The beneficial role of use of ultrasound in heterogeneous Fenton-like system over supported copper catalysts for degradation of p-chlorophenol

Abstract

A heterogeneous sono-catalytic system with addition of hydrogen peroxide ( U S H 2 O 2 + Cat . ) was employed for the degradation of 200 ppm of p-chlorophenol (4-CP) at 25 °C and 100 W of ultrasound power. One thousand and six hundred parts per million of initial hydrogen peroxide (H 2O 2) concentration and 1 g/L of catalyst loading over three heterogeneous copper catalysts, CuO, Cu/Al 2O 3 (Cu/Al) and CuO·ZnO/Al 2O 3 (Cu/Zn) was used. The benefits of ultrasound in a heterogeneous catalytic system were evaluated. A considerable synergistic effect of the U S H 2 O 2 + Cat . system was only achieved with supported catalysts (Cu/Al and Cu/Zn) possibly due to good dispersion of catalysts as a result of catalyst size reduction during ultrasound irradiation. Moreover, between the two supported copper catalysts, the Cu/Al provided promising catalytic performance by giving higher 4-CP and TOC removal accompanied with efficient H 2O 2 consumption. Experiments with a homogeneous copper catalyst revealed that use of ultrasound in a homogeneous system shows an adverse effect on decomposition of 4-CP.