Method for removing organic dye from wastewater

Patent metadata

Field	Value
Publication number	US-9334176-B1
Application number	US-201514637366-A
Country	US
Kind code	B1
Filing date	Mar 3, 2015
Priority date	Mar 3, 2015
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

The method for removing organic dyes from wastewater includes: (i) placing a magnetic polymer microsphere into contact with wastewater contaminated with organic dyes; (ii) permitting the organic dyes to adsorb onto the magnetic polymer microsphere; and removing the magnetic polymer microsphere using an external magnetic field applied by a magnet. The magnetic polymer microsphere has a ferromagnetic core surrounded by an adsorbent polymer.

First claim

We claim:

1. A method for removing organic dyes from wastewater, comprising the steps of:
placing magnetic polymer microspheres into contact with wastewater contaminated with organic dyes, the microspheres having an adsorbent polymer formed around a ferromagnetic core, the adsorbent polymer for adsorbing the organic dyes;
wherein the polymer comprises 4-aminophenol-formaldehyde and the ferromagnetic core comprises at least one nanoparticle of ferrite (Fe3O4);
leaving the microspheres in contact with the wastewater for a sufficient time to permit the organic dyes to adsorb onto the polymer of the magnetic polymer microspheres;
removing the magnetic polymer microspheres from the wastewater by applying an external magnetic field to the microspheres in the wastewater;
placing the polymer microspheres in contact with a regenerating solution to regenerate the microspheres;
separating the regenerated magnetic polymer microspheres from the regenerating solution; and
recycling the regenerated magnetic polymer microspheres;
whereby the regenerated magnetic polymer microspheres are available for continuously removing organic dyes from wastewater.

2. The method for removing organic dyes of claim 1 , wherein the regenerating solution comprises methanol.

3. The method for removing organic dyes of claim 1 , wherein the step of placing the magnetic polymer microspheres into contact with wastewater contaminated with organic dyes comprises placing the magnetic polymer microspheres into a flowing stream of the wastewater, the method further comprising the step of adjusting the wastewater to have a pH between 7 and 10.

4. The method for removing organic dyes of claim 1 , wherein the organic dye is Rose Bengal dye, the magnetic polymer microspheres having an adsorptive capacity of about 11.2 mg/g.

5. The method for removing organic dyes of claim 1 , wherein said magnetic polymer microspheres adsorb the organic dyes within less than 5 minutes of contact with the organic dyes.

6. The method for removing organic dyes of claim 1 , wherein the magnetic polymer microsphere adsorbs the organic dyes in neutral aqueous solution at a pH of 7.

7. The method for removing organic dyes of claim 1 , wherein the organic dye is bromophenol blue dye, the magnetic polymer microspheres having an adsorptive capacity of about 12.6 mg/g.

8. The method for removing organic dyes of claim 1 , wherein the polymer is prepared by reacting 4-aminophenol and formaldehyde in basic medium in an organic solvent.

9. The method for removing organic dyes of claim 8 , wherein the organic solvent is ethanol.

Assignees

• Univ King Saud

Inventors

• Alshehri Saad M
• Ahamad Tansir
• Naushad Mu
• Al-Othman Zeid A
• Aldalbahi Ali

Classifications

• C02F1/285 Primary

  using synthetic organic sorbents · CPC title

• C02F2101/308

  Dyes; Colorants; Fluorescent agents · CPC title

• B01J20/06

  comprising oxides or hydroxides of metals not provided for in group B01J20/04 · CPC title

• B01J20/26

  Synthetic macromolecular compounds · CPC title

• B01J20/3278

  Polymers being grafted on the carrier · CPC title