Comparison of efficiency of photochemical and sonochemical processes combined with hydrogen peroxide in removal of Direct Blue 71(DB71) from aqueous solution: A kinetic study

One of the important sources of environmental pollution existing in different industrial wastewater, including loom wastewater are dyes which are harmful for human health and environment. The purpose of this study was to investigate the efficiency of photochemical and sonochemical processes combined with hydrogen peroxide in removal of DB71 from aqueous solution.

This study was an experimental - laboratory study. At first, a reactor was designed and made. Then, optimum pH was determined which was 7 for photochemical and 3 for sonochemical process in constant condition. The effects of initial concentration of hydrogen peroxide, DB71 and contact time were studied at the constant optimum pH. Then data were interpreted and analyzed by use of Excel software and regression coefficient.

The results of this study showed that with increased initial concentration of DB71, its removal decreased. But removal efficiency of DB71 increased by increasing contact time and initial concentration of hydrogen peroxide. In addition, kinetic parameters were obtained by application of first–order (Langmuir-Hinshelwood) equations.

The results showed that UV/ H2O2 and US/H2O2 processes can be effective in the removal of DB71 from aqueous solutions. Considering dye removal efficiency and availability, photochemical process combined with hydrogen peroxide can be recommended as a fast effective method for removal of dyes from aqueous solutions.