Effect of pH
A 30.0 1.0 mg sample of nano-magnetic sorbent was placed in a
50.0 mL measuring flask and 1.0 mL of 0.1 mol L1 metal ion was then
added and followed by 9.0 mL of the selected acidic or buffer
solutions (pH 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 and 7.0). The reaction mixture
was shaken by an automatic shaker for 30 min at room temperature.
The adsorbed metal ion on the surface of nano magnetic sorbent was
separated from solution by the action and attraction of an external
magnet. The free metal ion in solution was transferred to a conical
flask and titrated against 0.01 mol L1 of EDTA by using the
appropriate buffer solution and indicator for each metal ion.