비결정질철산화물 원위치 형성을 통한 비소오염토양 안정화 및 X선 분광분석법의 활용에 대한 연구

Abstract

This study was conducted to investigate the in situ formation of amorphous Fe oxides as a stabilization technology in Ascontaminatedsoil. 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 solubilitybioavailability research consortium (SBRC) test indicated that a significant amount of As in untreated soil changed to anon-bioaccessible form after stabilization. The reason was attributed to the newly formed amorphous Fe oxides in thestabilized 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 inthe soil were transformed to crystalline Fe oxides such as goethite, and further decrease in SBRC extractable fraction ofAs was observed. The results suggest that co-precipitated As with amorphous Fe oxides can be further immobilized withtime, due to the crystallization of amorphous Fe oxides.