Research Progress on the Removal Performances and Mechanisms of Heavy Metal Ions from Aquatic Environments with MOFs
The acceleration of industrialization has been leading to increasingly severe global environmental pollution,particularly in heavy metal pollutants such as chromium,arsenic,lead,mercury,cadmium,zinc,copper and nickel,etc.Removal methods for heavy metals from aquatic environments mainly include ion exchange,coagulation and sedimentation,oxidation-reduction,adsorption,membrane filtration,and electrodialysis.Among them,adsorption is considered one of the most promising methods for its advantages such as low cost,simple operation,and strong adaptability.Metal-organic framework materials(MOFs)are widely used for heavy metal removal due to their large surface area,high porosity,rich active sites,strong tunability,and excellent thermal/chemical stability.Therefore,this paper focuses on the removal performance of MOFs and their composite materials for eight typical heavy metal ions.It also analyzes the effects of factors such as initial MOFs concentration,heavy metal ion concentration,contacting time,pH value,temperature,and co-existing ions on the removal performances of heavy metals.Based on this,the main mechanisms of MOFs for removing heavy metal ions are explained by adsorption,precipitation,and oxidation-reduction,adsorption can be divided into physical adsorption and chemical adsorption.Physical adsorption mainly includes electrostatic attraction,diffusion,and van der waals forces,while chemical adsorption mainly includes open metal sites/coordination,acid-base interactions,and hydrogen bonding.Meanwhile,surface precipitation or redox reactions occur during the adsorption process.Additionally,this paper proposes the future research direction and potential applications of MOFs in the prevention and control of heavy metal,providing a theoretical basis for the research and application of MOFs in the field of environmental pollution remediation.
NETL
NSTL
万方数据
维普
