resumo
The occurrence of pharmaceuticals in the environment and the water cycle, even at trace levels, has been a matter of great discussion in the literature in the recent years. Despite the clinical relevance of diclofenac (DCF), several studies indicate that it is one of the most frequently detected anti-inflammatory drugs in surface waters, with potential harmful impact on environment and human health. Herein, novel magnetic hybrid nanosorbents composed of magnetite cores encapsulated within a siliceous network highly enriched in a quaternary chitosan ( HTCC) were successfully prepared and tested in magnetically assisted removal of sodium diclofenac from aqueous solutions. The DCF adsorption by the produced core-shell nanoparticles was assessed based on several experimental parameters. It was found that under optimal conditions, the modelling of the equilibrium data was best fit with Langmuir and Toth models where the maximum adsorption capacity of DCF was 240.4 mg/g. These results indicate that these hybrid biosorbents are among the most effective magnetic systems for the removal of this pharmaceutical from water. Through the strategy proposed in this work, novel hybrid magnetic nanoparticles containing a cationic surface charge in a broad pH range, from acidic to neutral pH values, is reported. Therefore, these materials may provide a new way of removing a wider class of other anionic contaminants from water.
palavras-chave
REMOVAL; ADSORPTION; ADSORBENT; IONS; CHLORIDE; CARBON; PHARMACEUTICALS; TEMPERATURE; MECHANISM; PROPERTY
categoria
Chemistry; Polymer Science
autores
Soares, SF; Fernandes, T; Sacramento, M; Trindade, T; Daniel-da-Silva, AL
nossos autores
Ana Luísa Daniel da Silva
Investigador Principal
João Tiago Moniz Fernandes
Estudante de doutoramento
Margarida Menezes Amador Sacramento
Estudante de doutoramento
Sofia Soares
Investigador Júnior
Tito Trindade
Professor Catedráticoagradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by National funds through the FCT/MEC, and when appropriate cofinanced by the European Regional Development Fund (FEDER) under the PT2020 Partnership Agreement. The authors thank the RNME (National Electronic Microscopy Network) for microscopy facilities. S. F. Soares thanks the Fundacao para a Ciencia e Tecnologia (FCT) for the PhD grant SFRH/BD/121366/2016. T. Fernandes thanks FCT for the PhD grant SFRH/BD/130934/2017. A. L. D.-d.-S. acknowledges FCT for the research contract under the Program 'Investigador FCT' 2014. The authors thank Professor Dmitry Evtyugin (University of Aveiro, Portugal) for guidance in the determination of the molecular weight of the biopolymers.