TY - JOUR
T1 - Removal of dissolved Zn(II) using coal mine drainage sludge
T2 - Implications for acidic wastewater treatment
AU - Cui, Mingcan
AU - Jang, Min
AU - Cannon, Fred S.
AU - Na, Seunmin
AU - Khim, Jeehyeong
AU - Park, Jae Kwang
N1 - Funding Information:
This work was supported by the Basic Science Research Program through a National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology ( KRF-2009-0092799 ) and supported by a Korea University Grant, Korea Ministry of Environment , and research fund of Korea Mine Reclamation Corporation .
PY - 2013/2/5
Y1 - 2013/2/5
N2 - The mechanism for the removal of Zn(II) by using coal mine drainage sludge (CMDS) was investigated by spectroscopic analysis and observations of batch tests using model materials. Zeta potential analysis showed that CMDS25 (dried at 25 °C) and CMDS550 (dried at 550 °C) had a much lower isoelectric point of pH (pHIEP) than either goethite or calcite, which are the main constituents of CMDS. This indicates that the negatively charged anion (sulfate) was incorporated into the structural networks and adsorbed on the surface of CMDS via outer-sphere complexation. The removal of Zn(II) by CMDS was thought to be primarily caused by sulfate-complexed iron (oxy)hydroxide and calcite. In particular, the electrostatic attraction of the negatively charged functional group, FeOH-SO42-, to the dissolved Zn(II) could provide high removal efficiencies over a wide pH range. Thermodynamic modeling and Fourier transform infrared spectroscopy (FT-IR) demonstrated that ZnSO4 is the dominant species in the pH range 3-7 as the sulfate complexes with the hydroxyl groups, whereas the precipitation of Zn(II) as ZnCO3 or Zn5(CO3)2 (OH)6 through the dissolution of calcite is the dominant mechanism in the pH range 7-9.6.
AB - The mechanism for the removal of Zn(II) by using coal mine drainage sludge (CMDS) was investigated by spectroscopic analysis and observations of batch tests using model materials. Zeta potential analysis showed that CMDS25 (dried at 25 °C) and CMDS550 (dried at 550 °C) had a much lower isoelectric point of pH (pHIEP) than either goethite or calcite, which are the main constituents of CMDS. This indicates that the negatively charged anion (sulfate) was incorporated into the structural networks and adsorbed on the surface of CMDS via outer-sphere complexation. The removal of Zn(II) by CMDS was thought to be primarily caused by sulfate-complexed iron (oxy)hydroxide and calcite. In particular, the electrostatic attraction of the negatively charged functional group, FeOH-SO42-, to the dissolved Zn(II) could provide high removal efficiencies over a wide pH range. Thermodynamic modeling and Fourier transform infrared spectroscopy (FT-IR) demonstrated that ZnSO4 is the dominant species in the pH range 3-7 as the sulfate complexes with the hydroxyl groups, whereas the precipitation of Zn(II) as ZnCO3 or Zn5(CO3)2 (OH)6 through the dissolution of calcite is the dominant mechanism in the pH range 7-9.6.
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U2 - 10.1016/j.jenvman.2012.12.013
DO - 10.1016/j.jenvman.2012.12.013
M3 - Article
C2 - 23295677
AN - SCOPUS:84871959559
SN - 0301-4797
VL - 116
SP - 107
EP - 112
JO - Journal of Environmental Management
JF - Journal of Environmental Management
ER -