Interfacial interactions and ecological impacts of nanomaterials in heavy metal-contaminated soil remediation

Soil heavy metal pollution poses a serious threat and risk to global food production and human health. The remediation of soil heavy metal pollution using nanomaterials (NMs) has gradually become a research hotspot in the environmental field, but the environmental behavior and potential ecological risks associated with these NMs remain unknown. In this review, we summarize the types and characteristics of NMs and their mechanisms for immobilizing heavy metals in contaminated soil. We also discuss the spatial heterogeneity of the interactions between NMs and heavy metals in the rhizosphere and non-rhizosphere regions. Furthermore, potential ecological toxicity risk arising from NMs-based remediation are evaluated from a multi-level interface perspective (soil-NMs, soil-rhizosphere, and soil-human interfaces). Finally, we identify several challenges and research gaps to promote the future application of NMs in the remediation of heavy metal-contaminated soil.