TY - JOUR
T1 - Characterization of manganese oxide precipitates from Appalachian coal mine drainage treatment systems
AU - Tan, Hui
AU - Zhang, Gengxin
AU - Heaney, Peter J.
AU - Webb, Samuel M.
AU - Burgos, William D.
N1 - Funding Information:
This research was supported by the National Science Foundation through Grant No. CHE-0431328 and Grant No. EAR07-45374 , and by the Office of Surface Mining under Cooperative Agreement S07AP12478. A portion of this research was carried out at the National Synchrotron Light Source, Brookhaven National Laboratory, which is supported by the US Department of Energy, Division of Materials Sciences and Division of Chemical Sciences, under Contract No. DE-AC02-98CH10886. The SSRL beamline is supported by the US Department of Energy, Office of Biological and Environmental Research.
PY - 2010/3
Y1 - 2010/3
N2 - The removal of Mn(II) from coal mine drainage (CMD) by chemical addition/active treatment can significantly increase treatment costs. Passive treatment for Mn removal involves promotion of biological oxidative precipitation of manganese oxides (MnOx). Manganese(II) removal was studied in three passive treatment systems in western Pennsylvania that differed based on their influent Mn(II) concentrations (20-150 mg/L), system construction (±inoculation with patented Mn(II)-oxidizing bacteria), and bed materials (limestone vs. sandstone). Manganese(II) removal occurred at pH values as low as 5.0 and temperatures as low as 2 °C, but was enhanced at circumneutral pH and warmer temperatures. Trace metals such as Zn, Ni and Co were removed effectively, in most cases preferentially, into the MnOx precipitates. Based on synchrotron radiation X-ray diffraction and Mn K-edge extended X-ray absorption fine structure spectroscopy, the predominant Mn oxides at all sites were poorly crystalline hexagonal birnessite, triclinic birnessite and todorokite. The surface morphology of the MnOx precipitates from all sites was coarse and "sponge-like" composed of nm-sized lathes and thin sheets. Based on scanning electron microscopy (SEM), MnOx precipitates were found in close proximity to both prokaryotic and eukaryotic organisms. The greatest removal efficiency of Mn(II) occurred at the one site with a higher pH in the bed and a higher influent total organic C (TOC) concentration (provided by an upstream wetland). Biological oxidation of Mn(II) driven by heterotrophic activity was most likely the predominant Mn removal mechanism in these systems. Influent water chemistry and Mn(II) oxidation kinetics affected the relative distribution of MnOx mineral assemblages in CMD treatment systems.
AB - The removal of Mn(II) from coal mine drainage (CMD) by chemical addition/active treatment can significantly increase treatment costs. Passive treatment for Mn removal involves promotion of biological oxidative precipitation of manganese oxides (MnOx). Manganese(II) removal was studied in three passive treatment systems in western Pennsylvania that differed based on their influent Mn(II) concentrations (20-150 mg/L), system construction (±inoculation with patented Mn(II)-oxidizing bacteria), and bed materials (limestone vs. sandstone). Manganese(II) removal occurred at pH values as low as 5.0 and temperatures as low as 2 °C, but was enhanced at circumneutral pH and warmer temperatures. Trace metals such as Zn, Ni and Co were removed effectively, in most cases preferentially, into the MnOx precipitates. Based on synchrotron radiation X-ray diffraction and Mn K-edge extended X-ray absorption fine structure spectroscopy, the predominant Mn oxides at all sites were poorly crystalline hexagonal birnessite, triclinic birnessite and todorokite. The surface morphology of the MnOx precipitates from all sites was coarse and "sponge-like" composed of nm-sized lathes and thin sheets. Based on scanning electron microscopy (SEM), MnOx precipitates were found in close proximity to both prokaryotic and eukaryotic organisms. The greatest removal efficiency of Mn(II) occurred at the one site with a higher pH in the bed and a higher influent total organic C (TOC) concentration (provided by an upstream wetland). Biological oxidation of Mn(II) driven by heterotrophic activity was most likely the predominant Mn removal mechanism in these systems. Influent water chemistry and Mn(II) oxidation kinetics affected the relative distribution of MnOx mineral assemblages in CMD treatment systems.
UR - http://www.scopus.com/inward/record.url?scp=75849164991&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=75849164991&partnerID=8YFLogxK
U2 - 10.1016/j.apgeochem.2009.12.006
DO - 10.1016/j.apgeochem.2009.12.006
M3 - Article
AN - SCOPUS:75849164991
SN - 0883-2927
VL - 25
SP - 389
EP - 399
JO - Applied Geochemistry
JF - Applied Geochemistry
IS - 3
ER -