abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common pharmaceuticals used worldwide. They are widely detected in natural waters due to their persistence in wastewater treatment, and their removal is desirable in wastewater management. As a contribution to tackle this challenge, this study explores magnetic quaternary chitosan-based nanosorbents for the effective magnetically assisted removal of three NSAIDs (diclofenac, naproxen, and ketoprofen) from water. Toward this goal, silane groups were grafted onto the backbone of trimethyl chitosan through the reaction with an epoxide functionalized silane. Once silanized, the modified chitosan was employed to coat Fe3O4 nanoparticles. The prepared materials were characterized using FTIR spectroscopy and solid-state Si-29 and C-13 NMR spectroscopy, which confirmed the encapsulation of Fe3O4 nanoparticles with a hybrid siliceous material enriched in trimethyl chitosan. The effect of the initial NSAIDs concentration, pH, and contact time in the adsorption behavior was investigated. The kinetic data were well described by the pseudo-second-order kinetic model, indicating a chemisorption mechanism. The maximum adsorption capacities estimated from the Langmuir model were 188.5 mg/g (0.5925 mmol/g), 438.1 mg/g (1.7371 mmol/g), and 221.5 mg/g (0.8710 mmol/g) for diclofenac, naproxen, and ketoprofen, respectively. These adsorption capacities are higher than those of most reported sorbents, indicating the potential of these biosorbents to remove the selected NSAIDs using low-energy magnetically assisted separation.
keywords
METAL-ORGANIC FRAMEWORK; WASTE-WATER; HYBRID MATERIALS; TREATMENT PLANTS; CLOFIBRIC ACID; ADSORPTION; PHARMACEUTICALS; NAPROXEN; CARBON; FATE
subject category
Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied
authors
Soares, SF; Trindade, T; Daniel-da-Silva, AL
our authors
Ana Luísa Daniel da Silva
Principal Researcher
Sofia Soares
Junior Researcher
Tito Trindade
Full professorProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Projeto de Investigação Exploratória: Ana Luísa Silva (IF/00405/2014)
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. S.F. Soares thanks the Fundacao para a Ciencia e Tecnologia (FCT) for the PhD grant SFRH/BD/121366/2016. A.L.D.-d.-S. acknowledges FCT for the research contract under the Program `Investigador FCT' 2014 and for funding from the project IF/00405/2014.