IP Library Granted Patent US 9,328,003
Granted Patent B2
US 9,328,003 · App. 14/076,488 · Granted May 3, 2016

Method of heavy metal removal from water streams

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 9,328,003
App. No.
14/076,488
Granted
May 3, 2016
Kind
B2
Abstract

The invention provides methods and compositions for separating metals from a liquid medium, the method uses a copolymer derived from at least two monomers: acrylic-x and an alkylamine, wherein said polymer is modified to contain a functional group capable of scavenging one or more compositions containing one or more metals are disclosed. The treated liquid is then passed through a filtration system. The scavenging effect of the combination of the treatment with the filtration is unexpectedly greater than the sum of its parts.

Claims (27)

1. A method of removing one or more metals from a medium containing said metals which comprises the steps of:

(a) treating said medium containing metals with a composition comprising a copolymer derived from at least two monomers: acrylic-x and an alkylamine,

(b) passing the treated medium through a filter, and

(c) collecting said metals;

wherein said acrylic-x has the following formula:

wherein X is OH and salts thereof or NHR 2 and wherein R 1 and R 2 is H or an alkyl or aryl group, wherein the molecular weight of said polymer is between 500 to 200,000, and wherein said polymer is modified to contain a functional group capable of scavenging said medium containing one or more metals.

2. The method of claim 1 , wherein the filter is selected from the group consisting of: a sand filter, paper, and any combination thereof.

3. The method of claim 1 , wherein the filter is selected from the group consisting of: ultrafiltration, nanofiltration, microfiltration, reverse flow filtration, submerged membrane filtration, reverse osmosis, and any combination thereof.

4. The method of claim 1 , wherein said functional group is a dithiocarbamate salt group and wherein said polymer has between 5 to 100 mole % of said dithiocarbamate salt group.

5. The method of claim 1 , wherein the acrylic-x is acrylic acid or salts thereof and the alkylamine is pentaethylenehexamine or tetraethylenepetamine or diethylenetriamine or triethylenetetraamine or ethylenediamine, and wherein the molar ratio between acrylic-x and alkylamine is from 0.85 to 1.5; and wherein the molecular weight of said polymer is from 1,500 to 8,000; and wherein the polymer is modified to contain more than 20 mole percent dithiocarbamic acid or salts thereof.

6. The method of claim 1 , wherein the acrylic-x is acrylamide and the alkylamine is pentaethylenehexamine or tetraethylenepetamine or diethylenetriamine or triethylenetetraamine or ethylenediamine, and wherein the molar ratio between acrylic-x and alkylamine is from 0.85 to 1.5; and wherein the molecular weight of said polymer is from 1,500 to 8,000; and wherein the polymer is modified to contain more than 20 mole percent dithiocarbamic acid or salts thereof.

7. The method of claim 1 , wherein said medium is a process stream containing water.

8. The method of claim 1 , wherein the metals are selected from the group consisting of: copper, nickel, zinc, lead, mercury, cadmium, silver, iron, manganese, palladium, platinum, strontium, selenium, arsenic, cobalt, gold, and any combination thereof.

9. The method of claim 1 , further comprising an additional treatment of said process stream with a complexing amount of a water soluble ethylene dichloride ammonia polymer having a molecular weight of from 500 to 100,000 which contains 5 to 80 mole % of dithiocarbamate salt groups to form a complex of these metals.

10. The method of claim 1 wherein said polymer treatment occurs at a temperature at or below 300° C.

11. The method of claim 1 wherein the copolymer further comprises a fluorescent group.

12. The method of claim 1 , wherein said medium is treated with oxidant first before treatment with scavenging polymer.

13. The method of claim 1 , wherein said medium is pH adjusted first before treatment with scavenging polymer.

14. The method of claim 1 , wherein said medium is treated with another coagulant before, together or after treatment with scavenging polymer.

15. A method of removing one or more metals from water containing said metals which comprises the steps of:

(a) treating said water containing metals with a composition comprising a copolymer derived from at least two monomers: acrylic-x and an alkylamine,

(b) passing the treated water through a filter, and

(c) collecting said metals;

wherein said acrylic-x has the following formula:

wherein X is OH and salts thereof or NHR 2 and wherein R 1 and R 2 is H or an alkyl or aryl group, wherein the molecular weight of said polymer is between 500 to 200,000, and wherein said polymer is modified to contain a functional group capable of scavenging said medium containing one or more metals;

and wherein mixing conditions between the one or more metals and the composition are such that they form agglomerations of copolymer-metal complexes having a size distribution such that a majority of the complexes could not be collected but for the filter.

16. The method of claim 15 , wherein the filter comprises a membrane through which the water passes and the mixing occurs only during a duration of time that is too short for agglomerations of copolymer-metal complexes to form which are larger than the pore size of the membrane.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 1, 2017
From: NALCO COMPANY LLC
To: ECOLAB USA INC.
Reel/Frame 044347/0104 →
CHANGE OF NAME Recorded Sep 20, 2017
From: NALCO COMPANY
To: NALCO COMPANY LLC
Reel/Frame 043924/0587 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 15, 2013
From: MUSALE, DEEPAK A.; SCHWARZ, DANIEL E.; ZINN, PAUL J.; KEISER, BRUCE A.; SHAH, JITENDRA T.
To: NALCO COMPANY
Reel/Frame 031614/0190 →