Sonochemical reactions of dissolved organic matter

Property changes of Aldrich and Pahokee peat dissolved organic matter (DOM) at different ultrasonic frequencies and energy densities were systematically investigated. Exposure of DOM to ultrasound resulted in decreases in TOC, Color(465), specific UV absorbance (SUVA), aromaticity and molecular weight, while DOM acidity increased. Compared to 20 kHz ultrasound, greater sonochemical transformation of DOM occurred at 354 kHz and at higher energy density, due to greater (OH)-O-. radical production. The changes to DOM properties suggest that ultrasound may significantly affect DOM-pollutant interactions (e.g. facilitate desorption of hydrophobic organics from DOM or promote complexation between metallic cations and DOM).