Membrane processes for metal recovery and pollution control in metal process industries

• US 4,655,928 A
• Filed: 10/18/1983
• Issued: 04/07/1987
• Est. Priority Date: 10/18/1983
• Status: Expired due to Fees

• Current Assignee: GNB Technologies Inc.
• Original Assignee: GNB, Inc.
• Inventors: Gregor, Harry P., Milton, Everett C.
• Primary Examiner(s): SPEAR JR, FRANK
• Application Number:
  US06/543,191
• Time in Patent Office: 1,267 Days
• Field of Search: 210/259, 210/251, 210/638, 210/651, 210/652, 210/34.1, 210/195.1, 210/195.2
• US Class Current: 210/651
• CPC Class Codes: B01D 2311/2642 Aggregation, sedimentation, flocculation, precipitation or coagulation
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/445 with bipolar membranes; Water splitting
• CPC Class Codes: B01D 61/58 Multistep processes
• CPC Class Codes: C02F 2101/20 Heavy metals or heavy metal compounds
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage
• CPC Class Codes: C22B 13/04 by wet processes
• CPC Class Codes: C22B 15/0086 by physical methods
• CPC Class Codes: C22B 17/04 by wet processes
• CPC Class Codes: C22B 23/0453 Treatment or purification of solutions, e.g. obtained by leaching C22B23/0407 takes precedence
• CPC Class Codes: C22B 26/10 Obtaining alkali metals
• CPC Class Codes: C22B 7/006 Wet processes
• CPC Class Codes: H01M 10/54 Reclaiming serviceable parts of waste accumulators
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02W 30/84 Recycling of batteries or fuel cells

Abstract

A process for the treatment of an aqueous stream containing an acid or base and typically a precipitatable material such as a metal ion comprises:

(a) subjecting the aqueous stream to (i) a treatment to produce a relatively pure stream of water and a concentrated aqueous stream, and (ii) water splitting to produce a stream of base, a stream of acid and a dilute aqueous stream of a concentration lower than the concentrated aqueous stream, the treatments (i) and (ii) being effected in either order,

(b) recycling at least part of the pure water stream produced in (a)(i) to an earlier stream either in the production leading to said aqueous stream or to step (i) or (ii),

(c) recycling at least part of the acid and/or base streams produced in (a)(ii) to an earlier stream either in the production leading to said aqueous stream or to an earlier step in the process, and

(d) recycling at least part of the lower concentration stream produced in (a)(ii) to either (a)(i) or to another step in the process, whereby, when present, only the precipitatable material is removed from the aqueous stream, thereby obviating toxic waste disposal problems.

Claims

1. A closed process for the treatment of an aqueous effluent stream produced in the manufacture of lead storage batteries which effluent stream contains at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) treating the effluent stream by reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(b) treating the concentrate stream by water splitting, thereby producing acid, base, and deionate streams;

(c) recycling at least a portion of the pure water stream and the acid stream to the process from which the effluent stream evolved;

(d) recycling the base stream to at least one of the processes from which the effluent stream evolved, and the water splitting step (b); and

(e) recycling the deionate stream directly to the reverse osmosis step (a).

2. The process of claim 1 wherein the reverse osmosis step (a) is reversed with the water splitting step (b), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the reverse osmosis, and said concentrate stream being recycled into the water splitting step.

3. A closed process for the treatment of an aqueous effluent stream produced in the manufacture of lead storage batteries which effluent stream contains a precipitatable material and at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) treating the effluent stream to selectively precipitate and remove the precipitatable material without precipitating significant quantities of the acid or base, thereby producing an aqueous stream;

(b) treating the aqueous stream with reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(c) treating the concentrate stream by water splitting, thereby producing acid, base, and deionate streams;

(d) recycling the deionate stream directly to the reverse osmosis step (b); and

(e) selectively recycling the water, acid, and base streams to at least one of said closed aqueous effluent stream treatment process and the process from which the effluent evolved,

whereby most of the precipitatable material is extracted from the effluent in a relatively concentrated solid form.

4. The process of claim 3 wherein the reverse osmosis step (b) is reversed with the water splitting step (c), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the reverse osmosis step, and said concentrate stream being recycled to the water splitting step.

5. A closed process for treating an aqueous effluent stream which contains a precipitatable material and at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) precipitating with a precipitating base the precipitatable material in such quantities that a significant amount of the acid is not precipitated;

(b) removing the precipitated, precipitatable material, thereby producing an aqueous stream;

(c) treating the aqueous stream by reverse osmosis, thereby producing a relatively pure water stream and a concentrated aqueous stream;

(d) recycling the relatively pure water stream into the process from which the effluent evolved;

(e) treating the concentrated aqueous stream by water splitting wherein a neutral salt is added to the base stream produced therein, thereby producing acid, base, and deionate streams, said base stream containing the precipitating base of step (a) and the neutral salt;

(f) recycling the acid stream to the process from which the effluent stream evolved;

(g) separating the precipitating base from the base stream, thereby producing a base stream containing the neutral salt;

(h) recycling the base stream to the water splitting step (e);

(i) recycling the precipitating base to the precipitating step (a); and

(j) recycling the deionate stream directly to the reverse osmosis step (c),

whereby most of the precipitatable material is extracted from the effluent in a relatively concentrated solid form.

6. The process of claim 5 wherein the reverse osmosis step (c) is reversed with the water splitting step (e), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the reverse osmosis step, and said concentrate stream being recycled to the water splitting step.

7. The process of claims 5 or 6, wherein the effluent stream evolves from washing operations of head storage battery manufacturing;

and wherein;

(a) the precipitatable material comprises PbSO₄ ;

(b) the acid comprises H₂ SO₄ ;

(c) the precipitating base comprises Mg(OH)₂ ;

(d) the neutral salt comprises Na₂ SO₄.

8. The process of claim 5 or 6 for treating rinse water streams from acid/copper plating, wherein the rinse water streams comprise H₂ SO₄ and CuSO₄, and wherein the precipitating base comprises Mg(OH)₂ and the neutral base comprises Na₂ SO₄.

9. A closed process for treating spent pickling streams and rinse water streams from iron pickling wherein said spent pickling streams comprise FeCl₂, HCl, and NaCl, and the rinse water stream comprises FeCl₂ and HCl, said process, in which all streams produced therein are recycled, comprising:

(a) treating the spent pickling stream with water splitting, thereby producing acid, base, and deionate streams, wherein the base stream comprises NaOH, NaCl, and precipitated Fe(OH)₂ ;

(b) concentrating the acid stream by electrodialysis, thereby producing a concentrated acid stream and an electrodialysis deionate stream;

(c) recycling the concentrated acid stream to the iron pickling process;

(d) filtering the Fe(OH)₂ from the base stream;

(e) recycling part of the filtered base stream to the water splitting step (a);

(f) neutralizing the rinse water stream with part of the filtered base stream, thereby precipitating Fe(OH)₂ ;

(g) recycling the electrodialysis deionate and the deionate streams to the neutralization step (f);

(h) filtering the Fe(OH)₂, thereby producing an aqueous stream;

(i) treating the aqueous stream with reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(j) recycling the relatively pure water stream to the iron pickling process; and

(k) treating the concentrate stream in the water splitting step (a).

10. A closed process for treating a filtered effluent stream from nickel-cadmium battery manufacture, in which all streams produced therein are recycled, wherein the effluent contains NaOH, comprising:

(a) neutralizing the effluent stream with the acid stream described in step (d) below, thereby producing a neutralized stream;

(b) treating the neutralized stream with reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(c) recycling the pure water stream to the battery manufacture process;

(d) treating the concentrate stream with water splitting, thereby producing acid, base, and deionate streams;

(e) recycling the acid stream to the neutralization step (a);

(f) recycling the base stream which comprises NaOH to the battery manufacture process; and

(g) recycling the deionate stream directly to the reverse osmosis step (b).

11. The process of claim 10 wherein the reverse osmosis step (b) and the water splitting step (d) are reversed, and wherein the concentrate stream is recycled into the water splitting step, and the deionate stream is introduced into the reverse osmosis step.

12. A closed process for the treatment of an aqueous effluent stream produced in a metal-treating process which effluent stream contains at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) treating the effluent stream by reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(b) treating the concentrate stream by water splitting, thereby producing acid, base, and deionate streams;

(c) recycling at least a portion of the pure water stream and the acid stream to the process from which the effluent stream evolved;

(d) recycling the base stream to at least one of the processes from which the effluent stream evolved, and the water splitting step (b); and

(e) recycling the deionate stream directly to the reverse osmosis step (a).

13. The process of claim 12 wherein the reverse osmosis step (a) is reversed with the water splitting step (b), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the water splitting step.

14. A closed process for the treatment of an aqueous effluent stream produced in a metal treating process which effluent stream contains a precipitatable material and at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) treating the effluent stream to selectively precipitate and remove the precipitatable material without precipitating significant quantities of the acid or base, thereby producing an aqueous stream;

(b) treating the aqueous stream with reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(c) treating the concentrate stream by water splitting thereby producing acid, base, and deionate streams;

(d) recycling the deionate stream directly to the reverse osmosis step (b); and

(e) selectively recycling the water, acid, and base streams to at least one of said closed aqueous effluent stream treatment process and the process from which the effluent evolved,

whereby most of the precipitatable material is extracted from the effluent in a relatively concentrated solid form.

15. The process of claim 14 wherein the reverse osmosis step (b) is reversed with the water splitting step (c), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the reverse osmosis step, and said concentrate stream being recycled to the water splitting step.

16. A closed process for the treatment of an aqueous effluent stream which effluent stream contains at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) treating the effluent stream by reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(b) treating the concentrate stream by water splitting, thereby producing acid, base, and deionate streams;

(c) recycling at least a portion of the pure water stream and the acid stream to the process from which the effluent stream evolved;

(d) recycling the base stream to at least one of the processes from which the effluent stream evolved, and the water splitting step (b); and

(e) recycling the deionate stream directly to the reverse osmosis step (a).

17. The process of claim 16 wherein the reverse osmosis step (a) is reversed with the water splitting step (b), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the water splitting step.

18. A closed process for the treatment of an aqueous effluent stream which effluent stream contains a precipitatable material and at least one of an acid and a base, said process, in which all streams produced therein are recycled, comprising:

(a) treating the effluent stream to selectively precipitate and remove the precipitatable material without precipitating significant quantities of the acid or base, thereby producing an aqueous stream;

(b) treating the aqueous stream with reverse osmosis, thereby producing a relatively pure water stream and a concentrate stream;

(c) treating the concentrate stream by water splitting, thereby producing acid, base, and deionate streams;

(d) recycling the deionate stream directly to the reverse osmosis step (b); and

(e) selectively recycling the water, acid, and base streams to at least one of said closed aqueous effluent stream treatment process and the process from which the effluent evolved,

whereby most of the precipitatable material is extracted from the effluent in a relatively concentrated solid form.

19. The process of claim 18 wherein the reverse osmosis step (b) is reversed with the water splitting step (c), said aqueous stream being treated by water splitting, said deionate stream being recycled directly to the reverse osmosis step, and said concentrate stream being recycled to the water splitting step.