Abstract

The oxidative dechroming of leather shavings using hydrogen peroxide under ultrasound was studied. It was shown that the chrome removal rate from the shavings was influenced by reaction time, temperature, medium and intensity of ultrasound. When 20kHz and 40kHz ultrasound are employed, the intensity of ultrasound should be regulated to 7-8W/cm2. The proper circumstance for ultrasonic oxidation dechroming is 20°C and pH 9.0-10 adjusted by CaO. In these conditions, dechromed with 10% hydrogen peroxide (conc.30%) under ultrasound 8 times, a chrome removal rate of 99.46% can be achieved, which is markedly higher than 89.60%, the chrome removal rate using a conventional method of oxidation dechroming.