An integrated technique using zero-valent iron and UV/H2O2 sequential process for complete decolorization and mineralization of CI Acid Black 24 wastewater

The zero-valent iron (ZVI) reduction succeeds for decolorization, while UV/H2O2 oxidation process results into mineralization, so that this study proposed an integrated technique by reduction coupling with oxidation process in order to acquire simultaneously complete both decolorization and mineralization of C.I. Acid Black 24. From the experimental data, the zero-valent iron addition alone can decolorize the dye wastewater yet it demanded longer time than ZVI coupled with UV/H2O2 processes (Red-Ox). Moreover, it resulted into only about 30% removal of the total organic carbon (TOC), which was capable to be effectively mineralized by UV/H2O2 process. The proposed sequential ZVI-UV/H2O2 integration system cannot only effectively remove color and TOC in AB 24 wastewater simultaneously but also save irradiation power and time demand. Furthermore, the decolorization rate constants were about 3.77-4.0 times magnitude comparing with that by UV/H2O2 process alone. (c) 2006 Elsevier B.V. All rights reserved.