Thermally Partially Reduced Graphene Oxide Membranes for Water Recovery from Wastewater

For NASA#39;s space missions, water must be carried from Earth or generated by fuel cells, for the use of oxygen generation, drinking, food reconstitution, oral hygiene, and hygienic uses (showers, handwashing, and urine flushing). The high launch costs of fresh water to space and environmental health of crewmembers are the two major factors for water reclamation and reuse. Urine is expected to contribute approximately 81.4% of human wastewater in space. Therefore, wastewater treatment systems for spacecraft must address urine wastewater recycling. In addition, each of those three sources will have a variety of contaminants.nbsp;Improving the reliability of water recovery capabilities will most directly benefit future long-duration human missions beyond LEO by reducing the amount of spare equipment and emergency supplemental supplies of water that must be launched from Earth to ensure crew survival and mission success.nbsp; A secondary benefit of increasing water recovery is the reduction in volume of residual brine that must be stored or somehow disposed of.nbsp;Therefore, the Nanomatronix and UALR team seek to develop thermally partially reduced graphene oxide membrane-based filtration systems to overcome the issues discussed above. As a one atom thick two-dimensional (2D) carbon sheet, graphene has attracted great attention. As a graphene derivative, graphene oxide (GO) presents a plethora of exciting and promising properties. In our previous study, we demonstrated that partially, thermally reduced graphene oxide (RGO)-based filtration membranes are able to remove KMnO4 with a rejection rate gt;99%, at a thickness of 500 nm and a permeation rate 13 L h-1 m-2 bar-1, 10 times faster than that of commercial thin-film composite membranes used for desalination. In this proposal, we propose to use our RGO membrane water filtration technology for efficient water recovery of wastewater.nbsp;