Removal of Direct Blue 71 By Heterogeneous Sono, Photo and Sonophotocatalytic Oxidation: Zero Valent Copper Catalyst

Abstract

The sonolytic and sonocatalytic degradation of Direct Blue 71 (DB71) in the presence Zero Valent Copper (ZVC) sonotocatalysts were studied at 20 kHz using ultrasonic power of 95W and aqueous temperature of 20^◦C within 20 minutes. The effects of various operational parameters such as the pH and the amounts of catalysts on the sonochemical degradation were also investigated. US alone were found to be totally ineffective for bleaching the dyes. Sonochemical degradation of DB71 was strongly affected by the amounts of catalysts and the pH level. However, acidic pH was favoured for the sonocatalytic degradation of DB71 using catalysts. The ultrasonic degradation of dye was enhanced by catalysts addition. Accordingly, removal of 55.8% dye colour  was achieved with 1 gL⁻¹ of catalyst, 2.5 pH, 50 mgL^-1 and 20°C, during 20 minutes. The effect of H₂O₂ on sono, photo and sonophotocatalytic oxidations was investigated at these optimum conditions. It was observed that the colour removal efficiency was influenced by the solution H₂O₂. The highest colour removal was obtained as 78% by US/UV/ZVC/H₂O₂.