| 摘要 |
A water treatment method is provided to control both corrosion and scale excellently by maximally preventing a corrosion reaction generated on a surface of metal in a high hardness water quality condition and substantially suppressing scale of bivalent metal salts at the same time, and to use the phosphorous safely by lowering the concentration of phosphorous to less than 2 ppm. A water treatment method comprises the step of adding phosphorous(P), an acrylate copolymer, an azole-based compound, and a zinc ion into cooling water such that a concentration of the phosphorous(P) is controlled to a range of 0.1 to 2 ppm, concentration of the acrylate copolymer is controlled to a range of 0.1 to 15 ppm, a concentration of the azole-based compound is controlled to a range of 0.1 to 5 ppm, and concentration of the zinc ion is controlled to a range of 0.1 to 5 ppm relative to cooling water, and maintaining the concentrations of the respective components. The phosphorous(P) is derived from a compound selected from the group consisting of phosphoric acid, sodium phosphate(mono-basic, di-basic, tri-basic), potassium phosphate(mono-basic, di-basic, tri-basic), tetrapotassium pyrophosphate, sodium hexametaphosphate, 1-hydroxyethylidene-1,1-diphosphonic acid, hydroxyphosphono carboxylic acid, aminotrimethylene phosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, ethylenediamine tetramethylidene phosphonic acid, and mixtures thereof. The azole-based compound is selected from the group consisting of tolyltriazole, 20mercapto benzothiazole, benzotriazole, imidazole, and mixtures thereof. The zinc ion is provided from a zinc salt selected from the group consisting of zinc chloride, zinc sulfate, zinc nitrate, zinc oxide, and mixtures thereof. |
