Mechanisms and inorganic byproducts of trihalomethane compounds sonodegradation.

Organic pollutants can be sonodegraded by two pathways: pyrolysis, oxidation by free radicals, or the combination of both. The sonolytic degradation mechanisms and byproducts formation of aqueous trihalomethanes (THMs) were investigated at acoustic frequency of 20 kHz. The main sonodegradation mechanism of the chloroform, dichlorobromomethane, dibromochloromethane, and bromoform was found to be pyrolysis. The sonolysis degradation pathway of iodoform is free radicals oxidation. Hydrogen peroxide, nitrate, chloride, bromide, iodide, and iodate ions were detected and quantified as the inorganic products of the THMs sonication. A total of 48% TOC removal was achieved after a 180-min sonication of the THMs mixture.