Electrochemical Oxidation of Bentazon at Boron-doped Diamond Anodes - Implications of Operating Conditions in Energy Usage and Process Greenness
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2023-09-19 |
| Journal | Journal of the Mexican Chemical Society |
| Authors | Noe Valladares, Rubén Vázquez Medrano, Dorian Prato-García, Jorge G. Ibáñez |
| Institutions | Universidad Nacional de Colombia, Ibero American University |
| Citations | 1 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Advanced Electro-Oxidation using Boron-Doped Diamond Anodes
Section titled “Technical Documentation & Analysis: Advanced Electro-Oxidation using Boron-Doped Diamond Anodes”This documentation analyzes the research paper “Electrochemical Oxidation of Bentazon at Boron-doped Diamond Anodes” to highlight the critical role of high-quality MPCVD Boron-Doped Diamond (BDD) electrodes and to position 6CCVD as the premier supplier for replicating and advancing this electrochemical wastewater treatment technology.
Executive Summary
Section titled “Executive Summary”The study successfully demonstrates the high efficiency of Boron-Doped Diamond (BDD) anodes for the advanced electro-oxidation (AEO) and mineralization of the recalcitrant herbicide bentazon (Bn).
- High Efficiency Mineralization: Achieved maximum Bn removal of 86%, Total Organic Carbon (TOC) removal of 68%, and Chemical Oxygen Demand (COD) removal of 82%.
- Optimal Material Requirements: The process relies on high-quality BDD electrodes featuring a diamond conducting layer thickness of 1-10 µm, low resistivity (0.1 Ω cm), and heavy boron doping (500-8000 ppm).
- Low Energy Footprint: The best operational conditions yielded a highly competitive Specific Energy Consumption (ECTOC) of only 0.07 kWh gTOC-1.
- Scalable Configuration: Experiments utilized a modified Diachem® cell with a Cathode-Anode-Cathode (C-A-C) array, requiring large-area BDD plates (100 cm2 anode area).
- Process Control: Efficiency is highly sensitive to current density (j) and volumetric flow (v), confirming that mass transfer significantly influences the overall process performance.
- Green Technology Potential: The low ECTOC values, especially when coupled with renewable energy sources, position BDD-based AEO as a promising, sustainable solution for treating contaminated waters.
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the experimental setup and results, defining the material and operational requirements for high-performance BDD electro-oxidation systems.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| BDD Layer Thickness | 1-10 | µm | Diamond conducting layer |
| BDD Resistivity | 0.1 | Ω cm | Required for high electrochemical activity |
| Boron Concentration | 500 to 8000 | ppm | Heavy doping range |
| Anode Geometrical Area | 100 | cm2 | Area used in the modified Diachem® cell |
| Optimal Current Density (j) | 1.0 | mA cm-2 | Yielded highest TOC/COD removal |
| Optimal Volumetric Flow (v) | 750 | mL min-1 | Yielded highest TOC/COD removal |
| Maximum Bn Removal | 86 | % | Achieved at j=1.0 mA cm-2, v=500 mL min-1 |
| Maximum TOC Removal | 68 | % | Achieved at j=1.0 mA cm-2, v=750 mL min-1 |
| Maximum COD Removal | 82 | % | Achieved at j=1.0 mA cm-2, v=750 mL min-1 |
| Lowest Specific Energy Consumption (ECTOC) | 0.07 | kWh gTOC-1 | Best operational condition (100 mg L-1 Bn) |
| Electrolyte pH | 2 ± 0.1 | - | Supporting electrolyte condition |
| Electrolysis Time | 330 | min | Total duration of treatment |
Key Methodologies
Section titled “Key Methodologies”The electrochemical mineralization of bentazon was achieved using a closed-flow system optimized for mass transfer and current homogeneity.
- Electrochemical Cell: A non-divided, modified Diachem® cell was employed, configured with a parallel array of three BDD electrodes (Cathode-Anode-Cathode).
- Electrode Material Specification: BDD electrodes were utilized, characterized by a diamond conducting layer thickness between 1 and 10 µm, a resistivity of 0.1 Ω cm, and a boron concentration ranging from 500 to 8000 ppm.
- Electrode Dimensions: The anode had a geometrical area of 100 cm2, and the total cathode area was 100 cm2 (50 cm2 per side).
- Electrolyte Composition: A buffer solution of 0.04 M Na2SO4 and 0.05 M NaHSO4 was used as the supporting electrolyte, maintained at a highly acidic pH of 2 ± 0.1.
- Operational Parameters: Experiments were conducted by varying three key parameters:
- Current Density (j): 0.5, 1.0, and 1.5 mA cm-2.
- Initial Bentazon Concentration ([Bn]0): 10, 50, and 100 mg L-1.
- Volumetric Flow (v): 280, 500, and 750 mL min-1.
- Performance Metrics: Efficiency was assessed using normalized concentration values (%Bn, %TOC, %COD), Instantaneous Current Efficiency (ICE), and Specific Energy Consumption (ECTOC).
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”This research confirms the critical role of high-quality, heavily doped BDD in achieving efficient and cost-effective advanced electro-oxidation for environmental remediation. 6CCVD is uniquely positioned to supply the necessary materials and custom engineering support required to scale this technology.
Applicable Materials
Section titled “Applicable Materials”To replicate or extend this research, engineers require robust, low-resistivity diamond material. 6CCVD recommends the following:
- Heavy Boron-Doped Diamond (BDD) Wafers/Plates:
- Doping Range: We offer custom BDD doping, easily meeting the required 500-8000 ppm range to ensure the necessary low resistivity (0.1 Ω cm) for high hydroxyl radical generation.
- Thickness Control: We provide BDD layers from 0.1 µm up to 500 µm, allowing researchers to optimize the active layer thickness (1-10 µm used in the study) for maximum performance and material cost efficiency.
- Substrate Options: BDD can be grown on various substrates (e.g., Si, W, Nb) tailored for specific cell designs and thermal management requirements.
Customization Potential
Section titled “Customization Potential”The study utilized large-area electrodes (100 cm2) in a specific flow cell configuration. 6CCVD’s manufacturing capabilities directly address these needs:
| Research Requirement | 6CCVD Capability | Value Proposition |
|---|---|---|
| Large Area Electrodes | Custom plates/wafers up to 125 mm (PCD/BDD) | We can supply the 100 cm2 (approx. 100x100 mm) plates required for pilot-scale flow cells, ensuring scalability. |
| Specific Resistivity/Doping | Precise control over boron concentration | Guaranteed resistivity (e.g., 0.1 Ω cm) for optimal electrochemical performance and high current efficiency (ICE). |
| Electrode Integration | Custom metalization (Au, Pt, Ti, W, Cu) | For complex C-A-C arrays or filter-press cell integration, 6CCVD provides in-house metalization services for robust electrical contacts and corrosion resistance. |
| Surface Finish | Polishing options (Ra < 5 nm for inch-size PCD) | While AEO often uses rougher surfaces, we offer ultra-smooth finishes for fundamental studies requiring precise surface characterization. |
Engineering Support
Section titled “Engineering Support”The paper highlights that optimizing AEO performance requires balancing current density, mass transfer, and energy consumption. 6CCVD’s in-house PhD team specializes in diamond material science and electrochemical applications.
- Material Selection for AEO: Our experts can assist in selecting the optimal BDD doping level and layer thickness to maximize hydroxyl radical generation (BDD(•OH)) while minimizing parasitic oxygen evolution, crucial for maintaining low ECTOC in wastewater treatment projects.
- Scale-Up Consultation: We provide technical consultation on transitioning from lab-scale (100 cm2) to industrial-scale systems, focusing on material longevity and integration into complex flow reactors (like the Diachem® or filter-press designs mentioned).
- Global Supply Chain: We offer reliable global shipping (DDU default, DDP available) to ensure researchers and industrial partners receive high-specification diamond materials promptly, anywhere in the world.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract. We studied the mineralization of the herbicide bentazon (Bn) through advanced electro-oxidation using a non-divided modified Diachem® cell. The treatment system consisted of an array of three boron-doped diamond (BDD) electrodes: cathode-anode-cathode. The chosen variables of interest were current density (j = 0.5, 1.0, and 1.5 mA cm-2), the initial Bn concentration (10, 50, and 100 mg L-1), and the volumetric flow (v = 280, 500, and 750 mL min-1). In all cases, a 0.04 M Na2SO4 and 0.05 M NaHSO4 (pH ~ 2) solution was used as the supporting electrolyte. Results indicate that, at low current densities, up to 86 % of the Bn present in the solution can be removed (j = 1.0 mA cm-2 and v = 500 mL min-1); however, additional increases in j (from 1.0 to 1.5 mA cm-2) slightly increase (2-3 %) the removal efficiency but increase 55 % the carbon footprint and the treatment cost. Likewise, increases in the volumetric flow from 500 to 750 mL min-1 marginally affect the elimination of Bn and the removal of total organic carbon (TOC) in 1% and 4 %, respectively. The highest efficiencies for TOC (68 %) and COD (82 %) removals were obtained with the following operational conditions: j = 1.0 mA cm-2 and v = 750 mL min-1. Values obtained for the instantaneous current efficiency (ICE) showed an exponential reduction, suggesting that mass transfer influences importantly the efficiency of the process. Resumen. En este trabajo se estudió la mineralización del herbicida bentazón (Bn) por medio de electroooxidación avanzada utilizando una celda no dividida Diachem® modificada. El sistema de tratamiento consta de un arreglo de tres electrodos de diamante dopado con boro (BDD): cátodo-ánodo-cátodo. Las variables de interés seleccionadas fueron: la densidad de corriente (j = 0.5, 1.0 y 1.5 mA cm-2), la concentración inicial de Bn (10, 50 y 100 mg L-1) y el flujo volumétrico (v = 280, 500 y 750 mL min-1). En todos los casos se usó como electrolito soporte una solución de 0.04 M Na2SO4 y 0.05 M de NaHSO4 (pH ~ 2). Los resultados obtenidos indican que, a bajas densidades de corriente, se puede remover hasta el 86 % del Bn presente en solución (j = 1.0 mA cm-2 y v = 500 mL min-1); sin embargo, aumentos adicionales en j (de 1.0 a 1.5 mA cm-2) elevan ligeramente la eficiencia de remoción (2-3 %) pero incrementan hasta en un 55% la huella de carbono y el costo de tratamiento. De igual forma, incrementos en el flujo volumétrico de 500 a 750 mL min-1 afectan de forma marginal la eliminación del Bn y la remoción del carbono orgánico total (TOC) en un 1 % y 4 %, respectivamente. Las mayores eficiencias de remoción de TOC (68 %) y COD (82 %) se obtuvieron con las siguientes condiciones operativas: j = 1.0 mA cm-2 y v = 750 mL min-1. Los valores obtenidos de la eficiencia de corriente instantánea (ICE) presentaron una reducción exponencial, lo cual sugiere que la transferencia de masa tiene una influencia importante en la eficiencia del proceso.