Magnetic Hybrid Nanosorbents for the Uptake of Paraquat from Water


Although paraquat has been banned in European countries, this herbicide is still used all over the world, thanks to its low-cost, high-efficiency, and fast action. Because paraquat is highly toxic to humans and animals, there is interest in mitigating the consequences of its use, namely by implementing removal procedures capable of curbing its environmental and health risks. This research describes new magnetic nanosorbents composed of magnetite cores functionalized with bio-hybrid siliceous shells, that can be used to uptake paraquat from water using magnetically-assisted procedures. The biopolymers kappa-carrageenan and starch were introduced into the siliceous shells, resulting in two hybrid materials, Fe3O4@SiO2/SiCRG and Fe3O4@SiO2/SiStarch, respectively, that exhibit a distinct surface chemistry. The Fe3O4@SiO2/SiCRG biosorbents displayed a superior paraquat removal performance, with a good fitting to the Langmuir and Toth isotherm models. The maximum adsorption capacity of paraquat for Fe3O4@SiO2/SiCRG biosorbents was 257 mg (.) g(-1), which places this sorbent among the best systems for the removal of this herbicide from water. The interesting performance of the kappa-carrageenan hybrid, along with its magnetic properties and good regeneration capacity, presents a very efficient way for the remediation of water contaminated with paraquat.



subject category

Science & Technology - Other Topics; Materials Science


Fernandes, T; Soares, SF; Trindade, T; Daniel-Da-Silva, AL

our authors


This work was developed within 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 co-financed by FEDER under the PT2020 Partnership Agreement. The authors thank the RNME (National Electronic Microscopy Network) for microscopy facilities. Ana L. Daniel-da-Silva acknowledges FCT for the IF-2014 funding.

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