Selective removal of Pb(II) with lignin-based adsorbent

Authors: Liu, Zengshe - Kevin

Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/3/2023
Publication Date: 4/30/2023
Citation: Liu, Z. 2023. Selective removal of Pb(II) with lignin-based adsorbent [abstract]. American Oil Chemists' Society Annual Meeting & Exposition.

Interpretive Summary:

Technical Abstract: A way to use lignin, an abundant natural material, to remove heavy metal from water has been found. Because heavy metal pollution of the aquatic ecosystem is a serious environmental issue, ways to selectively bind these metals is of tremendous interest. Past researchers have tried to remove these metals using natural lignin, which contains some specific chemical groups that can bind to metals. However, it does not have a specific attraction to lead, a target of specific interest. Reported here is a way to modify lignin to improve this selectivity. Using the Mannich reaction, a chemical group was added to the lignin, which formed a new material in a one step process. The new adsorbent (AFL) displayed enhanced adsorption capacity (Qmax = 91.4 mg/g) and, more importantly, selectivity toward lead ions. Characterizations of the AFL material were carried out by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, elemental analysis, and X-ray photoelectron spectroscopy, and all show an intact 1-Aza-18-crown-6 moiety which is responsible for this new selectivity. Further, the new AFL material could be regenerated by desorption of Pb(II) ions and retained > 80% of its adsorption efficiency after four adsorption-desorption cycles. The AFL material will serve as a recyclable and bioresource-based adsorbent material for water purification engineering.