Modified kraft lignin for bioremediation applications

Abstract

Kraft lignin (KL) from industrial pulping of E. globulus wood was subjected to the oxidative modification with the aim to produce sorbent mimicking humic matter for the bioremediation purposes. Lignin was oxidized by polyoxometalate Na 5 [PMo 10 V 2 O 40 ] (POM), solely or in the presence of laccase, under pre-selected aerobic conditions (50-60 • C, 1-2h, oxygen pressure 5 bar). The most pronounced lignin oxidation without its depolymerisation was observed in the reaction system POM/O 2 . Modified lignins possessed increased amounts of COOH (up to 15 %) and CO (up to 500 %) groups, when compared to unmodified KL, and significantly higher molecular weights. Sorption capacity of KL before and after modification towards transition metals (cadmium (II) and mercury (II)) and triazine pesticide (atrazine) was assessed in batch experiments under equilibrium conditions. KL oxidation improved sorption capacity towards transition metals (up to 15 %) but not necessarily the uptake of atrazine that was higher for unmodified KL.

Nanocomposite Polymeric Materials Based on Eucalyptus Lignoboost® Kraft Lignin for Liquid Sensing Applications

“…Considering that sensors based on the polyurethanes, synthesized using kraft lignin isolated using conventional procedure, did not display sensitivity to Cu(II) [16], response of the sensor developed in this work can be attributed to the capability of phenolic hydroxyl groups to complex transition metals with higher specificity towards copper and mercury. This proposition is further corroborated by the reported higher chelating capacity of tannins with vicinal phenolic groups towards Cu(II) when compared to other bivalent transition ions, such This behavior can be explained by the differences in the composition of eucalyptus LignoBoost ® kraft lignin and other technical lignins [30][31][32], most noticeably, lower content of redox quinone type moieties and significantly higher content of polyphenolic groups with vicinal hydroxyls originating from concomitant tannins in the former [18]. In particular, the LignoBoost ® kraft lignin has a higher total content of total hydroxyl groups and higher relative content of phenolic hydroxyl groups compared to the technical kraft lignin obtained from the cooking of the same wood species, but isolated by the conventional procedure [32].…”

“…Contrary to these findings, LignoBoost ® kraft lignin-based sensor did not display redox sensitivity, showing a very low response to Cr(VI) and redox pair, but instead it showed a selective response to Cu(II). This behavior can be explained by the differences in the composition of eucalyptus LignoBoost ® kraft lignin and other technical lignins [30][31][32], most noticeably, lower content of redox quinone type moieties and significantly higher content of polyphenolic groups with vicinal hydroxyls originating from concomitant tannins in the former [18]. In particular, the LignoBoost ® kraft lignin has a higher total content of total hydroxyl groups and higher relative content of phenolic hydroxyl groups compared to the technical kraft lignin obtained from the cooking of the same wood species, but isolated by the conventional procedure [32].…”

“…This behavior can be explained by the differences in the composition of eucalyptus LignoBoost ® kraft lignin and other technical lignins [30][31][32], most noticeably, lower content of redox quinone type moieties and significantly higher content of polyphenolic groups with vicinal hydroxyls originating from concomitant tannins in the former [18]. In particular, the LignoBoost ® kraft lignin has a higher total content of total hydroxyl groups and higher relative content of phenolic hydroxyl groups compared to the technical kraft lignin obtained from the cooking of the same wood species, but isolated by the conventional procedure [32]. Considering that sensors based on the polyurethanes, synthesized using kraft lignin isolated using conventional procedure, did not display sensitivity to Cu(II) [16], response of the sensor developed in this work can be attributed to the capability of phenolic hydroxyl groups to complex transition metals with higher specificity towards copper and mercury.…”

Utilisation of Lignins in the Bioeconomy: Projections on Ionic Liquids and Molecularly Imprinted Polymers for Selective Separation and Recovery of Base Metals and Gold

“…Traditionally, lignin has been derived from the kraft and sulphite processes that are ubiquitous in the pulp and paper industry from since time memorial [167]. It has been reported [166,168,169] that over 50 million tonnes are produced annually worldwide.…”

Evaluación de la adsorción de CO₂ en un biocompósito basado en lignina y las redes metal orgánicas HKUST-1 y UiO-66-NDC

“…El espectros de la Figura 35 corresponde a la lignina adquirida de Aldrich y presenta las misma características que otros espectros encontrados en la bibliografía 101,102 . El espectro obtenido muestras gran similitud con el de lignina alkali obtenida mediante un proceso de extracción que tiene como fin obtener una lignina con menor contenido de sulfatos.…”