Examinando por Autor "Pazos, M."

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Activity and stability of bifunctional perovskite/carbon-based electrodes for the removal of antipyrine by electro-Fenton process
(Elsevier, 2023) Cruz del Álamo, Ana; Puga, Alicia; Pari, Miguel Ángel; Rosales, E.; Molina, Raúl; Pazos, M.; Martínez, F.; Sanromán, M.A.
Bifunctional perovskite/carbon-black(CB)/polytetrafluoroethylene(PTFE) electrodes for electro-generation and catalytic decomposition of hydrogen peroxide to oxidizing hydroxyl radicals have been fabricated. These electrodes were tested for electroFenton (EF) removal of antipyrine (ANT) as a model antipyretic and analgesic drug. The influence of the binder loading (20 and 40 wt % PTFE) and type of solvent (1,3-dipropanediol and water) was studied for the preparation of CB/PTFE electrodes. The electrode prepared with 20 wt % PTFE and water exhibited a low impedance and remarkable H2O2 electro-generation (about 1 g/L after 240 min, a production rate of ca. 6.5 mg/h⋅cm2 ). The incorporation of perovskite on CB/PTFE electrodes was also studied following two different methods: i) direct deposition on the CB/PTFE electrode surface and ii) addition in the own CB/PTFE/ water paste used for the fabrication. Physicochemical and electrochemical characterization techniques were used for the electrode’s characterization. The dispersion of perovskite particles in the own electrode matrix (method ii) exhibited a higher EF performance than the immobilisation onto the electrode surface (method i). EF experiments at 40 mA/cm2 and pH 7 (non-acidified conditions) showed ANT and TOC removals of 30% and 17%, respectively. The increase of current intensity up to 120 mA/cm2 achieved the complete removal of ANT and 92% of TOC mineralisation in 240 min. The bifunctional electrode also proved high stability and durability after 15 h of operation.
Novel 3D electro-Fenton reactor based on a catalytic packed bed reactor of perovskite/carbon microelectrodes for the removal of carbamazepine in wastewater
(Elsevier, 2024-08) Cruz del Álamo, A.; Puga, A.; Dias Soares, C.M.; Pariente, M.I.; Pazos, M.; Molina, R.; Sanromán, M.A.; Martínez, F.; Delerue-Matos, C.
This presents the efficacy of a 3D-ElectroFenton (3D-EF) reactor with active perovskite/carbon black/PTFE microelectrodes for the removal of carbamazepine (CZP) present in wastewater. Incorporating particle microelectrodes in the reactor enhanced the electron transfer and improved the electrocatalytic efficiency, leading to a more effective CZP removal. The optimal operational conditions were meticulously determined, including current intensity (0.05 – 0.3 A) and particle loading (0 – 1.5 g), to optimize the process and minimize energy consumption. The findings reveal that a current intensity of 0.2 A was the most effective, achieving 90% of CZP removal in 60 min and 3.86 kWh/mg of CZP. A higher current intensity of 0.3 A significantly increased the energy consumption (6.02 kWh/mg of CZP) for a total and faster CZP removal. The 3D-EF reactor was also operated continuously with ultrapure water and real urban wastewater fortified with CZP. A remarkable 62% CZP removal after 96 h on continuous operation was achieved with urban wastewater. Physicochemical and electrochemical characterization of microelectrodes demonstrated their high mechanical integrity and chemical stability. Our study underscores the potential of a 3D-EF system as a promising advanced oxidation process to address the continuous removal of antidepressant carbamazepine as one of the more resistant micropollutants of emerging concern in wastewater treatment, offering hope for a more efficient and sustainable future