Bioadsorption of trivalent and hexavalent chromium from aqueous solutions by sericin-alginate particles produced from Bombyx mori cocoons

Autor(es)

de Andrade, Julia Resende ; Carlos da Silva, Meuris Gurgel ; Gimenes, Marcelino Luiz ; Adeodato Vieira, Melissa Gurgel

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 25, n. 26, p. 16-pg., 2018-09-01.

Resumo

In this study, particles produced from sericin-alginate blend were used as non-conventional bioadsorbent for removing Cr(III) and Cr(VI) from aqueous solutions. Besides chromium mitigation, the use of sericin-alginate particles as bioadsorbent aims to offer an environmental solution of added value for sericin, which is a by-product from silk industry. Sericin-alginate particles in natura and loaded with Cr(III) and Cr(VI) were characterized using N-2 physical adsorption analysis, optical microcopy, mercury porosimetry, helium pycnometry, scanning electron microscope coupled with energy dispersive X-ray spectrometer, Fourier transform infrared spectrometer, and X-ray diffraction. Kinetic studies on the removal of Cr(III) (at pH=3.5) and Cr(VI) (at pH=2) indicate the ion exchange mechanism with Ca(II) and the predominance of external mass transfer resistance. Cr(VI) uptake occurs through an adsorption-coupled reduction process, and bioadsorption equilibrium is reached after similar to 1000min. Cr(III) bioadsorption occurs faster (similar to 210min). The Cr(VI) bioadsorption is endothermic, as bioadsorption capacity increases with temperature: 0.0783mmol/g (20 degrees C), 0.1960mmol/g (30 degrees C), 0.4570mmol/g (40 degrees C), and 0.7577mmol/g (55 degrees C). The three-parameter isotherm model of Toth best represents the equilibrium data of total chromium. From Langmuir isotherm model, the maximum bioadsorption capacity is higher for total chromium, 0.25mmol/g (30 degrees C), than for trivalent chromium, 0.023mmol/g (30 degrees C). The comparison of bioadsorption capacities with different biomaterials confirms sericin-alginate particles as potential bioadsorbent of chromium. (AU)

• Processo FAPESP: 15/13505-9 - Incorporação e liberação de fármacos em micropartículas de sericina e alginato
• Beneficiário: Melissa Gurgel Adeodato Vieira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/51824-8 - Desenvolvimento e avaliação de materiais a base de sericina e alginato para aplicação na área ambiental
• Beneficiário: Meuris Gurgel Carlos da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular