Kraft lignin and its derivates-A study on the adsorption of mono and multielement metals, potential use for noble metal recycling and an alternative material for solid base catalyst

Author(s)

Akiba, Naomi ; Omori, Alvaro T. ; Gaubeur, Ivanise

• Document type: Journal article
• Source: Chemosphere; v. 308, p. 8-pg., 2022-12-01.

Abstract

Lignin is a natural polymer containing diverse functional groups and displaying an affinity for metals. Kraft lignin can be used as a carbon source, as a cleaving lignin structure for aromatic macromers or in the addition and modification of functional groups by the development of new active chemical sites. In this context, the aim of the present study is to investigate the adsorption of mono and multi-element metals solutions on lignin derivatives (unmodified Kraft lignin, acetylated Kraft lignin, charcoal Kraft lignin and activated carbon Kraft lignin). Parameters that affect adsorption processes, such as pH, contact time and adsorbent dose, were optimized in each case. The best adsorption condition was obtained at pH 7.00, a contact time of 120 min and with adsorbent dose of 30 mg. Also, unmodified Kraft lignin shows high adsorption selectivity (99%) for gold and palladium in acidic solutions. Acetylated and charcoal Kraft lignin resulted in lower adsorption levels in comparison with unmodified Kraft lignin. Activated carbon, however, reached adsorptions of over 86% for all metals. Finally, unmodified Kraft lignin impregnated with palladium presents a promising heterogeneous support in the Suzuki-Miyaura reaction. (AU)

• FAPESP's process: 11/19730-3 - Cloud point extraction (CPE) and dispersive liquid-liquid microextraction (DLLME) applied in the development of analytical methods for metals preconcentration and spectrometric determination
• Grantee: Ivanise Gaubeur
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/18007-2 - EXPANDING THE USE OF CARROT BITS (Daucus carota) IN ORGANIC SYNTHESIS - APPLICATIONS IN TOTAL SYNTHESIS OF BIOACTIVE MOLECULES, NOVEL SUBSTRATES AND THE DEVELOPMENT OF A SCALE-UP METHODOLOGY
• Grantee: Alvaro Takeo Omori
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/23878-0 - Consolidation and innovation in the research line: analytical methods development combined to liquid phase microextraction
• Grantee: Ivanise Gaubeur
• Support Opportunities: Regular Research Grants