Sonochemical degradation of bisphenol A in natural water

Bisphenol A (BPA), an organic compound largely used in plastic industry as a monomer for production of epoxy resins and polycarbonate, disturb the behaviour of the aquatic life by its endocrine disrupting effect at low concentration [1]. This xenobiotic compound, can be released in the environment from bottles, packaging, landfill leachates paper and plastic plants [2-4]. In recent years, considerable interest has been shown on the application of ultrasound as an advanced oxidation process (AOP) for the treatment of hazardous contaminants in water. Ultrasonic irradiation of aqueous solutions induces acoustic cavitation, which can be defined as the cyclic formation, growth and collapse of microbubbles. Implosion of the cavities occurs adiabatically in extremely small intervals of time and releases large quantities of energy over a small location. During the collapse, thermal dissociation of water (sonolysis) yields OH radicals, which are reactive species able to oxidize the most part of the organic molecules. On the other hand, hydrophobic and volatile substrates can be destroyed predominantly by direct pyrolitic decomposition inside the cavitation bubbles. Natural waters are usually complex systems that contain significant amount of inorganic species, which may affect the efficiency of the AOP [5]. In this work, we demonstrate that the sonochemical treatment (300 kHz / 80 W) is a very promising alternative for the BPA removal in natural waters, even at low concentration of BPA (0.034 mg L) and high concentration of Cl, SO4 2and HCO3 (10, 1182 and 402 mg L respectively). 1. N. Ben-Jonathan, R. Steinmetz (1998), Trends Endocrinol. Metab., 93, 124-128. 2. T. Yamamoto, A. Yasuhara, H. Shiraishi, O. Nakasugi (2001), Chemosphere, 42 415-418. 3. M. Furhacker, S. Scharf, H. Weber, (2000), Chemosphere, 41, 751-756. 4. C. A. Staples, P. B. Dorn, G. M. Klecka, S. TO'Block, L. R. Harris (1998), Chemosphere, 36, 10, 2149-2173. 5. E. Lipczynska-Kochany, G. Sprah, S. Harms (1995), Chemosphere, 30, 1, 9-20.