Electrochemical Treatment Research Articles

Electrochemical Weakening Material Strength for Accelerated Thinning of Silicon Carbide Substrates

This paper presents a novel approach to expedite the thinning of silicon carbide (SiC) substrates, a crucial step in enhancing material performance and extending chip longevity by reducing volume resistivity. The traditional methods of SiC substrate thinning, such as diamond wheel grinding and plasma etching, have inherent limitations, including the risk of wafer breakage and high processing costs. In response to these challenges, we propose an innovative technique involving the electrochemical etching attenuation of SiC strength, offering a cost-effective and efficient solution.In this study, we employed an electrochemical method to initially weaken the SiC substrate from the surface to a defined depth, followed by fine-tuning its thickness using a conventional diamond grinding wheel. Remarkably, our results demonstrate that SiC substrates subjected to electrochemical treatment exhibit well-structured lattices free from residual stresses. This novel approach not only reduces the risk of wafer breakage but also enhances the material's integrity (Figure 1).To gain deeper insights into the effects of electrochemistry on SiC material strength, advanced characterization techniques, including scanning electron microscopy, were employed. Our findings reveal that the electrochemically treated SiC surface exhibits a sponge-like morphology, with a cross-sectional profile showcasing prominent columnar structures (Figure 2). This sponge-like structure is attributed to the removal of silicon atoms during anodization, affirming the effectiveness of electrochemical methods in rapidly attenuating the material strength of SiC substrates, thereby facilitating their efficient thinning through grinding without compromising substrate integrity.In summary, this research highlights the potential of electrochemical methodologies for the initial weakening of SiC substrates, leading to accelerated and cost-effective thinning processes. This breakthrough not only expedites SiC substrate thinning but also contributes significantly to the advancement of SiC substrate thinning and grinding techniques, promising substantial benefits for future semiconductor device fabrication. Figure 1

Electrochemical treatment of 4-chlorophenol by three-dimensional electrode reactors packed with plastic particles electrodes

The three-dimensional electrode reactors (TDER) filled with surface-modified plastic particles electrodes, was much more effective on electrolyzing 4-chlorophenol wastewater than by conventional electrolysis. The experimental results indicated that about 96.8 % of 4-chorophenol was degraded effectively, it was possibly decomposed into aromatic organic compounds and small-molecular organic acids by hydroxyl radicals generated on the surfaces of electrodes, and the biodegradability of treated 4-chlorophenol wastewater was also much more improved than that of the untreated, which would be more easily biologically degraded by the subsequent conventional activated sludge process. Furthermore, the 4-chorophenol wastewater could be co-degraded with high-concentration nitrate effectively, both 2-chlorophenol and 2,4-dichorophenol wastewaters were also similarly decomposed.

Theoretical and practical aspects of the mathematical description electrochemical purification of oil-contaminated soil

Abstract The electrochemical method is one of the most promising solutions for oil-contaminated soil remediation by passing small constant electric currents. The creation of installations for the electrochemical treatment of oil-contaminated soils requires an understanding of the ongoing processes, which can be achieved by developing a mathematical model. In this paper, we consider obtaining a mathematical description of the change of the oil pollution concentration from the time of direct current treatment and the distance to the electrodes, followed by experimental verification of the adequacy of the models to real electrochemical processes in oil-contaminated soils. The article shows the main approaches and stages of obtaining mathematical models for assessing the cleaning effectiveness. Mathematical models of pollutant concentration changes of the depending on the time and distance to the electrodes were obtained. A correlation between the most important design parameters of the installation and the parameters of the electrochemical process has been established. The resulting models can be used to design installations for electrochemical treatment of oil-contaminated soils.

Monte Carlo Simulation, Artificial Intelligence and Machine Learning-based Modelling and Optimization of Three-dimensional Electrochemical Treatment of Xenobiotic Dye Wastewater

The present study investigates the synergistic performance of the three-dimensional electrochemical process to decolourise methyl orange (MO) dye pollutant from xenobiotic textile wastewater. The textile dye was treated using electrochemical technique with strong oxidizing potential, and additional adsorption technology was employed to effectively remove dye pollutants from wastewater. Approximately 98% of MO removal efficiency was achieved using 15 mA/cm2 of current density, 3.62 kWh/kg of energy consumption and 79.53% of current efficiency. The 50 mg/L MO pollutant was rapidly mineralized with a half-life of 4.66 min at a current density of 15 mA/cm2. Additionally, graphite intercalation compound (GIC) was electrically polarized in the three-dimensional electrochemical reactor to enhance the direct electrooxidation and.OH generation, thereby improving synergistic treatment efficiency. Decolourisation of MO-polluted wastewater was optimized by artificial intelligence (AI) and machine learning (ML) techniques such as Artificial Neural Networks (ANN), Support Vector Machine (SVM), and random forest (RF) algorithms. Statistical metrics indicated the superiority of the model followed this order: ANN > RF > SVM > Multiple regression. The optimization results of the process parameters by artificial neural network (ANN) and random forest (RF) approaches showed that a current density of 15 mA/cm2, electrolysis time of 30 min and initial MO concentration of 50 mg/L were the best operating parameters to maintain current and energy efficiencies of the electrochemical reactor. Finally, Monte Carlo simulations and sensitivity analysis showed that ANN yielded the best prediction efficiency with the lowest uncertainty and variability level, whereas the predictive outcome of random forest was slightly better.Highlights• In-depth analysis of various artificial intelligence optimization techniques.• Prediction efficiency of artificial intelligence and machine learning algorithms.• 98% dye removal and 100% regeneration of graphite intercalation compound.• Advanced statistical analysis of targeted responses and data fitting techniques.• Analysis of uncertainties and variability using Monte Carlo simulation.

Evaluating The Effectiveness of Wastewater Treatment In the Reusable Packaging Industry: A Case Study of ALNER’S WWTP In Indonesia

The widespread use of single-use plastic packaging has become a significant environmental issue, particularly in the Global South. This study examines the innovative approach of the startup Alner, which employs a combination of electrochemical treatment and Moving Bed Biofilm Reactor (MBBR) technology in its wastewater treatment plant (WWTP) to manage wastewater generated from the cleaning of reusable packaging. Wastewater samples were collected before and after treatment, and analyzed for key parameters such as Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD5), Total Suspended Solids (TSS), oil and grease, ammonia, surfactants, and phosphates. The results demonstrated a significant reduction in all measured pollutants, with COD reduced by 99.58% and BOD5 by 99.56%. Post-treatment values for all parameters were well within the regulatory limits set by the Ministry of Environment and Forestry Regulation No. P68/MenLHK/Setjen/Kum.1/8/2016. This study underscores the potential of reuse models in reducing single-use plastic waste and highlights the importance of effective wastewater treatment in maintaining environmental sustainability. Alner's approach provides a scalable and environmentally friendly solution, setting a benchmark for similar initiatives in the industry, and supports the feasibility and sustainability of integrating advanced wastewater treatment technologies in the reusable packaging sector, offering a comprehensive solution to plastic pollution.

PERFORMANCE EVALUATION OF A SIMPLE ELECTROCHEMICAL TREATMENT MODEL FOR SALINE WASTEWATERS: PART A

This paper investigated the performance of the electrochemical treatment technique in removing chloride from saline (salty) wastewaters (brine). Saline wastewaters (between 10 x 103 mg/l and 40 x 103 mg/l of chloride) were prepared and subjected to electrochemical treatment using developed carbon–resin (anode) and aluminium (cathode) electrodes. Electrochemical treatment of the simulated brine was conducted on a laboratory scale. The influence of selected factors on the performance of the electrochemical process was monitored using fractional factorial experiments. These selected factors were optimized using steepest descent technique (between the minimum and maximum concentrations) and rate change of chloride removal efficacy through Microsoft Excel Solver. The optimum values of these selected factors were used to purify typical raw saline water. Efficacies of the process in removing chloride ions from the typical raw saline water was used to predict efficacy of the system using typical chloride concentration in seawater based on literature and previous studies. The study revealed the relationship between chloride removal efficacy (%), initial concentration of chloride, current through the wastewater and separation distance between the electrodes were best in the form of exponentials with coefficient of determination of 0.979, 0.920 and 0.977, respectively. The optimum values of these selected factors such as current, pH, treatment period and separation distance between the electrode (centre to centre of the electrode) were 10.5 A equivalent to 0.795 A cm-2 , 6.7, 2.75 hr and 42mm, respectively. It was concluded that electrochemical treatment with carbon electrodes is an effective tool for removing chloride from saline wastewater during electrochemical treatment.

Nitrosamine formation driven by electrochemical chlorination of urine-containing source waters: Effects of operational conditions

We investigated the formation of nitrosamines from urine during electrochemical chlorination (EC) using dimensionally stable anodes. Short-term electrolysis (< 1 h) of urine at 25 mA cm−2 generated seven nitrosamines (0.1–7.4 µg L−1), where N-nitrosodimethylamine, N-nitrosomethylethylamine, and N-nitrosodiethylamine were predominant with concentrations ranging from 1.2 to 7.4 µg L−1. Mechanistic studies showed that the formation kinetics of nitrosamines was influenced by urine aging and composition, with fresh urine generating the highest levels (0.9–5.8 µg L−1) compared with aged, centrifuged, or filtered urine (0.2–4.1 µg L−1). Concurrently, studies on urine pretreatment through filtration and centrifugation underscored the significance of nitrogenous metabolites (such as protein-like products and urinary amino acids) and particle-associated humic fractions in nitrosamine formation during EC of urine. This finding was confirmed through chromatographic and spectroscopic studies utilizing LCOCD, Raman spectra, and 3DEEM fluorescence spectra. Parametric studies demonstrated that the ultimate [nitrosamines] increased at a pH range of 4.5–6.2, and with increasing [bromide], [ammonium], and current density. Conversely, sulfate and carbonate ions inhibited nitrosamine formation. Moreover, the implications of EC in urine-containing source waters were evaluated. The results indicate that regardless of the urine source (individual volunteers, septic tank, swimming pool, untreated municipal wastewater), high levels of nitrosamines (0.1–17.6 µg L−1) were generated, surpassing the potable reuse guideline of 10 ng L−1. Overall, this study provides insights to elucidate the mechanisms underlying nitrosamine formation and optimize the operating conditions. Such insights facilitate suppressing the generation of nitrosamine byproducts during electrochemical treatment of urine-containing wastewater.

Tribocorrosion performance of TC4 anodized/carbon fiber composite in marine environment

The TC4 titanium alloy is extensively utilized in marine engineering due to its exceptional comprehensive performance. However, when subjected to harsh marine environments, the TC4 titanium alloy is susceptible to tribocorrosion, which can shorten the service life of components. This paper employs an electrochemical anodic oxidation treatment of the TC4 titanium alloy and a ceramic adhesive to fabricate a TC4 anodic oxidation/carbon fiber composite (CFCM) to address this challenge. Hence, A systematic study has been conducted on the friction and wear behavior of TC4 titanium alloy in artificial marine and air environments, focusing on exploring the tribocorrosion behavior and their intrinsic mechanisms in marine environments. The corrosion behavior of the TC4 titanium alloy was determined through kinetic potential polarization analysis. The results indicate that the anodized/carbon fiber composite can significantly enhance the tribocorrosion resistance of the material. Two orders of magnitude reduce the passivation corrosion density, and the corrosion potential increases to −0.136 V compared to the TC4 substrate. Furthermore, the wear mechanism is predominantly characterized by abrasive wear. This study offers novel insights for optimizing the selection of anticorrosive materials and designing coatings in marine engineering.

Electrochemical and bioelectrochemical treatment of steam-assisted gravity drainage water

This study compares electrochemical and bioelectrochemical approaches for treating Steam-Assisted Gravity Drainage (SAGD) water. Electrochemical treatment tests were carried out at applied voltages (Vap) of 1.4, 2.0, and 2.5 V. Bioelectrochemical treatment in a Microbial Electrolysis Cell (MEC) was conducted at the same applied voltages with microaeration of both electrode compartments. The two treatment approaches were thereafter combined in a continuous flow setup that consisted of an electrochemical cell (EC, Vap = 2.5 V) followed by MEC (Vap = 1.4 V). Chemical oxygen demand (COD), naphthenic acid, dissolved metals, and metalloid concentrations of SAGD water were substantially reduced after all treatments, thereby rendering the treated water less toxic according to ecotoxicological tests. However, the MEC treatment was more energy efficient resulting in the lowest specific energy consumption (SEC) value of 5.2 kWh/kgCOD. By replacing a Ti/IrO2-oxide current collector in the MEC with a custom-made Ti/NiCo-oxide mesh, the COD removal efficiency improved by 30%. The results suggest that a MEC equipped with Ti/NiCo-oxide current collector can provide cost-efficient treatment of SAGD water.

Exploring Oxygen Vacancy Effect in 1D Structural SnIP for CO2 Electro-Reduction to Formate.

1D nanostructures exhibit a large surface area and a short network distance, facilitating electron and ion transport. In this study, a 1D van der Waals material, tin iodide phosphide (SnIP), is synthesized and used as an electrocatalyst for the conversion of CO2 to formate. The electrochemical treatment of SnIP reconstructs it into a web-like structure, dissolves the I and P components, and increases the number of oxygen vacancies. The resulting oxygen vacancies promote the activity of the CO2 reduction reaction (CO2RR), increasing the local pH of the electrode surface and maintaining the oxidative metal site of the catalyst despite the electrochemically reducing environment. This strategy, which stabilizes the oxidation state of the catalyst, also helps to improve the durability of CO2RR. In practice, 1D structured SnIP catalyst exhibits outstanding performance with >92% formate faradaic efficiency (FEformate) at 300mAcm-2, a maximum partial current density for formate of 343mAcm-2, and excellent long-term stability (>100h at 100mAcm-2 with >86% FEformate). This study introduced a method to easily generate oxygen vacancies on the catalyst surface by utilizing 1D materials and a strategy to improve the durability of CO2RR by stabilizing the oxidation state of the catalyst.

Minimal doping approach to activate lattice oxygen participation in K2WO4 electrocatalysts for oxygen evolution reaction

Understanding oxygen redox processes is pivotal for advancing oxygen evolution catalysts, critical in electrochemical devices for renewable fuel synthesis. Thermodynamic instability of high entropy metal oxides can interfere with oxygen redox reactions via electrochemical reconstruction. Transforming a W5N4 pre-catalyst into thermodynamically stable K2WO4 through electrochemical treatment in KOH, and incorporating minimal Fe doping, modifies the oxygen evolution reaction (OER) pathway towards oxygen redox activity, significantly influenced by the pH of the electrolyte. The Fe-doped K2WO4 catalyst demonstrates superior OER performance, achieving 10 mA/cm^2 at an overpotential of merely 181 mV (without iR compensation) and sustaining a lifetime of 1200 h at 1000 mA/cm2. Electrochemical methods and DFT calculations confirmed Fe doping creates oxygen vacancies and increases electron density near the Fermi level, enhancing the OER pathway. This methodology offers a versatile approach to adapt high entropy catalysts for broad electrochemical energy conversion applications, highlighting its potential for innovation in renewable energy technologies.

FeMo modified Ru@TiO2 with ultralow Ru loading towards efficient degradation of methylene blue

Dimensionally stable RuO2-based anodes have achieved excellent performance in the field of electrochemical treatment of wastewater, however, the high price of Ru hinders its industrial application. Herein, TiO2 nanotubes-supported RuO2 with ultralow Ru loading (0.34 wt%) and trace Fe and Mo doping (RuFeMo@TiO2) was prepared as anode for efficient degradation of methylene blue. It shows that Fe and Mo doping reduce the oxidation state of Ru (Run+, n < 4). In addition, the potential electroactive sites of the electrodes are effectively enhanced by Mo doping. While the Fe doping is found to improve the generation of hydroxyl radicals (·OH) and superoxide anion (O2−), which are the dominant oxidants for the degradation of methylene blue. In result, the RuFeMo@TiO2 catalyst exhibits high performance towards methylene blue degradation of 97.5 % within 2 hours. It shows that the cooperation of trace transition metals enables efficient degradation of organic dye with ultralow-loaded Ru electrocatalyst, implying a promising application in wastewater treatment.

Enhancing dewaterability of water resource recovery facility solids with electrochemical treatment through synergetic effects of acidification and cation removal

Solids dewaterability is vital for water resource recovery facilities to effectively manage and dispose treatment residuals, and current methods for improving dewaterability is at the expense of chemical consumption. Herein, an electrochemical approach that integrates anodic acidification, electrooxidation, and cation removal was investigated to enhance solids dewaterability. The results show that the specific resistance to filtration (SRF) was decreased by > 97 % for raw solids before anaerobic digestion, anaerobically digested solids (ADS), and primary solids. ADS exhibited the highest conductivity and required the least energy (34.9 ± 1.3 kWh m−3 treated solids). Increasing the applied current density reduced treatment time but demanded greater energy consumption. Both acidification and cation removal were critical to dewaterability enhancement: acidification facilitated the flocculation of solids flocs through protonation of functional groups and the leaching of divalent ions, while cation removal reduced competition for proton binding, leading to improved dewaterability. The input of electrical energy for the electrochemical treatment can potentially be offset by revenue from recovered nutrient products and use of renewable energy. This study has demonstrated the feasibility of using electrochemical processes for solids treatment and resource recovery.

Electrochemical treatment of azo dye wastewater by dynamic flow diaphragm system: Response surface methodology optimization and energy consumption analysis

In this experiment, the degradation process of azo dye wastewater was studied based on the diaphragm double chamber electrochemical reactor, taking the mono azo dye amaranth as an example. Through the circulation flow of appropriate volume of wastewater in the cathode and anode chamber, the simultaneous action of cathode and anode was realized, and the degradation and decolorization efficiency of azo wastewater was improved while reducing energy waste. The optimal reaction conditions optimized by response surface methodology were as follows: the voltage was 20.74 V, the plate spacing was 4.89 cm, and the cycle speed was 60.66 rad / min. The optimal decolorization rate was 99.66 %. The energy consumption analysis of the dynamic flow diaphragm system electrochemical method and the static flow diaphragm system electrochemical method for the treatment of azo dye wastewater was compared and analyzed. In addition, the possible degradation process of azo dye wastewater by dynamic flow electrochemistry was inferred by ultraviolet spectroscopy and mechanism prediction analysis. The experimental results show the great potential of the dynamic flow membrane system process in the treatment of azo dyes.

Tackling Challenges of Long-Term Electrode Stability in Electrochemical Treatment of 1,4-Dioxane in Groundwater.

Electrochemical advanced oxidation is an appealing point-of-use groundwater treatment option for removing pollutants such as 1,4-dioxane, which is difficult to remove by using conventional separation-based techniques. This study addresses a critical challenge in employing electrochemical cells in practical groundwater treatment─electrode stability over long-term operation. This study aims to simulate realistic environmental scenarios by significantly extending the experimental time scale, testing a flow-through cell in addition to a batch reactor, and employing an electrolyte with a conductivity equivalent to that of groundwater. We first constructed a robust titanium suboxide nanotube mesh electrode that is utilized as both anode and cathode. We then implemented a pulsed electrolysis strategy in which reactive oxygen species are generated during the anodic cycle, and the electrode is regenerated during the cathodic cycle. Under optimized conditions, single-pass treatment through the cell (effective area: 2 cm2) achieved a remarkable 65-70% removal efficiency for 1,4-dioxane in the synthetic groundwater for over 100 h continuous operation at a low current density of 5 mA cm-2 and a water flux of 6 L m-2 h-1. The electrochemical cell and pulse treatment scheme developed in this study presents a critical advancement toward practical groundwater treatment technology.

Enhancing the PEEK composites-titanium interface performances through electrochemical treatment in fibre-metal laminates for aerospace applications

In this work, different surface treatments were investigated to improve the adhesion between grade 5 titanium alloy and carbon fibre-reinforced PEEK composites for aerospace applications. Three types of processes were compared: mechanical treatment (MT), carried out by sander with #80 grit sandpaper, chemical treatment, using a silane coupling agent (SIL) and electrochemical treatment, performed by anodic oxidation. The latter was performed by using an ethylene glycol solution composed of 0.5%wt of ammonium fluoride (NH4F) and variable volume content of deionized water: 5%v/v, 20 % v/v, 50 % v/v. The ammonium fluoride content was fixed, while the ethylene glycol percentage depend on the variation of water volume. Two values of electric potential were evaluated: 30V and 50V. Finally, for each potential and water content, three different anodizing times were studied: 10 min, 30 min, and 60 min. Morphology studies were performed through Scanning electron microscopy to evaluate how the anodizing parameters could affect the shape of the nanotubes (NTs) layers. Moreover, short beam shear tests were carried out to evaluate the achieved improvement given by the different surface treatments.

Modeling and Optimization of Electrochemical Advanced Oxidation of Clopidogrel Using the Doehlert Experimental Design Combined with an Improved Grey Wolf Algorithm

In this research, the optimization of the electrochemical advanced oxidation treatment for the degradation of Clopidogrel was investigated. This study examined the influence of various experimental parameters including applied current, initial Clopidogrel concentration, and ferrous ion concentration by the use of the Doehlert design within a response surface methodology framework. The improved grey wolf optimizer was applied in order to define the optimum operating conditions. The monitoring of clopidogrel concentration during treatment revealed that complete disappearance of clopidogrel was achieved under an initial clopidogrel concentration of 0.02 mM, current intensity of 0.55 A, Fe2+concentration of 0.7 mM, and a reaction time of 20 min in a solution containing 50 mM Na2SO4 at pH 3. A quadratic polynomial model was developed, and its statistical significance was confirmed through the analysis of variance, demonstrating a high level of confidence in the model (R2 = 0.98 and p-value &lt; 0.05). Furthermore, following electrolysis treatment for 480 min, the synthetic clopidogrel solutions underwent mineralization, achieving a 70.4% removal rate of total organic carbon. Subsequently, the applicability of the optimized process was tested on real pharmaceutical wastewater, and mineralization was investigated under the identified optimal conditions, resulting in a total organic carbon removal rate of 87% after 480 min of electrolysis time. The energy consumption for this system was calculated to be 1.4 kWh·kg−1 of the total organic carbon removed. These findings underscore the effectiveness and potential applicability of the electrochemical advanced oxidation for industrial wastewater treatment.

Optimized electrochemical treatment of semi-coking wastewater for enhanced degradation of biological toxicity using a Ru-Ir-Ti anode and Co-Ti cathode

The Co-Ti cathode was prepared to reduce the biological toxicity of semi-coke wastewater by electrochemical system with commercial ruthenium-iridium titanium (Ru-Ir-Ti) anode. Meanwhile, the removal rate of chemical oxygen demand (COD), volatile phenol (VP) and ammonia nitrogen (NH3-N) in wastewater were also evaluated. Hence, the influence of processing time (A), dilution multiple (B), initial pH (C), electrolyte concentration (D) and current density (D) were systematic explored. After treatment, with the optimized experiment condition of processing time (150 min), dilution multiple (300 times), initial pH (3.2), electrolyte concentration (0.15 mol/L), current density (16 mV/cm2), the B/C value of wastewater was greatly improved from 0.12 to 0.31, the removal rate of COD, NH3-N and VP was 96.82 %, 92.34 % and 97.07 %, respectively. The sequence of significance was B>D>E*E>B*D>A*D>D*D. This most effective degradation was owing to the simultaneously oxidization of both cathode and anode, turning the highly biological toxic wastewater to the biodegradable one. The direct oxidation reaction happened on anode, furthermore, the indirect oxidation reaction would be accelerated near the cathode because of active free radicals generation such as ·OH and O2•– when the cobalt’s valence changed from +2 to +3. It deserve to be mentioned in this research is that the direct and indirect oxidation simultaneously contributed to the degradation of biological toxicity, which is great beneficial for the further bio-chemical processing.

Replacing oxygen evolution reaction in water splitting process by electrochemical energy-efficient production of high-added value chemicals with co-generation of green hydrogen

The utilization of biomass represents a promising alternative to the use of fossil fuels in facing both the energy problem and environmental pollution. Using the electrochemical oxidation of organic pollutants instead of the oxygen evolution reaction at the anode and the hydrogen evolution reaction at the cathode of an electrolyzer, it is possible to make high-value chemicals, break down pollutants, and produce hydrogen efficiently at the same time. In this study, the scale-up of the electrochemical treatment was investigated by treating technical cashew nutshell liquid effluent using a photovoltaic-driven electrochemical reactor with two compartments and equipped with a boron-doped diamond electrode as the anode and a Ni stainless-steel mesh as the cathode. Tests were carried out varying the anode current densities (40, 70, and 100 mA cm-2), the nature of the electrolyte solution (NaOH and Na2SO4), and the concentration of technical cashew nutshell liquid (0.01, 0.05, or 0.10 %). The results clearly shown that it is possible to successfully scale up a divided electrochemical reactor (passing from the batch approach of previous works to the flow approach of this study), favoring a selective accumulation of acetate (600 mg L-1) in the anodic compartment. In addition, the simultaneous production of green hydrogen (0.182 L h-1) was achieved when electrolyzing a biomass effluent containing 0.10 % technical cashew nutshell liquid in 1 mol L-1 NaOH and applying a current density of 40 mA cm-2. In conclusion, the sustainable electrochemical transformation of the waste (from technical cashew nutshell liquid into valuable products and energy carriers) was successfully achieved. We believe that the results will help the energy transition towards zero carbon emission and a cost-effective production of hydrogen through an integrated-hybrid process.

An Anti-Scaling Strategy for Electrochemical Wastewater Treatment: Leveraging Tip-Enhanced Electric Fields.

Electrode scaling poses a critical barrier to the adoption of electrochemical processes in wastewater treatment, primarily due to electrode inactivation and increased internal reactor resistance. We introduce an antiscaling strategy using tip-enhanced electric fields to redirect scale-forming compounds (e.g., Mg(OH)2 and CaCO3) from the electrode-electrolyte interface to the bulk solution. Our study utilized Cu nanowires (Cu NW) with high-curvature nanostructures as the cathode, in contrast to Cu nanoparticles (Cu NP), Cu foil (CF), and Cu mesh (CM), to evaluate the electrochemical nitrate reduction reaction (NO3RR) performance in hard water conditions. The Cu NW/CF cathode demonstrated superior NO3RR efficiency, with an apparent rate constant (Kapp) of 1.04 h-1, significantly outperforming control electrodes under identical conditions (Kapp < 0.051 h-1). Through experimental and theoretical analysis, including COMSOL simulations, we show that the high-curvature design of Cu NW induced localized electric field enhancements, propelling OH- ions away from the electrode surface into the bulk solution, thus mitigating scale formation on the cathode. Testing with real nitrate-contaminated wastewater confirms that the Cu NW/CF cathode maintained excellent denitrification efficiency over a 60-day period. This study offers a promising perspective on preventing electrode scaling in electrochemical wastewater treatment, paving the way for more efficient and sustainable practices.