Abstract: Transition metal ions have the ability to increase the oxidation performance of the inorganic peroxy salts at room temperature by possibly lowering their activation energy or by producing more reactive free radicals. When two transition metal salts are used together to decompose dipersulfate, it provides synergistic oxidation activity, better than obtained by dipersulfate or dipersulfate with either copper or zinc alone. The transition metals mentioned are the water soluble salts of copper and zinc. Oxidation performance of sodium dipersulfate in presence of catalytic amount of copper and zinc salts was determined by measuring the destruction of crystal violet dye at a wavelength of 589 nm.

Abstract: A method for treating a recirculating water system which comprises introducing into said water system a multifunctional, multilayer tablet, wherein the multilayer tablet comprises a fast dissolving layer and a slow dissolving layer, wherein said fast dissolving layer releases a combination of active ingredients including a member selected from the group consisting of lithium hypochlorite, calcium hypochlorite, trichloroisocyanuric acid (TCCA), anhydrous sodium dichloroisocyanurate, sodium persulfate, potassium persulfate, potassium monopersulfate, sodium monopersulfate, and mixtures thereof, and at least one of a clarifier, chelating agent, sequesterant, algaestat, water softener, algaecide, corrosion inhibitor, scale inhibitor, flocculent, disintegrant, dispersant, colorant, dissolution control agent, fragrance, or surfactant and, wherein said slow dissolving layer includes a member selected from the group consisting of trichloroisocyanuric acid (TCCA), calcium hypochlorite, 1,3-dichloro-5,5-dimethylhydantoi