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

Abstract

Shale gas extraction processes generate a large amount of hypersaline wastewater, whose spills or discharges may significantly increase the bromide levels in downstream water supplies and result in the formation of brominated disinfection byproducts (DBPs) upon chlorination. Although a few studies have investigated selective bromide removal from produced water, the low removal efficiencies and complex system setups are not desirable. In this study, we examined a simple costeffective approach for selective bromide removal from produced water relying on the oxidation by unactivated peroxymonosulfate. More than 95% of bromide was removed as Br 2 (g) in less than 10 min under weakly acidic conditions without significant formation of Cl 2 (g) even when the chloride concentration was more than 2 orders of magnitude higher. A kinetic model considering the involved reactions was then developed to describe the process well under various reaction conditions. The organic compounds in the produced water neither noticeably lowered the bromide removal efficiency nor reacted with the halogen species to form halogenated byproducts. The tests in batch and continuously stirred tank reactor systems suggested that it was feasible to achieve both high bromide removal and neutral effluent pH such that further pH adjustment was not necessary before discharge. After the treatment, the effect of the produced water on DBP formation was largely eliminated.

Selective Transformation of Micropollutants in Saline Wastewater by Peracetic Acid: The Overlooked Brominating Agents

“…The undesired ClO 3 – and BrO 3 – are always formed in radical-based oxidation systems, due to the inevitable reactions between radical and halides. , In the PAA/X – system, ClO 3 – and BrO 3 – were not observed along the reaction. Though the reactions of ClO 3 – and BrO 3 – productions can occur (Table S17), sluggish reaction rates or low reactant concentrations make the intermediates and products insignificant . Indeed, the model simulation showed that the ClO 3 – and BrO 3 – concentrations were consistently below 10 –30 M (data not shown).…”

“…productions can occur (Table S17), sluggish reaction rates or low reactant concentrations make the intermediates and products insignificant. 51 Indeed, the model simulation showed that the ClO 3 − and BrO 3 − concentrations were consistently below 10 −30 M (data not shown). In addition, the mass balance was also calculated by the model simulation to investigate the formation of toxic halogenate DBPs in the PAA/X − system (Figure 5a).…”

Recent Advances in the Removal of Radioactive Iodine and Iodide from the Environment

“…More specifically, the reported studies have focused on developing different strategies and materials for iodine removal, such as nanoparticles, membrane filters (reverse osmosis, − nanofiltration, ,− ion exchange, , and electrodialysis), electrochemical techniques, , absorption techniques (layered double hydroxides, − modified activated carbon, ,− silver impregnated activated carbon, , silver-doped carbon aerogels, − ion exchange resins, , soils, − and composites), and oxidants …”

“…9 More specifically, the reported studies have focused on developing different strategies and materials for iodine removal, such as nanoparticles, 10 membrane filters (reverse osmosis, 11−14 nanofiltration, 11,13−17 ion exchange, 18,19 and electrodialysis 20 ), electrochemical techniques, 21,22 absorption techniques (layered double hydroxides, 23−28 modified activated carbon, 27,29−31 silver impregnated activated carbon, 32,33 silver-doped carbon aerogels, 34−37 ion exchange resins, 38,39 soils, 40−42 and composites 43 ), and oxidants. 44 There are 37 known isotopes of iodine ( 108 I to 144 I), and all isotopes decay except 127 I, which is a stable isotope of iodine that is used in the applications listed below. In chemistry, 127 I is primarily used in oxidation reactions, 45 iodine.…”