Continuous Monitoring of Total Organic Carbon Based on Supercritical Water Oxidation Improved by CuSO4 Catalyst

Abstract

A device that can detect the concentration of total organic carbon (TOC) continuously was designed by combining the technology of supercritical water oxidation (SCWO) and non-dispersive infrared analyzer (NDIR). CuSO4, as one of the common homogeneous catalysts in the SCWO of wastewater, was introduced into the device to lower the reaction temperature and improve the utilization efficiency of H2O2 oxidant. Catalyst use was seen to improve destruction rate significantly, when compared with the results obtained during the non-catalytic experiments. While the oxidant stoichiometric excess needed was ten times or more under non-catalytic condition, it only needed to be two for CuSO4 catalytic system. With CuSO4 solution pumped into the reaction system, lower energy consumption was required and less thermal and mechanical stresses exist within the detecting equipment. The device could detect the concentration of TOC for practical wastewater with low proportion of inorganic carbon precisely and continuously, while for those with high proportion of inorganic carbon a pre-treatment like acidification was needed.