A Sustainable Electrochemical-Based Solution for Removing Acetamiprid from Water

At a Glance

Metadata	Details
Publication Date	2023-10-04
Journal	Applied Sciences
Authors	Alana Maria Nunes de Morais, Danyelle Medeiros de Araújo, Inalmar D. Barbosa Segundo, Elisama Vieira dos Santos, Suely S.L. Castro
Institutions	Universidade do Estado do Rio Grande do Norte, Universidade Federal do Rio Grande do Norte
Citations	23
Analysis	Full AI Review Included

Executive Summary

This research evaluates the performance of Electrochemical Oxidation (EO) using two distinct anode materials—Dimensionally Stable Anodes (DSA) and Boron-Doped Diamond (BDD)—for the sustainable removal of the neonicotinoid insecticide Acetamiprid (ACT) from water.

Superior Mineralization: The BDD (non-active) anode demonstrated significantly superior performance in both degradation rate and mineralization efficiency compared to the DSA (active) anode (TiO₂-RuO₂-IrO₂).
High COD Removal: For high ACT concentration (300 mg L^-1) at 90 mA cm^-2, BDD achieved 71.4% Chemical Oxygen Demand (COD) removal within 60 minutes, whereas DSA only reached 47.5%.
Mechanism Confirmation: BDD’s high efficiency is linked to its high oxygen evolution potential (+1.7 V vs. Ag/AgCl), which favors the generation of highly reactive free hydroxyl radicals (OH) and sulfate-based oxidants (persulfate).
By-product Control: BDD electrolysis resulted in the complete disappearance of the characteristic ACT absorption band (245 nm) without generating new absorptive by-products, unlike DSA, which showed a persistent by-product band at 275 nm.
Cost vs. Performance Trade-off: While BDD offers higher decontamination efficacy and better water quality (lower DFZ coloration), its use implies higher treatment costs, necessitating further optimization for large-scale implementation.
SDG6 Alignment: The technology provides an efficient, advanced solution for eliminating recalcitrant organic pollutants, directly supporting Sustainable Development Goal 6 (Clean Water and Sanitation).

Technical Specifications

Parameter	Value	Unit	Context
Anode Type (Active)	TiO₂-RuO₂-IrO₂	N/A	Dimensionally Stable Anode (DSA)
Anode Type (Non-Active)	Boron-Doped Diamond	N/A	BDD
Electrode Geometrical Area	18	cm²	Both anodes and Ti cathode
Initial ACT Concentration (Low)	30	mg L^-1	Used for polarization curves and low-j degradation
Initial ACT Concentration (High)	300	mg L^-1	Used for COD and cost analysis
Applied Current Density (j) Range	30, 60, 90, 120	mA cm^-2	Experimental variable
Supporting Electrolyte	0.5	mol L^-1	Sodium Sulfate (Na₂SO₄)
BDD COD Removal Efficiency	71.4	%	At 90 mA cm^-2, 300 mg L^-1 ACT, 60 min
DSA COD Removal Efficiency	47.5	%	At 90 mA cm^-2, 300 mg L^-1 ACT, 60 min
BDD Oxygen Evolution Potential (E°)	+1.7	V vs. Ag/AgCl	High potential favors OH radical generation
DSA Oxygen Evolution Potential (E°)	+1.2	V vs. Ag/AgCl	Low potential favors direct oxidation and o.e.r.
ACT Characteristic Wavelength	245	nm	UV-Vis detection peak
By-product Wavelength (DSA)	275	nm	Observed at high j (90 and 120 mA cm^-2)
BDD Final Conductivity	11.5	mS cm^-1	Significant decrease due to persulfate electrosynthesis
Hydroxyl Radical Redox Potential (E°)	2.80	V/SHE	Standard oxidizing potential

Key Methodologies

The electrochemical oxidation (EO) process was conducted in a batch cell under controlled conditions to compare the catalytic activity of the DSA and BDD anodes.

Solution Preparation: Synthetic effluent was prepared using commercial ACT insecticide (20% purity) dissolved in distilled water at target concentrations (30 mg L^-1 or 300 mg L^-1). Sodium sulfate (0.5 mol L^-1 Na₂SO₄) was used as the supporting electrolyte.
Electrochemical Setup: Experiments utilized a single-sharing electrochemical cell containing 500 mL of solution, maintained under magnetic stirring. The anode (DSA or BDD, 18 cm²) and a titanium plate cathode were connected to a constant power supply.
Current Density Variation: Applied current density (j) was systematically varied (30, 60, 90, and 120 mA cm^-2) to determine the optimal operating conditions for both electrode materials.
Electrochemical Characterization: Linear polarization curves were recorded at 100 mV s^-1 to assess the onset potential of the oxygen evolution reaction (o.e.r.) and characterize the active vs. non-active nature of the anodes.
ACT Decay Monitoring: Samples were collected during electrolysis (up to 360 min) and analyzed using UV-Vis spectrophotometry (Varian Cary 50 Conc) to track the decay of the ACT characteristic absorption band at 245 nm.
Mineralization Assessment: Chemical Oxygen Demand (COD) was measured using HANNA kits (0-1500 ppm range, EPA method) to quantify the total organic matter removal and assess mineralization efficiency.
Water Quality Analysis: Effluent quality was assessed by measuring physicochemical parameters (pH, turbidity, salinity, conductivity) and estimating the Deutsche Farb Zah (DFZ) parameter to quantify solution coloration.

Commercial Applications

The findings are highly relevant for industrial and municipal water treatment sectors focused on eliminating persistent organic pollutants (POPs) using advanced electrochemical methods.

Pesticide and POP Remediation: Direct application in treating agricultural runoff, industrial wastewater, and contaminated groundwater containing neonicotinoids and other recalcitrant organic compounds.
Industrial Wastewater Treatment: Suitable for sectors requiring high mineralization rates (e.g., chemical manufacturing, pharmaceutical production) where conventional biological treatment is insufficient.
Water Reclamation and Reuse: The high efficiency of BDD in achieving low COD and minimal coloration makes the treated water suitable for non-potable reuse applications, such as industrial washing or irrigation.
Electrode Manufacturing and Supply: Provides performance metrics critical for the selection and deployment of high-performance anode materials (BDD) in commercial electrochemical reactors.
Sustainable Water Management: Supports the development of energy-efficient, chemical-free Advanced Oxidation Processes (EAOPs) as a core technology for achieving water security goals (SDG6).

View Original Abstract

Pesticides are used worldwide in agriculture to prevent insects and other pests that attack plants and their derivatives. Acetamiprid (ACT) is a type of insecticide belonging to the chemical group of neonicotinoids, which are widely used in agricultural planting to replace organophosphates. Therefore, in this work, the performance of the electrochemical oxidation (EO) process as an alternative solution to eliminate pesticides in water was evaluated. A dimensionally stable anode (DSA, TiO2-RuO2-IrO2) and boron-doped diamond (BDD) were tested as anodes for degrading ACT (30 and 300 mg L−1) by using different applied current densities (j): 30, 60, 90, and 120 mA cm−2. The degradation process was monitored by using ACT decay, spectrophotometric analysis, and chemical oxygen demand. The results clearly showed that ACT (30 mg L−1) was only eliminated from water at the DSA electrode when 90 mA cm−2 was applied, reaching higher removal efficiencies after 180 min of electrolysis. Conversely, ACT was quickly removed at all applied current densities used, at the same concentration. On the other hand, when the ACT concentration was increased (300 mg L−1), 71.4% of the COD removal was reached by applying 90 mA cm−2 using BDD, while no significant improvements were achieved at the DSA electrode when a higher concentration of ACT was electrochemically treated.

Tech Support

Original Source

DOI: https://doi.org/10.3390/app131910963

References

2020 - Electrochemical Oxidation of the Pesticide Nitenpyram Using a Gd-PbO2 Anode: Operation Parameter Optimization and Degradation Mechanism [Crossref]
2020 - A Review on the Photoelectro-Fenton Process as Efficient Electrochemical Advanced Oxidation for Wastewater Remediation. Treatment with UV Light, Sunlight, and Coupling with Conventional and Other Photo-Assisted Advanced Technologies [Crossref]
2021 - Finding a Suitable Treatment Solution for a Leachate from a Non-Hazardous Industrial Solid Waste Landfill [Crossref]
2018 - Electro-Fenton Catalyzed with Magnetic Chitosan Beads for the Removal of Chlordimeform Insecticide [Crossref]
2019 - Worldwide Pesticide Usage and Its Impacts on Ecosystem [Crossref]
2009 - Decontamination of Wastewaters Containing Synthetic Organic Dyes by Electrochemical Methods: A General Review [Crossref]
2022 - Highly Porous Seeding-Free Boron-Doped Ultrananocrystalline Diamond Used as High-Performance Anode for Electrochemical Removal of Carbaryl from Water [Crossref]
2023 - A Critical Review on Latest Innovations and Future Challenges of Electrochemical Technology for the Abatement of Organics in Water [Crossref]
2020 - Development of a Treatment Train for the Remediation of a Hazardous Industrial Waste Landfill Leachate: A Big Challenge [Crossref]