520c Effects of Ultrasonic Power and High Frequency on the Kinetics of the Sonochemical Oxidation of Aqueous Carbon Disulfide

Yusuf G. Adewuyi, Chemical Engineering, North Carolina Agricultural & Technical State University, 1601 East Market Street, Greensboro, NC 27411

Carbon disulfide (CS2) is a volatile liquid with pungent smell, which is toxic to animals and aquatic organisms, and can also decompose to carbonyl sulfide (OCS) and hydrogen sulfide (H2S) in aqueous environment. Anthropogenic sorces of CS2 in the aqueous environment include effluents from industries engaged in the manufacture of artificial leather, viscose, rayon, and other synthetic fibers. It is classified as a hazardous air pollutant under Title III of the 1990 Clean Air Act Amendment of the United States. Hence, its environmental remediation is of interest. In our previous studies, its kinetics and mechanisms of oxidation to sulfate as a predominant product at alkaline pH values by sonochemical oxidation using a 20 kHz ultrasonic probe in the absence and presence of H2O2 in ultrasonic batch reactors were investigated. Ultrasonic or acoustic cavitation involves the use of high-frequency sound waves in water to generate highly reactive species, particularly the hydroxyl (•OH), hydrogen (H•), hydroperoxyl (HO2•), and superoxide anion (•O2-) radicals and hydrogen peroxide (H2O2). In this work, the sonochemical oxidation of carbon disulfide was investigated with the aim of determining the optimum frequency and ultrasonic power using a novel high multi-frequency sonicator capable of operating at four pre-set frequencies (323 kHz, 581 kHz, 611 kHz and 1.3 MHz) and five different power settings for each frequency to determine optimal combined high frequency and ultrasonic intensity for effective degradation. The results of our studies, which should help in the design and optimization of sonochemical processes for water and wastewater remediation, will be presented.