Autor: |
Fraga, Tiago José Marques, da Silva, Luiz Filipe Félix, de Lima Ferreira, Letticia Emely Maria, da Silva, Maryne Patrícia, Marques Fraga, Daysianne Mikaella dos Santos, de Araújo, Caroline Maria Bezerra, Carvalho, Marilda Nascimento, de Lima Cavalcanti, Jorge Vinicius Fernandes, Ghislandi, Marcos Gomes, da Motta Sobrinho, Maurício Alves |
Předmět: |
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Zdroj: |
Environmental Science & Pollution Research; Mar2020, Vol. 27 Issue 9, p9718-9732, 15p |
Abstrakt: |
Amino-functionalized multilayer graphene oxide (Am-nGO) has been synthesized and applied to remove the reactive drimaren red (DR) from aqueous solutions. Infrared spectroscopy evidenced amine and amide presence by peaks at 1579 cm−1 and a band between 3300 and 3500 cm−1. Raman spectroscopy showed an increment in ID/IG ratio after amino-Fe3O4-functionalization of nGO from 1.05 to 1.20, referent to an increase in sp3 domain disorder. The isoelectric point of Am-nGO was pH 8.1. From kinetic study, the equilibrium was achieved within 90 min; moreover, pseudo-n-order model satisfactorily fitted to the experimental data. Kinetic constant (kn) was 0.71 mg1−n g1−n min−1 and modeled equilibrium sorption capacity (qe) 219.17 mg g−1. Equilibrium experiments showed monolayer adsorption capacity (qm) of 219.75 mg g−1, and BET model best fitted to the equilibrium data, indicating that the adsorption process happened with multiple layers formation. From sorption thermodynamics, the standard free energy of Gibbs and enthalpy were respectively − 31.91 kJ mol−1 (at 298 K) and 66.43 kJ mol−1. Such data evidence the spontaneous and chemical behavior of DR adsorption as a consequence of strong electron donor-receptor interactions between the dye and the nanosorbent. By phytotoxicity assessment, Am-nGO showed inexpressive inhibitory potential to American lettuce seeds in comparison with its precursor nGO and graphite nanoplatelets. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
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