#$%^&*AU2015202057B220161103.pdf#####Abstract The invention provides a process of removing or preventing biofouling in a volume of an aqueous liquid or on a surface in contact with an aqueous liquid, comprising (i) providing an aqueous composition (stock antifouling solution) containing a urea derivative and an active halogen source, wherein the molar ratio urea derivative/halogen is at least 1/1, and the pH of said aqueous composition is acidic and (ii) contacting said volume or said surface with said composition obtained in step i) wherein said active halogen source is selected from C12, DC-DMH, DC-MEH, TCCA, NaDCC, and a mixture of an oxidizer with a bromide source selected from HBr and a bromide. The invention further provide a process of preparing an antifouling or disinfecting composition comprising water, a urea derivative, and active bromine, comprising (i) preparing an aqueous solution of said urea derivative (ii) adding to said solution obtained in step i) an active chlorine source selected from the group consisting of C12, TCCA, Na-DCC, DC-DMH, and DC-MEH, at a temperature of between OC and 250C, while stirring, wherein the molar ratio urea/chlorine is greater than about 1/1, thereby obtaining an aqueous composition of stabilized chlorourea derivative and optionally (iii) admixing to said stabilized chlorourea derivative a bromide or HBr to an amount corresponding to a molar ratio Br/Cl of from 0.5 to 2.0, at a temperature of between OC and 25CC wherein a time period between said steps ii) and iii) is up to two years.
