초록 ▼

The present invention relates to a method for removing arsenic in arsenic contaminated water, especially for small drinking water systems such as those used in individual homes, rural areas, and small communities, by simply contacting arsenic-contaminated water with an arsenic removal medium. The pr

The present invention relates to a method for removing arsenic in arsenic contaminated water, especially for small drinking water systems such as those used in individual homes, rural areas, and small communities, by simply contacting arsenic-contaminated water with an arsenic removal medium. The present invention also relates to the composition of the arsenic removal medium, which comprises particles of calcium carbonate minerals and magnesium carbonate aggregates.

대표청구항 ▼

What is claimed is: 1. An arsenic removal medium for reducing the total concentration of arsenic compounds in water comprising calcium carbonate particles from calcium carbonate mineral in its natural or raw material form and at least one binder, wherein the calcium carbonate mineral is at least 70

What is claimed is: 1. An arsenic removal medium for reducing the total concentration of arsenic compounds in water comprising calcium carbonate particles from calcium carbonate mineral in its natural or raw material form and at least one binder, wherein the calcium carbonate mineral is at least 70% calcium carbonate particles. 2. The arsenic removal medium of claim 1, wherein the calcium carbonate mineral is selected from the group consisting of calcite, aragonite, dolomite, and mixtures thereof. 3. The arsenic removal medium of claim 1, wherein the calcium carbonate mineral comprises at least about 80% by weight of calcite. 4. The arsenic removal medium of claim 3, wherein the calcite is from limestone, marble, or mixtures thereof. 5. The arsenic removal medium of claim 1, wherein the calcium carbonate mineral comprises at least about 50% by weight of dolomite. 6. The arsenic removal medium of claim 5, wherein the dolomite is from dolomite rocks. 7. The arsenic removal medium of claim 1, further comprising magnesium carbonate. 8. The arsenic removal medium of claim 7, further comprising magnesium carbonate aggregates, wherein the magnesium carbonate aggregates are formed by contacting the calcium carbonate particles with an aqueous solution of a magnesium salt at an effective concentration. 9. The arsenic removal medium of claim 8, wherein the magnesium salt is a water-soluble magnesium salt of an organic acid selected from the group of carboxylic acids, hydroxycarboxylic acids, and dicarboxylic acids. 10. The arsenic removal medium of claim 9, wherein the organic acid is acetic acid. 11. The arsenic removal medium of claim 7, wherein the magnesium carbonate is in the form of magnesium carbonate particles. 12. The arsenic removal medium of claim 11, wherein the magnesium carbonate particles are made from reagent-grade magnesium carbonate. 13. The arsenic removal medium of claim 1, wherein the binder is a hydraulic cement. 14. The arsenic removal medium of claim 1, wherein the calcium carbonate particles are reacted with magnesium salts to form a coating of magnesium carbonate. 15. The arsenic removal medium of claim 13, wherein the hydraulic cement is Portland cement, modified Portland cement or masonry cement. 16. The arsenic removal medium of claim 1, wherein the binder is alkaline silicates, silica hydrosol, alumina, silica-alumina, gypsum, plaster of paris, or colloidal clays. 17. The arsenic removal medium of claim 1, wherein the calcium carbonate particles have a Brunaur, Emmett, and Teller (BET) specific surface area from 0.1 to 20 m2/g. 18. The arsenic removal medium of claim 1, wherein the calcium carbonate particles have a density no less than 0.2 g/cm2. 19. The arsenic removal medium of claim 18, wherein the calcium carbonate particles have a density from 0.5 to 2.0 g/cm2. 20. The arsenic removal medium of claim 1, wherein the calcium carbonate particles have a Brunaur, Emmett, and Teller (BET) specific surface area from 0.1 to 20 m2/g and a particle size diameter of approximately 0.001 to approximately 7 mm. 21. The arsenic removal medium of claim 1, wherein the calcium carbonate particles have a Brunaur, Emmett, and Teller (BET) specific surface area from 0.2 to 10 m2/g and a particle size diameter of approximately 0.001 to approximately 2 mm. 22. The arsenic removal medium of claim 1, wherein the calcium carbonate particles have a Brunaur, Emmett, and Teller (BET) specific surface area from 0.3 to 5 m2/g and a particle size diameter of approximately 0.001 to approximately 1 mm. 23. The arsenic removal medium of claim 1, wherein the calcium carbonate particles have a Brunaur, Emmett, and Teller (BET) specific surface area from 2 to 8 m2/g and a particle size diameter of approximately 0.005 to approximately 1 mm.