Abstract: WO₃ powder prepared under the optimal thermal decomposition conditions，was used as butyl xanthate to simulate the photocatalytic degradation of under visible light irradiation（λ≥420 nm）.The effect of various variables on the butyl xanthate degradation is investigated such as WO₃ dose，initial butyl xanthate concentration，pH value and degradation time.Under conditions of the butyl xanthate concentration of 40 mg/L，1.0 g/L WO₃ at pH=7 with the degradation time of 5 h，the degradation efficiency of xanthate reached 92%，and the removal efficiency of chemical oxygen demand(COD) was found to be 84%.Among these variables，the influence of solution pH on degradation butyl xanthate is most significant.The degradation of butyl xanthate is rapid at acidic solution media.The degradation rate reached 90% when pH=4 for 30 min.The kinetics studies showed that the butyl degradation of butyl xanthate followed the first class kinetic model at room temperature.The investigation of UV-Visible Absorption Spectrum on the degradation of butyl xanthate showed that only degradation product CS₂ appeared in process of degradation butyl xanthate.

Key words: Butyl xanthate, Photocatalysis, WO₃