Electron beam treatment for potable water reuse: Removal of bromate and perfluorooctanoic acid

Wang, Li; Batchelor, Bill; Pillai, Suresh D.; Botlaguduru, Venkata Sai Vamsi

doi:10.1016/j.cej.2016.05.034

Cited by 80 publications

(58 citation statements)

References 56 publications

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“…Final defluorination efficiencies ranged from 34.6 percent to 95 percent under various increasing concentrations of nitrate, alkalinity, and fluvic acid. The defluorination is possibly due to the formation of aqueous electrons and the formation of secondary radicals (Wang et al., ). An additional study further demonstrated eBeam‐mediated defluorination of PFOS and PFOA with decomposition efficiencies of 95.7 percent for PFOA and 85.9 percent for PFOS in an anoxic alkaline solution (pH = 13).…”

Section: Soil and Sediment Remediationmentioning

confidence: 99%

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A review of emerging technologies for remediation of PFASs

Ross

McDonough

Miles

et al. 2018

Remediation Journal

408

268

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The need for remediation of poly‐ and perfluoroalkyl substances (PFASs) is growing as a result of more regulatory attention to this new class of contaminants with diminishing water quality standards being promulgated, commonly in the parts per trillion range. PFASs comprise >3,000 individual compounds, but the focus of analyses and regulations has generally been PFASs termed perfluoroalkyl acids (PFAAs), which are all extremely persistent, can be highly mobile, and are increasingly being reported to bioaccumulate, with understanding of their toxicology evolving. However, there are thousands of polyfluorinated “PFAA precursors”, which can transform in the environment and in higher organisms to create PFAAs as persistent daughter products. Some PFASs can travel miles from their point of release, as they are mobile and persistent, potentially creating large plumes. The use of a conceptual site model (CSM) to define risks posed by specific PFASs to potential receptors is considered essential. Granular activated carbon (GAC) is commonly used as part of interim remedial measures to treat PFASs present in water. Many alternative treatment technologies are being adapted for PFASs or ingenious solutions developed. The diversity of PFASs commonly associated with use of multiple PFASs in commercial products is not commonly assessed. Remedial technologies, which are adsorptive or destructive, are considered for both soils and waters with challenges to their commercial application outlined. Biological approaches to treat PFASs report biotransformation which creates persistent PFAAs, no PFASs can biodegrade. Water treatment technologies applied ex situ could be used in a treatment train approach, for example, to concentrate PFASs and then destroy them on‐site. Dynamic groundwater recirculation can greatly enhance contaminant mass removal via groundwater pumping. This review of technologies for remediation of PFASs describes that: GAC may be effective for removal of long‐chain PFAAs, but does not perform well on short‐chain PFAAs and its use for removal of precursors is reported to be less effective; Anion‐exchange resins can remove a wider array of long‐ and short‐chain PFAAs, but struggle to treat the shortest chain PFAAs and removal of most PFAA precursors has not been evaluated; Ozofractionation has been applied for PFASs at full scale and shown to be effective for removal of total PFASs; Chemical oxidation has been demonstrated to be potentially applicable for some PFAAs, but when applied in situ there is concern over the formation of shorter chain PFAAs and ongoing rebound from sorbed precursors; Electrochemical oxidation is evolving as a destructive technology for many PFASs, but can create undesirable by‐products such as perchlorate and bromate; Sonolysis has been demonstrated as a potential destructive technology in the laboratory but there are significant challenges when considering scale up; Soils stabilization approaches are evolving and have been used at full scale but performance need to be assessed usin...

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Section: Soil and Sediment Remediationmentioning

confidence: 99%

“…Texas A&M University recently demonstrated defluorination of PFOA in aqueous samples by eBeam technology(Wang, Batchelor, Pillai, & Botlaguduru, 2016). The study measured defluorination efficiency as a function of molar concentration of free fluoride ions and initial molar concentration of PFOA to be treated.…”

mentioning

confidence: 99%

A review of emerging technologies for remediation of PFASs

Ross

McDonough

Miles

et al. 2018

Remediation Journal

408

268

View full text Add to dashboard Cite

show abstract

“…The small site occupancy for household water purifiers means that the technologies adopted must remove BrO − 3 within a short contact time and at high operational cost. The methods of degrading BrO − 3 from drinking water include activated carbon or resin adsorption [2], electron beam irradiation [3], membrane separation [4], biological reduction [5], zero-valent iron (ZVI) reduction [6], photo [7] or photocatalytic reduction [8], layered double hydroxide reduction [9], advanced reduction processes (ARPs) [10], and so on. Among these technologies, hydrated electron (e − aq )-based ARPs distinguished themselves in BrO − 3 degradation due to the high rate constants between e − aq and BrO − 3 (~10 9 M −1 ·s −1 ) [10,11]; thus, they show potential for their use in household drinking water purifiers, which are characterized by a small hydraulic retention time.…”

Section: Introductionmentioning

confidence: 99%

Efficient Reduction of Bromate by Iodide-Assisted UV/Sulfite Process

et al. 2018

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Bromate (BrO − 3 ) residue in drinking water poses a great health risk. Ultra-fast reduction of BrO − 3 , under aerobic conditions, was realized using an ultraviolet (UV)/sulfite process in the presence of iodide (UV/sulfite/iodide). The UV/sulfite/iodide process produced BrO − 3 removal efficiency of 100% at about 5 min with complete conversion to bromide, while UV/sulfite induced 13.1% BrO − 3 reduction under the same conditions. Hydrated electrons, generated from the photolysis of sulfite and iodide, was confirmed as the main contributor to BrO − 3 degradation (77.4% of the total contribution). As the concentration of iodide was kept constant, its presence remarkably enhancing the generation of hydrated electrons led to its consideration as a homogeneous catalyst in the UV/sulfite/iodide system. Sulfite played a role not only as a hydrated electron precursor, but also as a reactive iodine species shielding agent and a regenerant of iodide. Results surrounding the effects on common water quality parameters (pH, bicarbonate, nitrate, natural organic matter, and solution temperature) indicated that preferred degradation of BrO − 3 occurred in an environment of alkaline pH, low-content natural organic matter/bicarbonate/nitrate, and high natural temperature.(I − )/nitrilotriacetic acid [14,15], vacuum-UV irradiation [7], and photoexcitation of organic chromophores [16]. From a practical perspective, the key for-based ARPs is generating e − aq efficiently under ambient conditions. Hydrated electron generation by UV activation of sulfite (UV/sulfite) is promising due to its oxygen self-cleaning property. However, e − aq generation by UV/sulfite was dependent on a high concentration of sulfite and high pH due to the relatively low absorptivity and the protonation of sulfite. Recently, Li etc.[17] proposed a UV/sulfite/I − process to generate e − aq , and successfully realized efficient degradation of monochloroacetic acid (12.86 µM·min −1 ). Enhanced production of e − aq through such a process was based on two facts: (1) both sulfite and I − act as e − aq precursors; (2) sulfite can reduce the e − aq scavenging by reactive iodine species (RIS, e.g., I • , I •− 2 , and I − 3 ). Given the similar rate constant of e − aq toward monochloroacetic acid (1.0 × 10 9 M −1 ·s −1 [18]) and BrO − 3 (3.4 × 10 9 M −1 ·s −1 [10]), it is reasonable to speculate that the UV/sulfite/I − process can also degrade BrO − 3 with high efficiency. Yet, to the authors' knowledge, there exist no other reports using this process to degrade BrO − 3 under aerobic conditions. Furthermore, the BrO − 3 degradation performance using the UV/sulfite/I − process under aerobic conditions, and the possible factors that may affect the degradation efficiency (i.e., pH, anions, and natural organic matter (NOM)) are yet to be investigated.In this work, we aimed to (1) investigate the reduction efficiency of BrO − 3 in prepared water and real water in the UV/sulfite/I − process; (2) explore the mechanism of BrO − 3 reduction (role of sulfite/I − and contributo...

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“…Photolysis and UV‐radiation use a variety of UV wave lengths (185 to 470 nm), chemical reagents, and catalyst materials (Merino et al ) to facilitate formation of the radicals. Lastly, eBeam uses gamma ray emissions absorbed by water molecules to create the solvated electron (Wang et al ).…”

Section: Considerations For Available Pfas‐relevant Destruction Technmentioning

confidence: 99%