared to traditional methods, which rely on high-oxygen blowing (oxygen supply: 43–195 kg/tFe), multi-stage roasting, and hydrometallurgical refining, this approach eliminates roasting and hydrometallurgical steps (such as sodium/calcium roasting and the associated leaching–precipitation units), shortens the process chain, reduces oxygen consumption (>80 kg/tFe), and lowers environmental risks (Cr oxidation reduced > 40%). This study establishes a theoretical framework for achieving sustainable V/Cr separation, enhancing resource efficiency and minimizing pollution (e.g., Cr(VI)-containing wastewater, high-salinity NH₄⁺/Na⁺ wastewater). Full article

A recently discovered turquoise deposit in the Fangshankou area of Dunhuang, Gansu Province, has been relatively understudied compared to turquoise from other sources due to its short mining history. Currently, no relevant research literature on this deposit has been identified. Therefore, a systematic mineralogical and spectroscopic study of Dunhuang turquoise samples was conducted using conventional gemological testing methods, combined with techniques such as X-ray powder diffraction (XRD), electron probe microanalysis (EPMA), Fourier transform infrared spectroscopy (FTIR), laser Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), and X-ray fluorescence (XRF) mapping. The test results indicate that the turquoise samples from this area have a density ranging from 2.40 to 2.77 g/cm³ and a refractive index between 1.59 and 1.65. The samples generally exhibit a cryptocrystalline structure, with some displaying spherulitic radial and radial fibrous structures. The texture is relatively dense and hard, with particle diameters less than 10 μm. Chemically, the turquoise samples from this region are characterized by high Fe and Si content and relatively low Cu content. Samples contain, in addition to the turquoise mineral, other minerals such as quartz, goethite and alunite, etc. The oxide content ranges are as follows: w(P₂O₅) between 23.83% and 33.66%, w(Al₂O₃) between 26.47% and 33.36%, w(CuO) between 5.26% and 7.91%, w(FeO) between 2.46% and 4.11%, and w(SiO₂) between 0.97% and 10.75%. In the infrared absorption spectra of Dunhuang turquoise, the bands at 3510 cm⁻¹ and 3464 cm⁻¹ are attributed to ν(OH)⁻ stretching vibrations, while the bands near 3308 cm⁻¹ and 3098 cm⁻¹ are assigned to ν(M-H₂O) stretching vibrations. The infrared absorption bands near 1110 cm⁻¹ and 1058 cm⁻¹ are due to v[PO₄]³⁻ stretching vibrations, and the bands near 651 cm⁻¹, 575 cm⁻¹, and 485 cm⁻¹ are attributed to δ[PO₄]³⁻ bending vibrations. A clear correlation exists between the Raman spectral features and the infrared spectra of this turquoise. The hue and chroma of the turquoise from this area are primarily influenced by the mass fractions of Fe³⁺, Cu²⁺, and Fe²⁺, as well as their bonding modes with water molecules. The ultraviolet-visible spectra are attributed to O²⁻–Fe³⁺ charge transfer, the ⁶A₁–⁴E_g + ⁴A₁ transition of Fe³⁺ ions (D⁵ configuration) in hydrated iron ions [Fe(H₂O)₆]³⁺, and the spin-allowed ²E_g–²T_2g transition of Cu²⁺ ions in hydrated copper ions [Cu(H₂O)₄]²⁺. Associated minerals include goethite, alunite, jarosite, and quartz. Fine-grained quartz often exists as secondary micron-sized independent mineral phases, which have a certain impact on the quality of the turquoise. Full article

In this work, two novel nanoscale zero-valent iron (nZVI) composites (nanoscale zero-valent iron and copper-intercalated montmorillonite (MMT-nFe⁰/Cu⁰) and carbon microsphere-supported sulfurized nanoscale zero-valent iron (CMS@S-nFe⁰)) were used to treat soil contaminated with both Cr(VI) and p-nitrophenol (PNP), and added persulfate (PMS). Experiments found that the pollutant removal effect has a great relationship with the ratio of water to soil, the amount of catalyst, the amount of PMS, and the pH value. When the conditions are adjusted to the best (water–soil = 2:1, catalyst 30 g/kg, PMS 15 g/kg, pH 7–9), both materials fix Cr(VI) well and decompose PNP. The removal rates of Cr(VI) and PNP by the MMT-nFe⁰/Cu⁰ system are 90.4% and 72.6%, respectively, while the CMS@ S-nFe⁰ system is even more severe, reaching 94.8% and 81.3%. Soil column leaching experiments also proved that the fixation effect of Cr can last for a long time and PNP can be effectively decomposed. Through detection methods such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), we found that Cr(VI) was effectively reduced to Cr(III) by Fe⁰ and Fe²⁺ ions and subsequently transformed into stable FeCr₂O₄ spinel oxides, and the groups produced after the decomposition of PNP could also help fix the metal. This work provides a way to simultaneously treat Cr(VI) and PNP pollution, and also allows the use of multifunctional nZVI composites in complex soil environments. Full article

Traditional Fe-based materials are limited for Cr(VI) remediation due to low reactivity, oxidation, and aggregation. Although chitosan coatings improve stability, they hinder efficient liquid-solid separation. To overcome this, a novel phosphorus-modified magnetic chitosan adsorbent (PCC/Fe₃O₄) was synthesized using Fe₃O₄ as the core and tetrakis hydroxymethyl phosphonium sulfate (THPS) as a cross-linking agent. The composite exhibited a high surface area (20.67 m²/g) and superparamagnetism, enabling easy magnetic recovery. PCC/Fe₃O₄ demonstrated superior Cr(VI) removal capabilities compared to unmodified chitosan and raw Fe₃O₄, achieving a saturated adsorption capacity of 23.6 mg/g under the selected conditions (pH 6, initial Cr(VI) concentration of 1 mg/L), which were chosen to balance adsorption efficiency, adsorbent stability, and environmental relevance. The main removal mechanism includes electrostatic attraction, redox reaction, and ligand exchange. PCC/Fe₃O₄ maintained 86% efficiency after 5 d aging and >90% efficiency after five cycles, demonstrating excellent stability and reusability and strong potential for practical environmental remediation. Full article

Background/Objectives: Arthrospira platensis (A. platensis) is a cyanobacterium rich in bioactive compounds with proven antioxidant, antimicrobial, and stabilizing properties, making it an ideal candidate for the green synthesis of zinc oxide nanoparticles (ZnO NPs). This study aimed to synthesize ZnO NPs using A. platensis extract and to evaluate the influence of post-synthesis temperature on their physicochemical and antimicrobial properties. Methods: ZnO NPs were synthesized via a co-precipitation method using A. platensis extract, followed by post-synthesis treatments at 80 °C and 400 °C. Comprehensive characterization was performed using Ultraviolet–Visible Spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FT–IR), Field Emission Scanning Electron Microscopy (FE–SEM), and Energy Dispersive X-ray Spectroscopy (EDX) to assess optical, structural, and compositional features. Antioxidant activity (DPPH assay) and antimicrobial properties against Staphylococcus aureus, Escherichia coli, and Candida albicans were also evaluated. Results: FE–SEM analysis confirmed a temperature-dependent effect, with ZnO NPs synthesized at 80 °C appearing as polydispersed, irregular aggregates (45.2 ± 8.6 nm), while calcination at 400 °C yielded compact, angular nanoparticles (37.1 ± 6.3 nm). In contrast, pure ZnO NPs were smaller (26.4 ± 4.1 nm), and A. platensis extract alone showed amorphous, irregular structures. FTIR spectra demonstrated the involvement of biomolecules in nanoparticle capping and stabilization, whereas EDX analysis revealed that higher calcination reduced organic residues and increased zinc purity. Antioxidant assays indicated a decrease in phenolic and flavonoid content with increasing temperature, leading to reduced DPPH radical scavenging activity. Antimicrobial evaluation showed superior inhibition zones (17.8–26.0 mm) for A. platensis-ZnO NPs compared to the crude extract, with S. aureus being most susceptible, particularly to the 400 °C nanoparticles. Conclusions: The study demonstrates that A. platensis extract provides a sustainable and efficient route for ZnO NP biosynthesis. Calcination temperature significantly affects nanoparticle morphology, biochemical composition, and antimicrobial performance. These findings highlight the potential of A. platensis-ZnO NPs as eco-friendly antimicrobial agents for biomedical, pharmaceutical, and food preservation applications. Full article

The simultaneous and sustainable removal of a typical heavy metal (Cr(VI)) and benzoic acid (HBA) via an FeS₂/α-FeOOH/C/visible light system without consumption of extra reductive or oxidizing agents was performed to study the influence of HBA degradation on Cr(VI) reduction. The results showed that the influence order of different HBA options in accelerating Cr(VI) reduction was as follows: o-HBA > p-HBA > p-CBA > blank > m-HBA. With the addition of o-HBA, the Cr(VI) removal rate constant was increased by 1.5 times (0.047 to 0.119 min⁻¹). Almost 100% of Cr(VI) and 70% of o-HBA were removed within 60 min under the initial Cr(VI) and o-HBA concentrations of 10 and 5 mg/L. Quenching experiments indicated that photogenerated e⁻ and •O₂⁻ played an important role in Cr(VI) reduction, while photogenerated h⁺ and its derived •OH contributed to HBA degradation. Due to •O₂⁻ and •OH, separately ascribed to photogenerated e⁻ and h⁺, the timely consumption of •O₂⁻ and •OH accelerated the separation and generation of photogenerated carriers, further improving light utilization efficiency and resulting in synergetic improved removal performance for both Cr(VI) and o-HBA. Theoretical calculations indicated the electron-donating ability of hydroxy groups in o-HBA was better than that in other HBA, making the activation energy for addition reaction with •OH lower. Hence, •OH would be consumed more quickly, leading to a higher promotion effect from o-HBA on Cr(VI) reduction. The real wastewater treatment experiment indicated the high applicability of synthesized FeS₂/α-FeOOH/C for synergetic and sustainable removal of Cr(VI) and coexisting organic pollutants in electronic industry wastewater. Full article

Textile production contributes significantly to water pollution, making dye removal crucial for protecting water resources from toxic textile waste. The use of nano-adsorbents for water purification has emerged as a promising approach to removing pollutants from wastewater. Nickel Ferrite (NiFe₂O₄), Iron Oxide (Fe₂O₃), and Nickel Oxide (NiO) nanoparticles (NPs) were prepared via an auto-combustion sol–gel technique using chitosan as a capping and stabilizing agent. The prepared nanomaterials were characterized using various techniques such as XRD, UV-Vis DRS, FT-IR, Raman, EDX, SEM, and TEM to confirm their structure, particle size, morphology, functional groups on the surface, and optical properties. Subsequently, the adsorption of the methylene blue (MB) dye using the prepared nanomaterials was studied. NiFe₂O₄ NPs exhibited the best adsorption behavior compared to the mono-metal oxides. Moreover, all prepared nanomaterials were compatible with the pseudo-second-order model. Further investigations were conducted for NiFe₂O₄ NPs, showing that both the Freundlich and Langmuir isotherm models can explain the adsorption of the MB dye on the surface of NiFe₂O₄ NPs. Factors affecting MB dye adsorption were discussed, such as adsorbent dose, concentration of the MB dye, contact time, pH, and temperature. NiFe₂O₄ NPs exhibited a maximum removal efficiency of the MB dye, reaching 96.8% at pH 8. Different water sources were used to evaluate the ability of NiFe₂O₄ NPs to purify a wide range of water types. Full article

In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized via a green chemistry approach using aqueous extract of Camellia sinensis var. assamica (Assam green tea) as a bioreductant and stabilizing agent. Phytochemical analysis of the extract revealed high levels of phenolics (338.57 ± 3.90 mg GAE/mL) and flavonoids (123.92 ± 1.34 µg QE/mL), along with strong antioxidant and reducing activity, supporting its efficacy in nanoparticle formation. ZnO NPs were synthesized at various extract concentrations, with 25% yielding optimal characteristics based on UV–Vis spectrophotometry (λ_Max ≈ 390–410 nm). Structural characterization using XRD confirmed the hexagonal wurtzite phase, and SAXS indicated particle sizes of 58–60 nm. FE-SEM analysis showed semi-spherical agglomerated particles ranging from 74 to 76 nm, while EDX verified the elemental purity of Zn and O. FT-IR spectroscopy confirmed the presence of Zn–O stretching and phytochemical residues on the nanoparticle surface. Stability studies over four weeks revealed red shifts in absorbance and reduced peak intensity at ambient and elevated temperatures, suggesting nanoparticle agglomeration. Antimicrobial assays demonstrated strong antifungal activity of the ZnO NP solution against Candida albicans and, upon concentration, significant antibacterial activity against Streptococcus mutans. The synthesized ZnO NPs exhibit promising potential as eco-friendly antimicrobial agents, particularly for applications in oral healthcare. Full article

Precision and real-time detection of hydrogen peroxide (H₂O₂) are essential in pharmaceutical, industrial, and defence sectors due to its strong oxidizing nature. In this study, silver (Ag)-doped CeO₂/Ag₂O-modified glassy carbon electrode (Ag-CeO₂/Ag₂O/GCE) has been developed as a non-enzymatic electrochemical sensor for the sensitive and selective detection of H₂O₂. The synthesized Ag-doped CeO₂/Ag₂O nanocomposite was characterized using various advanced techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). Their optical, magnetic, thermal, and chemical properties were further analyzed using UV–vis spectroscopy, electron paramagnetic resonance (EPR), thermogravimetric-differential thermal analysis (TG-DTA), and X-ray photoelectron spectroscopy (XPS). Electrochemical sensing performance was evaluated using cyclic voltammetry and amperometry. The Ag-CeO₂/Ag₂O/GCE exhibited superior electrocatalytic activity for H₂O₂, attributed to the increased number of active sites and enhanced electron transfer. The sensor displayed a high sensitivity of 2.728 µA cm⁻² µM⁻¹, significantly outperforming the undoped CeO₂/GCE (0.0404 µA cm⁻² µM⁻¹). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 6.34 µM and 21.1 µM, respectively, within a broad linear detection range of 1 × 10⁻⁸ to 0.5 × 10⁻³ M. The sensor also demonstrated excellent selectivity with minimal interference from common analytes, along with outstanding storage stability, reproducibility, and repeatability. Owing to these attributes, the Ag-CeO₂/Ag₂O/GCE sensor proved effective for real sample analysis, showcasing its potential as a reliable, non-enzymatic platform for H₂O₂ detection. Full article

By modulating the mass ratio of hydrothermal agents to cobalt/iron precursors, Co₃O₄ nanowires were successfully integrated into spinel-type Co/Fe@NF, forming a heterojunction anode for alkaline water electrolysis (AWE) hydrogen production. This Co₃O₄ nanowire-assembled CoFe₂O₄ nanosheet anode (Co/Fe(5:1)@NF) exhibits exceptional electrochemical oxygen evolution reaction (OER) performance, requiring only 221 mV overpotential to achieve 10 mA cm⁻². Sulfamethoxazole (SMX) was employed as a model pollutant to investigate the anode sacrificial material; it achieved approximately 95% SMX degradation efficiency, reducing the OER potential of 50 mV/10 mA cm⁻². SMX oxidation coupled with Co/Fe heterojunction structure partially substitutes the OER. Co/Fe heterojunction generates an internal magnetic field, which induces the formation of novel active species within the system. ·O₂⁻ is the newly formed active oxygen species, which enhanced the proportion of indirect SMX oxidation. Quantitative analysis reveals that superoxide radical-mediated indirect oxidation of SMX accounts for approximately 38.5%, Fe(VI) for 9.4%, other active species for 6.1%, and direct oxidation for 46.0%. The nanowire–nanosheet assembly stabilizes a high-spin configuration on the catalyst surface, redirecting oxygen intermediate pathways toward triplet oxygen (³O₂) generation. Subsequent electron transfer from nanowire tips facilitates rapid ³O₂ reduction, forming superoxide radicals (·O₂⁻). This study effectively driven by indirect oxidation, with cathodic hydrogen production, providing a novel strategy for utilizing renewable electricity and reducing OER while offering insights into the design of Co/Fe-based catalyst. Full article

Beryl is classified as a cyclosilicate mineral, and its color is primarily determined by the type and oxidation state of trace elements. In this study, natural yellow-green beryl was used as the research subject, and heat treatment experiments were performed at various temperatures under both oxidizing and reducing atmospheres. A combination of analytical techniques, including electron probe microanalysis (EPMA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and ultraviolet-visible spectroscopy (UV-Vis), were employed to systematically investigate the composition, structure, and chromogenic mechanisms of beryl before and after heat treatment. The experimental results indicate that heat treatment under both atmospheres can lead to the transformation of yellow-green beryl into blue, with 500–600 °C under a reducing atmosphere identified as the optimal treatment condition. With increasing temperature, beryl gradually dehydrates, resulting in a faded blue color and reduced transparency. Even after treatment at 700 °C, no significant changes in unit cell parameters were observed, and both type I and type II water were retained, indicating that the color change is not attributed to crystal structure transformation or phase transitions. The study reveals that the essential mechanism of color modification through heat treatment lies in the valence change between Fe²⁺ and Fe³⁺ occupying channel and octahedral sites. The observed color variation is attributed to changes in absorption band intensity resulting from charge transfers of O²⁻ → Fe³⁺ and Fe²⁺ → Fe³⁺. This study provides theoretical insights and technical references for the color enhancement of beryl through heat treatment. Full article

We investigated the influence of gold deposition on the magnetic behavior, biocompatibility, and bioactivity of CoFe₂O₄ (MCF) nanomaterials (NMs) functionalized with sodium citrate (Cit) or glycine (Gly). The resulting multifunctional plasmonic nanostructured materials (MCF-Au-L, where L is Cit, Gly) exhibit superparamagnetic behavior with magnetic saturation of 59 emu/g, 55 emu/g, and 60 emu/g, and blocking temperatures of 259 K, 311 K, and 322 K for pristine MCF, MCF-Au-Gly, and MCF-Au-Cit, respectively. The MCF NMs exhibit a small uniform size (with a mean size of 7.1 nm) and an atomic ratio of Fe:Co (2:1). The gold nanoparticles (AuNPs) show high heterogeneity as determined by high-resolution transmission electron microscopy (HR-TEM) and energy-dispersive X-ray spectroscopy (EDX). The UV-Vis spectroscopy of the composites reveals two localized surface plasmons (LSPs) at 530 nm and 705 nm, while Fourier Transformed-Infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirm the presence of Cit and Gly on their surface. Subsequent biocompatibility tests confirm that MCF-Au-L NMs do not exert hemolytic activity (hemolysis < 5%). In addition, the CCK-8 viability assay tests indicate the higher sensitivity of cancerous cells (A549) to the photoactivity of MCF-Au compared to healthy Detroit 548 (D548) cell lines. We use advanced microscopy techniques, namely atomic force, fluorescence, and holotomography microscopies (AFM, FM, and HTM, respectively) to provide further insights into the nature of the observed photoactivity of MCF-Au-L NMs. In addition, in situ radiation, using a modified HTM microscope with an IR laser accessory, demonstrates the photoactivity of the MCF-Au NMs and their suitability for destroying cancerous cells through photodynamic therapy. The combined imaging capabilities demonstrate clear morphological changes, NMs internalization, and oxidative damage. Our results confirm that the fabricated multifunctional NMs exhibit high stability in aqueous solution, chemical solidity, superparamagnetic behavior, and effective IR responses, making them promising precursors for hybrid cancer therapy. Full article

This study reports the synthesis and evaluation of iron molybdate (Fe₂(MoO₄)₃) and iron tungstate (FeWO₄) as photocatalysts for the degradation of a real industrial effluent from aluminum anodizing processes under visible light irradiation. The oxides were synthesized via a co-precipitation method in an aqueous medium, followed by microwave-assisted hydrothermal treatment. Structural and morphological characterizations were performed using X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, ultraviolet–visible (UV–vis), and photoluminescence (PL) spectroscopies. The effluent was characterized by means of ionic chromatography, total organic carbon (TOC) analysis, physicochemical parameters (pH and conductivity), and UV–vis spectroscopy. Both materials exhibited well-crystallized structures with distinct morphologies: Fe₂(MoO₄)₃ presented well-defined exposed (001) and (110) surfaces, while FeWO₄ showed a highly porous, fluffy texture with irregularly shaped particles. In addition to morphology, both materials exhibited narrow bandgaps—2.11 eV for Fe₂(MoO₄)₃ and 2.03 eV for FeWO₄. PL analysis revealed deep defects in Fe₂(MoO₄)₃ and shallow defects in FeWO₄, which can influence the generation and lifetime of reactive oxygen species. These combined structural, electronic, and morphological features significantly affected their photocatalytic performance. TOC measurements revealed degradation efficiencies of 32.2% for Fe₂(MoO₄)₃ and 45.3% for FeWO₄ after 120 min of irradiation. The results highlight the critical role of morphology, optical properties, and defect structures in governing photocatalytic activity and reinforce the potential of these simple iron-based oxides for real wastewater treatment applications. Full article

Fenton oxidation can contribute to meeting effluent standards for COD in actual wastewater treatment plant effluents. However, Fenton oxidation is prone to produce iron sludge waste. The application of heterogeneous Fenton-like systems based on Fenton iron mud carbon in wastewater treatment plants is essential for Fenton iron mud reduction and recycling. In this study, a Fenton iron mud carbon catalyst/Ferrate salts/H₂O₂ (FSC/Fe(VI)/H₂O₂) system was developed to remove chemical oxygen demand (COD) from secondary effluents at the pilot scale. The results showed that the FSC/Fe(VI)/H₂O₂ system exhibited excellent COD removal performance with a removal rate of 57% under slightly neutral conditions in laboratory experiments. In addition, the effluent COD was stabilized below 40 mg·L⁻¹ for 65 days at the pilot scale. Fe(IV) and ¹O₂ were confirmed to be the main active species in the degradation process through electron paramagnetic resonance (EPR) and quenching experiments. C=O, O-C=O, N sites and Fe⁰ were responsible for the generation of Fe(IV) and ¹O₂ in the FSC/Fe(VI)/H₂O₂ system. Furthermore, the cost per ton of water treated by the pilot-scale FSC/Fe(VI)/H₂O₂ system was calculated to be only 0.6209 USD/t, further confirming the application potential of the FSC/Fe(VI)/H₂O₂ system. This study promotes the engineering application of heterogeneous Fenton-like systems for water treatment. Full article