Sonochemical and photosonochemical degradation of endocrine disruptor 2-phenoxyethanol in aqueous media

2-Phenoxyethanol (PhE) has been shown to induce hepatotoxicity, renal toxicity, and hemolysis in subchronic and chronic studies in multiple species. It is one of the endocrine disrupting compounds, which are listed as priority emerging water contaminates. In this work, the removal of PhE at variable concentrations from water has been achieved using high frequency ultrasound (600 kHz) in batch mode. 100 min of irradiation was required for the complete disappearance of PhE (10 mg L-1) and for the removal of more than 60% of the initial solution COD. Several parameters were evaluated for the ultrasound application: the initial concentration of PhE (2-400 mg L-1), applied power (40-120 W), dissolved gas (air and N-2), pH (2-10) and temperature (15-45 degrees C). Additionally, the effect of combining ultrasound with UV irradiation (15 mW cm(-2), 253.7 nm) on the degradation of PhE was evaluated. The degradation rate increased notably with increasing initial PhE concentration and power, whereas pH and liquid temperature did not affect significantly the removal rate of the pollutant. Air atmosphere showed the best degradation yield than nitrogen. UV-assisted ultrasound (US) provided a significant enhancement in the oxidation of the organic matter. After 2 h of treatment, 94% of initial COD was removed using US/UV system, whereas 76% was eliminated with UV and 65% with US alone.