Abstract
The anion effect was investigated for the copper adsorption on NH 2-MCM-41 from Cu(NO3)2 and CuSO4 solution. The copper adsorption was higher and faster in the presence of SO 42- anion compared to NO3-. The MCM-41 possesses well-ordered mesopores that are readily accessible and a uniform surface that is amenable to the attachment of the chemical moieties for creating tailored adsorption sites. The adsorption sites on NH 2-MCM-41 were created by grafting aminopropyls on MCM-41, and the random deposition resulted in a site distribution best described by the Freundlich equation. The majority of the adsorption sites (i.e. up to 70%) are readily accessible to Ca2+ adsorption. The remaining sites were only accessible in the presence of SO42-. Evidence showed that the SO42- anion affects the adsorption by interacting with the dissolved copper to form [CuSO4]0 species, coadsorbing with Cu2+ to form stable complexes, and may even indirectly react with the weakly acidic silanol groups to liberate aminopropyls for more Cu2+ adsorption.
Original language | English |
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Pages (from-to) | 9376-9383 |
Number of pages | 8 |
Journal | Industrial and Engineering Chemistry Research |
Volume | 47 |
Issue number | 23 |
DOIs | |
Publication status | Published - 3 Dec 2008 |
Externally published | Yes |