Heavy metal removal by nanobiotechnology

Abstract Nanobiotechnology is an emerging era to deal with heavy metals and metalloid pollution lead by various biological and chemically nanostructured elements. The competitive efficiency and specificity of such nanostructures reside within the structural phenomena, which are influenced by the spatial arrangements of atoms that result in various geometries, such as nanotubes, nanospheres, nanocomposites, and nanoparticles. Often, these structural changes significantly modulate their physio-chemical properties that can be utilized for quenching heavy metals from the severely polluted sites. Although at a lower concentration, the heavy metals are an integral constituent of ecological chemistry, various anthropogenic activities have led to an upsurge in their concentration leading to environmental disturbances and health hazards. This chapter highlights various natural and anthropogenic sources of heavy metals and addresses their dispersion and distribution in the environment through the integration of nanotechnology with physical, chemical, and biological approaches of heavy metal remediation. Comparative studies of various nanomaterials are also an essential component of the present chapter. The discussion is centered on their pilot-scale applications, their recovery, and sustainability. Furthermore, their efficiency and limitations are outlined concluding with promising future directions.