Super and selective adsorption of cationic dyes using carboxylate-modified lignosulfonate by environmentally friendly solvent-free esterification.

Herein, following the strategy of sustainable, environment protection, circular economy development, carboxylate-modification lignosulfonate polymer (M-LSP) was synthesized from lignosulfonate by solvent-free esterifying with maleic anhydride (MA) by one step, and was used to remove the dyes by adsorption. FT-IR and XPS were used to confirm successful preparation of M-LSP. The result is that: M-LSP is apt to adsorb cationic dye.