Carbon nanotubes impregnated with metallic nanoparticles and their application as an adsorbent for the glyphosate removal in an aqueous matrix

• Published in: Journal of environmental chemical engineering Vol. 9; no. 2; p. 105178
• Main Authors: Diel, Júlia C., Franco, Dison S.P., Nunes, Isaac dos S., Pereira, Hércules A., Moreira, Kelly S., de L. Burgo, Thiago A., Foletto, Edson L., Dotto, Guilherme L.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-04-2021
• Subjects: Carbon nanotubes; Glyphosate, adsorption; Green synthesis; Iron nanoparticles; Carbon nanotubes; Iron nanoparticles; Glyphosate, adsorption; Green synthesis
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2021.105178

Carbon nanotubes with multiple walls (MWCNTs) were modified via green synthesis methodology, with metal nanoparticles (MPNs-Fe). The prepared material (MWCNT/MPNs-Fe) was characterized and used to remove the herbicide glyphosate (GLY) from an aqueous matrix through the adsorption process. The characterization results indicated the presence of MPNs-Fe incorporated between the tangled wires of the MWCNTs, thus confirming the green synthesis success. The kinetic studies showed a percentage of GLY removal of up to 86.23% (for C0 = 35 mg L−1), with the process equilibrium being reached in 120 min. The pseudo-first-order model demonstrated a greater prediction capacity for the system. The Sips isotherm model was best suited to the equilibrium data, providing a maximum adsorption capacity of 43.66 mg g−1 (298 K). The thermodynamic behavior showed that the process is spontaneous and favorable, with exothermic nature. The material's application in close to real circumstances presented the removals of 68.38% and 40.33% for two simulated effluents with different compositions. The adsorption regeneration tests found that the adsorption kept similar adsorption capacities after six cycles. Therefore, it can be concluded that the MWCNT/MPNs-Fe synthesized in the present work is a promising alternative as an adsorbent in the treatment of effluents and waters containing GLY.
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•An adsorbent was developed by impregnation of Fe nanoparticles on carbon nanotubes.•The adsorbent MWCNT/MPNs-Fe was prepared by green synthesis.•MWCNT/MPNs-Fe was applied in glyphosate adsorption.•Glyphosate removal of up to 86% was reached in 120 min.