The presence of acetaminophen (ACTP) in aquatic environments has become a significant concern due to its environmental persistence and the potential formation of toxic transformation products. This study systematically compares the performance of three electrochemical advanced oxidation processes (EAOPs), electro-oxidation (EO), electro-Fenton (EF), and solar photo-electro-Fenton (SPEF), for the degradation and mineralization of ACTP in aqueous media using boron-doped diamond (BDD) electrodes. Reactions were conducted under varying operational parameters, including current densities (15–60 mA cm⁻²), initial ACTP concentrations (10–30 mg L⁻¹), and Fe²⁺ dosages. In the SPEF system, natural sunlight was utilized as the source of UV-A irradiation (30–35 W m⁻²). Among the evaluated processes, SPEF exhibited the highest degradation efficiency, achieving up to 97% ACTP removal and 78% chemical oxygen demand (COD) reduction within 90 min. High-performance liquid chromatography (HPLC) analysis identified phenol and catechol as major intermediates, suggesting a degradation pathway involving hydroxylation, aromatic ring cleavage, and subsequent oxidation into low-molecular-weight carboxylic acids. Kinetic modeling revealed pseudo-first-order behavior, with a maximum rate constant of 0.0865 min⁻¹ under optimized conditions determined via Box–Behnken experimental design. Additionally, SPEF demonstrated enhanced energy efficiency (~0.052 kWh gCOD⁻¹) and improved oxidant regeneration under solar radiation, highlighting its potential as an environmentally friendly and cost-effective alternative for pharmaceutical wastewater treatment. These results support the implementation of SPEF as a sustainable strategy for mitigating the environmental impact of emerging contaminants, especially in regions with high solar availability and limited technological resources.

This study explores a hybrid advanced electrochemical oxidation process (EAOP) intensified by solar irradiation and ozone for the treatment of wastewater containing COVID-19-related pharmaceuticals. Pilot-scale trials were performed in a 30 L compound parabolic collector (CPC)-type photoreactor with a boron-doped diamond (BDD–BDD) electrode configuration. Under optimal conditions (50 mg L⁻¹ paracetamol, 0.05 M Na₂SO₄, 0.50 mM Fe²⁺, pH 3.0, and 60 mA cm⁻²), the solar photoelectro-Fenton (SPEF) process achieved 78% chemical oxygen demand (COD) reduction within 90 min, with catechol and phenol detected as the main aromatic intermediates. When applied to a four-drug mixture (dexamethasone, paracetamol, amoxicillin, and azithromycin), the solar photoelectro-Fenton (SPEF–ozone (O₃)) system reached 60% degradation and 41% COD removal under solar conditions. The results highlight the synergistic effect of ozone and solar energy in enhancing the electrochemical oxidation process (EAOP) performance and demonstrate the potential of these processes for scalable and sustainable removal of pharmaceutical contaminants from wastewater.

The discharge of dye-laden effluents remains an environmental challenge since conventional treatments remove color but not the organic load. This study systematically compared anodic oxidation (AO), electro-Fenton (EF), and photoelectro-Fenton (PEF) processes for three representative industrial dyes, such as Coriasol Red CB, Brown RBH, and Blue VT, and their ternary mixture, using boron-doped diamond (BDD) and Ti/IrO₂–SnO₂–Sb₂O₅ (MMO) anodes. Experiments were conducted in a batch reactor with 50 mM Na₂SO₄ at pH =3.0 and current densities of 20–60 mA cm⁻². Kinetic analysis showed that AO-BDD was most effective at low pollutant loads, EF-BDD became superior at medium loads due to efficient H₂O₂ electrogeneration, and PEF-MMO dominated at higher loads by fast UVA photolysis of surface Fe(OH)²⁺ complexes. In a ternary mixture of 120 mg L⁻¹ of dyes, EF-BDD and PEF-MMO achieved >98 % decolorization in 22–23 min with pseudo-first order rate constants of 0.111–0.136 min⁻¹, whereas AO processes remained slower. COD assays revealed partial mineralization of 60–80 %, with EF-BDD providing the most consistent reduction and PEF-MMO minimizing treatment time. These findings confirm that decolorization overestimates efficiency, and electrode selection must be tailored to dye structure and effluent composition. Process-selection rules allow concluding that EF-BDD is the best robust dark option, and PEF-MMO, when UVA is available, offers practical guidelines for cost-effective electrochemical treatment of textile wastewater.

The discharge of dye-laden effluents remains an environmental challenge since conventional treatments remove color but not the organic load. This study systematically compared anodic oxidation (AO), electro-Fenton (EF), and photoelectro-Fenton (PEF) processes for three representative industrial dyes, such as Coriasol Red CB, Brown RBH, and Blue VT, and their ternary mixture, using boron-doped diamond (BDD) and Ti/IrO₂–SnO₂–Sb₂O₅ (MMO) anodes. Experiments were conducted in a batch reactor with 50 mM Na₂SO₄ at pH = 3.0 and current densities of 20–60 mA cm⁻². Kinetic analysis showed that AO-BDD was most effective at low pollutant loads, EF-BDD became superior at medium loads due to efficient H₂O₂ electrogeneration, and PEF-MMO dominated at higher loads by fast UVA photolysis of surface Fe(OH)²⁺ complexes. In a ternary mixture of 120 mg L⁻¹ of dyes, EF-BDD and PEF-MMO achieved >98% decolorization in 22–23 min with pseudo-first-order rate constants of 0.111–0.136 min⁻¹, whereas AO processes remained slower. COD assays revealed partial mineralization of 60–80%, with EF-BDD providing the most consistent reduction and PEF-MMO minimizing treatment time. These findings confirm that decolorization overestimates efficiency, and electrode selection must be tailored to dye structure and effluent composition. Process selection rules allow us to conclude that EF-BDD is the best robust dark option, and PEF-MMO, when UVA is available, offers practical guidelines for cost-effective electrochemical treatment of textile wastewater.