Patent US4419246A successfully refreshed from Google Patents.
US4419246A
Expired / Lapsed
US
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Removal of heavy metal ions
Assignee: EIDP Inc
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Filing: 1982-09-30
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Granted: 1983-12-06
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Expires: 2002-09-30
Abstract
Abstract Heavy metal ions bonded to complexing agent can be precipitated from waste streams with a combination of a magnesium ion, calcium hydroxide and peroxygen compound.
Inventors
- 👤 Madhusudan D. Jayawant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:48
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/72; C02F1/722; C02F2101/00; C02F2101/10; C02F2101/20; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
163 words
Method for removing from a aqueous waste or process stream heavy metal ions selected from iron, copper and nickel present in complexed water-soluble form comprising contacting with agitation said waste or process stream for a residence time of at least 0.1 hour at a pH adjusted to between about 10.2 and 12.5 with a magnesium ion donor compound, a peroxygen compound and either calcium hydroxide or calcium oxide so as to form derivatives of said heavy metal ions which precipitate, and removing said precipitate from the waste or process stream, leaving a total content of iron, copper and nickel of less than 15 mg/l in the treated aqueous waste, said magnesium compound being present, basis magnesium, in a minimum ratio of 0.05:1 by weight the total weight of iron, copper and nickel, and said peroxygen compound being present, on the basis of active oxygen, at a weight ratio of 0.12:1 to 50:1 of the total weight or organic carbon in the waste stream.
Claim 2
Dependent Claim
163 words
Method for removing from a aqueous waste or process stream heavy metal ions selected from iron, copper and nickel present in complexed water-soluble form comprising contacting with agitation said waste or process stream for a residence time of at least 0.1 hour at a pH adjusted to between about 10.2 and 12.5 with a magnesium ion donor compound, a peroxygen compound and either calcium hydroxide or calcium oxide so as to form derivatives of said heavy metal ions which precipitate, and removing said precipitate from the waste or process stream, leaving a total content of iron, copper and nickel of less than 15 mg/l in the treated aqueous waste, said magnesium compound being present, basis magnesium, in a minimum ratio of 0.05:1 by weight the total weight of iron, copper and nickel, and said peroxygen compound being present, on the basis of active oxygen, at a weight ratio of 0.12:1 to 50:1 of the total weight or organic carbon in the waste stream.
Claim 3
Dependent Claim
20 words
Method of claim 1 wherein the magnesium compound is selected from magnesium sulfate, bromide, chloride, nitrate, hydroxide, oxide and carbonate.
Claim 4
Dependent Claim
11 words
Method of claim 1 wherein the magnesium compound is magnesium sulfate.
Claim 5
Dependent Claim
11 words
Method of claim 1 wherein the peroxygen compound is hydrogen peroxide.
Claim 6
Dependent Claim
11 words
Method of claim 1 wherein the peroxygen compound is potassium monopersulfate.
Claim 7
Dependent Claim
11 words
Method of claim 1 wherein the peroxygen compound is peroxyacetic acid.
Claim 8
Dependent Claim
11 words
Method of claim 1 wherein the peroxygen compound is monoperoxysulfuric acid.
Claim 9
Dependent Claim
19 words
Method of claim 1 wherein the peroxygen compound is one or several of alkali metal percarbonates, perborates and perphosphates.
Claim 10
Dependent Claim
26 words
Method of claim 1 wherein the magnesium is present in a ratio of 0.1 to 3:1 by weight of total amount of iron, copper and nickel.
Claim 11
Dependent Claim
29 words
Method of claim 1 wherein peroxygen compound, basis active oxygen, is present at a weight ratio of 0.25:1 to 25:1 of the total organic carbon content of said stream.
Claim 12
Dependent Claim
30 words
Method of claim 1 wherein peroxygen compound, basis active oxygen, is present at a weight ratio of 0.5:1 to 5:1 of the total organic carbon content of the waste stream.
Claim 13
Dependent Claim
13 words
Method of claim 1 wherein said residence time is 0.1 to 48 hours.
Claim 14
Dependent Claim
13 words
Method of claim 1 wherein said residence time is 0.5 to 24 hours.
Claim 15
Dependent Claim
117 words
Method of removing from an aqueous waste stream heavy metal ions selected from iron, copper and nickel present in complexed water-soluble form comprising contacting with agitation said stream at a pH adjusted to between 10.2 to 12.5 with magnesium sulfate present, basis magnesium, at a minimum ratio of 0.05:1 by weight of the total amount of iron, copper and nickel; hydrogen peroxide, basis active oxygen, present at a weight ratio of 0.12:1 to 50:1 of the total organic carbon content of said stream; and calcium hydroxide and, after a residence time of 0.1 to 48 hours, removing the precipitated ions from said stream leaving a total content of iron, copper and nickel of less than 15 mg/l.
Claim 16
Dependent Claim
117 words
Method of removing from an aqueous waste stream heavy metal ions selected from iron, copper and nickel present in complexed water-soluble form comprising contacting with agitation said stream at a pH adjusted to between 10.2 to 12.5 with magnesium sulfate present, basis magnesium, at a minimum ratio of 0.05:1 by weight of the total amount of iron, copper and nickel; hydrogen peroxide, basis active oxygen, present at a weight ratio of 0.12:1 to 50:1 of the total organic carbon content of said stream; and calcium hydroxide and, after a residence time of 0.1 to 48 hours, removing the precipitated ions from said stream leaving a total content of iron, copper and nickel of less than 15 mg/l.
Claim 17
Dependent Claim
137 words
Method for removing from an aqueous waste or process stream heavy metal ions selected from iron, copper and nickel present in complexed water-soluble form comprising contacting with agitation said stream at a pH adjusted to between 10.2 and 12.5 with a magnesium ion donor compound and either calcium hydroxide or calcium oxide and, after a residence time of at least 0.1 hour, removing the precipitated ions from said stream, leaving a total content of iron, copper and nickel of less than 15 mg/l, said magnesium compound being present, basis magnesium, in a minimum ratio of 0.05:1 by weight of the total weight of iron, copper and nickel, and said peroxygen compound being present, on the basis of active oxygen, at a weight ratio of 0.12:1 to 50:1 of the total weight of organic carbon in said stream.
Claim 18
Dependent Claim
137 words
Method for removing from an aqueous waste or process stream heavy metal ions selected from iron, copper and nickel present in complexed water-soluble form comprising contacting with agitation said stream at a pH adjusted to between 10.2 and 12.5 with a magnesium ion donor compound and either calcium hydroxide or calcium oxide and, after a residence time of at least 0.1 hour, removing the precipitated ions from said stream, leaving a total content of iron, copper and nickel of less than 15 mg/l, said magnesium compound being present, basis magnesium, in a minimum ratio of 0.05:1 by weight of the total weight of iron, copper and nickel, and said peroxygen compound being present, on the basis of active oxygen, at a weight ratio of 0.12:1 to 50:1 of the total weight of organic carbon in said stream.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |