Green nanomaterials: Synthesis and applications in wastewater treatment

In the present era, the global challenge of water scarcity is motivating researchers towards innovation and advancements in existing water treatment technologies and novel solutions. Nanomaterials (NMs) have gained extensive use in the past decade, particularly in treating wastewater, notably colored wastewater. Their broad utilization can be attributed to their intrinsic characteristics and superior removal capabilities. However, the conventional methods of nanomaterial production pose environmental risks, prompting the need for a sustainable and eco-friendly approach. As the global population surges, waste accumulates and strains natural resources. Utilizing waste materials for NP production not only presents an economical and clean method but also aids waste management. Components from various parts of plants, waste biomass like fruit peels, vegetable scraps, and biogenic precursors like algae and bacteria serve as capping and reducing agents, crucial for green nanomaterial synthesis. Mechanosynthesis methods like hydrothermal, sol-gel, sonochemical, planetary ball mill, and solid-state reactions can be employed effectively for GNMs preparation. The synthesis of GNMs is lowcost, non-toxic, and eco-friendly and can be used to treat various types of wastewater. Researchers have successfully employed these developed GNMs for photocatalytic dye degradation or reduction in wastewater. This review article provides a comprehensive analysis of the ongoing research within the scientific community, accompanied by future prospects and potential solutions to challenges.