TY - JOUR
T1 - Mechanisms of phosphate removal by Micron-Scale Zero-Valent iron
AU - Zhao, Ying
AU - Li, Qingxu
AU - Shi, Qiantao
AU - Xi, Beidou
AU - Zhang, Xinyi
AU - Jian, Zhiqiang
AU - Zhou, Gaoting
AU - Meng, Xiaoguang
AU - Mao, Xuhui
AU - Kang, Dejun
AU - Gong, Bin
N1 - Publisher Copyright:
© 2023
PY - 2023/8/15
Y1 - 2023/8/15
N2 - Extensive studies have been carried out on phosphate removal by zero valent iron (ZVI). Different mechanisms of phosphate removal by ZVI such as phosphate adsorption and precipitation of ferric phosphate and vivianite (Fe3(PO4)2·8H2O) have been reported. In this study, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray powder diffraction (XRD), and X-ray absorption near edge spectroscopy (XANES) were used to elucidate the mechanisms of phosphate removal by micron-scale zero-valent (mZVI). Time-series ATR-FTIR analysis revealed that phosphate was removed by ZVI in two steps: a) adsorption of phosphate in the first 3 days, and b) slow conversion of the adsorbed phosphate into the precipitated form in 6 days. XRD and XANES analysis determined that iron oxides, ferric ion, and ZVI with oxide layer inhibited the formation of vivianite, resulting in the formation of phosphate precipitates, such as H2Fe(II)P2O7. The results suggested that phosphate is removed by ZVI mainly through precipitation under aerobic conditions. The knowledge gained in this study improves the fundamental understanding of the phosphate removal processes via ZVI.
AB - Extensive studies have been carried out on phosphate removal by zero valent iron (ZVI). Different mechanisms of phosphate removal by ZVI such as phosphate adsorption and precipitation of ferric phosphate and vivianite (Fe3(PO4)2·8H2O) have been reported. In this study, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray powder diffraction (XRD), and X-ray absorption near edge spectroscopy (XANES) were used to elucidate the mechanisms of phosphate removal by micron-scale zero-valent (mZVI). Time-series ATR-FTIR analysis revealed that phosphate was removed by ZVI in two steps: a) adsorption of phosphate in the first 3 days, and b) slow conversion of the adsorbed phosphate into the precipitated form in 6 days. XRD and XANES analysis determined that iron oxides, ferric ion, and ZVI with oxide layer inhibited the formation of vivianite, resulting in the formation of phosphate precipitates, such as H2Fe(II)P2O7. The results suggested that phosphate is removed by ZVI mainly through precipitation under aerobic conditions. The knowledge gained in this study improves the fundamental understanding of the phosphate removal processes via ZVI.
KW - Adsorption
KW - Phosphate
KW - Precipitation
KW - Vivianite
KW - Zero valent iron
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U2 - 10.1016/j.seppur.2023.123706
DO - 10.1016/j.seppur.2023.123706
M3 - Article
AN - SCOPUS:85159096522
SN - 1383-5866
VL - 319
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 123706
ER -