Structural Variation of Lignin and Lignin–Carbohydrate Complex in Eucalyptus grandis × E. urophylla during Its Growth Process

Abstract

The removal of heavy metals ions from wastewater by an economic, high-effective, and environmentally friendly method is particularly important. In this study, an effective lignin-based bio-adsorbent (SAPL-1.5), which contained specific functional groups and spatial cross-linking structures, was synthesized through chemical modification. SAPL-1.5 was comprehensively characterized by 31 P, 1 H, 13 C NMR, and elemental analysis as compared to the raw lignin. The results showed that the chemical reactivity of lignin was significantly improved after phenolation process, and the adsorption groups were successfully grafted onto lignin macromolecule. In addition, the influences of pH, SAPL-1.5 dosage, contact time, and initial Pb (II) concentration on the adsorption performance was systematically investigated. The highest adsorption capacity reached to 130.2 mg/g (Pb (II), 140 mg/L), and a removal efficiency of 100% was achieved (Pb (II), 20 mg/L). Moreover, the adsorption isotherm and adsorption kinetics indicated that the results were fitting well with the Langmuir and pseudo-second-order model, respectively. Furthermore, the removal efficiency of SAPL-1.5 for Pb (II) (20 mg/mL) still maintained over 85% after 5 cycles. Therefore, the lignin-based material obtained could be considered as a promising potential adsorbent with a low cost, high performance and reutilization for its application in the wastewater treatment process. It is believed that the lignin-based bio-sorbent can enlarge the lignin valorization in the current biorefinery process.

Total utilization of lignin and carbohydrates in Eucalyptus grandis: an integrated biorefinery strategy towards phenolics, levulinic acid, and furfural

“…Finally, temperature for 240 °C and time for 4 h in MeOH were chosen as the optimized condition for RCF reaction of Eucalyptus. Gel permeation chromatography (GPC) analysis exhibited a significant decrease in molecular weight (M w = 470-430 g mol −1 ) relative to the isolated milled wood lignin (MWL, 5630 g/mol) [50] and enzymatic mild acidolysis lignin (EMAL, 8100 g mol −1 ) from Eucalyptus tree [34].…”

Structural characterization of lignin from D. sinicus by FTIR and NMR techniques

“…The higher proportion of β-O-4 ′ substructures is advantageous to the successive depolymerization and amelioration of lignin (28,29). Thus the D. sinicus could serve as efficient feedstock for biorefinery industries (30,31).…”

Coupling organosolv fractionation and reductive depolymerization of woody biomass in a two-step catalytic process

“…In the plant cell wall, phenyl glycoside, benzyl ether and -ester bonds are the typical lignin-carbohydrate interlinkages. 33 In order to determine the impact of acid on delignification, we chose phenyl glycoside (PG) and glyceryl trioleate (GT) as model compounds representing these lignin-carbohydrate bonds. The product yield is shown in Figure 1.…”