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CH3041
SURFACE SORPTION
•Most minerals contain hydr[oxide] surfaces
    M-OH + Mez+  D  M-OMez+ + H+           Me = Metal,
                                                                                              M=Si, Al
•
•
D
D
D
D
        Mez+(sorbed) D Mez+(aq)


      MeLz+(sorbed) D MeLz+(aq)


            Lz+(sorbed) D Lz+(aq)
Chemisorption.
Surface rxn where
covalent bonds are formed.
• The sorption of
phosphate occurs
by displacement.
M-OH

M-OH
M-O

M-O
OH

O
P + 2OH-
+ HPO42-D
• When organic ligands (L) are bound to the
metal then the
scheme must
be modified :