Method for removing heavy metals from wastewater

Patent metadata

Field	Value
Publication number	US-10501341-B2
Application number	US-201916426503-A
Country	US
Kind code	B2
Filing date	May 30, 2019
Priority date	Dec 4, 2015
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

Cross-linked polymeric resins from anilines linked together with polyamine alkyl chains. A process for producing the cross-linked polymeric resins by Mannich-type polycondensation of anilines and diaminoalkanes linked together by an aldehyde and subsequent basification. In addition, a method for removing heavy metals, such as Pb (II) and As (V) from aqueous solution via contacting and treatment with the cross-linked polymeric resins.

First claim

The invention claimed is:

1. A method for removing a heavy metal from an aqueous solution, comprising:
contacting a cross-linked polymeric resin with the aqueous solution comprising at least one heavy metal;
wherein the cross-linked polymeric resin has the following formula (I)

or a salt, solvate, tautomer or stereoisomer derived from the cross-linked polymeric resin of formula (I);
wherein each R 1 is independently selected from H, an alkyl, a cycloalkyl, and an aryl;
each R 2 is independently selected from H, —F, —Cl, —Br, —CN, —OR 3 , an alkyl, a cycloalkyl, and an aryl;
each R 3 is independently selected from —H, an alkyl, a cycloalkyl, and an aryl;
n is a positive whole number in the range of 2-16;
X is a positive whole number; and
A 1 forms a bond to A 2 of another monomer unit; and
adsorbing the heavy metal onto the cross-linked polymeric resin to form a heavy metal loaded cross-linked polymeric resin and a heavy metal depleted aqueous solution.

2. The method of claim 1 , further comprising:
desorbing the heavy metal from the heavy metal loaded cross-linked polymeric resin by treating with an acid to form a cross-linked polyamine terpolymer;
treating the cross-linked polyamine terpolymer with a base to reform the cross-linked polymeric resin; and
reusing the cross-linked polymeric resin up to 15 times without a loss in adsorption capacity.

3. The method of claim 1 , wherein the heavy metal is at least one ion selected from the group consisting of Co, Cu, Zn, As, Sr, Mo, Cd, and Pb.

4. The method of claim 1 , wherein the heavy metal is at least one selected from the group consisting of lead (II) and arsenic (V).

5. The method of claim 1 , wherein the cross-linked polymeric resin has an adsorption capacity in the range of 100-1000 μg of heavy metal per g of the cross-linked polymeric resin.

6. The method of claim 1 , wherein the aqueous solution has a pH in the range of 2 to 8.

7. The method of claim 1 , wherein the aqueous solution has an initial heavy metal concentration in the range of 50 μg L −1 to 1250 μg L −1 .

8. The method of claim 1 , wherein the cross-linked polymeric resin is present at a concentration in the range of 0.05-5.0 g of resin per L of the aqueous solution during the contacting.

9. The method of claim 1 , wherein the cross-linked polymeric resin is contacted with the aqueous solution for 0.1 to 24 hours.

10. The method of claim 1 , wherein the contacting is performed at a temperature in the range of 20° C. to 60° C.

11. The method of claim 1 , wherein greater than 80% of the total mass of the heavy metal is removed from the aqueous solution.

12. The method of claim 1 , wherein formula (I) each R 1 , R 2 , and R 3 is —H and n is 4; and
wherein the aqueous solution comprises lead (II) and at least one additional heavy metal selected from the group consisting of Co, Cu, Zn, As, Sr, Mo, and Cd; and
wherein greater than 90% of the total mass of lead (II) is removed from the aqueous solution.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al Hamouz Othman Charles Sadeq
• Akintola Oluwafemi S
• Awadh Tawfik Abdo Saleh

Classifications

• B01J20/3425

  of sorbents or filter aids comprising organic materials · CPC title

• C08G73/0266

  Polyanilines or derivatives thereof · CPC title

• C02F2103/001

  Runoff or storm water · CPC title

• C02F2101/20

  Heavy metals or heavy metal compounds · CPC title

• B01J20/28014

  characterised by their form · CPC title