Cu/N doped lignin for highly selective efficient removal of As(v) from polluted water

Lignin is a widely used adsorbent for removing heavy metal ions from water. Lignin can be extracted from black liquor and its inert surface properties limit its adsorption performance. In this paper, a new type of modified lignin adsorbent doped with Cu/N was prepared by the reaction of lignin with triethylenetetramine (TETA) and CuCl₂. The adsorption capacities of the Cu/N-doped lignin (Cu/N-Lignin) adsorbents, N-doped lignin (N-Lignin) adsorbents and undoped lignin (U-Lignin) on three anions (As (V), Cl^- and Cr (VI)) were systematically studied. In the solution with these three mixed ions, the removal rate of the Cu/N-Lignin adsorbents on As (V), Cl^- and Cr (VI) was 86.44%, 0% and 39.48%. The adsorption capacity of Cu/N-Lignin to As(V) was 253.5 mg/g. Under the same adsorption conditions, the selectivity of the Cu/N-Lignin adsorbents to anions was Cl^-