Hexavalent chromium removal from water: adsorption properties of in natura and magnetic nanomodified sugarcane bagasse

Autor(es)

Abilio, Thais Eduarda ^[1] ; Soares, Beatriz Caliman ^[1] ; Jose, Julia Cristina ^[1] ; Milani, Priscila Aparecida ^[1] ; Labuto, Georgia ^[2] ; Carrilho, Elma Neide Vasconcelos Martins ^{[3, 1]}

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Lab Mat Polimer & Biossorventes, BR-13600970 Araras, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Quim, BR-09913030 Diadema, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Ciencias Nat Matemat & Educ, BR-13600970 Araras, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 28, n. 19, SI, p. 24816-24829, MAY 2021.
• Citações Web of Science: 0

Resumo

Biosorption has become a viable and ecological process in which biological materials are employed as adsorbents for the removal of potentially toxic metals, such as hexavalent chromium, from aqueous matrices. This work proposed the use of in natura (SB) and nanomodified sugarcane bagasse (SB-NP) with ferromagnetic nanoparticles (Fe3O4) to adsorb Cr(VI) from water. These materials were analyzed by X-ray Spectroscopy (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) to investigate their morphology and interaction with Cr(VI). It was observed the efficient impregnation of magnetite on the SB surface and the presence of functional groups such as O-H, C-H, C=O, C-O-C, C-O, and Fe-O (characteristic of magnetite). The best conditions for Cr(VI) removal in aqueous medium were determined by assessing the pH at the point of zero charge (pH(PZC) = 6.1 and 5.8 for SB and SB-NP, respectively), adsorption pH and kinetics, and adsorption capacity. Batch procedures were performed using increasing concentrations of Cr(VI), 10-100 mg/L at pH 1.0, and 30 min of contact time. The adsorbent dose was 10 mg/L, and the experimental adsorption capacities (SCexp) for SB, NP, and SB-NP were 1.49 +/- 0.06 mg/g, 2.48 +/- 0.57 mg/g, and 1.60 +/- 0.08 mg/g, respectively. All Cr contents were determined by flame atomic absorption spectrometry (FAAS). The pseudo-2nd-order kinetic equation provided the best adjustments with r(2) 0.9966 and 0.9931 for SB and SB-NP, respectively. Six isotherm models (Langmuir, Freundlich, Sips, Temkin, Dubinin-Radushkevich, and Hill) were applied to the experimental data, and Freundlich, Dubinin-Radushkevich (D-R), and Temkin were the models that best described the experimental sorption process. The binding energy values (E) provided by the D-R model were 0.11 +/- 0.25, 0.09 +/- 0.20, and 0.08 +/- 0.25 kJ/mol, for NP, SB-NP, and SB, respectively, and denote a physical interaction for the studied adsorbate-adsorbent system. The nanomodification of the biomass slightly improved the efficiency for the sorption of Cr(VI) and facilitated the removal of Cr(VI)-containing biosorbents from water medium. (AU)

• Processo FAPESP: 16/06271-4 - Desenvolvimento de materiais adsorventes a partir de resíduo de biomassa de levedura proveniente de processos fermentativos industriais para remoção de contaminantes emergentes de águas e efluentes
• Beneficiário: Geórgia Christina Labuto Araújo
• Modalidade de apoio: Auxílio à Pesquisa - Regular