Green-synthesized nanoparticles for treatment of wastewater: an environmentally sustainable pollution remediation technology

Abstract Water is vital for life on Earth, and its unavailability or poor quality has severe consequences for all aspects of human life, including food, health, and environment. Anthropogenic activities have caused widespread pollution of water resources worldwide. Although some remediation methods and techniques have been developed, considering the extent, quantity, and varied nature of pollutants, new and sustainable technologies are urgent needed to remediate polluted water and wastewater. In recent times, the use of nanomaterials for the treatment of wastewater has gained considerable importance owing to their high accuracy and precise remediation. Nanoparticles (NPs) exhibit enhanced chemical reactivity, high surface area, lower costs and energy requirements, and efficient regeneration for reuse, making them ideal materials for wastewater treatment. The conventional method of NP production is hazardous, and application of volatile chemicals results in secondary pollution, yet biogenic NPs are inexpensive and environmentally safe. Plants, bacteria, algae, and fungi produce a range of alkaloids, flavonoids, carbohydrates, polymers, proteins, and numerous antioxidants that are effectively used as capping and stabilizing agents in NP synthesis. In this chapter, we discuss the synthesis of biogenic NPs from different organisms and their potential applications in wastewater remediation. Moreover, to supplement the existing research gaps, different strategies are also recommended.