Chemical modification of four lignocellulosic materials to improve the Pb2+ and Ni2+ ions adsorption in aqueous solutions. Issue 5 (October 2019)

• Record Type: Journal Article
• Authors: Santos, Pitágoras Fonseca; Neris, Jordan Brizi; Martínez Luzardo, Francisco Heriberto; Velasco, Fermin Garcia; Tokumoto, Miriam Sanae; da Cruz, Rosenira Serpa
• Is Part Of: Journal of environmental chemical engineering. Volume 7:Issue 5(2019)
• Publication Date: 2019-10
• Subjects: Toxic ions -- Adsorption isotherms -- Water treatment -- Chemical hydrolysis; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2019.103363
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: The water contamination by metal ions arising from industrial, mining and agricultural activities increase is a recurring problem that makes necessary new research for effective and low-cost water treatments. This study aimed to increase the adsorption capacity of Pb 2+ and Ni 2+ ions for different lignocellulosic materials (banana peel (BP), eucalyptus bark (EB), maize cob (MC) and maize leaf (ML) by alkali and acidic hydrolysis chemical treatments. The fibers chemical modifications were evaluated using the FTIR and the Boehm method. The Pb 2+ and Ni 2+ ions concentrations in the solutions were quantified by the Energy-Dispersive X-ray Fluorescence Spectrometer. The results demonstrated that the alkali-treatment was the most efficient in increasing the adsorption capacity of Pb 2+ and Ni 2+ ions for all the fibers. The kinetics and isotherms adsorption of the alkali-modified eucalyptus bark (BEB) and alkali-modified banana peel (BBP) were studied due to their highest adsorption capacity compared to the other fibers. The Ni 2+ ions adsorption reached equilibrium after 6 and 30 min, while the Pb 2+ ions after 1 min, for the BBP and BEB fibers respectively. The single-element isotherm that best fitted the experimental data was Langmuir. The highest maximum adsorption capacity values ​​obtained for Pb 2+ and Ni 2+ ions were 65.9 ± 13.8 (BBP) and 17.1 ± 1.0 (BBP) mg g −1, respectively. The main active sites responsible for adsorption are the basic sites (predominantly carboxylates ions). The lignocellulosic fibers demonstrated higher adsorption affinity with Pb 2+ ions.