Process for purifying water
AssigneeDegremont
InventorFrancois Marie Fiessinger
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Abstract
The invention relates to a process for the purification of water intended for human consumption or industrial use, and a process for the clarification of urban or industrial waste water, by means of a solution of a polymeric aluminum hydroxide which is prepared immediately before its use by adding an alkaline or alkaline-earth hydroxide to an aluminum salt. The conditions of preparation are chosen so as to prevent the formation of monomeric aluminum hydroxide.
Claims7
A process for purifying water containing material dissolved and/or suspended therein, which comprises mixing the water with an effective amount of a solution of a polymeric aluminum hydroxide prepared by treating a solution containing up to 2.5 moles/liter of aluminum chloride with a solution consisting essentially of water and an alkaline or alkaline-earth hydroxide, under vigorous agitation, the resulting solution of the polymeric aluminum hydroxide having a pH of 4.5-5.5, a molar ratio of OH to aluminum of from 2.3 to 2.7 and a concentration of aluminum of from 0.025 to 0.40 mole/liter, and separating floc from the thus treated water.
A process for purifying water containing material dissolved and/or suspended therein, which comprises mixing the water with an effective amount of a solution of a polymeric aluminum hydroxide prepared by treating a solution containing up to 2.5 moles/liter of aluminum chloride with a substance consisting essentially of calcium hydroxide powder or a suspension of calcium hydroxide in water, under vigorous agitation, the resulting solution of the polymeric aluminum hydroxide having a pH of 4.5-5.5, a molar ratio of OH to aluminum of from 2.3 to 2.7 and a concentration of aluminum of from 0.025 to 0.40 mole/liter, and separating floc from the thus treated water.
Dependencies are inferred from the claim text.