Diphenyl chlorophosphate （DPCP）, which acts as a simulant of nerve warfare agent, is decontaminated by ozone in this study. Experimental results show that DPCP can be degraded rapidly by ozone. In the optimum working conditions, 99% 50 mg/L DPCP are degraded in 16min, and 30% total organic carbon of the solution is reduced. The free radical accelerant, Fe2＋, and inhibitors, 2-propanol and tert-butanol significantly influence the degradation efficiency of DPCP, therefore, free radical is the most important oxidant for the DPCP degradation reaction in this system. Ozone can be decomposed to hydroxyl radical, which would attack DPCP to start the degradation reaction. Furthermore, parts of DPCP would be mineralized, and degradation of toluene probably is the controlling step of the mineralization of DPCP. Finally, the reaction pathways are predicted for the degradation of DPCP by ozone.
