Highly efficient selective elimination of heavy metals from solutions by different strategies

Due to the potential perniciousness of heavy metals, wastewater contaminated by them has become the most severe environmental problems. Water pollution poses very negative implications for the survival of living beings. This review summarizes the recent progress of the widely adopted techniques for eliminating heavy metals from aqueous solutions and expatiates their principles, characteristics, and applications. The chemical precipitation, ion-exchange, adsorption, and membrane separation are commonly easy operations, cost-effective, and broadly applicable. Bioremediation, photocatalysis, and electrochemical techniques are environmentally friendly with less secondary pollution and highly adaptable. Herein, the current state and prospects of these techniques for environmental remediation are comprehensively reviewed. The removal efficiency, interaction mechanism, and applicable scene for each strategy are well presented from macroscopic results, advanced spectroscopy characterization, and theoretical calculation. In the end, the challenges of different techniques for heavy metal ions elimination in the future were described.