Bromide Ions Specific Removal and Recovery by Electrochemical Desalination

Abstract

Removal and recovery of bromide ions by electro-oxidation and electro-reduction are presented using hybrid physical adsorption and capacitive deionization cells, which contain activated carbon cloth electrodes. This is a proof of concept research with results, which indicate that when comparing the removal and recovery quantities of bromide and chloride ions (starting with the same initial concentration of 0.05 M for both salts), the desalination capacity of the bromide ions is larger by almost 2 orders of magnitude than that of the chloride ions; thus, we obtained specific desalination of bromide ions from a solution containing chloride ions. Removal and recovery of 3.5 mmol of bromide ions were achieved by a working electrode with 1 g of activated carbon cloth, and the calculated energy consumption for the removal and recovery of 1 g of bromide ions was about 2.24 kJ/g.

Recent advances in ion selectivity with capacitive deionization

“…Another technique reported in literature is the use of faradaic reactions at the electrodes for ion-separation. 111 Cohen et al used activated carbon electrodes in an asymmetric CDI cell with an oversized counter electrode to selectively remove Br À present in a mixture with Cl À . The potential of the working electrode was controlled, and the cell voltage was monitored.…”

Highly Efficient Bromide Removal from Shale Gas Produced Water by Unactivated Peroxymonosulfate for Controlling Disinfection Byproduct Formation in Impacted Water Supplies

“…However, the bromide removal efficiency requires further improvement given that the removal of 15 mM bromide took up to 6.5 h in the lab-scale tests . Another study employed hybrid physical adsorption and capacitive deionization using activated carbon cloth electrodes, and the bromide desalination capacity was almost 2 orders of magnitude higher than that of chloride when bromide and chloride were at the same concentration (50 mM) . However, this preference for bromide removal may become less when the chloride concentration is more than 2 orders of magnitude higher than that of bromide, a common situation in produced water.…”

“…22 Another study employed hybrid physical adsorption and capacitive deionization using activated carbon cloth electrodes, and the bromide desalination capacity was almost 2 orders of magnitude higher than that of chloride when bromide and chloride were at the same concentration (50 mM). 24 However, this preference for bromide removal may become less when the chloride concentration is more than 2 orders of magnitude higher than that of bromide, a common situation in produced water. This is because chloride can become much more competitive for adsorption at higher concentrations.…”

Tandem Efficient Bromine Removal and Silver Recovery by Resorcinol-Formaldehyde Resin Nanoparticles

“…Yet, selective recovery remains challenging for typical porous adsorbents. The generated HBr can be further distilled to a purified chemical or be oxidized to recover Br 2 for deep removal by chemical oxidation or electrochemical processes. , …”

“…The generated HBr can be further distilled to a purified chemical or be oxidized to recover Br 2 for deep removal by chemical oxidation 15 or electrochemical processes. 33,34 Impressively, the as-prepared colloidal RF NPs delivered a distinguished Br 2 conversion capacity of 7441 mg g RF −1 after 12 h at room temperature (RT), a ∼2-fold Br 2 removal capacity compared with the state-of-the-art Br 2 -capture materials. 12 The synthesis of low-cost RF NPs can be easily scaled up in batches for practical applications.…”