Res. Chem. Intermed.
, Vol. 30, No. 7-8, pp. 735–753 (2004)
Also available online - www.vsppub.com
Sonochemical reactions of dissolved organic matter
, YU-PING CHIN
HAROLD W. WALKER
and PATRICK G. HATCHER
Department of Civil and Environmental Engineering and Geodetic Science,
The Ohio State University, Columbus, OH 43210, USA
Department of Geological Sciences, The Ohio State University, Columbus, OH 43210, USA
Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
Received 24 March 2004; accepted 16 June 2004
Abstract—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
, 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
OH 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).
Keywords: Natural organic matter; dissolved organic matter; ultrasound;
aromaticity; Aldrich; Pahokee.
Sonication has been explored as an oxidation technology for the treatment of
refractory organic pollutants in water [1, 2] and contaminated sediment (Ref. 
and data not shown), and for disinfection  and membrane cleaning (Ref.  and
data not shown) in drinking water applications. The presence of natural organic
matter (NOM), however, may signiﬁcantly inﬂuence the effectiveness of ultrasound
in these systems. NOM is present in natural waters due to the degradation of
plant and animal matter. The chemical structure of NOM is ill-deﬁned , varies
depending on the source, but typically includes aromatic, aliphatic, carboxylic and
phenolic functional groups . NOM can undergo a variety of reactions in natural
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