Polyurethane (PU) media impregnated by different amounts of MgO were synthesized and estimated for the removal performance of high-level Mn(II) in aqueous phase. The kinetic tests of Mn(II) removal (130 mg L-1 initial Mn(II) concentration) by MgO impregnated PU (PUMgO) showed that the highest removal rate was 0.49 h-1 using 12 g MgO impregnated PU (PUMgO-12). The Mn(II) removal capacity of PUMgO-12 reached about 400 mg Mn (g of media)-1. Correspondingly, the highest removal capacity based on the mass of MgO was 1067 mg Mn (g of MgO)-1, which is 2-3 order higher than those of other conventional materials (limestone or dolomite), frequently used in mine drainage treatment. Through analyzing pH, Mn(II) and Mg(II) concentration, the proposed major mechanism of Mn(II) removal by PUMgO was the manganese hydrolysis followed by oxidation, catalytically assisted by Mn(II). Corresponding to the proposed mechanism of Mn(II) removal, the XRD analysis revealed that the dominant Mn and Mg species in PU were turned out to be Mn3O4 and Mg(OH)2, respectively. Based on the kinetic and BET results, the clogging effect of oxidized manganese species into pores led to the increase of Mn3O4 particles as Mn(II) concentration increased.
Bibliographical noteFunding Information:
This study was funded by the Korea Mine Reclamation Corp. project “Developing a biotic–abiotic complex system for Mn-contaminated AMD” and partly supported by an Exploratory Research Grant Scheme (ERGS) grant funded by the government of Malaysia (MOHE), No. ER009-2013A .
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All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Filtration and Separation