Methods and systems for the controlled production of aqueous halogen solutions with varying compositions are disclosed. According to an embodiment, aqueous solutions of hypochlorite ions are modified through the sequential addition of pH adjusting chemicals, non-chloride halide ions, and halogen stabilizing compounds. Sensors, for measuring physical and chemical properties of the solutions as they change due to the impact of the various chemical reactions, are linked to a control system which, in turn, can control the input of one or more chemicals. The control system facilitates the production of a solution with desired characteristics in terms of pH, specific halogen composition, degree of halogen stabilization, and limiting the production of undesired by products such as bromate ions.

Methods and systems for the controlled production of aqueous halogen solutions with varying compositions are disclosed. According to an embodiment, aqueous solutions of hypochlorite ions are modified through the sequential addition of pH adjusting chemicals, non-chloride halide ions, and halogen stabilizing compounds. Sensors, for measuring physical and chemical properties of the solutions as they change due to the impact of the various chemical reactions, are linked to a control system which, in turn, can control the input of one or more chemicals. The control system facilitates the production of a solution with desired characteristics in terms of pH, specific halogen composition, degree of halogen stabilization, and limiting the production of undesired by products such as bromate ions.

Adding acid to a solution containing bleach and soluble bromide salt accelerates the reaction producing sodium hypobromite which has a pronounced yellow color. The amount of acid needed to provide complete reaction can be controlled by measuring light absorbed by the solution. Add acid until Absorbance stops increasing, indicating complete conversion of NaBr to NaOBr. The amount of acid added can also be controlled by measuring pH before and after adding NaBr to diluted bleach. When enough acid has been added to fully neutralize sodium hydroxide in the bleach and provide nearly 100% conversion, the difference between the two pH values becomes positive and continuous to increase, whereby acid feed can be controlled to make pH change equal to or greater than a predetermined positive value.

Adding acid to a solution containing bleach and soluble bromide salt accelerates the reaction producing sodium hypobromite which has a pronounced yellow color. The amount of acid needed to provide complete reaction can be controlled by measuring light absorbed by the solution. Add acid until Absorbance stops increasing, indicating complete conversion of NaBr to NaOBr. The amount of acid added can also be controlled by measuring pH before and after adding NaBr to diluted bleach. When enough acid has been added to fully neutralize sodium hydroxide in the bleach and provide nearly 100% conversion, the difference between the two pH values becomes positive and continuous to increase, whereby acid feed can be controlled to make pH change equal to or greater than a predetermined positive value.