Carbon Nanomaterials For Wastewater Treatment

The research progress made in recent years in removal of organic-inorganic pollutants from wastewater using various types of carbon materials as adsorbents such as carbon nanotubes, carbon nanofibers, graphenes, graphitic carbon nitride, fullerene, activated carbon spheres, and carbon quantum dots is reviewed. These carbon nanomaterials with hierarchical structures are efficient and economical adsorbents. The techniques of metal impregnation and doping help to control the porosity and surface area of nanomaterials. Electrostatic forces, pi-pi and pi-e interactions, van der Waals weak forces, and oxygen-containing groups are considered responsible for the removal of pollutants from wastewater. The carbon nanomaterial-based photocatalysts are applied successfully in decomposition of persistent dyes under visible light. Fe3O4 magnetic material is employed as recyclable adsorbent after treatment of wastewater. Freundlich and Langmuir models are found more suitable to calculate the adsorption efficiency and adsorption kinetics of pollutants. Criteria and properties of carbon nanomaterials are discussed that might play a significant role in remediation of wastewater.