Method of improving langelier index of city water and an apparatus therefor

摘要

A method is disclosed for reducing the corrosiveness of a water supply, and preventing the generation of red water caused by iron rust, by modifying the Langelier index of the water, which comprises:(1) determining the amount of carbon dioxide required to increase the concentration of free carbonic acid in the water based on the existing and desired Langelier indices, and the acceptable pH range, of the water supply;(2) dissolving the said amount of carbon dioxide gas in the water to generate free carbonic acid in the water; and(3) adding a substantially saturated aqueous solution of slaked lime to the water supply such that the free carbonic acid is neutralised and the desired Langelier index is achieved.;An apparatus for carrying out the method is also disclosed.