Abstract
Catalytic hydrothermal oxidation of 4-chlorophenol (CP) has been examined using the slurry flow reactor system. The mixed suspension containing CP, hydrogen peroxide and Cu2O catalyst was reacted with pressure, temperature and flow rate controlled at 10 MPa, 100-200°C and 1.0-16.0 cm3/min, respectively. The remarkable enhancement of CP decomposition by Cu2O catalyst was observed at 133-166°C. The semi-quantitative analysis of hydroxyl radicals generated by catalytic hydrothermal oxidation using salicylic acid as a molecular probe revealed that the production of hydroxyl radical was substantially enhanced by Cu2O catalyst at the same temperature as the decomposition of CP was enhanced. It was thus indicated that hydroxyl radicals were formed by Fenton-like reaction with Cu+ ions. It was also found that the degradation of CP was complete in less than 10 sec and that oxalic acid was produced as an intermediate.
