The efficacious of AOP-based processes in concert with electrocoagulation in abatement of CECs from water/wastewater
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-04-11 |
| Journal | npj Clean Water |
| Authors | Zeinab Hajalifard, Milad Mousazadeh, Sara Khademi, Nastaran Khademi, Mehdi Hassanvand Jamadi |
| Institutions | National Iranian Oil Company (Iran), Aarhus University |
| Citations | 59 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: MPCVD Diamond for Advanced Electro-Oxidation
Section titled âTechnical Documentation & Analysis: MPCVD Diamond for Advanced Electro-OxidationâExecutive Summary
Section titled âExecutive SummaryâThis review highlights the critical role of hybrid Electrocoagulation (EC) and Advanced Oxidation Processes (AOPs) in treating Contaminants of Emerging Concern (CECs) in wastewater. The findings strongly validate the need for high-performance diamond materials, positioning 6CCVD as the essential supplier for scaling this technology.
- Enhanced Performance: Integrating EC with AOPs (EC-EO, EC-Fenton, EC-Ozone) significantly improves pollutant removal efficiency (up to 99.99% E. coli, 98% Phenol) and reduces overall energy consumption compared to standalone methods.
- Material Requirement: Boron-Doped Diamond (BDD) anodes are identified as the optimal electrode material for EC-Electrooxidation (EC-EO) due to their superior oxidation potential, enabling the complete mineralization of recalcitrant organic pollutants.
- Mechanism: BDD facilitates direct electrochemical oxidation by generating physiosorbed active oxygen, leading to the conversion of organics into CO2 and H2O, overcoming the limitations of partial oxidation seen with âactiveâ anodes.
- Key Applications: Hybrid EC-AOP systems are highly effective for degrading persistent contaminants, including PFASs (Per- and polyfluoroalkyl substances), pharmaceuticals (e.g., Ofloxacin, Atorvastatin), and complex industrial effluents (e.g., landfill leachate, tannery wastewater).
- Scaling Challenge: The paper notes that BDD is âvery expensive.â 6CCVD addresses this directly by offering custom, high-quality BDD films and substrates designed for large-area industrial deployment, mitigating the cost barrier for scale-up.
- 6CCVD Value Proposition: We provide the necessary SCD and BDD materials, custom dimensions (up to 125mm), and specialized metalization required to transition this promising lab-scale research into robust, continuous industrial treatment systems.
Technical Specifications
Section titled âTechnical SpecificationsâThe following critical data points extracted from the review highlight the performance achieved using BDD and related electrode materials in hybrid EC-AOP systems:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Optimal Anode Material (EC-EO) | Boron-Doped Diamond (BDD) | N/A | Highest oxidation potential for complete organic mineralization |
| COD Removal (EC-EO) | 95% | % | Fe/BDD electrodes, Industrial container wash water (Ref 66) |
| Phenol Removal (EC-EO) | 88.7% | % | Fe/Al/SS/BDD electrodes, Pistachio processing wastewater (Ref 195) |
| E. coli Inactivation (EC-EO) | 99.99% | % | Fe/Ti/SbO2 electrodes, Municipal wastewater (Ref 196) |
| TOC Removal (EC-EF/BDD) | 100% | % | EC(Fe)-Peroxicoagulation/EF (BDD) for Real textile wastewater (Ref 144) |
| Current Density (EC-EO) | 22.2 | mA/cm2 | Fe/BDD electrodes, Estrogenic compounds removal (Ref 67) |
| Current Density (EC-EF/BDD) | 20.0 | mA/cm2 | EC-EF (BDD) for Antibiotic Resistance Genes (Ref 147) |
| Anodic Potential Requirement | ~2.0 | V per SHE | Required for hydroxyl radical generation on non-active anodes (e.g., BDD) |
| PFAS Removal (EC-EO) | 99% | % | Zn/SS electrodes in EC, Ti4O7 electrode in EO (Ref 64) |
Key Methodologies
Section titled âKey MethodologiesâThe successful implementation of hybrid EC-AOP systems relies on precise control over material selection and operational parameters:
- Electrode Material Selection: Non-active anodes, primarily Boron-Doped Diamond (BDD), are selected for the Electrooxidation (EO) stage to achieve direct electrochemical oxidation and complete mineralization (conversion to CO2 and H2O).
- Oxidation Mechanism: BDD anodes utilize a high overpotential to generate physiosorbed active oxygen (MOx(OH)), which promotes the complete oxidation of organic compounds (Eq. 13).
- Hybrid Sequencing: Electrocoagulation (EC) is typically employed as a rapid pre-treatment step (e.g., 10-30 min) using sacrificial anodes (Fe or Al) to remove colloidal particles, reduce turbidity, and lower the overall energy demand for the subsequent AOP stage.
- Current Density Application: High current densities (ranging from 10 to 42 mA/cm2 in reviewed studies) are applied during the EO phase to maximize the generation rate of highly reactive hydroxyl radicals (OH).
- pH Optimization: While BDD-based EC-EO can operate effectively across a range of pH values, Electro-Fenton (EF) processes require strict acidic conditions (pH †3) for optimal H2O2 generation and Fe2+ activation.
- Alternative Anodes: Other non-active anodes mentioned include lead dioxide, antimony-doped tin oxide, and non-stoichiometric titanium oxides (Ti4O7/EbonexÂź), often used as substrates for BDD or other coatings.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the advanced diamond materials necessary to replicate and scale the high-performance hybrid EC-AOP systems detailed in this research. We provide the foundational materials that enable the highest oxidation potential and long-term stability required for industrial wastewater treatment.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend the research on EC-EO and EC-EF systems, 6CCVD recommends the following specialized materials:
| Material Grade | Application Focus | Key Capability Match |
|---|---|---|
| Boron-Doped Diamond (BDD) | Non-active anodes for Electrooxidation (EO) and Electro-Fenton (EF). | Highest oxidation potential for complete mineralization of recalcitrant CECs (PFASs, pharmaceuticals). |
| Polycrystalline Diamond (PCD) | Large-area, robust substrates for BDD deposition. | Custom plates/wafers up to 125mm diameter, ideal for large-scale industrial electrode manufacturing. |
| Single Crystal Diamond (SCD) | High-purity substrates for specialized research requiring ultra-low defect density. | SCD thickness control from 0.1”m to 500”m, suitable for high-precision BDD film growth. |
Customization Potential for Industrial Scale-Up
Section titled âCustomization Potential for Industrial Scale-UpâThe paper identifies the high cost and complexity of BDD electrodes as a major barrier to industrial scale-up. 6CCVD mitigates these challenges through specialized manufacturing capabilities:
- Large-Area Electrodes: We offer PCD plates/wafers up to 125mm in diameter, enabling the production of large-format BDD electrodes necessary for high-throughput continuous flow reactors.
- Custom Substrates: We provide diamond substrates (up to 10mm thick) tailored for optimal BDD film adhesion and conductivity, addressing the need for stable, long-life electrodes.
- Advanced Metalization: The research frequently utilizes complex electrode structures (e.g., Ti/IrO2, Fe/BDD, Ti4O7). 6CCVD offers in-house metalization services (Au, Pt, Pd, Ti, W, Cu) to create custom contacts and multi-layer electrode assemblies, ensuring robust electrical connection and longevity in harsh electrochemical environments.
- Precision Polishing: For applications requiring precise film uniformity or low surface roughness (e.g., Ra < 1nm for SCD, < 5nm for PCD), 6CCVDâs polishing capabilities ensure optimal surface preparation for BDD deposition and consistent electrochemical performance.
Engineering Support
Section titled âEngineering SupportâThe successful transition of hybrid EC-AOP systems from batch lab mode to continuous industrial scale requires deep material and process expertise.
6CCVDâs in-house PhD team specializes in material science and electrochemical applications. We offer consultation services to assist engineers and scientists with:
- Material Selection: Optimizing BDD doping levels and film thickness (0.1”m - 500”m) to balance oxidation efficiency, cost, and electrode lifespan for specific wastewater matrices (e.g., landfill leachate, textile effluent).
- Electrode Design: Assisting with the design of custom electrode geometries and metal contacts to handle the high current densities (up to 42 mA/cm2) required for effective Electrooxidation projects.
- System Integration: Providing technical guidance on integrating BDD anodes into complex hybrid systems (EC-EO, EC-EF) to maximize synergistic effects and minimize energy consumption.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Combining electrocoagulation with another process is a potential strategy for increasing the efficiency of water and wastewater pollutant removal. The integration of advanced oxidation processes (AOPs) and electrocoagulation (EC) demonstrates improved performance. The mechanism of the EC combined with ozone (O 3 ), hydrogen peroxide (H 2 O 2 ), sulfate radicals, electrooxidation (EO), Fenton/electro-Fenton, and UV is discussed. This review sheds light on EC-AOP hybrid processes in terms of their mechanisms, development, challenges, and their potential application for the removal of contaminants of emerging concern (CECs). The majority of the articles claimed improved performance of the EC process when combined with AOP as a pre-treatment, especially in terms of removing recalcitrant contaminants. For instance, the integrated EC-Fenton/photo-Fenton processes have been shown to be a promising treatment to virtually complete removal of the phenolic compounds in oil refinery wastewater. In EC-EO process, boron doped diamond (BDD) anode, despite being costly electrode, has the highest oxidation potential and is therefore the most suitable type for the mineralization of organic pollutants. PFASs are more effective at being removed from water through zinc and Ti 4 O 7 electrodes in EC-EO treatment. Furthermore, the peroxone and synergistic effects between O 3 and coagulants played almost equal dominant role to removal of ibuprofen using hybrid EC-O 3 . However, enough data for conducting these integrated processes at industrial scale or with real wastewaters do not exist, and so there is a lack for comprehensive and systematic approaches to address complexity of such systems. Although a great number of papers were focused on the degradation of effluents from different industries, viruses, and pharmaceuticals, there is not sufficient research in terms of the removal of herbicides, pesticides, microplastics, and micropollutants.