Abstract: The present invention provides a use of an inorganic salt or acid capable of producing free phosphate or fluoride ion in reducing the hardness and/or alkalinity of a water system containing residual antiscalant. In the lab test, it is found that the addition of a suitable amount of sodium phosphate or sodium fluoride may induce alkalinity reduction as well as hardness reduction. The production efficiency can be enhanced since the scaling was relieved and heat exchange efficiency can be improved. Meanwhile, lower scaling stress also means lower antiscalant dosage and cost, and thus the total operation cost can be reduced.

Abstract: The present invention provides a use of an inorganic salt or acid capable of producing free phosphate or fluoride ion in reducing the hardness and/or alkalinity of a water system containing residual antiscalant. In the lab test, it is found that the addition of a suitable amount of sodium phosphate or sodium fluoride may induce alkalinity reduction as well as hardness reduction. The production efficiency can be enhanced since the scaling was relieved and heat exchange efficiency can be improved. Meanwhile, lower scaling stress also means lower antiscalant dosage and cost, and thus the total operation cost can be reduced.