Behavior of Metal Compounds in the Supercritical Water Oxidation Process

The potential use of Supercritical Water Oxidation (SCWO) technology for the production of potable water from wastewater and human waste has led to an interest in the fate of metals, particularly toxic metals, in the SCWO process. While it has been observed that many metallic components of waste streams form refractory oxides which precipitate with the salts in the reactor, some metals such as mercury and lead may form volatile compounds as well. MODAR has frequently monitored effluents for heavy metal content, but lack of data on the feed composition has precluded a detailed study of fate and distribution. In a recent study, however, a synthetic feed with known metal concentrations was subjected to SCWO. The results of analysis of the effluents from this experiment give a better insight into the fate of metals in SCWO.