On removal of heavy metals from wastewater by nano-scale zero-valent iron and its preparation method

Heavy metal pollution in sewage is a major environmental problem commonly faced by all countries. Nanometer zero-valent iron (nZVI) and its modified materials, with the advantages of small particle size, high activity, large specific surface area, and strong reduction ability, are currently one of the hot spots of research at home and abroad. It has broad application prospects in water heavy metal pollution, water treatment and remediation. In this paper, the commonly used preparation methods and modification methods of nZVI and the characteristics of different methods for preparing nZVI were summarized. The main mechanism of the interaction between nZVI and heavy metals was emphasized, including adsorption, reduction and coprecipitation. This paper summarized the mechanism and research progress of nZVI on lead, chromium, zinc and cadmium treatment in sewage treatment. The nZVI has a good removal ability on these elements and plays an important role in environmental pollution purification. Finally, the paper pointed out the shortcomings of iron-based nanomaterials in the remediation of heavy metals and looked forward to their application in the field of heavy metal remediation of sewage. Some suggestions were provided based on nZVI materials and their potential improvements in future applications in environmental remediation.