NaFeEDTA Decomposition and Hematite Nanoparticle Formation in Supercritical Water Oxidation

Metal complex ethylenediaminetetraacetic acid (NaFeEDTA) was effectively decomposed by supercritical water oxidation (SCWO) with hydrogen peroxide in a plug-flow reactor. The effects of the oxidant amount and temperature on the decomposition rate and efficiency were more significant than that of pressure. The amount of oxidant significantly affected the decomposition rate and efficiency at lower temperatures. The decomposition kinetics of NaFeEDTA as the total organic carbon in the SCWO process was described using a global rate expression. In addition, as a byproduct, hematite ((alpha)-Fe2O3) in the range of 50-450 nm with regular shape was obtained from the decomposition of NaFeEDTA by the SCWO process. The size and shape of the metal oxide was controlled by the SCWO condition.