Abstract:The effects of Cu 2+ on the catalytical degradation of acid chrome blue K (ACBK) in UV-TiO 2 and H 2 O 2 processes were studied. In these two processes, Cu 2+ markedly depressed the catalytical degradation of ACBK by its interaction with ACBK. Through this interaction, the new complex Cu(ACBK) 2 formed. The formation of this new complex was favorable to protect some groups in ACBK from the oxidation of reactive oxygen generated in UV-TiO 2 and H 2 O 2 processes, and consequently had suppressing effects on degradation of ACBK. In addition, Cu 2+ also inhibited the degradation of ACBK in UV-TiO 2 process by influencing the adsorption of ACBK on the surface of TiO 2 particles.