Achieving Electrochemical-Sustainable-Based Solutions for Monitoring and Treating Hydroxychloroquine in Real Water Matrix

At a Glance

Metadata	Details
Publication Date	2022-01-11
Journal	Applied Sciences
Authors	Danyelle Medeiros de Araújo, Elisama Vieira dos Santos, Carlos A. Martínez‐Huitle, Achille De Battisti
Institutions	Universidade Federal do Rio Grande do Norte, University of Ferrara
Citations	14
Analysis	Full AI Review Included

Technical Documentation & Analysis: High-Efficiency BDD for Electrochemical Water Treatment

This document analyzes the research paper “Achieving Electrochemical-Sustainable-Based Solutions for Monitoring and Treating Hydroxychloroquine in Real Water Matrix” to highlight the critical role of high-quality Boron Doped Diamond (BDD) electrodes and to demonstrate 6CCVD’s capability to supply the necessary materials for replicating and scaling this advanced oxidation technology.

Executive Summary

The research successfully validates the use of Boron Doped Diamond (BDD) electrodes in electrochemical oxidation (EO) for the complete removal of Hydroxychloroquine (HCQ), a persistent micropollutant, from real river water matrices.

Complete HCQ Degradation: BDD anodes achieved 100% removal of 26.7 mg L^-1 HCQ within 120 minutes across all tested current densities (15-45 mA cm^-2).
High Organic Matter Removal: The process demonstrated significant mineralization, achieving up to 84% Chemical Oxygen Demand (COD) removal at the highest current density (45 mA cm^-2).
Material Validation: The BDD electrode, characterized by a 2.68 µm diamond layer and 500 mg L^-1 boron doping, proved highly effective as a non-active anode for generating powerful heterogeneous •OH radicals.
Scalability Potential: Increased current density (j) directly accelerated the reaction rate (pseudo-first-order kinetics), confirming that BDD performance is tunable for industrial scale-up requirements.
SDG6 Alignment: The integration of BDD-based electrochemical technology provides a robust, efficient, and effective strategy for achieving clean water and sanitization outcomes (Sustainable Development Goal 6).
6CCVD Relevance: The required BDD specifications (precise doping, controlled thickness, and custom area) are core competencies of 6CCVD’s MPCVD manufacturing process.

Technical Specifications

The following hard data points relate to the BDD electrode characteristics and the electrochemical oxidation performance metrics achieved in the study.

Parameter	Value	Unit	Context
Anode Material	Boron Doped Diamond (BDD)	N/A	Working electrode for Advanced Oxidation Process (AOP)
Cathode Material	Titanium (Ti)	N/A	Counter electrode
BDD Geometric Area	13.5	cm²	Exposed area during electrolysis
Diamond Layer Thickness	2.68	µm	BDD film specification
Boron Content	500	mg L^-1	Doping concentration in BDD
sp³/sp² Ratio	225	N/A	High quality material indicator
Applied Current Densities (j)	15, 30, 45	mA cm^-2	Galvanostatic treatment conditions
Initial HCQ Concentration	26.7	mg L^-1	Polluted river water sample
HCQ Removal Time	120	min	Time required for 100% HCQ decay at all j
Maximum COD Removal	84	%	Achieved at 45 mA cm^-2 (after 90 min)
Apparent Rate Constant (k)	0.118	min^-1	Highest rate achieved at 45 mA cm^-2
Oxygen Evolution Potential	+1.85	V vs Ag/AgCl (3 M)	Confirms high overpotential characteristic of BDD

Key Methodologies

The electrochemical treatment utilized a galvanostatic approach in an acidic river water matrix to maximize the production of oxidizing species.

Electrode Configuration: A two-electrode system was employed in an undivided batch reactor (250 mL), using BDD as the anode and Ti as the cathode, separated by approximately 2 cm.
Electrolyte Preparation: 250 mL of polluted river water (initial HCQ concentration ≈26.7 mg L^-1) was acidified with 10 mL of 0.1 M H₂SO₄ to maintain physical-chemical conditions and act as a supporting electrolyte.
BDD Characteristics: The BDD anode featured a 2.68 µm diamond layer thickness, 500 mg L^-1 boron content, and a 13.5 cm² geometric area.
Operation Mode: Experiments were conducted under galvanostatic control for 120 minutes, applying current densities (j) of 15, 30, and 45 mA cm^-2.
Reaction Mechanism: The high oxygen evolution overpotential of the BDD anode facilitated the efficient electrogeneration of free heterogeneous •OH radicals (BDD + H₂O → BDD(•OH) + H⁺ + e^-), which drove the rapid oxidation and mineralization of HCQ.
Monitoring: HCQ decay was tracked in real-time using a cork-graphite sensor via Differential Pulse Voltammetry (DPV), while overall organic matter removal was quantified using Chemical Oxygen Demand (COD) measurements.

6CCVD Solutions & Capabilities

6CCVD is uniquely positioned to support the replication, optimization, and industrial scale-up of this BDD-based electrochemical water treatment technology. Our MPCVD capabilities ensure the delivery of high-performance diamond materials tailored precisely to AOP requirements.

Applicable Materials

To replicate or extend this research, high-quality, heavily doped diamond is essential.

Material Recommendation: Heavy Boron Doped Diamond (BDD) Wafers and Plates.
- 6CCVD provides BDD optimized for electrochemical applications, ensuring the high sp³ content necessary for maximum •OH radical generation and stability under high current densities.
- We offer precise control over the boron doping concentration, easily meeting or exceeding the 500 mg L^-1 specification cited in the paper.

Customization Potential

The success of this EO process relies on specific BDD geometry and film quality. 6CCVD offers complete customization to meet research and industrial demands.

Research Requirement	6CCVD Capability	Value Proposition
Custom Dimensions	Plates/wafers up to 125mm (PCD/BDD) and custom laser cutting services.	We can provide the exact 13.5 cm² geometric area used in the study, or large-format plates for pilot-scale reactors.
Thickness Control	SCD/PCD/BDD thickness from 0.1 µm up to 500 µm. Substrates up to 10mm.	We guarantee the precise 2.68 µm diamond layer thickness, ensuring optimal electrochemical performance and cost efficiency.
Counter Electrode (Ti)	We offer custom metalization services including Ti, Pt, Au, Pd, W, and Cu.	We can supply the BDD anode pre-mounted or metalized with the required Ti cathode contact layers, streamlining reactor assembly.
Surface Finish	Polishing capability to Ra < 5nm (Inch-size PCD/BDD).	High-quality polishing ensures uniform current distribution and maximizes active surface area for consistent radical production.

Engineering Support

6CCVD’s in-house team of PhD material scientists specializes in diamond electrochemistry and AOPs.

Material Selection: We provide consultation on optimizing BDD parameters (doping level, thickness, and sp³/sp² ratio) to maximize current efficiency (%TCE) and minimize energy consumption (EC) for similar micropollutant degradation projects.
Scale-Up Assistance: Our expertise supports engineers transitioning from laboratory-scale 13.5 cm² electrodes to large-scale, flow-through reactor designs, ensuring material stability and performance under industrial conditions.
Global Logistics: We offer reliable global shipping (DDU default, DDP available) to ensure rapid delivery of custom BDD electrodes worldwide.

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

View Original Abstract

Hydroxychloroquine (HCQ) has been extensively consumed due to the Coronavirus (COVID-19) pandemic. Therefore, it is increasingly found in different water matrices. For this reason, the concentration of HCQ in water should be monitored and the treatment of contaminated water matrices with HCQ is a key issue to overcome immediately. Thus, in this study, the development of technologies and smart water solutions to reach the Sustainable Development Goal 6 (SDG6) is the main objective. To do that, the integration of electrochemical technologies for their environmental application on HCQ detection, quantification and degradation was performed. Firstly, an electrochemical cork-graphite sensor was prepared to identify/quantify HCQ in river water matrices by differential pulse voltammetric (DPV) method. Subsequently, an HCQ-polluted river water sample was electrochemically treated with BDD electrode by applying 15, 30 and 45 mA cm−2. The HCQ decay and organic matter removal was monitored by DPV with composite sensor and chemical oxygen demand (COD) measurements, respectively. Results clearly confirmed that, on the one hand, the cork-graphite sensor exhibited good current response to quantify of HCQ in the river water matrix, with limit of detection and quantification of 1.46 mg L−1 (≈3.36 µM) and 4.42 mg L−1 (≈10.19 µM), respectively. On the other hand, the electrochemical oxidation (EO) efficiently removed HCQ from real river water sample using BDD electrodes. Complete HCQ removal was achieved at all applied current densities; whereas in terms of COD, significant removals (68%, 71% and 84% at 15, 30 and 45 mA cm−2, respectively) were achieved. Based on the achieved results, the offline integration of electrochemical SDG6 technologies in order to monitor and remove HCQ is an efficient and effective strategy.

Tech Support

Original Source

DOI: https://doi.org/10.3390/app12020699

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