ABSTRACT
Studies on biosorption and desorption of Cr(lll) on algae (Eucheuma spinosum) adsorbent have been carried
out. These studies included determination of biosorbent acidity, optimum pH, contact time of biosorption, isoterm
and biosorption capacity, and mechanisms of interaction between Cr(lll) and algae (E. spinosum) biosorben.
Mechanisms of interaction were evaluated by sequential desorption of Cr(lll) on algae biosorben by using aquadest,
1M HCI and 0.05 M NazEDTA. The result showed that the total acidity of algae biosorbent was 4.15:i: 0.33 mmollg,
the optimum pH was 3, and the optimum contact time was 20 min. Biosorption capacity of algae (E. spinosum)
toward chromium (III) was 57.33 mglg. The highest desorption of Cr(lll) achieved when 1 M HCI was used, i.e.
51,01%, wheareas desorptions using aquadest and 0.05 M NazEDTA were relatively low, i.e. 2.07% and 2.38%
respectively. This result indicates that the main interaction mechanism of Cr(lll) on algae was electrostatic attraction.
Keywords: Biosorption, Cr(lll), Eucheuma Spinosu
