Factors influencing As(V) stabilization in the mine soils amended with iron-rich materials

Mijin Kim, Juhee Kim, Minhee Kim, Yong Seong Kim, Seung Mo Nam, Deok Hyun Moon, Seunghun Hyun

Research output: Contribution to journalArticle

Abstract

Chemical stability of As(V) in amended mine-impacted soils was assessed according to functions of incubation period (0, 1, 2, 4, and 6 months), amendment dose (2.5 and 5%), and application timing (0 and 3rd month). Six soils contaminated with 26–209 mg kg−1 of As(V) were collected from two abandoned mine sites and were treated with two alkaline iron-rich materials (mine discharge sludge (MS) and steel-making slag (SS)). Seventeen to 23% of As(V) in soils was labile. After each designated time, As(V) stability was assessed by the labile fractions determined with sequential extraction procedures (F1–F5). Over 6 months, a reduction (26.9–70.4%) of the two labile fractions (F1 and F2) and a quantitative increase (7.4–29.9%) of As(V) in F3 were observed (r2 = 0.956). Two recalcitrant fractions (F4 and F5) remained unchanged. Temporal change of As(V) stability in a sample was well described by the two-domain model (kfast, kslow, and Ffast). The stabilization (%) correlated well with the fast-stabilizing domain (Ffast), clay content (%), and Fe oxide content (mg kg−1), but correlated poorly with kinetic rate constants (kfast and kslow). Until the 3rd month, the 2.5%-MS amended sample resulted in lower As(V) stabilization (25–40%) compared to the 5% sample (50–60%). However, the second 2.5% MS addition on the 2.5% sample upon the lapse of the 3rd month led to a substantial reduction (up to 38%) of labile As(V) fraction in the following 4th and 6th months. As a result, an additional 15–25% of As(V) stability was obtained when splitting the amendment dose into 3-month intervals. In conclusion, the As(V) stabilization by Fe-rich amendment is time-dependent and its efficacy can be improved by optimizing the amendment dose and its timing.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalEnvironmental Science and Pollution Research
DOIs
Publication statusAccepted/In press - 2017 Sep 4

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Keywords

  • Abandoned mine
  • Amendment
  • As(V)
  • Stabilization

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution
  • Health, Toxicology and Mutagenesis

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