The chemical degradation of Malachite Green dye has been studied by using UV/H2O2 system in presence of transition metal ions (Fe2+, Mn2+ and Ti2+). The degradation reaction was carried out by circulating the aqueous dye solution in a custom-made UV reactor with the help of a variable speed peristaltic pump. The effects of initial concentration of dye, concentration of Hydrogen peroxide, operating temperature, pH, Ultrasound vibrations and transition metal ions were investigated on the time required for complete degradation of the dye. It has been found that under optimum conditions the dye could be degraded in minimum possible time especially in presence of transition metals like iron. The intermediate products obtained during the degradation process were subjected to FTIR spectroscopy for structural analysis. The residue spectra did not show any band revealing the presence of any aromatic ring. To check the completion of the reaction the final residue was analyzed for total organic carbon (TOC). All such tests indicated that the dye has been completely degraded leaving no detectable residue

Waheed-uz-Zaman, Amara Dar, Jamil Anwar and Ayesha Munir