Systems and methods for bromide separation and reuse

Patent metadata

Field	Value
Publication number	US-2017362098-A1
Application number	US-201715624465-A
Country	US
Kind code	A1
Filing date	Jun 15, 2017
Priority date	Jun 15, 2016
Publication date	Dec 21, 2017
Grant date	—

Abstract

In one aspect, systems and methods for the efficient and cost-effective removal of bromide from wastewater streams are described herein. Briefly, a system for bromide removal comprises pretreatment apparatus operable for at least partial removal of background ionic species from the wastewater stream and/or dilution of the background ionic species in the wastewater stream. The system also comprises bromide capture apparatus operable for removal of bromide from the pretreated wastewater stream, wherein the system removes bromide from the wastewater stream at an efficiency of at least 80 percent. In some embodiments, bromide is recovered from the capture apparatus and reused in flue gas treatment applications.

First claim

1 . A system for removing bromide from a wastewater stream comprising:
pretreatment apparatus operable for at least partial removal of background ionic species from the wastewater stream or dilution of the background ionic species in the wastewater stream; and bromide capture apparatus operable for removal of bromide from the pretreated wastewater stream, wherein the system removes bromide from the wastewater stream at an efficiency of at least 80 percent.

2 . The system of claim 1 , wherein the background ionic species comprise alkaline earth cations, alkali cations, sulfate, chloride or mixtures thereof.

3 . The system of claim 2 , wherein the pretreatment apparatus comprises ion exchange media.

4 . The system of claim 3 , wherein the ion exchange media comprises anion exchange media.

5 . The system of claim 4 , wherein the ion exchange media further comprises cation exchange media.

6 . The system of claim 2 , wherein the pretreatment apparatus comprises one or more membranes for removal of the background ionic species.

7 . The system of claim 2 , wherein the pretreatment apparatus comprises one or more chambers or conduits for dilution of the wastewater stream.

8 . The system of claim 7 , wherein the chambers or conduits support a dilution factor of at least 4.

9 . The system of claim 1 , wherein electrical conductivity of wastewater stream is less than 5 mS/cm upon exit of the pretreatment apparatus.

10 . The system of claim 1 , wherein electrical conductivity of wastewater stream is less than 3.5 mS/cm upon exit of the pretreatment apparatus.

11 . The system of claim 2 , wherein the bromide capture apparatus comprises separation media exhibiting higher selectivity for bromide relative to the background ionic species.

12 . The system of claim 11 , wherein the separation media comprises strong base anion exchange media.

13 . The system of claim 1 further comprising one or more bromide collection chambers or conduits connected to the bromide capture apparatus.

14 . The system of claim 1 further comprising apparatus for discharging the treated wastewater.

15 . The system of claim 1 , wherein the wastewater is sourced from wet flue gas desulfurization apparatus.

16 . The system of claim 15 , wherein the system removes bromide from the wastewater at an efficiency of at least 85 percent.

17 . The system of claim 1 further comprising bromide recovery apparatus in fluid communication with the bromide capture apparatus, the bromide recovery apparatus comprising one or more chambers for collection and concentration of bromide received from the bromide capture apparatus.

18 . A method of removing bromide from a wastewater stream comprising:
contacting the wastewater stream with pretreatment apparatus operable for at least partial removal of background ionic species from the wastewater stream or dilution of the background ionic species in the wastewater stream; and contacting the pretreated wastewater stream with bromide capture apparatus operable for removal of bromide from the pretreated wastewater stream, wherein bromide is removed from the wastewater stream at an efficiency of at least 80 percent.

19 . The method of claim 18 , wherein the background ionic species comprise alkaline earth cations, alkali cations, sulfate, chloride or mixtures thereof.

20 . The method of claim 19 , wherein the pretreatment apparatus comprises ion exchange media for the removal of the background ionic species.

21 . The method of claim 20 , wherein the ion exchange media comprises anionic exchange media.

22 . The method of claim 19 , wherein the pretreatment apparatus comprises one or more membranes for the removal of the background ionic species.

23 . The method of claim 19 , wherein the pretreatment apparatus comprises one or more chambers or conduits for dilution of the wastewater stream.

24 . The method of claim 23 , wherein the wastewater stream is diluted by at least a factor of four in the pretreatment apparatus.

25 . The method of claim 19 , wherein the electrical conductivity of wastewater stream is less than 5 mS/cm upon exit of the pretreatment apparatus.

26 . The method of claim 19 , wherein electrical conductivity of wastewater stream is less than 3.5 mS/cm upon exit of the pretreatment apparatus.

27 . The method of claim 19 , wherein bromide capture apparatus comprises separation media exhibiting higher selectivity for bromide relative to the background ionic species.

28 . The method of claim 18 further comprising discharging the treated wastewater.

29 . The method of claim 28 further comprising recovering the bromide from the capture apparatus.

30 . The method of claim 29 , wherein the bromide is recovered as a salt.

31 . The method of claim 30 , wherein the wastewater is sourced from wet flue gas desulfurization apparatus.

32 . The method of claim 31 further comprising using the bromide salt in mercury emission control apparatus.

Assignees

• Univ North Carolina Charlotte

Inventors

• Amburgey James E
• Keen Olya Stepanovna
• Sun Mei

Classifications

• C02F2101/12

  Halogens or halogen-containing compounds · CPC title

• C02F2001/422

  using anionic exchangers · CPC title

• C02F2103/18

  from the purification of gaseous effluents · CPC title

• C02F1/42 Primary

  by ion-exchange (ion-exchange in general B01J) · CPC title

• B01D53/64

  Heavy metals or compounds thereof, e.g. mercury · CPC title