Sonolytic debromination of ambroxol process wastewater

In this study ultrasound was examined in terms of its effectiveness in treating wastewater containing ambroxol and process water from ambroxol synthesis. The organic bromine contents of the water samples investigated were in the 20-1200 mg l(-1) range. Ultrasound is capable to debrominate the ambroxol molecule rendering it biologically degradable. The debromination rate increases with the ultrasound intensity and the 0.4 order of the organic bromine concentration. Temperature and pH have only a small influence. Bromide ions reduce the debromination efficiency of the ultrasound. No removal of the organic carbon could be observed during ultrasonic treatment. The process water from ambroxol syntheses shows higher sonolytical debromination rates than the ambroxol model water. After extracting the process water with butyl acetate, the debromination reaction of the remaining organic bromine is considerably smaller. Argon increases the debromination under certain circumstances. The specific electric energy requirements for sonolysis vary between 7 and 920 kWh g(-1) of removed organic bromine. (C) 2002 Elsevier Science Ltd. All rights reserved.