The application and the development of the graphene in water treatment

It is a great challenge for the ecological field to handle the pollution of heavy metals and organic compounds. Because of the bottleneck of the traditional methods and techniques, graphene (GN), a two- dimensional material, attributing to its special structure, which is in the form of a honeycomb-like sheet of carbon just one atom thick, has a great deal of unique properties, such adsorption performance, selective permeability and catalytic activity. This thesis will elaborate on the application of the graphene in water treatment, concluding and discussing the preparation and development of the material. For adsorption performance, the main study direction is graphene aerogel (GA). The hydrothermal self-assembly method, chemical cross-linking method and template method are the main preparations of GA. The product has high specific surface area, excellent mechanical properties and porous structure, which contribute to the excellent adsorption performance dealing with heavy metals and organic dyes in sewage. For selective permeability, the main study is graphene membrane. Spin coating, vacuum filtration and Layer-by-layer assembly are the main approaches for the preparations of graphene membrane. Graphene membrane technology research focuses on nanofiltration, desalination of seawater (reverse osmosis), high efficiency oil-water separation, enhanced contamination resistance and composite membrane design. Moreover, other applications of graphene in water treatment, using its catalytic activity, can decompose organic contaminants and be reused. As the result shows, graphene has various applications and preparations in water treatment, despite there are some challenges and issues, such as the sustainable performance, stability and the control of the costs.