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Removal of Orange G dye from water by heterogeneous electro Fenton-based processes using Ti4O7 anode and different iron-based catalysts

MetadataDetails
Publication Date2025-04-01
JournalEmergent Materials
AuthorsFatima Ezzahra Titchou, Rachid Aı̈t Akbour, Mohamed Hamdani, Mehmet A. Oturan
Citations1
AnalysisFull AI Review Included

Technical Documentation & Analysis: MPCVD Diamond for Advanced Oxidation Processes (EAOPs)

Section titled “Technical Documentation & Analysis: MPCVD Diamond for Advanced Oxidation Processes (EAOPs)”

This documentation analyzes the research comparing Boron-Doped Diamond (BDD) anodes against cost-effective alternatives (Ti4O7) in Electrochemical Advanced Oxidation Processes (EAOPs) for dye removal.

  • Performance Benchmark: The study utilized a BDD/Carbon-Felt (CF) cell as the high-performance benchmark for Anodic Oxidation (AO), achieving 84.25% Total Organic Carbon (TOC) removal.
  • Cost-Effective Alternative: The Heterogeneous Photoelectro-Fenton (HPEF) process using a Ti4O7/CF cell achieved comparable mineralization (82.33% TOC removal).
  • Energy Efficiency Advantage: The HPEF-Ti4O7/CF system demonstrated significantly lower energy consumption (EC: 0.32 kWh (kg TOC)-1) compared to the AO-BDD/CF benchmark (EC: 0.44 kWh (kg TOC)-1).
  • Catalyst Sustainability: Recycled Stainless Steel (SS) sludge was identified as the most effective heterogeneous catalyst, maintaining 89% efficiency over five reuse cycles.
  • Material Validation: The research confirms BDD as the superior non-active anode for maximizing pollutant degradation kinetics, while validating the need for cost-effective, scalable alternatives like Ti4O7/CF.
  • 6CCVD Value Proposition: 6CCVD provides the high-purity BDD films necessary for benchmark performance and offers custom engineering support to optimize electrode geometry and integration for industrial EAOP scale-up.
ParameterValueUnitContext
BDD Anode Dimensions4 x 10 x 0.20cmAnode used for AO benchmark
BDD Anode TypeThin FilmN/AHigh O2 overpotential material
Cathode Area64cm2Carbon-felt (CF) material
Optimal Current Density (HEF)1.67mA cm-2Maximized TOC removal (54.33%)
Optimal pH3.00 (±0.30)N/AMaintained for maximum efficiency
Electrolyte Concentration50mMNa2SO4 supporting electrolyte
TOC Removal (AO-BDD/CF)84.25%After 5 h electrolysis (Benchmark)
TOC Removal (HPEF-Ti4O7/CF)82.33%After 5 h electrolysis (Optimized alternative)
Energy Consumption (AO-BDD/CF)0.44kWh (kg TOC)-1Benchmark EC
Energy Consumption (HPEF-Ti4O7/CF)0.32kWh (kg TOC)-1Optimized EC (27% reduction vs. BDD)
MCE (AO-BDD/CF)14.98%Mineralization Current Efficiency
MCE (HPEF-Ti4O7/CF)11.54%Mineralization Current Efficiency
UV Source Wavelength400nmUV LED 400 Solo lamp (UV-A)

The electrochemical advanced oxidation processes (EAOPs) were conducted using a controlled batch setup with specific material and operational parameters:

  1. Electrode Configuration: Experiments utilized an undivided electrolytic cell (230 mL volume) with a Carbon-Felt (CF) cathode and either a Magnéli phase Ti4O7 anode or a Boron-Doped Diamond (BDD) thin film anode.
  2. Galvanostatic Control: Electrolysis was performed at room temperature (20 ± 2 °C) under constant current conditions, testing densities of 0.83, 1.67, and 3.33 mA cm-2.
  3. Catalyst Integration: For HEF and HPEF processes, 10 mg of heterogeneous iron-based catalysts (SS sludge, Pyrite, etc.) were introduced into the solution.
  4. Oxygen Management: Compressed air was continuously bubbled at 1.5 L min-1 throughout the electrolysis to maintain constant oxygen saturation, essential for H2O2 generation at the cathode.
  5. Photo-Irradiation (HPEF): A low-power (1.50 W) UV-A LED lamp (400 nm peak) was mounted 4 cm above the solution to promote photo-Fenton reactions and catalyst regeneration.
  6. Material Characterization: Catalysts were analyzed using X-ray Diffraction (PXRD) and Scanning Electron Microscopy with Energy Dispersive X-ray Analysis (SEM-EDX) to confirm composition (e.g., magnetite in SS sludge).
  7. Performance Metrics: Efficiency was evaluated based on Color Removal (UV-Vis), TOC Removal (mineralization rate), Mineralization Current Efficiency (MCE), and Energy Consumption (EC).

This research confirms the critical role of high-performance anode materials like BDD in setting the benchmark for advanced oxidation processes. 6CCVD is uniquely positioned to support the replication and industrial scaling of this technology.

To replicate the high-efficiency benchmark established in this paper, researchers require premium anode materials:

  • Boron-Doped Diamond (BDD): 6CCVD supplies high-purity BDD films, which are essential for achieving the high oxygen evolution overpotential (E°(OH/H2O)=2.80 V/SHE) necessary for efficient hydroxyl radical generation and the 84.25% TOC removal rate demonstrated by the AO-BDD/CF cell.
  • Single Crystal Diamond (SCD): For future HPEF studies requiring enhanced UV transmission or specific optical properties, 6CCVD offers Optical Grade SCD substrates, providing superior chemical inertness and transparency compared to standard materials.

The scalability and optimization of EAOP systems rely heavily on precise electrode engineering. 6CCVD’s custom manufacturing capabilities directly address the needs highlighted by this research:

Research Requirement6CCVD Custom SolutionTechnical Advantage
Electrode Size/GeometryCustom Dimensions: Plates/wafers up to 125mm (PCD) and SCD/BDD films up to 500”m thickness.Allows direct scale-up of the 4 cm x 10 cm BDD anode geometry for pilot studies and industrial reactors.
Electrode IntegrationCustom Metalization: Internal capability for Au, Pt, Pd, Ti, W, and Cu deposition.Enables optimized electrical contacts on BDD films and integration with alternative cathode materials (like Carbon-felt) to ensure uniform current density (e.g., 1.67 mA cm-2).
Surface FinishPrecision Polishing: Ra < 1nm (SCD) and Ra < 5nm (Inch-size PCD).Provides highly controlled surface morphology for BDD films, critical for consistent radical generation and long-term stability in aggressive acidic environments (pH 3).
Substrate ThicknessFlexible Thickness: SCD (0.1”m - 500”m), PCD (0.1”m - 500”m), Substrates (up to 10mm).Supports the fabrication of robust, long-lasting electrodes suitable for continuous wastewater treatment applications.

The paper explicitly notes that the high fabrication cost of BDD poses a challenge for large-scale applications. 6CCVD’s in-house PhD team provides expert consultation to navigate this trade-off:

  • Material Selection Optimization: We assist engineers in balancing the superior performance of BDD against the cost-effectiveness of alternative materials (like Ti4O7) for specific Wastewater Treatment (EAOP) projects.
  • Process Enhancement: Our team provides guidance on optimizing electrode geometry and doping levels to maximize Mineralization Current Efficiency (MCE) and minimize Energy Consumption (EC), directly supporting the sustainability goals of this research.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Abstract Removal of Orange G (OG) dye from water by anodic oxidation (AO), heterogeneous electro Fenton (HEF), and heterogeneous photoelectro-Fenton (HPEF) processes was systematically investigated under different operating conditions. Four distinct heterogeneous catalysts were used in this study: titaniferous sand, pyrite, and sludge derived from electrocoagulation using stainless steel (SS sludge) or iron electrodes (iron sludge); within an electrolytic cell equipped with a Ti 4 O 7 anode and carbon-felt (CF) cathode, a cost-effective configuration for advanced oxidation processes. The optimal operating conditions were chosen based on comparison of total organic carbon (TOC) removal efficiency, mineralization current efficiency (MCE (%)), and energy consumption (EC). A key highlight is the comparison of Ti 4 O 7 /CF and BDD/CF cells, demonstrating that the former cell offers comparable degradation efficiency with significantly improved MCE and low EC values, underscoring its potential as a cost-efficient alternative to traditional AO systems. The used iron-based materials were characterized using SEM-EDS and X-ray diffraction analyses. Besides, reusability runs were performed to demonstrate the sustainability of the most effective catalyst, the SS sludge. Results showed that the most effective treatment of OG solution was achieved using SS sludge, with a stable activity even after five cycles. The HPEF process with Ti 4 O 7 /CF cell exhibited comparable degradation efficiency as the AO process with the BDD/CF cell. Specifically, both the AO process using BDD/CF cell and HPEF with Ti 4 O 7 /CF cell achieved similar mineralization efficiencies, i.e., 84.25% and 82.33%, respectively, while the latter exhibited better MCE and EC values. These findings establish the HPEF process using Ti 4 O 7 /CF cell as an innovative, sustainable, and energy-efficient alternative for dye removal, advancing the application of heterogeneous catalysts in wastewater treatment.