Method of treating (meth)acrylic monomer-containing wastewater

• US 5,135,663 A
• Filed: 10/18/1991
• Issued: 08/04/1992
• Est. Priority Date: 10/18/1991
• Status: Expired due to Term

• Current Assignee: Loctite Corporation (Henkel AG & Co KGaA)
• Original Assignee: Loctite Corporation (Henkel AG & Co KGaA)
• Inventors: Newberth, Frederick F. III, Henrikson, Albert J., Joffee, Lawrence B., Artavanis-Tsakonas, Calliope, Welch, Edward K. II
• Primary Examiner(s): Silverman, Stanley S.
• Assistant Examiner(s): MCCARTHY, NEIL
• Application Number:
  US07/779,229
• Time in Patent Office: 291 Days
• Field of Search: 210/702, 210/719, 210/724, 210/725, 210/726, 210/727, 210/734, 210/738, 210/708, 210/805, 210/749, 210/757, 210/765, 524/845
• US Class Current: 210/719
• CPC Class Codes: C02F 1/54 using organic material
• CPC Class Codes: C02F 1/70 by reduction C02F1/4676 takes precedence
• CPC Class Codes: C02F 2103/36 from the manufacture of organic compounds

Abstract

A method of treating wastewater containing (meth)acrylic monomer, such as is produced by aqueous washing of porous parts impregnated with a sealant composition containing such monomer. The monomer-containing wastewater is (1) adjusted in pH to a value in the range of from about 8 to about 10, and (2) contacted with an effective amount of a reducing agent which is polymerizingly effective for the monomer, to yield corresponding polymer from the monomer. The wastewater is mixed with a cationic flocculating agent in sufficient quantity to flocculate the polymer in the wastewater, and the resulting wastewater is physically separated to recover a monomer- and polymer-reduced wastewater effluent which may be discharged to receiving waters.

Claims

1. A method of treating wastewater comprising an aqueous medium containing (meth)acrylic monomer, comprising:

(a) adjusting the pH of the aqueous medium to a value in the range of from about 8 to about 10, by addition of base thereto;

(b) contacting the aqueous medium with an effective amount of a reducing agent which is polymerizingly effective for the monomer to yield corresponding polymer from the monomer;

(c) mixing a cationic flocculating agent with the aqueous medium, in sufficient quantity to flocculate the polymer in the aqueous medium; and

(d) physically separating the polymer-containing aqueous medium and recovering a monomer- and polymer-reduced aqueous medium effluent.

2. A method according to claim 1, wherein the amount of reducing agent contacted with the aqueous medium is from about 0.01% to about 2.0%, by weight based on the weight of the aqueous medium.

3. A method according to claim 1, wherein the concentration of monomer in the aqueous medium is from about 0.01% to about 20% by weight, based on the weight of wastewater.

4. A method according to claim 1, wherein the mixing of the cationic flocculating agent with the aqueous medium is carried out under gentle agitation conditions.

5. A method according to claim 1, wherein the reducing agent is selected from the group consisting of:

(i) erythorbic acid, salts, and derivatives thereof;

(ii) ascorbic acid, salts, and derivatives thereof;

(iii) thiourea; and

(iv) sulfite compounds; and

(iv) mixtures thereof.

6. A method according to claim 1, wherein the reducing agent comprises an alkali metal salt of erythorbic acid.

7. A method according to claim 1, wherein the reducing agent comprises sodium erythorbate.

8. A method accord to claim 1, wherein the reducing agent comprises a sulfite compound.

9. A method according to claim 8, wherein the sulfite compound comprises a compound selected from the group consisting of alkali metal sulfites, bisulfites, and metabisulfites.

10. A method according to claim 1, wherein step (a) is carried out before step (b).

11. A method according to claim 1, wherein step (c) is carried out after step (b), but prior to any substantial polymerization of the monomer.

12. A method according to claim 1, wherein steps (a) and (b) are carried out concurrently.

13. A method according to claim 1, wherein pH is adjusted to a value in the range of from about 8.5 to about 9.5 in the pH adjusting step.

14. A method according to claim 1, wherein the cationic flocculating agent comprises a cationic polyacrylamide.

15. A method according to claim 1, wherein the base is selected from the group consisting of sodium hydroxide, ammonium hydroxide, and potassium hydroxide.

16. A method according to claim 1, wherein the physical separation of the polymer-containing aqueous medium comprises filtration.

17. A method according to claim 1, comprising treating the aqueous medium with a de-emulsifier which is coalescingly effective for the monomer, prior to substantial polymerization of the monomer.

18. A method according to claim 1, wherein monomer- and polymer-reduced aqueous medium effluent is treated to remove residual reducing agent therefrom and then recirculated and used as a rinsing medium for washing of impregnated porous parts.

19. A method of treating wastewater comprising an aqueous medium containing (meth)acrylic monomer, comprising:

(a) adjusting the pH of the aqueous medium to a value in the range of from about 8 to about 10, by addition of base thereto;

(b) contacting the aqueous medium with an effective amount of a reducing agent which is polymerizingly effective for the monomer to yield corresponding polymer from the monomer; and

(c) physically separating the polymer-containing aqueous medium and recovering a monomer- and polymer-reduced aqueous medium effluent.