US3899405A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of removing heavy metals from water and apparatus therefor
Assignee: Boeing North American Inc
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Filing: 1974-06-07
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Granted: 1975-08-12
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Expires: 1994-06-07
Abstract
Abstract A method of removing heavy metals such as mercury, nickel, zinc, lead, cadmium, and copper from contaminated aqueous solutions, such as waste waters, including the steps of passing the aqueous solution through an electrochemical cell containing an oxidation resistant anode and a cathode comprising a bed of tin or tincoated particles; electroplating (and amalgamating in the case of mercury) the heavy metal in solution onto the surface of the tin or tin-coated particles in the electrochemical cell; and discharging the aqueous solution substantially free of heavy metal.
Inventors
- 👤 Marlowe L Iverson
- 👤 Lowell R Mccoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:45
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/46; C02F1/461; C02F1/46104; C02F1/46109; C02F1/46114; C02F1/467; C02F1/4676; C02F1/4678; C25; C25C; C25C1/00; C02F2101/00; C02F2101/10; C02F2101/20
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
84 words
A METHOD OF EMOVING A HEAVY METAL FROM AN AQUEOUS SOLUTION CONTAINING THE SAME COMPRISING: PASSING THE SOLUTION THROUGH AN ELECTROCHEMICAL CELL CONTAINING AN ANODE AND A CATHODE COMPRISING A BED OF PARTICLES HAVING TIN SURFACES, CONTACTING SAID PARTICLES WITH A CATHODICALLY POLARIZED COLLECTOR, PASSING A DIRECT CURRENT FROM SAID ANODE THROUGH THE SOLUTION TO SAID PARTICLES WHEREBY HEAVY METAL IS REMOVED FROM THE SOLUTION AND DEPOSITED ON THE TIN SURFACES OF SAID PARTICLES AND DISCHARGING THE AQUEOUS SOLUTION OF REDUCED HEAVY METAL CONTENT.
Claim 2
Independent Claim
84 words
A METHOD OF EMOVING A HEAVY METAL FROM AN AQUEOUS SOLUTION CONTAINING THE SAME COMPRISING: PASSING THE SOLUTION THROUGH AN ELECTROCHEMICAL CELL CONTAINING AN ANODE AND A CATHODE COMPRISING A BED OF PARTICLES HAVING TIN SURFACES, CONTACTING SAID PARTICLES WITH A CATHODICALLY POLARIZED COLLECTOR, PASSING A DIRECT CURRENT FROM SAID ANODE THROUGH THE SOLUTION TO SAID PARTICLES WHEREBY HEAVY METAL IS REMOVED FROM THE SOLUTION AND DEPOSITED ON THE TIN SURFACES OF SAID PARTICLES AND DISCHARGING THE AQUEOUS SOLUTION OF REDUCED HEAVY METAL CONTENT.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein said particles are particulate tin.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein said particles are tin-coated nonmetallic substrates.
Claim 5
Dependent Claim
24 words
The method of claim 1 wherein an applied potential of from about 2 to 12 volts is maintained between said anode and said particles.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein said heavy metal is selected from the group consisting of mercury, nickel, zinc, cadmium and copper.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein said bed of particles is intermittently fluidized.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein the solution has a residence time in said bed within the range of from about 0.5 to about 4 minutes.
Claim 9
Dependent Claim
23 words
The method of claim 1 wherein the heavy metal is at least one metal selected from the group consisting of copper and nickel.
Claim 10
Dependent Claim
13 words
The method of claim 1 wherein said bed of particles is continuously fluidized.
Claim 11
Dependent Claim
14 words
The method of claim 1 wherein said heavy metal is recovered from said particles.
Claim 12
Dependent Claim
24 words
The method of claim 10 wHerein the heavy metal is recovered by contacting the bed of particles with an aqueous solution of nitric acid.
Claim 13
Independent Claim
109 words
A method of removing heavy metal from an aqueous solution comprising: passing an aqueous solution containing at least one heavy metal selected from the group consisting of mercury, nickel, zinc, cadmium and copper through an electrochemical cell containing an anode and a cathode, said cathode comprising a bed of particles having tin surfaces; contacting said bed of particles with a cathodically polarized collector; maintaining an applied potential of between about 2 to 12 volts between the anode and cathode and passing a direct electric current therebetween, whereby the heavy metal is deposited on the tin surfaces of the particles; and discharging the aqueous solution of reduced heavy metal content.
Claim 14
Independent Claim
109 words
A method of removing heavy metal from an aqueous solution comprising: passing an aqueous solution containing at least one heavy metal selected from the group consisting of mercury, nickel, zinc, cadmium and copper through an electrochemical cell containing an anode and a cathode, said cathode comprising a bed of particles having tin surfaces; contacting said bed of particles with a cathodically polarized collector; maintaining an applied potential of between about 2 to 12 volts between the anode and cathode and passing a direct electric current therebetween, whereby the heavy metal is deposited on the tin surfaces of the particles; and discharging the aqueous solution of reduced heavy metal content.
Claim 15
Dependent Claim
37 words
The method of claim 12 wherein the aqueous solution is passed through said electrochemical cell at a rate sufficient to provide a residence time in said bed of particles of from about 0.5 to about 4 minutes.
References Cited (Backward Citations)
US3457152A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |