Electrochemical removal of organic pollutants represents an attractive methodology in water depollution. The key challenges for researchers comprise finding simple, affordable electrode materials with satisfactory efficiency in all ranges of pollutant concentration. Electrochemical oxidation of a mixture of phenol-based dyes: bromocresol green (BCG), cresol red (CR), and thymol blue (TB), in sulphate medium, at total concentration not exceeding 15 ppm, has been performed using simply prepared, low-cost composite electrodes, based on graphene nanoplatelets (GNP) and metallic oxides (TiO₂ and SnO₂) loaded on stainless steel substrate: GNP@SS, SnO₂/GNP@SS, and TiO₂/GNP@SS. Electrodes were characterised by XRD, FTIR, and electrochemical techniques. The degradation kinetics of initial dyes was tracked with UPLC and GC-MS chromatography for 6 h, at a current density of 10 mA/cm². GC-MS analysis of the degradation products revealed oxidised aromatic compounds as the main products, while TOC analysis confirmed a total mineralisation extent in the range of 30–35%. The proposed degradation mechanism involves the attack of OH-radical, as the main oxidising agent, to the hydroxyl oxygens of dye phenolic rings. Obtained results provide useful information for the further development of affordable laboratory-scale and industrial systems for the complete removal of phenol-based compounds.

This paper presents a comparative analysis of three carbon-based electrodes: bare multiwalled carbon nanotubes (MWCNT), SnO₂/MWCNT, and PbO₂/graphene-nanoribbons (PbO₂/GNR) composites, as anodes for the electrooxidative degradation of Rhodamine B as a model organic pollutant. Anodic electrooxidation of Rhodamine B was performed on all three electrodes, and the decolorization efficiency was found to increase in the order MWCNT < PbO₂/GNR < SnO₂/MWCNT. The electrodes were characterized by X-ray photoelectron spectroscopy (XPS) and linear sweep voltammetry (LSV). It was proposed that, in the 0.1 M Na₂SO₄ applied as electrolyte, observed decolorization mainly occurs in the interaction of Rhodamine B with OH radical adsorbed on the anode. Finally, the obtained results were complemented with Density Functional Theory (DFT) calculations of OH-radical interaction with appropriate model surfaces: graphene(0001), SnO₂(001), and PbO₂(001). It was found that the stabilization of adsorbed OH-radical on metal oxide spots (SnO₂ or PbO₂) compared to carbon is responsible for the improved efficiency of composites in the degradation of Rhodamine B. The observed ability of metal oxides to improve the electrooxidative potential of carbon towards organic compounds can be useful in the future design of appropriate anodes.

Apricot kernel shells were evaluated as a sustainable activated carbon precursor for wastewater treatment using experimental and theoretical methods. Two adsorbents were synthesized: physically activated with CO₂ (AKS-CO₂) and chemically activated with H₃PO₄ (AKS-H₃PO₄). Comprehensive materials characterization and adsorption tests using Pb²⁺ ions and Rhodamine B dye (RhB) as model pollutants revealed that AKS-H₃PO₄ significantly outperformed its physically activated counterpart. With an exceptionally high specific surface area (1159.4 m²/g) enriched with phosphorus-containing functional groups, the chemically activated carbon demonstrated outstanding removal efficiencies of 85.1% for Pb²⁺ and 80.3% for RhB. Kinetic studies showed Pb²⁺ adsorption followed pseudo-second-order kinetics, indicating chemisorption, while RhB adsorption fitted pseudo-first-order kinetics, suggesting intra-particle diffusion control. The thermodynamic analysis confirmed the spontaneity of both processes: Pb²⁺ adsorption was exothermic under standard conditions with positive isosteric heat at higher concentrations, reinforcing its chemisorption nature, whereas RhB adsorption was endothermic, consistent with physisorption. Density Functional Theory (DFT) calculations further elucidated the mechanisms, revealing that Pb²⁺ preferentially binds to oxygen-containing functional groups, while RhB interacts through hydrogen bonding and π–π stacking. These findings establish chemically activated apricot kernel shell carbon as a high-performance adsorbent, exhibiting exceptional removal capacity for both ionic and molecular contaminants through distinct adsorption mechanisms.

This review presents a comprehensive overview of electrochemical-based technologies as emerging and sustainable methods for treating pesticide-contaminated wastewater. Core processes, including electro-Fenton, electrocoagulation, and electrochemical oxidation, as well as their hybrid combinations, have demonstrated high degradation efficiency, operational flexibility, and the ability to achieve complete mineralization of persistent pesticides. A bibliometric analysis covering 1997–2025 reveals growing global interest in these technologies, particularly in hybrid systems such as photoelectro-Fenton and solar-assisted electrochemical treatments, which offer improved degradation rates and reduced energy demand. Compared to conventional and biological approaches, electrochemical methods provide superior pollutant removal without generating excessive sludge or secondary contamination. Future advancements should focus not only on optimizing operational parameters but also on overcoming current methodological limitations through the development of durable and selective electrode materials and the integration of renewable energy sources, ultimately enhancing process efficiency and sustainability. Coupling electrochemical treatments with complementary physicochemical or biological methods may further improve mineralization and reduce costs. Overall, electrochemical technologies represent a promising pathway toward efficient, scalable, and environmentally friendly wastewater treatment systems capable of mitigating pesticide pollution and protecting aquatic ecosystems.

The efficiency of electrochemical advanced oxidation processes (EAOPs) is fundamentally governed by hydroxyl-radical (•OH) generation. While direct experimental measurements of these transient species remain complex and impractical, robust computational methods for predicting their temporal profiles are notably scarce. This work presents a semi-empirical methodology based on H₂O₂ measuring experiments that enables indirect •OH quantification. We employed a recently developed carbon-based electrode and the priority pollutant bisphenol A (BPA) as the model system. The system achieved 92.3% BPA degradation with 84% mineralization efficiency during 5-h electrooxidation at 15 mA/cm². Gas chromatography/mass spectrometry (GC/MS) was used for tracking BPA and detection of intermediates. On this basis, we developed a computational model that successfully predicts temporal concentration profiles of all reactive species interacting with •OH, along with degradation kinetics across current densities (10–20 mA/cm²). By incorporating predictions from the Toxicity Estimation Software Tool (T.E.S.T.), the developed model accurately simulates time-dependent evolution of relative toxicity throughout the treatment process. The presented approach has a general character and requires rather simple experimental input to predict and optimize degradation outcome in terms of input concentration, degradation time, current density, and final toxicity. Further modifications of the model would enable widening to other EAOPs systems.

The management and treatment of pharmaceutical waste has recently attracted increasing attention from the scientific and professional community. Residues derived from nonsteroidal anti-inflammatory drugs (NSAIDs) represent carbon-rich precursors suitable for thermal conversion into carbon materials with adaptable structural properties. Moreover, these materials show potential as functional materials due to their high surface area, porosity, and surface functional groups, enabling applications in adsorption and catalysis. The aim of this study was to investigate the influence of calcination temperature on morphological and compositional transformations of NSAID-derived materials. Samples were thermally treated at 400, 600, and 800 °C in air and characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). SEM analysis revealed pronounced temperature-dependent structural evolution from compact carbonaceous morphology at 400 °C to heterogeneous microstructures containing elongated and needle-like domains at 800 °C. EDX analysis confirmed progressive elemental redistribution with increasing temperature, indicating gradual decomposition of the organic matrix and enrichment of inorganic phases. The obtained results provide insight into the thermal transformation mechanisms of pharmaceutical-derived materials and demonstrate their potential as precursors for functional carbon-based materials.