Person: Gutiérrez Sánchez, Pablo
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First Name
Pablo
Last Name
Gutiérrez Sánchez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Identifiers
3 results
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Item Extraction of neonicotinoid pesticides from aquatic environmental matrices with sustainable terpenoids and eutectic solvents(Separation and Purification Technology, 2022) Gutiérrez Sánchez, Pablo; Navarro, Pablo; Álvarez Torrellas, Silvia; García, Juan; Larriba Martínez, MarcosThe potential environmental impact and adverse effects of the occurrence of pesticides in the aquatic environment have raised great social and political concern, leading to their control by means of several regulations, such as the European Directive 98/83/EC. In this regard, the three neonicotinoid pesticides analyzed in this work (acetamiprid, imidacloprid, and thiamethoxam) have been included in the surface water European Watch Lists under the Water Framework Directive. This research proposes the use of terpenoid-based solvents for the extraction of the three emerging contaminants previously mentioned. An initial screening of the extraction solvents was carried out through the COSMO-RS methodology, selecting the most favourable pure terpenes, eutectic terpenoid-based and conventional solvents. Furthermore, relevant issues were experimentally analyzed, such as extraction in more realistic multicomponent mixtures together with key parametric studies covering operating temperature and matrix influence. Carvacrol, a pure terpenoid not applied before as an extraction solvent of pesticides, has been revealed as an effective and sustainable substitute for conventional solvents for the first time to the best of our knowledge. Specifically, carvacrol exhibited overall extraction yields of around 97.5 % from a river water matrix at a volumetric S/F ratio of 0.1 and 303.2 K. High extraction yields from river water matrices regardless of temperature pointed to the potential of this solvent for a wide range of industrial application.Item Efficient removal of antibiotic ciprofloxacin by catalytic wet air oxidation using sewage sludge-based catalysts: degradation mechanism by DFT studies(Journal of Environmental Chemical Engineering, 2023) Gutiérrez Sánchez, Pablo; Álvarez Torrellas, Silvia; Larriba Martínez, Marcos; Gil, María Victoria; Garrido Zoido, Juan Manuel; García Rodríguez, JuanIn this work, the sewage sludge-derived activated carbon (SAC) loaded with iron nanoparticles (FeSAC) showed a highly effective catalytic activity in the degradation of the antibiotic ciprofloxacin by the CWAO reaction. The properties of FeSAC catalyst were studied by using N2 adsorption-desorption measurements at 77 K, scanning electron microscopy, X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The CWAO reaction was evaluated at different temperatures (120–140 ºC), total pressure (10–30 bar) and catalyst doses (0.1–0.7 g/L) in a batch reactor. In this regard, temperature and catalyst dosage showed a significant impact on the removal of the tested antibiotic. By using a catalyst dose of 0.7 g/L, ciprofloxacin degradation and CO2 selectivity were higher than 99 % and 60 %, respectively, and were achieved within two hours at 140 °C and 20 bar. The loss of the active phase (Fe) of the catalyst in the reaction medium was measured, obtaining negligible values (less than 24 ppb). This catalyst showed high stability under the tested reaction conditions. In addition, a potential equation was proposed to correctly describe the evolution of ciprofloxacin degradation. The calculated activation energy of the CWAO process was 53.8 kJ/mol. Additionally, Density Functional Theory (DFT) calculations were performed to illustrate the degradation mechanism of ciprofloxacin, where the electronic energies indicated the compounds that are most difficult to degrade by CWAO. Finally, a proof of concept using an environmentally-relevant matrix was carried out, verifying the technical feasibility of the synthesized catalyst for its application with more complex matrices, consecutive reaction cycles and at a low treatment costItem Evaluation of the adsorptive and catalytic properties of sludge-based carbon materials for the efficient removal of antibiotics listed in the European Decision 2020/1161/EU(Journal of Environmental Chemical Engineering, 2023) Álvarez Torrellas, Silvia; Segura, Yolanda; de Mora, A.; Gutiérrez Sánchez, Pablo; Sanz Santos, Eva; Corrochano, Noelia; Larriba Martínez, Marcos; Pariente, M. I.; Martínez, Fernando; García, Juan JoséIn this work, sludge from an oily refinery and urban wastewater treatment plant have been used for the synthesis of activated carbons using ZnCl2 and KOH as activating agents. The materials were used as adsorbents and catalysts for the removal of three antibiotics, e.g., sulfamethoxazole (SMX), trimethoprim (TMP) and ciprofloxacin (CPX). The activated carbons have been fully characterized. Thus, the BET surface area of the materials ranged from 183 to 784 m2/g. Qe values of 127.3 mg/g for SMX onto U-ZnCl2; 168.5, and 179.6 mg/g for TMP and CPX, respectively, onto R-KOH were obtained. The best fitting of kinetic data was found by using pseudo-second order (PSO) model, while Freundlich and Liu models successfully fitted the equilibrium adsorption isotherms. SMX, TMP and CPX adsorption mechanisms were governed by pore filling, π-π interactions and H-bonds. R-KOH material was used for wastewater treatment, finding that the adsorption capacity decreased due to a competitive effect. Regarding the Fenton process, the U-ZnCl2 carbon achieved the total SMX degradation after 60 min. In contrast, TMP and CPX showed the highest depletion in only 20 min. The higher performances of the U-ZnCl2 material may be due to a higher C/O ratio and high N and Zn contents. In the experiments with a real aqueous matrix, similar conversions were achieved, although the kinetic constants resulted in slightly lower values. So, it could be stated that adsorption and Fenton oxidation performance were influenced by the different properties of the carbon materials.