Experimental study on adsorption characteristics of Cu2+ and Zn2+ by datong lignite

Abstract

In view of the high content of Cu2+ and Zn2+ in acid mine drainage (AMD), the adsorption properties of lignite for Cu2+ and Zn2+ were studied. The adsorption performance of lignite for Cu2+ and Zn2+ was revealed by combining with FT-IR, XPS and EDS. The results showed that the adsorption kinetic model of lignite for Cu2+ and Zn2+ conformed to the quasi-first-order kinetic model. The isothermal adsorption line fitting models of lignite for Cu2+ and Zn2+ were in accordance with the Langmuir model and the Freundlich model, respectively. The maximum equilibrium adsorption capacities of lignite for Cu and Zn were 67.84 mg/g and 55.5 mg/g. The adsorption process of Cu2+ and Zn2+ by lignite involved electrostatic, coordination and ion exchange. Under the condition of coexistence of two kinds of ion, the adsorption site of lignite had stronger binding ability to copper ions.