Investigations in sono-enzymatic degradation of ibuprofen.

The drug ibuprofen (IBP) appears frequently in the wastewater discharge from pharmaceutical industries. This paper reports studies in degradation of IBP employing hybrid technique of sono-enzymatic treatment. This paper also establishes synergy between individual mechanisms of enzyme and sonolysis for IBP degradation by identification of degradation intermediates, and Arrhenius & thermodynamic analysis of the experimental data. Positive synergy between sonolysis and enzyme treatment is attributed to formation of hydrophilic intermediates during degradation. These intermediates form due to hydroxylation and oxidation reactions induced by radicals formed during transient cavitation. Activation energy and enthalpy change in sono-enzymatic treatment are lower as compared to enzyme treatment, while frequency factor and entropy change are higher as compared to sonolysis. Degradation of IBP in sono-enzymatic treatment is revealed to be comparable with other hybrid techniques like photo-Fenton, sono-photocatalysis, and sono-Fenton.