| Summary: | The utilization of pectin-Na as adsorbent has been studied for Cd(II). The
adsorbent has been obtained by the saponification of pectin�s orange waste of Citrus
sinensis (L.) Osbeck with NaOH for 24 hours at 70o C. The pectin-Na was
characterized by infra red spectrophotometer (FTIR), it has been studied also the
effect of adsorption parameters (pH, time, and concentration of Cd(II)) on the
adsorption of Cd(II) on pectin-Na, and the adsorption selectivity of pectin-Na for
Cd(II) with the presence of Pb(II) or Zn(II).
Adsorption of Cd(II) was done in batch mode as a function of pH, contact
time, and variation of concentration of Cd(II). The effect of Pb(II) or Zn(II) on the
adsorption of Cd(II) was also studied. Adsorption was performed with initial
concentration of Cd(II) 100 mg L-1 and the solution pH range from 2 to 9. The
adsorbed Cd(II) was calculated by subtracting the concentration of Cd(II) left in the
solution after adsorption to the initial concentration. The concentration of Cd(II) was
determined using atomic absorption spectroscopy.
The results showed the characterization of pectin-Na with FTIR was observed
by the lowering of C=O peak in ester at 1743,65 cm-1 which originally existed in
pectin. It is an indication the presence of exchange of CH3+ with Na+. Adsorption of
Cd(II) on pectin-Na was optimum at pH 7 and followed pseudo second order
adsorption kinetics with adsorption rate constant 3.68 g mmol-1 min-1. The adsorption
capacity was 0.20 mmol g-1 but the adsorption was still inselective with the presence
of Pb(II) or Zn(II).
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