A comparison of electrooxidation of phenol on boron doped diamond and mixed metal oxide anodes
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-11-21 |
| Journal | Global NEST International Conference on Environmental Science & Technology |
| Authors | Borislav N. MalinoviÄ, Tijana DjuriÄiÄ, Helena Prosen, Aleksander Kravos, SaĆĄa MiÄin |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: High-Efficiency Phenol Electrooxidation using BDD Anodes
Section titled âTechnical Documentation & Analysis: High-Efficiency Phenol Electrooxidation using BDD AnodesâExecutive Summary
Section titled âExecutive SummaryâThis research confirms the superior performance of Boron Doped Diamond (BDD) anodes over Mixed Metal Oxide (MMO) anodes for the electrochemical oxidation (EO) of phenolic wastewater contaminants. The findings strongly validate BDD as the material of choice for high-efficiency Advanced Oxidation Processes (AOPs).
- Material Superiority: BDD anodes demonstrated significantly higher phenol removal efficiency (Ef) and lower energy consumption (EC) compared to MMO (Ti/IrO2-RuO2) anodes under identical operating conditions (j=20 mA/cm2).
- Peak Performance: A maximum phenol removal efficiency of 99.9% was achieved using the BDD anode in conjunction with NaCl electrolyte in just 60 minutes.
- Low Toxicity Recommendation: While NaCl provided the fastest removal, the authors recommend BDD used with Na2SO4 (99.3% Ef) or H2SO4 (94.8% Ef) due to the formation of less toxic by-products, demonstrating BDDâs robust performance across various electrolytes.
- Energy Efficiency: The lowest energy consumption recorded was 116.62 kWh/kgphenol at 99.9% efficiency (BDD/NaCl), confirming BDDâs commercial viability for industrial wastewater treatment.
- Electrode Classification: The study reinforces BDDâs role as an âinactiveâ electrode (high oxygen evolution overpotential), which promotes the generation of highly potent hydroxyl radicals (âąOH) for effective contaminant mineralization.
- 6CCVD Relevance: The successful application relies entirely on high-quality, robust BDD material, a core specialization of 6CCVD for electrochemical applications.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results comparing BDD and MMO anodes:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Anode Material Comparison | BDD vs MMO (Ti/IrO2-RuO2) | N/A | Electrochemical Oxidation (EO) |
| Initial Phenol Concentration | 50 | mg/L | Model wastewater |
| Anode Useful Area | 28.26 | cm2 | Batch reactor setup |
| Applied Current Density (j) | 20 | mA/cm2 | Constant current operation |
| Cathode Material | Stainless Steel (SS) EN 1.4301/AISI 304 | N/A | Counter electrode |
| Target Electrolyte Conductivity | â 3 | mS/cm | Achieved using various supporting electrolytes |
| BDD Performance (NaCl) | |||
| Removal Efficiency (Ef) | 99.9 | % | Achieved in 60 min |
| Energy Consumption (EC) | 116.62 | kWh/kgphenol | Lowest recorded EC at peak efficiency |
| BDD Performance (Na2SO4) | |||
| Removal Efficiency (Ef) | 99.3 | % | Achieved in 160 min |
| Energy Consumption (EC) | 320.88 | kWh/kgphenol | Recommended for lower toxicity by-products |
| MMO Performance (NaCl) | |||
| Removal Efficiency (Ef) | 48.23 | % | Achieved in 120 min |
Key Methodologies
Section titled âKey MethodologiesâThe electrooxidation experiments were conducted in a batch electrochemical reactor under controlled conditions to compare the performance of the BDD and MMO anodes.
- Wastewater Preparation: Model wastewater was prepared by dissolving 99.5% phenol in distilled water to achieve an initial concentration of 50 mg/L.
- Electrolyte Selection: Three supporting electrolytes were tested: NaCl (2 g/L), Na2SO4 (2 g/L), and H2SO4 (2.5 mL/L 2 M). Concentrations were adjusted to ensure approximately equivalent conductivity (â 3 mS/cm).
- Electrode Setup:
- Anodes: BDD on a Niobium (Nb) substrate and MMO (IrO2/RuO2 mixture) on a Titanium (Ti) substrate.
- Cathode: Stainless Steel (SS) plate (EN 1.4301/AISI 304).
- Geometry: Electrode distance was 2 cm; useful anode area was 28.26 cm2.
- Electrolysis Conditions: The process was performed at ambient temperature, with constant stirring (300 rpm) and a fixed current density (j) of 20 mA/cm2.
- Analysis: Phenol concentration was monitored using standard spectrophotometric methods (4-aminoantipyrine) and High-Performance Liquid Chromatography (HPLC-DAD). Degradation products were identified using LC-MS/MS and SPME GC-MS.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-performance BDD materials required to replicate, scale, and optimize this critical wastewater treatment research. Our capabilities ensure material quality, dimensional precision, and robust integration necessary for industrial electrochemical applications.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research, the highest quality Boron Doped Diamond (BDD) is essential.
| 6CCVD Material | Description & Application | Customization Potential |
|---|---|---|
| Heavy Boron Doped PCD | Polycrystalline Diamond (PCD) with high boron concentration, ideal for âinactiveâ anodes requiring high oxygen evolution overpotential (EO). Provides the necessary stability and efficiency for AOPs. | Available in plates/wafers up to 125mm diameter. |
| Boron Doped SCD | Single Crystal Diamond (SCD) for applications demanding ultra-low surface roughness (Ra < 1nm) and maximum material purity/uniformity. | Thicknesses from 0.1”m to 500”m. |
| Custom Substrates | While the paper used Nb, 6CCVD can supply BDD films on various conductive substrates (e.g., Si, W, Ti) tailored to specific reactor designs and mechanical requirements. | Custom substrate preparation and integration. |
Customization Potential
Section titled âCustomization PotentialâThe success of industrial EO systems relies on precise electrode engineering. 6CCVD offers comprehensive services to meet the exact specifications of advanced electrochemical reactors:
- Custom Dimensions and Shapes: The paper used a 28.26 cm2 anode. 6CCVD can supply BDD plates/wafers in custom dimensions up to 125mm (PCD) and utilize advanced laser cutting services to produce complex electrode geometries required for flow cells or specialized batch reactors.
- Metalization Services: The BDD film requires robust electrical contact to the substrate. 6CCVD offers in-house metalization capabilities, including deposition of Ti, W, Cu, Pt, Pd, and Au, ensuring low-resistance contacts and long-term stability in corrosive electrochemical environments.
- Surface Finish Optimization: For flow systems where fluid dynamics are critical, 6CCVD provides precision polishing services, achieving surface roughness (Ra) < 5nm for inch-size PCD, optimizing mass transfer kinetics.
Engineering Support
Section titled âEngineering SupportâThe choice of BDD material (doping level, substrate, and surface finish) directly impacts the efficiency and selectivity of the EO process (e.g., minimizing toxic by-products).
- 6CCVDâs in-house PhD team specializes in diamond electrochemistry and can assist engineers and scientists with material selection for similar Phenol Degradation and Industrial Wastewater Treatment projects.
- We provide consultation on optimizing BDD film thickness (0.1”m - 500”m) and boron doping levels to maximize hydroxyl radical generation and minimize energy consumption (EC).
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Phenolic compounds are widespread in wastewater from various industries. Since the phenols are potentially carcinogenic for humans and hazardous for the environment, their presence in wastewater raises concerns. In this paper electrooxidation process was used for treatment of synthetical prepared wastewater containing phenol. Initial phenol concentration in wastewater was 50 mg/L with addition of different supporting electrolytes (NaCl, Na2SO4, H2SO4). The treatment was performed in a batch electrochemical reactor at constant current density of 20 mA/cm2. Boron doped diamond (BDD) and mixed metal oxide (MMO) anode materials were examined, and stainless steel was used as cathode. Phenol concentration before and after treatment was determined by standard spectrophotometric method with 4-aminoantipyrine, while transformation products were identified by different chromatographic methods. Experiments have shown that the treatment is very efficient and with low energy consumption, wherein the phenol removal efficiency mostly depends on the duration of treatment and the type of supporting electrolyte.