Microinteraction Analysis between Heavy Metals and Coexisting Phases in Heavy Metal Containing Solid Wastes

Heavy metal containing solid wastes (HMSWs), the byproduct from industrial activities, bring severe environmental issues and health risks to human. Separating heavy metals from HMSWs for resourcing is the most effective way to mitigate their environmental risk. However, the composition of HMSWs is of great complexity, including various heavy metals with relatively low concentration, as well as coexisting phases with different types and inhomogeneous microstructures. These complexities lead to strong interactions between heavy metals and coexisting phases, causing the incomplete separation of heavy metals. Therefore, understanding their microinteractions is a necessary precondition to realize the full resourcing of HMSWs. This Review focuses on recent achievements for analyzing such microinteractions. Advanced characterization techniques are summarized, by which a multidimensional analysis method is put forward. Then, microinteractions of heavy metals with coexisting phases are clearly discussed, and three typical interactions of aggregation/encapsulation, adsorption, and substituted doping are prudently summarized. It is expected that developing targeted methods to destruct the above interactions is an efficient way to improve the heavy metal separation. Therefore, this Review will provide a sufficient understanding of microstructures in complex HMSWs, which is further expected to promote the technological development on decontamination of HMSWs.