Removing Arsenic from Water with Acid-Activated Clay
AssigneeFuel Tech, Inc.
InventorMingming Fang
Life of this patent
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Abstract
The description relates to a composition and a method for reducing the concentration of arsenic in water. Contaminated water is contacted with acid-activated clay characterized by a removal efficiency for arsenic of at least 95 wt %. Following sufficient contact, the water is separated from the acid-activated clay. In preferred form, the acid activated clay is characterized by a BET surface area of at least about 200 m2/gram.
Claims18
A composition for removing arsenic from contaminated water comprises:
- a. an acid-activated clay selected from the group consisting of bentonite, montmorillonite, hectorite, talc, vermiculite, saponite, nontronite, kaolinite, halloysite, illite, and chlorite and mixtures thereof;
- b. a water-soluble oxidizer that can oxidize arsenite to arsenate at the ambient temperature and pressure in water.
A composition according to any preceding claim in unit dosage form for the batch wise arsenic removal of a relatively small predetermined volume of contaminated water.
A composition according to any preceding claim in unit dosage form for treating a volume of contaminated water, the acid-activated clay dosage to the volume of the contaminated water is in the range from about 1 to about 25, preferably 2 to about 15, more preferably from about 4 to about 10 g/liter of contaminated water.
A composition according to any preceding claim in unit dosage form for treating a volume of contaminated water, the oxidizer dosage to the volume of the contaminated water is in the range from about 0.2 to about 5, preferably 0.4 to about 2.5, more preferably from about 0.8 to about 1.5 mg/liter of contaminated water.
A method for removing arsenic from contaminated water which comprises contacting the contaminated water with:
- a. an acid-activated clay selected from the group consisting of bentonite, montmorillonite, hectorite, talc, vermiculite, saponite, nontronite, kaolinite, halloysite, illite, and chlorite and mixtures thereof;
- b. a water-soluble oxidizer that can oxidize arsenite to arsenate at the ambient temperature and pressure.
A method according to any preceding claim in unit dosage form for the batch wise arsenic removal of a relatively small predetermined volume of contaminated water.
A method according to any preceding claim in unit dosage form for treating a volume of contaminated water, the acid-activated clay dosage to the volume of the contaminated water is in the range from about 1 to about 25, preferably 2 to about 15, more preferably from about 4 to about 10 g/liter of contaminated water.
A method according to any preceding claim in unit dosage form for treating a volume of contaminated water, the oxidizer dosage to the volume of the contaminated water is in the range from about 0.2 to about 5, preferably 0.4 to about 2.5, more preferably from about 0.8 to about 1.5 mg/liter of contaminated water.
Dependencies are inferred from the claim text.