Abstract:
Mineral processing wastewater contains a large amount of heavy metal ions. If not properly treated, it will pollute water sources and soil, and endanger human health. Zeolites possess excellent adsorption properties and ion exchange characteristics, making them cost−effective and highly efficient in removing heavy metal ions from water. This study utilizes natural zeolite minerals as adsorption materials to investigate the removal efficiency and mechanisms of various heavy metal ions in the interference sorting process under different conditions. It discusses the removal effect and mechanism of zeolite and its modified materials on the heavy metal ions that interfere with the separation process under different conditions. The performance and mechanism of removing heavy metal ions in simulated tailings leachate under static and dynamic conditions were studied. The results of the static adsorption experiments on single heavy metal ions indicate that zeolite has good removal efficiency for Cu
2+, Pb
2+, Zn
2+, and Mn
2+, with the adsorption capacity ranking as Pb
2+ > Cu
2+ > Zn
2+ > Mn
2+. The adsorption process of four types of ions all conform to the Langmuir isotherm model, which is a monolayer adsorption. The pseudo-second order kinetic model can describe the process of zeolite adsorbing four kinds of heavy metal ions well. Zeolite removes heavy metal ions through the combined action of ion exchange and surface electrostatics. Due to the existence of competitive adsorption, the adsorption capacity of zeolite to different cations with the same valence state is quite different. This is mainly influenced by the hydration radius of the different cations. Under dynamic conditions, the removal of Cu
2+, Mn
2+, Pb
2+, and Zn
2+ by zeolite reaches equilibrium at 102 h, 64 h, 900 h, and 78 h, respectively. The effective working time of zeolite is longer, and it can be used as the medium material of permeation reaction grid (PRB) It is used for in−situ remediation of groundwater polluted by leachate from polymetallic mine tailings, and has good social and economic benefits.