Advances in the Applications of Nanomaterials for Wastewater Treatment

Freshwater is in limited supply, and the growing population further contributes to its scarcity. The effective treatment of wastewater is essential now more than ever, because waterborne infections significantly contribute to global deaths, and millions of people are deprived of safe drinking water. Current wastewater treatment technologies include preliminary, primary, secondary, and tertiary treatments, which are effective in removing several contaminants; however, contaminants in the nanoscale range are often difficult to eliminate using these steps. Some of these include organic and inorganic pollutants, pharmaceuticals, pathogens and contaminants of emerging concern. The use of nanomaterials is a promising solution to this problem. Nanoparticles have unique properties allowing them to efficiently remove residual contaminants while being cost-effective and environmentally friendly. In this review, the need for novel developments in nanotechnology for wastewater treatment is discussed, as well as key nanomaterials and their corresponding target contaminants, which they are effective against. The nanomaterials of focus in this review are carbon nanotubes, graphene-based nanosheets, fullerenes, silver nanoparticles, copper nanoparticles and iron nanoparticles. Finally, the challenges and prospects of nanoparticle utilisation in the context of wastewater treatment are presented.