RH-Fe-MCM-41 adsorption efficiency and capacity were examined with arsenic in lower concentrations in aqueous solution under varying pH values. The adsorption of arsenite (As3 + ) and arsenate (As5 + ) by RH-Fe-MCM-41 at the molar ratio of Si/Fe 10 gave removal efficiencies of 47% and 99% for As3 + and As5 + , respectively, in the 100–1,000 μg l−1 concentration range. For the adsorption test of arsenic the best conditions were found to be an equilibrium time of 12 h at pH 7 for As3 + and 2 h at pH 4 for As5 + . The adsorption capacity by the Langmuir constants (Qm) for As3 + and As5 + were 416.67 μg g−1 and 277.78 μg g−1, respectively, while the Freundlich constants (KF) were 0.583 μg g−1 for As3 + and 112.87 μg g−1 for As5 + . The fit for As5 + was good with both the Langmuir and Freundlich isotherms by considering the R2 values, which were quite similar (0.916 and 0.912); As3 + fit well only with the Langmuir isotherm. The impregnation of iron (Fe3 + ) into the RH-Fe-MCM-41 structure increases the adsorption capacity of As3 + and As5 + both by oxidizing As3 + to As5 + and by co-precipitation with As5 + .
Research Article|June 01 2009
Adsorption of arsenic in aqueous solution by RH-Fe-MCM-41
K. W. Kim
K. W. Kim
2International Environmental Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea E-mail: firstname.lastname@example.org
3Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea E-mail: email@example.com
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Water Science and Technology: Water Supply (2009) 9 (2): 121-126.
W. Tong-on, S. Sthiannopkao, K. W. Kim, S. Chiarakorn; Adsorption of arsenic in aqueous solution by RH-Fe-MCM-41. Water Science and Technology: Water Supply 1 June 2009; 9 (2): 121–126. doi: https://doi.org/10.2166/ws.2009.246
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