Table 4.

Lignin as an adsorbent for dye removal.

Material	Adsorbent	Adsorption Capacity	Reference
Brilliant Red HE-3B dye	Wheat straw lignin	10.17 mg/g	[50]
Methylene Blue dye	Esterified Lignin	31.23 mg/g	[74]
Brilliant Red 2BE dye	Etherified lignin-${\mathrm{Fe}}^{3+}$ complex	73.6 mg/g	[75]
Anthraquinonic dye	Chitosan-alkali lignin complex	≥90%	[76]
Procion Blue dye	Carboxymethylated lignin-${\mathrm{Al}}^{3+}$ complex Carboxymethylated lignin-${\mathrm{Mn}}^{2+}$ complex	73.52 mg/g 55.16 mg/g	[77]
Methylene Blue	Reticulated formic lignin	34.12 mg/g	[50]