Nano zero-valent iron (nZVI), possessing excellent reductive activity and adsorption performance, has been and will be widely applied in the remediation of contaminated soil and groundwater. However, superior reactive nZVI can also interact with soil components, which may not only affect soil properties and its ecological functions but also impact on the existing form and remediation function of nZVI.Interactions between nZVI and soil air, pore water, clay minerals, organic matter, and microorganism are addressed, and the influences on the soil composition and property and on the transformation and function of nZVI are discussed. Under the influence of soil components, nZVI may be transformed to various iron-based chemicals, such as Fe₃O₄, γ-Fe₂O₃, α-Fe₂O₃, α-FeOOH, and γ-FeOOH. Meanwhile, nZVI and its derivates would affect the soil environment by altering soil air composition, pore water pH, and/or physicochemical properties of soil clay minerals and organic matter. Furthermore, nZVI can also affect the soil microbial community, facilitating or inhibiting microbial growth and reproduction. The microbe initiating transformation can regulate the remediation function and fate of nZVI in the soil environment. At the end of the text, future research directions are put forward. This review is believed to boost scientific research and technology advance in environmental applications of nZVI.
Contents
1 Introduction
2 Interaction between nZVI and soil air and its environmental implication
2.1 Interaction between soil air and nZVI and its effect on the transformation and function of nZVI
2.2 Effects of nZVI on soil air and its environmental implication
3 Interaction between nZVI and soil pore water and its environmental implication
3.1 Interaction between soil pore water and nZVI and its effect on the transformation and function of nZVI
3.2 Environmental behavior of nZVI in soil pore water
3.3 Effects of nZVI on soil pore water and its environmental implication
4 Interaction between nZVI and clay minerals and its environmental implication
4.1 Interaction between clay minerals and nZVI and its effect on the transformation and function of nZVI
4.2 Effects of nZVI on clay minerals and its environmental implication
5 Interaction between nZVI and soil organic matter and its environmental implication
5.1 Interaction between soil organic matter and nZVI and its effect on the transformation and function of nZVI
5.2 Effects of nZVI on soil organic matter and its environmental implication
6 Interaction between nZVI and soil microorganisms and its environmental implication
6.1 Toxicity mechanisms of nZVI to soil microorganisms
6.2 Effects of nZVI on soil microbial community structure
6.3 Interaction between soil microorganisms and nZVI and its potential impact
7 Conclusion