Jinhee Park1·Hyeonyong Chung1·Sang Hyun Kim1·Jinsung An2·Kyoungphile Nam1*
1Department of Civil &
Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
2Department of Biological & Environmental Engineering, Semyung University, 65 Semyung-ro, Jecheon-si, Chungcheongbuk-do 27136, Republic of Korea
This study was conducted to investigate the in situ formation of
amorphous Fe oxides as a stabilization technology in As-contaminated soil.
After addition of ferric nitrate and the neutralizing agent, most of
extractable fractions of As in soil (i.e., SO42- and PO43--extractable
As) was converted into As bound to amorphous Fe oxides. In addition, results of
solubility bioavailability research consortium (SBRC) test indicated that a
significant amount of As in untreated soil changed to a non-bioaccessible form
after stabilization. The reason was attributed to the newly formed amorphous Fe
oxides in the stabilized soil, which was confirmed by linear combination of
fitting (LCF) using X-ray absorption spectroscopy (XAS) analysis.
Interestingly, after five months of aging of the stabilized soil, ferrihydrite
and schwertmannite newly formed in the soil were transformed to crystalline Fe
oxides such as goethite, and further decrease in SBRC extractable fraction of
As was observed. The results suggest that co-precipitated As with amorphous Fe
oxides can be further immobilized with time, due to the crystallization of
amorphous Fe oxides.
Keywords: Co-precipitation, Arsenic, Amorphous Fe oxides, Crystallization, X-ray absorption spectroscopy (XAS)
2020; 25(2): 9-15
Published on Jun 30, 2020
Department of Civil & Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea