الفهرس | Only 14 pages are availabe for public view |
Abstract In particular, the use of reactive dyes poses certain problems, including the presence of large amounts of hydrolyzed dye. The objective of this work is to minimize the pollution caused by hydrolyzed reactive dye in the effluents of their dye bath, by using advanced oxidation processes (AOPs): ultraviolet irradiation in combination with hydrogen peroxide (UV/H2O2) and ferrous ions for decolorizing two reactive azo dyes (C.I. Reactive Blue 221 (R.B.221) and C.I. Reactive Red 195 (R.R.195)) in aqueous solution and treated textile-manufacturing wastewater. The effects of different reaction parameters such as initial pH, time, hydrogen peroxide concentration and UV intensity were investigated. C.I. Reactive Blue 221 (R.B.221) was degraded by photodegradative oxidation, without needing ferrous ions. This is due to the presence of copper ions in the main structure of the dye which are thought to have the same action of ferrous ions in the oxidation process, effective system conditions were found to be pH of 2, hydrogen peroxide concentration 10mM at UV irradiation with intensity 45 watt and contact time 2 hrs. The second dye C.I. Reactive Red 195 (R.R.195) was degraded by Photo- Fenton oxidation, effective system conditions were found to be pH of 4, hydrogen peroxide to iron molar ratio of 50:3 at UV irradiation with intensity 45watt. The color removal efficiency at the optimum conditions during photodegradation process and Photo-Fenton like process was evaluated with respect to the time-dependant reduction of the color intensity, as well as, with ecological parameters such as TOC & COD. |