Green nanomaterial-based sustainable analysis of contaminant-remediation in wastewater: A bird’s-eye view on recent advances and limitations

Wastewater released from domestic and industrial sources contains a variety of contaminants that are of emerging concern. Conventional wastewater treatment methods, such as filtration, heat treatment, and oxidation, are effective in degrading many such contaminants. However, these traditional methods can be expensive, require large land areas, produce significant amounts of sludge, and have limited capacity for handling waste. Additionally, conventional techniques often lead to incomplete mineralization of contaminants, raising concerns about potential environmental contamination with toxic substances and their impacts on ecosystems. Therefore, developing more effective methods for treating wastewater contaminants is essential to address the growing challenges in wastewater management. Green nanotechnology offers several advantages for the detection and degradation of various contaminants, including heavy metals, pesticides, plastics, pharmaceutical residues, and radioactive waste. The fabrication of green nanomaterials are cost-effective, non-toxic, and ecofriendly. They can be employed for the treatment of wastewater. There is increasing evidence that plant extracts, microbial enzymes, and other biogenic products such as algae and fungi can efficiently reduce metal ions to fabricate nanomaterials, which demonstrate improved photocatalytic and adsorption capabilities. Furthermore, nanomaterials offer complete degradation of contaminants under specific environmental conditions and hence have promising scopes for wastewater treatment. However, there are challenges to the widespread application of nanotechnology in wastewater treatment, such as the limited availability of raw materials, difficulties in controlling the shapes and sizes of nanoparticles, and obstacles in large-scale production.