Preparation of Mg,N-co-doped lignin adsorbents for enhanced selectivity and high adsorption capacity of As(Ⅴ) from wastewater

Among various environmental problems,water pollution has drawn more and more attention.To develop an adsorbent with enhanced selectivity and high capacity for As(V)oxyanion,a novel lignin-based adsorbent was prepared by doping with N and modifying with Mg^(2+),using thiethylenetetramine(TETA)and MgCl_(2) as the source of N and Mg^(2+),respectively.N-doped lignin(NL)shows a high selectivity for As(Ⅴ),which is further enhanced by modifying with Mg^(2+)(MNL).MNL shows an excellent reusability.The adsorption isotherms and kinetics of MNL for As(Ⅴ)follow Langmuir isotherms model and pseudo-second-order kinetics model,respectively.The adsorption of MNL for As(Ⅴ)achieved a maximum adsorption capacity of 687.46 mg g^(−1) and the equilibrium was established within 30 min.This study offers a novel idea on the recycle of the waste of paper industry and provides a new technology for As(Ⅴ)adsorption from wastewater.