Design of graphene oxide membranes: a sustainable and revolutionary solution for water desalination

Full text: Water is an essential molecule for life, its distribution on the Earth's surface is extremely uneven and its scarcity is an issue being discussed all over the world. Currently, it is estimated that around 748 million people on the planet do not have access to drinking water sources. In this scenario, desalination of sea water is a promising alternative. This technique needs to be improved, considering that 97% of the planet's water is found in the oceans and seas [1]. With the advent of nanostructures, especially of the nanoporous graphene membranes, the filtration processes have obtained encouraging results. In this scenario, this project proposes a sustainable and revolutionary solution to this issue: design of nanostructured graphene oxide membranes for water desalination. Graphene oxide was prepared using modified Hummers method through the oxidation/exfoliation of expanded graphite. The membranes for water desalination were produced through immobilization of GO on different membranes supports. The structural, morphological and textural characterization of the GO and GO membranes was done by X-ray diffractometry, infrared spectroscopy, X-ray photoelectron thermogravimetry, spectroscopy, Atomic Force Microscopy, scanning electron microscopy and high-resolution transmission electron microscopy. The desalination tests were performed and the efficiency of the filtration using these two models will be evaluated by mass difference and electrical conductivity measurements of the salt and filtered solution. The reduction of water salinity observed during the filtration tests indicates that GO membranes are excellent alternatives to conventional water desalination membranes. References [1] Elimelech, M.; Phillip, W. A. The future of seawater desalination: energy, technology, and the environment. science, v. 333, n. 6043, p. 712-717, 2011. ISSN 0036-8075. (author)