Detailed Information

Cited 0 time in webofscience Cited 0 time in scopus
Metadata Downloads

Unraveling iron speciation on Fe-biochar with distinct arsenic removal mechanisms and depth distributions of As and Fe

Authors
Xu, ZiboWan, ZhonghaoSun, YuqingCao, XindeHou, DeyiAlessi, Daniel S.Ok, Yong SikTsang, Daniel C. W.
Issue Date
1-12월-2021
Publisher
ELSEVIER SCIENCE SA
Keywords
Engineering biochar; Arsenic immobilization; Redox reaction; Co-precipitation; Iron transformation; Green and sustainable remediation
Citation
CHEMICAL ENGINEERING JOURNAL, v.425
Indexed
SCIE
SCOPUS
Journal Title
CHEMICAL ENGINEERING JOURNAL
Volume
425
URI
https://scholar.korea.ac.kr/handle/2021.sw.korea/137628
DOI
10.1016/j.cej.2021.131489
ISSN
1385-8947
Abstract
Tailored manipulation of iron speciation has become a critical challenge for the further development of Fe-biochar as an economical and eco-friendly amendment for arsenic (As) immobilization. Herein, a series of Fe-biochars with manipulated iron speciations were fabricated by controlling the carbon structures and pyrolysis conditions. Results revealed that abundant labile-/amorphous-C induced more reductive-Fe(0) formation (10.9 mg g(-1)) in the Fe-biochar. The high Fe(0) content resulted in the effective As immobilization (4.34 mg g(-1) As(V) and 7.72 mg g(-1) As(III)) as evidenced by Pearson correlation coefficient (PCC) analysis. The hierarchical depth distributions of As and Fe on the Fe-biochar caused by the redox reaction and concomitant sorption of As proved the decisive role of Fe(0). An iron-oxide shell (similar to 10-20 nm) with a high arsenic accumulation was revealed on the surface, while deeper within the particles, Fe(0) was found to be associated with elemental As (As(0), up to 19.4%). By contrast, pyrolysis with the stable-/graphitic-C generated more amorphous-Fe (61.9 mg g(-1)) on the Fe-biochar, which accounted for the high As removal (10.1 mg g(-1) As(V) and 7.70 mg g(-1) As(III)) despite the limited Fe(0) content. In comparison to the reductive Fe(0), distinct depth distribution was observed that the As/Fe ratio was marginally changed within 200 nm depth of the amorphous-Fe biochar after As decontamination. Co-precipitation of As with Fe released from amorphous-Fe contributed to this depth distribution, as evidenced by the high correlation between released-Fe and As immobilization capacity (PCC as 0.84-0.95). This study unveiled a crucial role of iron speciation on distinct mechanisms for As removal, guiding the application-oriented design of multifunctional Fe-biochar for broad environmental remediation.
Files in This Item
There are no files associated with this item.
Appears in
Collections
College of Life Sciences and Biotechnology > Division of Environmental Science and Ecological Engineering > 1. Journal Articles

qrcode

Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.

Altmetrics

Total Views & Downloads

BROWSE