Person: García Rodríguez, Juan
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First Name
Juan
Last Name
García Rodríguez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
9 results
Search Results
Now showing 1 - 9 of 9
Item Degradation Kinetics of Bisphenol A by Catalytic Wet Oxidation with Ruthenium-Impregnated Carbon Nanosphere Catalysts(chemistry proceedings, 2022) Serra-Pérez, Estrella; Ovejero Escudero, Gabriel; García Rodríguez, JuanDifferent countries in Europe have proposed some restrictions about bisphenol A (BPA), considered an endocrine disruptor, for the production of food packing and toys for children, for example, Denmark, France, Sweden, Belgium, Austria and Norway. However, it is still being found in wastewater effluents. In this study, BPA was degraded by catalytic wet air oxidation employing ruthenium-impregnated carbon nanosphere catalysts (CNS). The catalyst was synthesized with a mixture of resorcinol and formaldehyde and later, a pyrolysis treatment was impregnated by 1, 2, 5, 7 and 10% of ruthenium and activated with hydrogen at 350 °C. The experimental installation was a batch Hastelloy high-pressure reactor of 100 mL of volume with an electrical jacket and a variable-speed magnetic drive. The concentration of BPA was followed by high-performance liquid chromatography. After the study of different experiment variables (temperature (110–150 °C), pressure (20–50 bar), initial concentration of BPA (5–30 mg L−1) and catalyst mass (50–300 mg)) in a batch reactor of 100 mL of volume, two different potential models (r = k CaBPA and r = k CaBPA Pb Cc Ru) were used for simulating the kinetic behavior of BPA from the adjustment of the experimental data obtained for CWAO reactions. It also tested different loads of ruthenium (1–10%) in BPA degradation. Both adjustments had a correlation factor of 0.98 and reproduced all the experiments well, being better than those ones with 20 mg L−1 of initial concentration of BPA. BPA degradation was above 97% at 90 min of reaction time from 2% of Ru in the catalyst.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 Insights of emerging contaminants removal in real water matrices by CWPO using a magnetic catalyst(Journal of Environmental Chemical Engineering, 2021) Huacallo Aguilar, Ysabel; Álvarez Torrellas, Silvia; Gil, Maria Victoria; Larriba Martínez, Marcos; García Rodríguez, JuanThe study was focused on the application of catalytic wet peroxide oxidation (CWPO) with a synthesized magnetic catalyst (Fe3O4/MWCNTs) for the treatment of real water matrices spiked with pharmaceutical compounds. CWPO was carried out by modifying the initial pH of surface water (SW), wastewater treatment plant (WWTP) effluent, brewery wastewater (BW) and hospital wastewater (HW), and the effect of the addition of the emerging pollutants naproxen (NAP) and diclofenac (DCF). From the experimental results, pH and concentration of NAP and DCF in CWPO were crucial factors in the successful pollutants removal from water matrices. The lab-prepared catalyst showed high removal rates of NAP and DCF from different water matrices spiked with the NAP-DCF mixture at pH 5.0. The highest average removal rate of TOC (75%), NAP (66%), DCF (76%), TN (39%) and aromaticity (68.39%) was obtained for SW matrix using 1.0 g L−1 of catalyst, pH ≈ 5.0, 5 mM of H2O2 and 60 °C. The mineralization decreased with the increase of the initial TOC concentration of the tested matrix. By CWPO tests of the real water matrices it was demonstrated that DCF removal was higher than NAP. From the recyclability tests, the catalyst demonstrated high activity and stability along three consecutive CWPO cycles of 8 h each one. The pseudo-second order model well-described the degradation of NAP and DCF. Finally, aromaticity and toxicity of the effluents were greatly reduced after CWPO treatment. This work demonstrated that CWPO with the magnetic catalyst is an efficient method to remove DCF-NAP mixtures from real aqueous matricesItem Influence of transition metal-based activating agent on the properties and catalytic activity of sewage sludge-derived catalysts. Insights on mechanism, DFT calculation and degradation pathways(Journal of Molecular Liquids, 2023) Gutiérrez Sánchez, Pablo; Álvarez Torrellas, Silvia; Larriba Martínez, Marcos; Gil, María Victoria; Garrido Zoido, Juan Manuel; García Rodríguez, JuanResearch studies combining the detailed physicochemical properties' analysis, the catalytic activity in different real aqueous matrices, the proposal of degradation mechanisms and the stability of the intermediates/by-products by means of the Density-functional theory (DFT) are scarce. Therefore, this work gives a step forward in the field of circular economy and the removal of emerging pollutants such as the antibiotic ciprofloxacin, covering all the previously aspects mentioned, using four iron and nickel-based catalysts from two different sewage sludge. Experimental results revealed a significant influence of both the source of the sewage sludge and the activating agent used (iron chloride, nickel chloride and a mixture of both) on the physicochemical properties of the materials and, hence, on their catalytic activity. FTIR studies and chemical composition evidenced that the use of this biomass precursor leads to the generation of a wide variety of functional groups and heteroatoms in the synthesized catalyst structure. Moreover, they showed a combination of Type I-IV isotherms with H3-H4 type hysteresis loops, being mainly mesoporous materials and exhibiting a moderate microporosity except when nickel chloride was used solely as activating agent. The carbonaceous materials reached ciprofloxacin adsorption capacities in the range of 40.4–73.9 mg/g. The use of nickel chloride showed the lowest adsorption contribution and catalytic activity. The bimetallic catalyst (synthesized from a mixture of iron and nickel chloride) showed slightly higher catalytic activity than that found for the iron catalyst, but the metal leaching was also considerably higher. Consequently, the use of iron chloride solely as activating agent seems to be the better alternative, achieving a maximum ciprofloxacin removal around 99.7 % and an iron leaching concentration into the reaction medium of 0.48–0.61 mg/L. The main degradation pathways of ciprofloxacin were proposed according to the detection of LC-MS intermediates and DFT calculation, indicating the most likely areas of attack of reactive species on atoms with a high Fukui index (f0)Item Novel approach for azole fungicides extraction from aqueous environments using terpenes and eutectic solvents(Journal of Environmental Chemical Engineering, 2023) Rodríguez Llorente, Diego; García Fernández de la Puente, Enrique; García Rodríguez, Juan; Larriba Martínez, MarcosThe presence of azole fungicides in aquatic environments is a significant issue due to their toxicity and persistence related to a low removal of these compounds by conventional processes in wastewater treatment plants. A growing environmental public concern is reflected in the inclusion of these compounds in the 2020 and 2022 European Surface Water Watch Lists. Therefore, it is necessary to develop efficient processes that allow their removal sustainably. This work applies liquid-liquid extraction using terpenes as green solvents and terpene-based eutectic solvents to remove azole fungicides from aqueous streams imazalil, metconozale, penconazole, prochloraz, and tebuconazole. First, an initial screening was performed by molecular simulation using the COSMO-RS method. The selected solvents were applied in the individual extraction of azole fungicides, and selecting the solvents thymol+octanoic acid and carvacrol. These solvents have been tested in studies with surface water matrix on the effect of temperature, initial concentration, and pH on extraction performance. From these results, it has been shown that carvacrol is the solvent that is least affected by these variables and obtains extraction yields higher than 97.88%, with a Solvent/Feed ratio up to 0.050, outperforming the conventional solvent methyl isobutyl ketone. This solvent has been used in solvent reuse cycles obtaining a reduction of less than 1% in three extraction cycles. Therefore, carvacrol is presented as a sustainable solvent for the extraction of azole fungicides from aqueous environments.Item Sustainable recovery of phenolic antioxidants from real olive vegetation water with natural hydrophobic eutectic solvents and terpenoids(Environmental Research, 2023) Rodríguez Llorente, Diego; Martín Gutiérrez, Diego; Suárez Rodríguez, Pablo; Navarro Tejedor, Pablo; Álvarez Torrellas, Silvia; García Rodríguez, Juan; Larriba Martínez, MarcosOlive oil production leads to the generation of olive mill wastewater (OMWW). Due to the presence of phenolic compounds, they are difficult to process, but they represent a source of high-added value chemicals since they have antioxidant and therapeutic properties. This work has studied the extraction of phenolic compounds from a type of OMWW, olive vegetation water, which presents these compounds in a more diluted dosage than in other studied to date, to revalue this waste stream. A real olive vegetation water from a Spanish olive oil producer was used, and liquid-liquid extraction was applied. Terpenoids and terpene-based hydrophobic eutectic solvents were systematically used to extract phenolic compounds following the concentrations of tyrosol, catechol, caffeic acid, and total phenolic content. By molecular simulation with the COSMO-RS method, 4 terpenoids, and 2 eutectic solvents were selected and compared with 2 conventional solvents. The Solvent/Feed ratio in the extraction of phenolic compounds was studied, showing that the solvents with the highest extraction results were geraniol, eucalyptol, and eutectic solvent menthol + camphor, which outperformed conventional solvents methyl isobutyl ketone and diisopropyl ether. Menthol + camphor gave total phenol extraction yields of 88.73% at a Solvent/Feed ratio in volume of 0.50, surpassing all solvents tested. A solvent reuse and regeneration process was applied by back-extraction of the 4 solvents: FTIR results showed the stability of the solvents while maintaining yields in the solvent reuse process. The phenolic compounds could be concentrated in the alkaline phase to factors up to 49.3 to the initial concentration in olive vegetation water. The alkaline phases were neutralized to obtain a precipitate with a caffeic acid content of up to 26 % wt%, and a tyrosol-rich supernatant with a concentration of up to 6.54 g/L. This work proposes a process using natural solvents to extract phenolic compounds from olive vegetation water.Item Insights into the Kinetics Degradation of Bisphenol A by Catalytic Wet Air Oxidation with Metals Supported onto Carbon Nanospheres(Catalysts, 2021) Serra-Pérez, Estrella; García Rodríguez, JuanEmerging pollutants are an increasing problem in wastewater globally. Bisphenol A (BPA) is one compound belonging to this group. This work proposes the study of the employment of several metal-supported (2 wt. %) carbon nanospheres (CNS) for BPA degradation by catalytic wet-air oxidation. Several techniques were used for the catalyst characterization: thermogravimetry, X-ray diffractometry (XRD), Fourier transformed infrared spectrometry (FTIR), determination of isoelectric point, elemental analysis, X-ray fluorescence (XRF), scanning electron microscopy (SEM), and N2 adsorption–desorption isotherms. Different loads of Ru in the catalyst were also tested for BPA degradation (1, 2, 5, 7, and 10%), being the first minimum value to achieve a conversion above 97% in 90 min 2 wt. % of Ru in the CNS-Ru catalyst. In the stability test with CNS-Ru and CNS-Pt, CNS-Pt demonstrated less activity and stability. Two potential models were proposed to adjust experimental data with CNS-Ru(2%) at different conditions of BPA initial concentration, catalyst mass, temperature, and pressure of the reaction. Both models showed a high determination coefficient (R2 > 0.98). Finally, the efficiency of CNS-Ru and CNS-Pt was tested in a real hospital wastewater matrix obtaining better results the CNS-Pt(2%) catalyst.Item Application of Sludge-Based Activated Carbons for the Effective Adsorption of Neonicotinoid Pesticides(Applied Sciences, 2021) Sanz-Santos, Eva; Álvarez-Torrellas, Silvia; Ceballos, Lucía; Larriba Martínez, Marcos; Águeda Maté, Vicente Ismael; García Rodríguez, JuanThe amount of sludge produced in wastewater treatment plants (WWTPs) has increased over the years, and the methods used to reduce this waste, such as incineration, agricultural use, or disposal in landfills, cause problems of secondary pollution. For this reason, it is necessary to find sustainable and low-cost solutions to manage this waste. Additionally, emerging and priority pollutants are attracting attention from the scientific community as they can generate health problems due to inadequate removal in conventional WWTPs. In this work, a pharmaceutical industry sludge was used as a precursor in the synthesis of four activated carbons (ACs) using different activating agents (ZnCl2, FeCl3∙6H2O, Fe(NO3)3∙9H2O, and Fe(SO4)3∙H2O), to be used for the removal by adsorption of three neonicotinoid pesticides included in latest EU Watch List (Decision 2018/840): acetamiprid (ACT), thiamethoxam (THM), and imidacloprid (IMD). The prepared ACs showed micro–mesoporous properties, obtaining relatively slow adsorption kinetics to reach equilibrium, but despite this, high values of adsorption capacity (qe) were obtained. For example, for AC-ZnCl2 (SBET = 558 m2/g), high adsorption capacities of qe = 128.9, 126.8, and 166.1 mg/g for ACT, THM, and IMD, respectively, were found. In most cases, the adsorption isotherms showed a multilayer profile, indicating an important contribution of the mesoporosity of the activated carbons in the adsorption process.Item Flow-based recovery of acetic acid from aqueous solutions using bio-derived terpenes as extracting solvents(Separation and Purification Technology, 2023) Rodríguez Llorente, Diego; Liu, Yu; de Mello, John C.; García Rodríguez, Juan; Larriba Martínez, MarcosThe ability to recover acetic acid and related byproducts from wastewater treatment plants would unlock a sustainable source of important building block-chemicals that are currently derived from fossil fuels. We report here a two-stage flow-based procedure for the extraction and alkaline back-extraction of acetic acid from an aqueous feed solution, using geraniol or eucalyptol as bio-derived organic solvents. In the first stage, acetic acid is extracted from the feed solution into the organic solvent; and, in the second stage, acetic acid is back-extracted into a 2-M NaOHaq solution, leaving a regenerated solvent that may be used for further extractions. Recovery efficiencies of up to 51 % and 37 % were obtained using geraniol and eucalyptol, respectively. By back-extracting acetic acid into a smaller volume of NaOH than the feed solution from which it was extracted, more than threefold enhancements in acetic acid concentration were achieved with respect to the feed solution. Overall acetic acid recovery efficiencies of 57 ±1% and 46 ±2% were obtained for geraniol and eucalyptol, respectively. Both solvents were successfully used for multiple extraction/back-extraction cycles, with geraniol giving a stable concentration of back-extracted acetic acid over the course of ten cycles.