Carbon-Based Nanomaterials in Water and Wastewater Treatment Processes

The observed increase in the diversity and level of pollutant content in the water environment forces the development of more effective technologies for their removal. Using nanomaterials in water and wastewater treatment offers numerous opportunities to remove organic and inorganic contaminants that are hardly removable in conventional processes. In this group, carbon-based nanomaterials, mainly carbon nanotubes (CNTs), graphene (Gr), and graphene oxide (GO), are very popular. This review aims to present the directions and diversity of applications of carbon-based nanomaterials (CNMs) in water and wastewater technology, as well as the challenges and environmental dangers that new solutions entail. Authors also present the results of the research on the changes in properties of GO produced in the laboratory as water suspension and a freeze-dried product over time. The results confirm the significant influence of the form of graphene oxide and its storage time on the structural properties, hydrophilicity, and stability of GO. Therefore, they should be considered when selecting an adsorbent or reaction catalyst in environmental applications for developing new greener and sustainable methods of treatment and purification, which use fewer reagents and release safer products.