Supercritical Water Oxidation: A Promising Wastewater Treatment Technology

Supercritical water oxidation (SCWO) is a water treatment technology that operates above the critical point of water. The main benefits of SCWO are its ability to completely oxidize organic compounds and mineralize/separate inorganic compounds from wastewater. This suggests SCWO technology can conceptually be applied as a single step water treatment system. Additionally, with proper design and operations it is capable of handling liquid waste streams with high solid loading, thus eliminating the need for extensive pretreatment of the waste stream. This paper provides a description of commercial, academic and NASA developed SCWO reactors. A trade study is presented that shows SCWO is competitive with the International Space Station (ISS) state-of-the-art water recovery systems in all categories except power. However, thermal and mechanical energy recovery approaches are discussed that could be used to reduce SCWO energy consumption to a level that is more competitive with the ISS state-of-the art.