Lignin-based hyper-cross-linked resin as an adsorbent for aniline from aqueous solution

Lignin serves as an ideal substrate for the synthesis of chemically functionalized hyper-cross-linked resins due to the structural composition of its aromatic rings, aliphatic side chains, and multiple active functional groups. These resins have shown to be highly effective in the adsorption of aromatic compounds. In this study, hyper-cross-linked polymer (HCPs-3), synthesized using 1,3,5-triphenyl and lignin, demonstrated a significant adsorption capacity for aniline, with a maximum adsorption capacity (q_max) of 189.2 mg/g at 303 K. This adsorption capacity reached equilibrium within 80 min, supporting the suitability of the pseudo-first-order rate model for kinetics analysis. The process benefited significantly from the high surface area and presence of abundant micro/mesopores. Acid-base interactions and hydrogen bonding were found to be crucial in enhancing the adsorption efficiency.