Pilot scale investigation of an advanced photo-electro-chemical oxidation process for treatment of effluents from pesticides manufacturing plants
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-08-28 |
| Journal | Global NEST International Conference on Environmental Science & Technology |
| Authors | Vasilis C. Sarasidis, Panagiota Petsi, Konstantinos V. Plakas, A.J. Karabelas |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: BDD for Advanced Oxidation Processes (AOP)
Section titled âTechnical Documentation & Analysis: BDD for Advanced Oxidation Processes (AOP)âThis document analyzes the research paper âPilot scale investigation of an advanced photo-electro-chemical oxidation process for treatment of effluents from pesticides manufacturing plantsâ to highlight the critical role of Boron-Doped Diamond (BDD) electrodes and connect the material requirements directly to 6CCVDâs specialized manufacturing capabilities.
Executive Summary
Section titled âExecutive Summaryâ- Application Validation: Successful pilot-scale implementation of a hybrid Advanced Oxidation Process (AO/HâOâ/UV-C) for treating highly recalcitrant industrial wastewater from a pesticides manufacturing plant.
- Material Criticality: The system relies fundamentally on Boron-Doped Diamond (BDD) electrodes for the electrochemical anodic oxidation (AO) component, which generates powerful hydroxyl radicals (â˘OH) for mineralization.
- Performance Metrics: Achieved outstanding removal efficiencies under near-optimal conditions (40 mA/cm² current density, 0.6 W/L UV-C dose), resulting in 71% Total Organic Carbon (TOC) removal and 93% color removal.
- Micropollutant Degradation: The BDD-based system demonstrated exceptional effectiveness, achieving complete degradation (>99%) of 53 out of 54 identified organic micropollutants.
- Process Synergy: High HâOâ utilization (80-90%) confirmed the synergistic effect of combining BDD anodic oxidation with UV-C photolysis, leading to enhanced mineralization kinetics.
- Scalability Confirmation: The results validate the hybrid BDD technology as an attractive, sustainable alternative for full-scale treatment of heavily polluted industrial effluents, replacing costly conventional methods.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results, focusing on the optimal operating conditions (Exp. No 5) that yielded maximum performance.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Anode Material | Boron Doped Diamond (BDD) | N/A | Electrochemical Cell (EC) |
| Cathode Material | Stainless Steel (SS304) | N/A | Electrochemical Cell (EC) |
| Electrode Active Area | 0.01 | m2 | 10 x 10 cm plates |
| Optimal Current Density (CD) | 40 | mA/cm2 | Near-optimal performance (Exp. No 5) |
| UV-C Dose | 0.6 | W/L | Constant across all tests |
| Optimal H2O2 Dosing Rate | 1140 | mg¡L-1¡h-1 | On-Line Dosing (OLD) mode |
| Recirculation Flow Rate | 8.4 | L/min | Exp. No 5 |
| Maximum TOC Removal | 71 | % | After 27h treatment (Exp. No 5) |
| Maximum Color Removal | 93 | % | After 27h treatment (Exp. No 5) |
| Micropollutant Degradation | >99 | % | 53 out of 54 compounds degraded |
| Initial Wastewater TOC Load | 891 - 1100 | mg/L | High recalcitrant organic load |
Key Methodologies
Section titled âKey MethodologiesâThe pilot unit was designed to integrate BDD-based anodic oxidation (AO) with HâOâ/UV-C photolysis, targeting the efficient generation and utilization of hydroxyl radicals (â˘OH).
- Wastewater Pre-treatment: Effluent underwent preliminary coagulation/separation, followed by cartridge filtration (5-25 Âľm nominal pore size) to minimize Total Suspended Solids (TSS) and prevent fouling of the BDD electrodes.
- Electrochemical Cell (EC) Configuration: A commercial plate-and-frame cell was utilized, equipped with 10 x 10 cm BDD anodes and SS304 cathodes. PVDF spacers were implemented to optimize fluid distribution and flow conditions.
- Hybrid Reactor Setup: The EC was connected in series with a UV photoreactor (10 L volume) containing two 40W germicidal lamps (253.7 nm emission) to facilitate HâOâ photolysis.
- HâOâ Dosing Strategy: Experiments compared two modes of HâOâ addition:
- Once Through (OT): HâOâ added directly into the 160 L feed tank at the start.
- On-Line Dosing (OLD): HâOâ injected at a constant rate throughout the experiment, proving superior due to higher utilization (80-90%).
- Operational Parameters: The system was operated in batch mode (45L treated volume) while systematically varying current density (11 to 40 mA/cm²), recirculation flow rate (5.2 to 9.0 L/min), and treatment time (up to 27h).
- Cleaning Protocol: Post-experiment cleaning involved disassembling the cell to meticulously clean electrodes and spacers, followed by a 1-hour rinse of the entire unit with fresh water.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThis research confirms that high-performance, custom-manufactured Boron-Doped Diamond (BDD) is essential for achieving high mineralization rates in advanced electrochemical wastewater treatment. 6CCVD is uniquely positioned to supply the materials and engineering support required to replicate, optimize, and scale this technology.
| Requirement from Research | 6CCVD Solution & Capability | Technical Advantage for Replication/Scale-up |
|---|---|---|
| High-Performance Electrode Material | Heavy Boron-Doped Diamond (BDD) Plates. | Our BDD material offers the necessary high conductivity and wide electrochemical window required for efficient, non-selective generation of hydroxyl radicals (â˘OH) at the anode surface, crucial for degrading recalcitrant organics. |
| Custom Electrode Dimensions | Custom Plates/Wafers up to 125 mm. | The paper used 100 mm x 100 mm plates (0.01 m2). 6CCVD provides BDD plates in these exact dimensions and can scale up to 125 mm (PCD) or supply thicker substrates (up to 10 mm) for robust industrial reactor designs. |
| Thickness Requirements | SCD/PCD Thickness from 0.1 Âľm to 500 Âľm. | We offer precise control over diamond layer thickness, ensuring optimal material usage and cost-effectiveness for large-area electrode manufacturing. |
| Electrode Integration & Contact | In-House Custom Metalization Services. | To ensure stable, low-resistance electrical contacts necessary for high current density operation (up to 40 mA/cm²), 6CCVD offers internal metalization capabilities including Ti, Pt, Au, Pd, W, and Cu. |
| Surface Quality for Flow Dynamics | Polishing Services (Ra < 5 nm for PCD). | While the paper focused on electrochemical activity, 6CCVD can provide specific surface roughness (Ra) control to optimize fluid dynamics and minimize fouling potential in high-flow recirculation systems. |
| Project Support & Optimization | In-House PhD Engineering Team Support. | 6CCVDâs experts can assist researchers and engineers in selecting the optimal BDD doping level, thickness, and surface preparation required to maximize current efficiency and minimize energy consumption for similar Advanced Oxidation Process (AOP) projects. |
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
This paper reports on the effectiveness of an innovative hybrid advanced oxidation process-scheme aiming to degrade recalcitrant organic compounds in industrial effluents. Following targeted experimental work, a pilot unit was developed/built combining two advanced oxidation processes, based on in-situ production of powerful hydroxyl radicals (HOď); i.e., electrochemical anodic oxidation (AO) employing boron-doped diamond (BDD) electrodes and photochemical oxidation via H2O2 photolysis under UV-C irradiation (H2O2/UV-C). The pilot-unit was operated, in batch mode for six months in a pesticides manufacturing plant, treating colored effluents characterized by high, recalcitrant organic load (typically ~3300 mg/L COD, ~1000 mg/L TOC). The effect was examined of key process parameters, including current density, UV-C dose, H2O2 concentration, recirculation flow rate and processing time, on system performance, mainly regarding organic-matter mineralization and discoloration rate. For the aforementioned effluent organic load, applying a near-optimal set of process-parameter values (i.e. 40 mA/cm2 current density, 0.65 W/L UV-C dose, âon-lineâ dosing of approx. 1140 mgďL-1ďh-1 H2O2 and 8.4 L/min recirculation flow rate), TOC and color removal reached 71% and 93%, respectively. The effectiveness of the combined AO/H2O2/UV-C process, mainly due to high utilization of injected H2O2 (approx. 80-90%), is judged as remarkable, considering that complete degradation (>99%) was observed of the 53 out of the total 54 organic compounds identified in the wastewater. Furthermore, the treated effluents by the hybrid AO/H2O2/UV-C process meet the standards (i.e. COD<1000 mg/L and TSS<350 mg/L) for safe disposal to local/regional biological effluent-treatment plant. Therefore, the demonstrated technology is an attractive, sustainable alternative to the currently employed special treatment, which involves chemical coagulation/granular activated carbon adsorption and necessitates costly extra-treatment of the resulting secondary wastes. Steps are currently in progress towards implementation at large scale, of the hybrid AO/H2O2/UV-C technology, for treatment of similar heavily polluted industrial effluents.