DHydrogen peroxide (H2O2) is a strong oxidant and its application in the treatment of various inorganic and organic pollutants is well established. Still H2O2 alone is not effective for high concentrations of certain refractory contaminants because of low rates of reaction at reasonable H2O2 concentrations. Improvements can be achieved by using transition metal salts (e.g. iron salts) or ozone and UV-light can activate H2O2 to form hydroxyl radicals, which are strong oxidants. Oxidation processes utilising activation of H2O2 by iron salts, classically referred to as Fenton's reagent is known to be very effective in the destruction of many hazardous organic pollutants in water. The first part of our paper presents a literature review of the various Fenton reagent reactions which constitute the overall kinetic scheme with all possible side reactions. It also summarises previous publications on the relationships between the dominant parameters (e.g. [H2O2], [Fe 2+],...). The second part of our review discusses the possibility of improving sludge dewaterability using Fenton's reagent. (C) 2003 Elsevier Science B.V. All rights reserved.