**8. Conclusion**

Because of many advantage like easy-operation, energy-efficiency, and easy scale-up, and environmental friendliness; membrane-based separation technology attracted many separation fields. But the membrane fabricated afflicted with bottlenecks like- fouling, have low resistance to chlorine, strong acids/alkaline, high temperature and organic solvents, and suffer from aperture shrinkage under high pressure and high energy cost. One of the methods to resolve the mentioned problems is through enhancing a membrane castoff in separation process.

A tremendous amount of effort has been paid to develop new membranes and develop novel membrane structures with greater chemical stability, thermal stability, water permeability, as well as high selectivity, which in turn yield less energy consumption. Since 2004 researcher focused on carbon-based materials especially one material—graphene. Graphene, and its derivative graphene oxide (GO) and carbon nanotubes (CNTs). They have been demonstrated notable potential in the field of membrane. The basic characters for their suitability are: their strong mechanical strength, high resistance to strong acids/alkaline and organic solvents, and easy availability. Among them, GO selected for evolving nano-building materials for the manufacturing of novel separation membrane due to its high mechanical strength, high chemical inertness, nearly frictionless surface, its flexibility, suitability for largescale production and its cost-effectiveness.

The Nobel Prize winning material, graphene is taken as one of the most wonderful achievements in the field of science and technology. It is an atomically-thin (0.35 nm in thickness), it is a two-dimensional sheet with a honeycomb structure made up of sp2 hybridization carbon atoms which are linked together with strong sigma keys.

Preparation of GO from graphene essentially comprise two steps: oxidation of graphite and exfoliation of graphite oxide and is carried out by simply six different kinds of oxidation process. To get GO membranes it need only a final steps of integrating GO suspension with the support by vacuum filtration, dip coating or interfacial polymerization.
