New oxygenated carbonaceous adsorbents prepared by combined radiant/microwave heating for the removal of Pb 2+ in aqueous solution

Abstract

Abstract This paper presents a new procedure to obtain efficient carbonaceous adsorbents for the removal of Pb2+ in aqueous solution. Experimental procedure includes a pre-treatment of pecan nut shells using radiant heating at low temperatures (280-340 °C), followed by microwave radiation heating (Microwave Assist Technology: MAT) and using a L16 orthogonal array of Taguchi method to find the optimal preparation conditions, setting as the response variable the removal of Pb2+ in aqueous solution. The obtained materials were characterized using elemental analysis, FT-IR spectroscopy, potentiometric titration, nitrogen adsorption isotherms at -196 °C and SEM/EDX analysis. Full Pb2+ adsorption isotherms in aqueous solution were studied using stirred batch systems at 30 °C, pH 5, and using a mass to volume ratio of 2 g/L. The best performing adsorbent rendered an outstanding Pb2+ sorption capacity (261 mg/g), in spite of its rather low porosity. Such a high capacity was explained in terms of the materials surface chemistry, because the obtained carbons have a high amount of acidic and oxygenated groups, as well as calcium deposits. Also, the optimum conditions of each factor level obtained from the orthogonal array allowed to obtain a highly efficient carbon for Pb+2 removal.

Citation

Durán-Jiménez, G., Hernández-Montoya, V., Montes-Morán, M. A., & Teutli-León, M. (2015). New oxygenated carbonaceous adsorbents prepared by combined radiant/microwave heating for the removal of Pb 2+ in aqueous solution. Journal of Analytical and Applied Pyrolysis, 113, 599-605. https://doi.org/10.1016/j.jaap.2015.04.001

• Journal Article Type: Article
• Acceptance Date: Apr 1, 2015
• Online Publication Date: Jun 3, 2015
• Publication Date: May 1, 2015
• Deposit Date: Jun 24, 2022
• Journal: Journal of Analytical and Applied Pyrolysis
• Print ISSN: 0165-2370
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 113
• Pages: 599-605
• DOI: https://doi.org/10.1016/j.jaap.2015.04.001
• Public URL: https://nottingham-repository.worktribe.com/output/8636252
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0165237015300115?via%3Dihub