Sustainable Wastewater Treatment and Water Reuse via Electrochemical Advanced Oxidation of Trypan Blue Using Boron-Doped Diamond Anode - XGBoost-Based Performance Prediction

At a Glance

Metadata	Details
Publication Date	2025-10-15
Journal	Sustainability
Authors	Sevtap Tırınk
Institutions	Iğdır Üniversitesi
Analysis	Full AI Review Included

Technical Analysis and Documentation: Boron-Doped Diamond for Advanced Electrooxidation

Executive Summary

This research validates the superior performance of Boron-Doped Diamond (BDD) anodes in the electrochemical advanced oxidation (EAO) of complex organic pollutants, specifically the azo dye Trypan Blue (TB). 6CCVD is uniquely positioned to supply the high-specification BDD materials required to replicate and scale this sustainable wastewater treatment technology.

High Efficiency: BDD anodes achieved exceptional TB removal efficiency, reaching up to 99.73% under optimized acidic conditions (pH 2.0).
Material Validation: The study confirms BDD’s role as the most suitable anode material due to its high oxygen evolution potential (OEP), chemical inertness, and non-active surface, which maximizes hydroxyl radical (•OH) generation and prevents passivation.
Optimal Parameters: Key operational parameters were identified, including optimal current densities (0.530 and 0.757 mA/cm²) and supporting electrolyte concentrations (40-60 mM Na₂SO₄) for balancing removal efficiency and energy consumption.
Scalable Geometry: The experiments utilized rectangular BDD plates (55 x 120 mm), a geometry 6CCVD can precisely manufacture and customize for industrial scale-up.
Data-Driven Optimization: The integration of a machine learning model (XGBoost) achieved high predictive accuracy (R² = 0.954), demonstrating a framework for rapid, energy-efficient process optimization.
6CCVD Value Proposition: We provide custom, high-quality Boron-Doped PCD electrodes necessary for developing sustainable, energy-efficient EAO systems for industrial wastewater treatment.

Technical Specifications

The following hard data points were extracted from the experimental section, highlighting the critical parameters for BDD electrooxidation performance.

Parameter	Value	Unit	Context
Anode Material	Boron-Doped Diamond (BDD)	N/A	Used for high oxidative potential
Anode Geometry	Rectangular Plate	N/A	Dimensions: 55 x 120 mm
Effective Anode Area	132	cm²	Geometric surface area
Cathode Material	Stainless Steel (SS 316)	N/A	Counter electrode
Initial Dye Concentration Tested	100, 200, 400	mg/L	Trypan Blue (TB)
Optimal Initial pH	2.0	N/A	Maximized •OH generation and dye-surface interaction
Current Density Range Tested	0.152 to 1.136	mA/cm²	Range tested
Optimal Current Density	0.530 and 0.757	mA/cm²	Optimal balance of efficiency and energy consumption
Maximum Removal Efficiency	99.73	%	Achieved at 100 mg/L, 200 rpm, pH 2.0
Optimal Electrolyte Conc. (Na₂SO₄)	40 to 60	mM	Enhanced conductivity and oxidant formation
Initial Solution Conductivity	10,950 to 38,700	µS/cm	Measured at 25 °C
Total Electrolysis Time	60	min	Duration of each experimental run
XGBoost Prediction Accuracy (R²)	0.954	N/A	Coefficient of determination on test data

Key Methodologies

The electrooxidation experiments utilized a controlled batch reactor setup coupled with advanced machine learning modeling for optimization.

Reactor Setup: Experiments were conducted in a 250 mL circular-bottom Plexiglas reactor under continuous stirring, maintained at a constant temperature of 25 °C.
Electrode Configuration: BDD electrodes (anode) and SS 316 plates (cathode) were used in a parallel plate configuration (55 x 120 mm).
Solution Composition: Synthetic TB dye solutions (100-400 mg/L) were treated. Anhydrous sodium sulfate (Na₂SO₄) was employed as the supporting electrolyte (20-100 mM).
Parameter Variation: Key operational variables systematically evaluated included:
- Current Density (0.152, 0.378, 0.530, 0.757, 1.136 mA/cm²).
- Initial pH (2, 5, 6, 8, 11).
- Stirring Speed (200, 400, 600 rpm).
Performance Analysis: TB removal efficiency was determined spectrophotometrically (λ_max = 590 nm). Energy consumption (EC) was calculated in watt-hours per liter (Wh/L).
Machine Learning Modeling: The XGBoost algorithm was trained on 80% of the experimental data to predict TB removal efficiency, utilizing hyperparameter optimization (Grid Search) to achieve high generalization performance (R² > 0.95).

6CCVD Solutions & Capabilities

The successful implementation of this advanced oxidation process hinges entirely on the quality and specifications of the Boron-Doped Diamond anode. 6CCVD provides the necessary high-performance materials and customization services to transition this research into scalable industrial applications.

Applicable Materials

The research requires a robust, high-stability anode material capable of generating strong oxidants (•OH) without passivation.

Recommended Material: Heavy Boron Doped PCD (Polycrystalline Diamond).
Justification: 6CCVD’s MPCVD BDD is engineered for electrochemical applications, offering the wide potential window and chemical inertness critical for high-efficiency, long-term operation, especially under the highly acidic (pH 2.0) and high current density conditions identified as optimal in the paper.

Customization Potential

The study utilized specific rectangular plates (55 x 120 mm). 6CCVD excels at providing custom geometries essential for pilot and industrial reactor designs.

Requirement	6CCVD Capability	Benefit to Researcher/Engineer
Custom Dimensions	Plates/wafers up to 125 mm (PCD). In-house laser cutting for custom rectangular or complex shapes.	Exact replication of experimental geometry (55 x 120 mm) or scaling up to larger, inch-size anodes for industrial reactors.
Thickness Control	SCD/PCD thickness from 0.1 µm to 500 µm. Substrates up to 10 mm.	Precise control over diamond layer thickness and substrate material (e.g., Si, Nb, or Ti) for optimized conductivity and cost efficiency.
Metalization	Internal capability for Au, Pt, Pd, Ti, W, Cu deposition.	Ensures robust, low-resistance electrical contacts for high-current density operation, crucial for maximizing energy efficiency (EC).
Surface Finish	Polishing down to Ra < 5 nm (Inch-size PCD).	Guarantees uniform current distribution and reproducible electrochemical performance across large-area anodes.

Engineering Support

The paper highlights the complexity of optimizing parameters like current density to avoid parasitic reactions and minimize energy consumption.

Expert Consultation: 6CCVD’s in-house PhD team provides expert material consultation to assist engineers in selecting the optimal BDD doping concentration and geometry for specific Azo Dye Electrooxidation projects.
Process Optimization: We help clients correlate BDD material properties (e.g., doping level, surface morphology) with critical operational parameters (current density, voltage) to achieve the best balance between high removal efficiency and low energy consumption, directly addressing the optimization challenge presented in the research.
Global Supply Chain: We offer reliable global shipping (DDU default, DDP available), ensuring timely delivery of custom BDD electrodes to support international R&D and manufacturing schedules.

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

View Original Abstract

Azo dyes are widely used in the textile industry due to their vibrant colors and chemical stability; however, wastewater containing these dyes poses significant environmental and health risks due to their toxic, persistent, and potentially carcinogenic properties. In this study, the treatment of wastewater containing trypan blue dye was investigated using the electrooxidation process with boron-doped diamond electrodes, and the efficiency of the process was modeled through the Extreme Gradient Boosting (XGBoost) algorithm. In the experimental phase, the effects of key operational parameters, including current density, pH, electrolysis time, and supporting electrolyte concentration, on TB dye removal efficiency were systematically evaluated. Based on the experimental data obtained, a machine learning-based XGBoost prediction model was developed, and hyperparameter optimization was performed to enhance its predictive performance. The model achieved high accuracy (R2 = 0.996 for training and 0.954 for testing) and yielded low error metrics (RMSE and MAE), confirming its reliability in predicting removal efficiency. This study presents an integrated and data-driven approach for improving the efficiency and sustainability of electrooxidation processes and offers an environmentally friendly and effective method for the treatment of azo dye-contaminated wastewater.

Tech Support

Original Source

DOI: https://doi.org/10.3390/su17209134

References

2025 - Optimization of Coagulation Process Parameters for Reactive Red 120 Dye Using Ferric Chloride via Response Surface Methodology [Crossref]
2023 - A review of environmental impact of azo dyes
2024 - Electrocoagulation-based AZO DYE (P4R) removal rate prediction model using deep learning [Crossref]
2019 - Toxicity assessment of biologically degraded product of textile dye acid red g [Crossref]
2024 - Evaluation of parameters in the removal of azo Red 40 dye using electrocoagulation
2024 - Treatment of azo dye-containing wastewater in a combined UASB-EMBR system: Performance evaluation and membrane fouling study [Crossref]