Microbial nanostructures and their application in soil remediation

The field of nanobiotechnology is rapidly gaining prominence since it involves the construction of inorganic nanoparticles using plants, plant extracts, fungi, and bacteria that mitigate the risks related to their physicochemical methods of synthesis. This biogenic approach also improves its applicability in various biomedical and bioremediation fields. Nanoparticles exhibit higher reactivity and sorption capacity in comparison to larger particles therefore, they are far more superior in tackling the issues of environmental pollution and ecological restoration. Previous studies also indicate that they are better substitutes to the more traditional and aggressive methods of decontamination. The concept of nanobioremediation further explores the synthesis of sustainable nanostructures and their potential in the removal of impurities from the soil, water, and air. This chapter explores the efficiency of biogenically produced nZVI; metal oxide nanostructures (CuO, ZnO, TiO2, CeO2, MnO2); Au; Ag; Pd; PbS; and CdS nanostructures in soil remediation and highlights their versatility in the removal of both inorganic and organic soil pollutants along with the risks and drawbacks associated with their use. Modifications of nZVI such as assistance by electrokinetics, coating with macromolecules or surfactants, and its integration with microbes is further highlighted as it greatly reduces the ecotoxicity associated with bare nZVI.