Effect of Cr(VI) concentration on gas and particle production during iron oxidation in aqueous solutions containing Cl ions

Hyangsig Ahn, Ho Young Jo, Ji Hun Ryu, Yong Kwon Koh

Research output: Contribution to journalArticle

Abstract

Zero-valent iron (ZVI) is commonly used as a medium in permeable reactive barriers (PRBs) because of its high reducing ability. The generation of H2 gas in PRBs, however, can decrease the permeability of PRBs and reduce the contact area between the PRB and contaminated groundwater. This study investigated the effect of the initial Cr(VI) concentration ([Cr(VI)init]) in aqueous solutions containing Cl ions on the generation of H2 gas. ZVI chips were reacted in reactors with 0.5-M NaCl solutions with [Cr(VI)init] ranging between 51 and 303 mg/L. The initial pH was set at 3. The oxidation of ZVI chips by Cr(VI) in aqueous solutions containing Cl ions produced H2 gas and particles (Fe(III)–Cr(III)(oxy)hydroxides). The Cr(VI) removal from aqueous solutions increased as the [Cr(VI)init] increased, as did H2 gas generation. The positive effect of [Cr(VI)init] on H2 gas generation might be due to an increase in the redox potential gradient as [Cr(VI)init] increases. This increased gradient would enhance H+ ion penetration through the passive film (Fe(III)–Cr(III)(oxy)hydroxides), which formed on the ZVI surface, by diffusion from the solution to pits beneath the passive film.

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalEnvironmental Technology (United Kingdom)
DOIs
Publication statusAccepted/In press - 2016 Jun 24

Fingerprint

reactive barrier
Iron
aqueous solution
Gases
Ions
oxidation
iron
Oxidation
ion
gas
Hydroxides
hydroxide
redox potential
penetration
effect
particle
chromium hexavalent ion
permeability
Groundwater
groundwater

Keywords

  • chromium
  • hydrogen gas
  • Iron
  • oxidation
  • reduction

ASJC Scopus subject areas

  • Environmental Chemistry
  • Waste Management and Disposal
  • Water Science and Technology

Cite this

Effect of Cr(VI) concentration on gas and particle production during iron oxidation in aqueous solutions containing Cl ions. / Ahn, Hyangsig; Jo, Ho Young; Ryu, Ji Hun; Koh, Yong Kwon.

In: Environmental Technology (United Kingdom), 24.06.2016, p. 1-7.

Research output: Contribution to journalArticle

@article{0eba2f16d8f642e3b05a19f7adb1286f,
title = "Effect of Cr(VI) concentration on gas and particle production during iron oxidation in aqueous solutions containing Cl− ions",
abstract = "Zero-valent iron (ZVI) is commonly used as a medium in permeable reactive barriers (PRBs) because of its high reducing ability. The generation of H2 gas in PRBs, however, can decrease the permeability of PRBs and reduce the contact area between the PRB and contaminated groundwater. This study investigated the effect of the initial Cr(VI) concentration ([Cr(VI)init]) in aqueous solutions containing Cl− ions on the generation of H2 gas. ZVI chips were reacted in reactors with 0.5-M NaCl solutions with [Cr(VI)init] ranging between 51 and 303 mg/L. The initial pH was set at 3. The oxidation of ZVI chips by Cr(VI) in aqueous solutions containing Cl− ions produced H2 gas and particles (Fe(III)–Cr(III)(oxy)hydroxides). The Cr(VI) removal from aqueous solutions increased as the [Cr(VI)init] increased, as did H2 gas generation. The positive effect of [Cr(VI)init] on H2 gas generation might be due to an increase in the redox potential gradient as [Cr(VI)init] increases. This increased gradient would enhance H+ ion penetration through the passive film (Fe(III)–Cr(III)(oxy)hydroxides), which formed on the ZVI surface, by diffusion from the solution to pits beneath the passive film.",
keywords = "chromium, hydrogen gas, Iron, oxidation, reduction",
author = "Hyangsig Ahn and Jo, {Ho Young} and Ryu, {Ji Hun} and Koh, {Yong Kwon}",
year = "2016",
month = "6",
day = "24",
doi = "10.1080/09593330.2016.1198423",
language = "English",
pages = "1--7",
journal = "Environmental Technology (United Kingdom)",
issn = "0959-3330",
publisher = "Taylor and Francis Ltd.",

}

TY - JOUR

T1 - Effect of Cr(VI) concentration on gas and particle production during iron oxidation in aqueous solutions containing Cl− ions

AU - Ahn, Hyangsig

AU - Jo, Ho Young

AU - Ryu, Ji Hun

AU - Koh, Yong Kwon

PY - 2016/6/24

Y1 - 2016/6/24

N2 - Zero-valent iron (ZVI) is commonly used as a medium in permeable reactive barriers (PRBs) because of its high reducing ability. The generation of H2 gas in PRBs, however, can decrease the permeability of PRBs and reduce the contact area between the PRB and contaminated groundwater. This study investigated the effect of the initial Cr(VI) concentration ([Cr(VI)init]) in aqueous solutions containing Cl− ions on the generation of H2 gas. ZVI chips were reacted in reactors with 0.5-M NaCl solutions with [Cr(VI)init] ranging between 51 and 303 mg/L. The initial pH was set at 3. The oxidation of ZVI chips by Cr(VI) in aqueous solutions containing Cl− ions produced H2 gas and particles (Fe(III)–Cr(III)(oxy)hydroxides). The Cr(VI) removal from aqueous solutions increased as the [Cr(VI)init] increased, as did H2 gas generation. The positive effect of [Cr(VI)init] on H2 gas generation might be due to an increase in the redox potential gradient as [Cr(VI)init] increases. This increased gradient would enhance H+ ion penetration through the passive film (Fe(III)–Cr(III)(oxy)hydroxides), which formed on the ZVI surface, by diffusion from the solution to pits beneath the passive film.

AB - Zero-valent iron (ZVI) is commonly used as a medium in permeable reactive barriers (PRBs) because of its high reducing ability. The generation of H2 gas in PRBs, however, can decrease the permeability of PRBs and reduce the contact area between the PRB and contaminated groundwater. This study investigated the effect of the initial Cr(VI) concentration ([Cr(VI)init]) in aqueous solutions containing Cl− ions on the generation of H2 gas. ZVI chips were reacted in reactors with 0.5-M NaCl solutions with [Cr(VI)init] ranging between 51 and 303 mg/L. The initial pH was set at 3. The oxidation of ZVI chips by Cr(VI) in aqueous solutions containing Cl− ions produced H2 gas and particles (Fe(III)–Cr(III)(oxy)hydroxides). The Cr(VI) removal from aqueous solutions increased as the [Cr(VI)init] increased, as did H2 gas generation. The positive effect of [Cr(VI)init] on H2 gas generation might be due to an increase in the redox potential gradient as [Cr(VI)init] increases. This increased gradient would enhance H+ ion penetration through the passive film (Fe(III)–Cr(III)(oxy)hydroxides), which formed on the ZVI surface, by diffusion from the solution to pits beneath the passive film.

KW - chromium

KW - hydrogen gas

KW - Iron

KW - oxidation

KW - reduction

UR - http://www.scopus.com/inward/record.url?scp=84976291160&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84976291160&partnerID=8YFLogxK

U2 - 10.1080/09593330.2016.1198423

DO - 10.1080/09593330.2016.1198423

M3 - Article

SP - 1

EP - 7

JO - Environmental Technology (United Kingdom)

JF - Environmental Technology (United Kingdom)

SN - 0959-3330

ER -