Method for simultaneous removal of arsenic and fluoride from aqueous solutions
AssigneeIonics, Incorporated
InventorsGerald A. Krulik, Paul H. Dick, Josh H. Golden, Jay Jung, Gennadiy Sverdlov
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Abstract
A method of removing arsenic and fluoride from aqueous solutions in the same process is provided. Specifically, the pH of the aqueous solution is adjusted to a pH in the range of about 5 to 8. A combination of calcium salts, and ferric or aluminum salts are added to form insoluble arsenic and fluoride bearing solids. The solids are then removed from the aqueous solution.
Claims17
A method of removing arsenic and fluoride from an aqueous solution, characterized in that the aqueous solution is treated with calcium to form fluoride bearing particles and a combination of ferric or aluminum iron salts at a pH in the range of about 5 to 8 to form insoluble arsenic and fluoride bearing solids including said fluoride bearing particles;
- and removing said solids from the aqueous solution simultaneously reducing the level of arsenic and fluoride in said solution to a desired level by passing the aqueous solution through a microfiltration membrane having a pore size in the range from 0.5 to 10 microns at a flow rate of at least 200 gallons per square foot of membrane per day.
A method of removing arsenic and fluoride from an aqueous solution, comprising the steps of:
- providing an aqueous solution including arsenic and fluoride;
- adjusting the pH of the aqueous solution to a pH in the range of about 5 to 8;
- adding calcium salt into the aqueous solution to form fluoride bearing particles;
- adding ferric or aluminum salts into the aqueous solution to form a metal hydroxide floc which absorbs both said fluoride particles and arsenic to produce insoluble arsenic and fluoride bearing solids;
- and
- removing said arsenic and fluoride bearing solids from the aqueous solution simultaneously reducing the level of arsenic and fluoride in said solution to a desired level by passing the aqueous solution through a microfiltration membrane having a pore size in the range from 0.5 to 10 microns at a flow rate of at least 200 gallons per square foot of membrane per day.
Dependencies are inferred from the claim text.