Navegando por Autor "Souza, Guilherme Botelho Meireles de"
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- ItemDegradation of antibiotic amoxicillin from pharmaceutical industry wastewater into a continuous flow reactor using supercritical water gasification(2023) Dias, Isabela Milhomem; Mourão, Lucas Clementino; Andrade, Laiane Alves de; Souza, Guilherme Botelho Meireles de; Viana, Julio Cezar Vieira; Oliveira, Sérgio Botelho de; Alonso, Christian GonçalvesIn recent years the concern with emerging pollutants in water has become more prominent, especially pharmaceutical residues, such as antibiotics due to the influence to increase antibacterial resistance. Further, conventional wastewater treatment methods have not demonstrated efficiency for the complete degradation of these compounds, or they have limitations to treat a large volume of waste. In this sense, this study aims to investigate the degradation of amoxicillin, one of the most prescribed antibiotics, in wastewater via supercritical water gasification (SCWG) using a continuous flow reactor. For this purpose, the process operating conditions of temperature, feed flow rate, and concentration of H2O2 was evaluated using Experimental Design and Response Surface Methodology techniques and optimized by Differential Evolution methodology. Total organic carbon (TOC) removal, chemical oxygen demand (COD) degradability, reaction time, amoxicillin degradation rate, toxicity of degradation by-products, and gaseous products were evaluated. The use of SCWG for treatment achieved 78.4% of the TOC removal for the industrial wastewater. In the gaseous products, hydrogen was the majority component. Furthermore, high-performance liquid chromatography analyses demonstrated that the antibiotic amoxicillin was degraded. For a mass flow rate of 15 mg/min of amoxicillin fed into the reaction system, 14.4 mg/min was degraded. Toxicity tests with microcrustacean Artemia salina showed slight toxicity to treated wastewater. Despite that, the outcomes reveal the SCWG has great potential to degrade amoxicillin and may be applied to treat several pharmaceutical pollutants. Aside from this, carbon-rich effluents may lead to a significant energy gaseous product, especially, hydrogen and syngas.
- ItemHydrogen production via supercritical water gasification of glycerol enhanced by simple structured catalysts(2023) Mourão, Lucas Clementino; Souza, Guilherme Botelho Meireles de; Dias, Isabela Milhomem; Oliveira, Sérgio Botelho de; Souza, Thiago Leandro de; Alonso, Christian GonçalvesThe supercritical water gasification (ScWG) technology is a promising alternative for H2-rich gas production from renewable sources, such as residual glycerol from biodiesel manufacture. Combined with heterogeneous catalysts, the ScWG process can achieve improved selectivity towards the desired products and high conversion efficiency in short reaction times. In this work, the efficiency of a synthesized Ni-based catalyst supported in cordierite (CRD) honeycomb structure on the ScWG of glycerol was evaluated and compared with two commercial automotive catalysts. Initially, to determine the best experimental conditions, the ScWG experiments were conducted in the absence of catalysts at constant conditions pressure (25 Mpa) and volumetric flow rate (10 mL min−1). The temperature range of 400–700 °C and glycerol feed composition between 10 and 34 wt% were evaluated. The catalysts evaluated were characterized by SEM-EDS, XRD, N2 adsorption/desorption, XRF, WDS and TGA. The liquid and gaseous products were analyzed by TOC and gas chromatography, respectively. Results indicated that Ni/CRD catalyst showed the highest H2 yield (5.38 mol H2 per mol of glycerol fed) and long-term stability. Additionally, a comparison between the experimental results on the ScWG of glycerol and simulated thermodynamic equilibrium data was also reported. Thus, results demonstrated the great potential of the prepared catalyst to improve H2-rich gas production from glycerol gasification.
- ItemManagement of waste printed circuit boards via supercritical water technology(2022) Souza, Guilherme Botelho Meireles de; Pereira, Mariana Bisinotto; Santos, Lucas Francisco dos; Alonso, Christian Gonçalves; Jegatheesan, Veeriah; Cardozo Filho, LúcioIn this study, the application of the supercritical water technology on the management of waste printed circuit boards (PCBs) obtained from small information technology (IT) and communication equipment was conducted. Initially, an extensive recycling-oriented characterization of waste printed circuit boards was conducted through a combination of several physicochemical analyzes such as MP-AES, XRF, TG/DTA, CHNS elemental analysis, SEM and XRD. Afterwards, at supercritical conditions of water (Tc > 374.29 °C and Pc > 22.089 MPa), the optimal conditions for the degradation of the organic polymers present in the waste PCBs were defined by a response surface methodology. A complete organic degradation rate (ODR) was achieved at 600 °C, reaction time of 60 min, waste PCBs load of 15 g and flow-rate of 5 mL min−1. After the removal of the organic polymers, the metals were liberated, and the metal recovery efficiency (MRE) reached values higher than 90% at all evaluated conditions. Then, initial insights on the subsequent treatment of the liquid decomposition by-products generated during the supercritical water (ScW) processing of waste PCBs were provided. A total organic carbon reduction of 99.88% was achieved via the ScW oxidation process using the same experimental apparatus. The treated solution was successfully re-used in the ScW processing of waste PCBs instead of clean water. Moreover, hydrogen, methane, CO2, and CO were identified as the major gaseous products associated to the supercritical water treatment of waste PCBs. Finally, a novel strategy to enhance the production of combustible gases, through the addition of ethanol and glycerol, and increase the economic feasibility of the supercritical water processing of waste PCBs was proposed.
- ItemNb2O5 supported catalysts for cross-coupling reactions(2020) Souza, Guilherme Botelho Meireles de; Ribeiro, Thiago Soares Silva; Mourão, Lucas Clementino; Pereira, Mariana Bisinotto; Leles, Maria Inês Goncalves; Liao, Luciano Morais; Oliveira, Guilherme Roberto de; Alonso, Christian GonçalvesPalladium and nickel supported on Nb2O5 were synthesized via wet impregnation method and tested for the Suzuki-Miyaura reaction. The catalysts were characterized by X-ray fluorescence, textural analysis, scanning and transmission electron microscopy, thermogravimetry/differential thermal analysis and X-ray diffraction. Palladium catalyst resulted in high isolated yields (91%). Satisfactory yields (48%) were achieved employing the nickel catalyst. Hot filtration experiments were performed to evaluate the reaction heterogeneity. The catalysts were submitted to consecutive reactions runs to assess recyclability. Deactivation was attributed to catalyst loss by filtration between cycles, minor leaching of the active phase and poisoning by inorganic species.
- ItemSimultaneous recycling of waste solar panels and treatment of persistent organic compounds via supercritical water technology(2023) Pereira, Mariana Bisinotto; Souza, Guilherme Botelho Meireles de; Espinosa, Denise Crocce Romano; Pavão, Leandro Vitor; Alonso, Christian Gonçalves; Cabral, Vladimir FerreiraThe study addresses the application of the supercritical water technology in the simultaneous recycling of obsolete solar panels and treatment of persistent organic compounds. The obsolete solar panels samples were characterized by TEM-EDS, SEM, TG-DTA, XRD, WDXRF, MP-AES and elemental analysis. Initially, the optimized parameters for the degradation of solid organic polymers present in residual solar panels via oxidation in supercritical water were defined by an experimental design. Under optimized conditions, 550 °C, reaction time of 60 min, volumetric flow rate of 10 mL min−1 and hydrogen peroxide as oxidant agent, real laboratory liquid wastewater was used as feed solution to achieve 99.6% of polymers degradation. After the reaction, the solid product free of organic matter was recovered and characterized. On average, a metal recovery efficiency of 76% was observed. Metals such as aluminum, magnesium, copper, and silver, that make up most of the metallic fraction, were identified. Only H2, N2 and CO2 were observed in the gaseous fraction. Then, initial data on the treatment of the liquid decomposition by-products, generated during ScW processing, were reported. A total organic carbon reduction of 99.9% was achieved after the subsequential treatment via supercritical water oxidation using the same experimental apparatus. Finally, insights on the scale-up, energy integration and implementation costs of a ScW solid processing industrial unit were presented using the Aspen Plus V9 software.
- ItemSulfonated carbons from agro-industrial residues: simple and efficient catalysts for the Biginelli reaction(2022) Nascimento, Letícia Gomes do; Dias, Isabela Milhomem; Souza, Guilherme Botelho Meireles de; Mourão, Lucas Clementino; Liao, Luciano Morais; Viana, Julio Cezar Vieira; Liao, Luciano Morais; Oliveira, Guilherme Roberto de; Alonso, Christian GonçalvesThe Biginelli reaction is a one-pot acid-catalyzed cyclocondensation of an aromatic aldehyde, urea, and ethyl acetoacetate to synthesize dihydropyrimidinones (DHPMs). DHPMs are extremely important due to their wide-ranging pharmacological activities, and, for this reason, the Biginelli reaction has been at the forefront of investigations by various research groups. Here, we report the production of sulfonated carbons from agro-industrial wastes (rice husk and tomato bagasse) applied as an inexpensive and efficient heterogeneous catalyst for the synthesis of DHPMs. Catalysts were easily prepared by carbonization using sulfuric acid at 200 °C for 6 hours. The coal surface was characterized by N2 adsorption–desorption isotherms at −196 °C, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and textural analysis. Infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and Raman analysis proved the sulphonation of catalysts. In addition, other complementary analyses were also carried out, such as elemental analysis of the contents of carbon, nitrogen, oxygen, and sulphur. Then, exploratory catalytic tests were carried out to define the optimal reaction conditions. For this purpose, the effects of different solvents, reaction temperatures, molar ratios of the reactants, and catalyst loads were investigated. The best results were achieved using the catalyst prepared from rice husk (CRH). A yield of 92% of DHPMs was achieved in a short reaction time under solvent-free conditions. Moreover, the catalyst was recovered and reused without a significant decrease in the yield. These findings show that the agro-industrial wastes can be explored to find novel and potential catalysts.
- ItemSupercritical water technology: an emerging treatment process for contaminated wastewaters and sludge(2022) Souza, Guilherme Botelho Meireles de; Pereira, Mariana Bisinotto; Mourão, Lucas Clementino; Santos, Mirian Paula dos; Oliveira, José Augusto de; Aldaya Garde, Ivan Aritz; Alonso, Christian Gonçalves; Jegatheesan, Veeriah; Cardozo Filho, LúcioThe destruction of toxic, persistent, refractory, and hazardous organic compounds, often present at high concentrations in both industrial and municipal wastewaters, remains a major challenge to be overcome, mainly due to the inefficiencies of conventional processes. Notwithstanding, the search for novel treatment methods has received great attention recently. Supercritical water technology has proved to be a very promising treatment method for contaminated wastewaters and sludges. Performances of supercritical water technology in treating wastewaters from a wide variety of industries including pulp and paper, pharmaceutical, textile, pesticides, dairy, petrochemical, explosives, and distillery were reviewed. Furthermore, the effects of main operating conditions, namely temperature, pressure, residence time on the treatment efficiency, usually reported in terms of total organic carbon and chemical oxygen demand removal were summarized. In addition, well-known technical challenges faced by supercritical water processes such as corrosion, salt deposition, clogging, elevated running costs and possible solutions to mitigate those challenges have been discussed. At last, the future scope of the supercritical water technology is expected to be driven by policies aiming at the reduction of greenhouse gas emissions, environmental protection, mitigation of climate changes and the production of commercial gases from highly efficient treatment of contaminated organic wastewaters and sludges.
- ItemTreatment of hormones in wastewater from the pharmaceutical industry by continuous flow supercritical water technology(2021) Mourão, Lucas Clementino; Souza, Guilherme Botelho Meireles de; Dias, Isabela Milhomem; Andrade, Laiane Alves de; Souza, Paula Letícia de Melo; Cardozo Filho, Lúcio; Oliveira, Guilherme Roberto de; Oliveira, Sérgio Botelho de; Alonso, Christian GonçalvesHormones are bioactive, ubiquitous, and persistent organic molecules that demand effective treatment when released in the environment. However, most conventional treatments are inefficient or not suitable for large-scale applications. This study describes the use of supercritical water (SCW) technology in the degradation of hormones in wastewater from the pharmaceutical industry. Initially, the treatment was developed with synthetic wastewater (SW) containing hormone prepared from commercial desogestrel pills and, later, with real industrial wastewater (IW). All the experimental tests were conducted in a continuous flow reactor in the absence of catalysts. Both liquid and gas phases generated during the process were analyzed by instrumental techniques. The liquid phase was characterized by total organic carbon (TOC), chemical oxygen demand (COD), high-performance liquid chromatography (HPLC), and phytotoxicity assays. The gas phase was characterized by gas chromatography (GC). TOC reductions of SW and IW samples, both treated at 700 °C and feed flow rate of 10 mL min−1 were 87.2% and 88.4%, respectively. Phytotoxicity assays indicated a significant reduction in the toxicity of the IW treated at 700 °C. Thus, considering the gas production, especially hydrogen, and the high toxicity mitigation, the IW treatment via SCW is quite promising.
- ItemValorization of e-waste via supercritical water technology: an approach for obsolete mobile phones(2023) Souza, Guilherme Botelho Meireles de; Pereira, Mariana Bisinotto; Mourão, Lucas Clementino; Alonso, Christian Gonçalves; Jegatheesan, Veeriah; Cardozo Filho, LúcioThe improper handling of electronic waste has not only severe environmental impacts but also results in the loss of high economic potential. To address this issue, the use of supercritical water (ScW) technology for the eco-friendly processing of waste printed circuit boards (WPCBs) obtained from obsolete mobile phones has been explored in this study. The WPCBs were characterized via MP-AES, WDXRF, TG/DTA, CHNS elemental analysis, SEM and XRD. A L9 Taguchi orthogonal array design was employed to evaluate the impact of four independent variables on the organic degradation rate (ODR) of the system. After optimization, an ODR of 98.4% was achieved at a temperature of 600 °C, a reaction time of 50 min, a flowrate of 7 mL min−1, and the absence of an oxidizing agent. The removal of the organic content from the WPCBs resulted in an increase in the metal concentration, with up to 92.6% of the metal content being efficiently recovered. During the ScW process, the decomposition by-products were continuously removed from the reactor system through the liquid or gaseous outputs. The liquid fraction, which was composed of phenol derivatives, was treated using the same experimental apparatus, achieving a total organic carbon reduction of 99.2% at 600 °C using H2O2 as the oxidizing agent. The gaseous fraction was found to contain hydrogen, methane, CO2, and CO as the major components. Finally, the addition of co-solvents, namely ethanol and glycerol, enhanced the production of combustible gases during the ScW processing of WPCBs.