The IIOAB Journal SPECIAL ISSUE ON FRONTIERS IN INDUSTRIAL MICROBIOLOGY AND ENVIRONMENTAL BIOTECHNOLOGY

The oxidative degradation of Procion Red MX-5B by solar Fenton’s has been investigated using sunlight as irradiation source in presence of hydrogen peroxide and Fe2+. Maximum decolorization (99%) and COD removal (97%) for MX-5B was obtained at H2O2 dose of 16.6 mM and at 30 min irradiation time. Fe2+ dose of 0.36 mM was optimum for Procion Red MX-5B degradation. The solar degradation mechanism occurs in three steps in which initially the more active bonds were hydroxylated. The N=N and the C-S bonds of sulphonate group form organic acids, SO42+ and NH4+. At the same time, the aromatic acids produced initially were further oxidized to aliphatic acids. MX-5B undergoes oxidation leading to non toxic and biodegradable ultimate breakdown products, such as, oxalic acid and acetic acid. Solar Fenton process not only oxidizes but also helps in decolorization and nearly mineralization of the dyes at low dose of reactants. _____________________________________________________