Effective Removal of Mercury Ions in Aqueous Solutions: A Review

Background: Due to its high toxicity and bioaccumulation, the existence of mercury in the environment is always a big threat to human beings. In order to control mercury pollution, scientists have put great efforts in the past decades. Methods: Precipitation, adsorption, membrane separation, biological treatment and ion exchange are reviewed as a remover for mercury removal. For each material type, we not only reported on the removal mechanism, but also discussed the best areas for it. The correlation method and step-to-step focusing method have been used for references. Conclusion: With the exploration and application of research, people have mastered a variety of mature technologies for the treatment of mercury-containing wastewater. Using inexpensive adsorbents is a cost-effective method for treating low concentrations of heavy metal wastewater. Ion exchange with a fast removal rate has been widely used in the field of heavy metal removal from wastewater. The biological treatment method can effectively treat low-concentration mercurycontaining wastewater. However, there is still a need to develop novel mercury removers with high capacity, fast removal rate, and low removal limit. Nanomaterials with a high specific surface area on substrate with synergistic effects, such as high adsorption and ion exchange, are the future research points.