One-step silanization and amination of lignin and its adsorption of Congo red and Cu(II) ions in aqueous solution

• Published in: International journal of biological macromolecules Vol. 159; pp. 222 - 230
• Main Authors: An, Liangliang, Si, Chuanling, Bae, Jin Ho, Jeong, Hanseob, Kim, Yong Sik
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.09.2020
• Subjects: Adsorption; Amination; Amine-silanization; Congo Red - chemistry; Copper - chemistry; Dyes; Heavy metals; Hydrogen-Ion Concentration; Ions - chemistry; Kinetics; Kraft lignin; Lignin - chemistry; Metals, Heavy; Molecular Structure; Molecular Weight; Osmolar Concentration; Propylamines - chemistry; Silanes - chemistry; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Waste Water - chemistry; Wastewater; Water Pollutants, Chemical - chemistry; Water Purification; Amine-silanization; Dyes; Wastewater; Heavy metals; Kraft lignin
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.05.072

In this work, silanized and aminated lignin (SAL) was synthesized in one step and its adsorption of Congo red and Cu(II) ions in aqueous solution was explored. Lignin was subjected to amine-silanization with (3-aminopropyl) triethoxysilane (APTES). Structural characterization substantiated successful amine-silanzation of lignin and formation of multi-layer APTES intermolecular crosslinked structure. The prepared SAL (nitrogen content = 6.1%) exhibited enhanced molecular weight, thermal stability, and water- and organic solvent-resistance properties. Additionally, the present of the porous structure of particle surface and an increase in the specific surface area and zeta potential promoted the accessibility of contaminants to the effective adsorption sites of SAL. Adsorption experiments showed that both Congo red and Cu(II) ion could be completely removed at original pH value, and their adsorption involved electrostatic attraction and complexation, respectively. The adsorption isotherms and kinetics were well described by the Langmuir and pseudo-second-order equations, respectively. The results showed that SAL is a promising adsorbent for the treatment of effluents. [Display omitted] •A one-step approach for silanization and amination of lignin (SAL) was developed.•Both Congo red and Cu(II) ions could been completely removed at initial pH value.•SAL is a promising adsorbent for the treatment of effluents.