Novel Lignin–Poly(N-methylaniline) Composite Sorbent for Silver Ion Removal and Recovery

Lignin–poly( N -methylaniline) (lignin–PNMA) nanocomposites were synthesized via a chemical oxidative polymerization of N -methylaniline in the presence of enzymatic hydrolysis lignin (EHL). The lignin–PNMA composite consists of well size-distributed particles of 68.3 nm in mean diameter. This nanocomposite was further used as a novel sorbent for silver ions from aqueous solution. The lignin–PNMA nanocomposite particles exhibited excellent an adsorption property of silver ions compared to those of poly( N -methylaniline) and EHL. The saturated capacity of silver ions onto the lignin–PNMA nanocomposites was up to 1556.8 mg g –1 at 30 °C. Characterization results of the sorption product, i.e., lignin–PNMA nanocomposite particles after sorption, revealed that silver nanoparticles were achieved on the surface of lignin–PNMA nanocomposite particles. The results indicated that lignin–PNMA nanocomposites can be effectively used as a reactive sorbent to remove and recover silver ions from aqueous solution.