Cavitation‐induced pyrolysis of toxic chlorophenol by high‐frequency ultrasonic irradiation

p‐Chlorophenol (4‐CP) is a recalcitrant organic pollutant that is biologically toxic in industrial wastewater. A high‐frequency ultrasonic device operated at 1.7 MHz was designed and used successfully to degrade 4‐CP. Iodine liberation in the KI aqueous solution confirmed that effective cavitation occurred under the high‐frequency ultrasonic irradiation. No products or intermediate products were detected following the sonochemical degradation by 1H–nuclear magnetic resonance spectrum and mass spectrum after ultrasonic irradiation. It was concluded that the dominant degradation mechanism was high‐temperature pyrolysis to inorganic products in ultrasonic cavities rather than free‐radical oxidation. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 413–417, 2003.

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