Research progress on heavy metals removal from wastewater by biochar-supported nano zero-valent iron

Nano zero-valent iron (nZVI) has a large specific surface area, high reactivity and unique core-shell structure, which has a good application prospect in the removal of heavy metals in water. However, nZVI itself has some disadvantages such as easy agglomeration and oxidation deactivation, and its industrial promotion and application are limited. The biochar-supported nano-zero-valent iron (nZVI@BC) composite prepared by loading nZVI on biochar (BC) can overcome the shortcomings of nZVI to a certain extent and improve the reaction activity of nZVI with heavy metals. The research status of nZVI@BC removal of heavy metals from water was reviewed. The preparation of nZVI@BC with different BC materials, the modification of BC and the influence of nZVI modification on the removal performance of heavy metals from nZVI@BC were emphatically introduced. The reaction mechanism of nZVI@BC removal of several typical heavy metals was described. The development prospect of nZVI@BC in removing heavy metals from water was also prospected.