Removal of Rhodamine B Dye from Wastewater by Ultrasound-Assisted Fenton Process: A Comparison between Bath and Probe Type Sonicators

摘要

Sono-Fenton process is effective in treatment of turbid or dark wastewater. There are two ways of dispersing ultrasound in a solution - direct by probe and indirect by bath. In this work, a comparative study between the performances of the two methods of sonication has been reported in case of sono-Fenton degradation of Rhodamine B in water. Study of the influences of other process parameters viz pH, initial dye concentration, initial H2O2 concentration and initial Fe~(2+centration on the decolorisation efficiency were carried out for both types of sonicators. Blank experiments without ultrasound and without Fenton s reagent were also performed for reference. Without ultrasound, the decolorisation by Fenton s reagent only was 73.68% whereas with ultrasound it was 92.39% for bath-type and 93.85% for probe-type sonicator under high initial dye concentration (0.5 kg/m3). However, under low catalyst [Fe~(2+] dosage, decolorisation was 94% with probe sonicator and 55% with sonicator bath. Mineralization of the dye in terms of COD removal was studied. COD of 30.66% and 32.91% respectively were removed by bath-type and probe-type sonicators after 15 min of reaction whereas decolorisation was more than 99% under identical conditions. The results indicate that sono-Fenton process can be an effective treatment process for wastewaters containing organic dyes.