143 documents found, page 1 of 15
Bimetallic-zeolite nanomaterials as catalysts for degradation of azorubine dye ...
Mrabet, Imane El; Santos, Bebiana L. C.; Tanji, Karim; Rombi, Elisabetta; Parpot, Pier; Fonseca, A. M.; Zaitan, Hicham; Neves, Isabel C.Solutions containing equal concentrations of each metal ion pair (Zn/Fe, Co/Fe, Ni/Fe) were simultaneously added to the zeolite NaY using the ion-exchange method. The resulting bimetallic-zeolites were used as heterogeneous catalysts for the Fenton-like reaction for azorubine dye degradation. The optimization of the reaction parameters was assessed using the Box-Behnken design by studying the influence of H2O2 ...
Immobilization of laccase on grape seed-derived hydrochar and biochar as sustai...
Sá, Helena Isabel Oliveira; Michelin, Michele; Tavares, T.; Sanroman, Maria Angeles; Rosales, Emilio; Neves, Isabel C.Pharmaceutical active compounds pose a serious global threat due to their continuous release into aquatic systems. This study explores an innovative approach for the degradation of acetaminophen (APAP), sulfamethoxazole (SMX) and tetracycline (TC) by the covalent immobilization of crude laccase from Lentinus sajor-caju on grape seed-derived biochar (GS-BC-Lac) and hydrochar (GS-HC-Lac). Characterization through...
Zeolite modification for optimizing Fenton reaction in methylene blue dye degra...
Carvalho, Ana P.; Costa, José; Martins, Angela; Fonseca, António; Neves, Isabel C.; Nunes, NelsonTextile dyes often prove resistant to conventional wastewater treatment processes because of their complex molecular structures. Advanced oxidation methods, such as the Fenton reaction, have thus been recognized as a promising approach for environmental remediation by decomposing these pollutants. This work aimed to study the efficacy of modified zeolites as catalysts in the Fenton reaction for dye degradation,...
Antimicrobial agents based on metal-ion zeolite materials: a multivariate appro...
Guedes, Joana; Gonçalves, Diogo B.; Rodrigues, Catarina F.; Parpot, Pier; Fonseca, A. M.; Almeida Aguiar, Cristina; Neves, Isabel C.Bacteria are susceptible to zeolites doped with metal ions. Although the complete mode of action remains unclear, it is widely accepted that metal ions kill bacteria by inducing the production of reactive oxygen species (ROS), which are detrimental to microbial life processes. In this study, two zeolite structures, MFI and LTA, were selected as hosts for the preparation of various metal-ion zeolite materials, w...
Copiapite group: occurrence and properties in mining contamination scenarios
Barroso, Ana; Valente, Teresa Maria Fernandes; Antunes, Isabel Margarida Horta Ribeiro; Marinho Reis, A. Paula; Neves, Isabel C.The copiapite group shows a wide range of chemical compositions, allowing the identification of several mineral phases (e.g., aluminocopiapite and magnesiocopiapite). These minerals, typically observed in mining environments, are formed from evaporation and acid mine drainage (AMD) precipitation. In these areas, the copiapite has been studied to comprehend its ability to store some potentially toxic elements (P...
Y and ZSM-5 hierarchical zeolites prepared using a surfactant-mediated strategy...
Ruggiu, Andrea; Carvalho, Ana Paula; Rombi, Elisabetta; Martins, Angela; Rocha, João; Parpot, Pier; Neves, Isabel C.; Cutrufello, Maria GiorgiaDiffusional limitations associated with zeolite microporous systems can be overcome by developing hierarchical zeolites, i.e., materials with a micro- and mesoporous framework. In this work, Y and ZSM-5 zeolites were modified using a surfactant-mediated hydrothermal alkaline method, with NaOH and cetyltrimethylammonium bromide (CTAB). For Y zeolite, after a mild acidic pretreatment, the effect of the NaOH+CTAB ...
Preliminary evaluation of zeolite-based platforms as potential dual drug delive...
Bertão, Ana Raquel; Ivasiv, Viktoriya; Almeida Aguiar, Cristina; Correia, Patrícia R.; Fonseca, António M.; Bañobre-López, Manuel; Baltazar, FátimaSeveral zeolite-based delivery systems (ZDS) built with faujasite structure were prepared containing silver (Ag+) and 5-Fluorouracil (5-FU) as antimicrobial and antineoplastic agents, respectively. The idea behind this drug combination is an answer to the increasing evidence of colonization of tumor microenvironments by pathogenic microorganisms and their active role in tumor growth. Two ZDS with a fixed load o...
Valorization of plant by-products in the biosynthesis of silver nanoparticles w...
Rocha, Verónica Patrícia Moreira; Ferreira-Santos, Pedro; Aguiar, Cristina; Neves, Isabel C.; Tavares, T.Biosynthesis based on natural compounds has emerged as a sustainable approach for the production of metallic nanoparticles (MNP). The main objective of this study was to biosynthesize stable and multifunctional silver nanoparticles (AgNP) using different plant by-products as reducers and capping agents. Extracts obtained from Eucalyptus globulus, Pinus pinaster, Citrus sinensis, Cedrus atlantica and Camellia si...
Machine learning-assisted optimization of drug combinations in zeolite-based de...
Bertão, Ana Raquel; Teixeira, Filipe; Ivasiv, Viktoriya; Parpot, Pier; Almeida Aguiar, Cristina; Fonseca, A. M.; Bañobre-López, Manuel; Baltazar, FátimaTwo independent artificial neural network (ANN) models were used to determine the optimal drug combination of zeolite-based delivery systems (ZDS) for cancer therapy. The systems were based on the NaY zeolite using silver (Ag+) and 5-fluorouracil (5-FU) as antimicrobial and antineoplastic agents. Different ZDS samples were prepared, and their characterization indicates the successful incorporation of both pharm...
Chemical modification of zeolites for the recovery of rare earth elements evalu...
Barros, Óscar José Maciel; Parpot, Pier; Neves, Isabel C.; Tavares, T.Rare earth elements (REE) are a significant group of valuable elements used in diverse and relevant applications in our daily lives. The mining and processing of the original ores, as well as the final wastes disposal, produce wastewater with variable concentrations of REE to be recovered. Sorbent materials like zeolites have been employed in adsorption processes to capture diverse pollutants from wastewater. T...