Adsorption of Cobalt Ion from Aqueous Solution Using Biomaterial of Microalgae Oscillatoria sp Isolated from Teluk Jakarta

Abstract

The adsorption of cobalt onto biomaterial of microalga Oscillatoria sp was investigated via batch experiment. Marine alga Oscillatoria sp was isolated from Teluk Jakarta Indonesia. The characterization of the functional group with FTIR spectrum showed microalgae have a functional group of O-H, C = O, COO, C-O-C, NH, C-S, C-H and PO43-. Adsorption of cobalt ion was investigated as a function of time, pH, initial cobalt concentration, the dosage of biosorbent, salinity dan shaking. Equilibrium and kinetic adsorption were obtained from the batch experiment. The cobalt adsorption followed the Langmuir and Freundlich, isotherm models. The Freundlich constant (Kf) and n were 0.1186 (mg/g) (L.mol)1/n and 8.43 mg/L, respectively. The maximum adsorption capacity was 4.71 mg/g at pH 8. Oscillatoria sp could adsorb cobalt even at a lower concentration, indicating a good affinity for metal. Kinetic studies showed that the adsorption of cobalt ion followed a pseudo-firstorder with k1 = 1.2×10-3 min-1.