Abstract

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

Author(s): Akram M, ChowdhuryA and Chakrabarti S

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 Fe2+ concentration 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 [Fe2+] 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.