The removal of Cu(II) by a mesoporous material, FSM-16, was studied using electron paramagnetic resonance (EPR) spectroscopy and surface complexation modeling (SCM). Free copper ions, adsorbed and precipitated Cu(II) species were qualitatively identified by in situ EPR spectroscopy of Cu-FSM-16 suspensions at room temperature and at 77K. In addition, the adsorbed species was identified as a Cu(II) species with an axial symmetry from an analysis of the EPR spectra of "dry" Cu-FSM-16 at 77K. On the basis of the EPR results, the removal of Cu(II) as a function of pH under various experimental conditions was successfully simulated by assuming two removal mechanisms such as surface complexation and surface precipitation. In the acidic pH range (<pH 6), free copper ions were predominant, and surface complexed then surface precipitated species became dominant as the pH increased.
ASJC Scopus subject areas
- Environmental Engineering
- Civil and Structural Engineering
- Ecological Modelling
- Water Science and Technology
- Waste Management and Disposal