The effect of ultrasound on polycyclic aromatic hydrocarbons in aqueous media

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants which pose a potential threat to human health and environmental quality. An investigation to determine the ability of ultrasonic radiation to desorb PAHs adsorbed on the surface of solid substrates and to chemically alter these chemicals in aqueous solutions and suspensions has been conducted. The data indicate that enhanced transport of adsorbed PAH from a glass surface can be induced by treatment with ultrasonic radiation of varying intensities. Furthermore, chemical alteration can be induced under intense (147 watts/cm$\sp2)$ ultrasonic treatment. The extent of reaction is a function of irradation time at this ultrasonic intensity. Reaction products from ultrasonic treatment of aqueous solutions of biphenyl, analysed by gas chromatography (GC) and mass spectrometry (MS), include ortho-, meta-, and para-(1,1 biphenyl) -ol. The principal product from ultra-sonic treatment of aqueous phenanthrene appears to be a phenanthrenediol. The use of ultrasound to treat PAH contaminated aqueous solutions in tandem with other methodologies appears promising. However, the toxicity of reaction product mixtures produced by ultrasonic treatment remains to be determined.