Removal of Hexavalent Chromium Using Activated Carbons Derived from Marine Algae Gracilaria and Sargassum Sp

Industrial wastewater contain higher quantities of salts besides chromium (VI) ions, therefore, the effect of these salts on the adsorption of chromium (VI) should be studied. In this research, the batch removal of toxic hexavalent chromium ions from wastewater and aqueous solution using two different activated carbon marine algae Gracilaria (red algae) and Sargassum sp. (brown algae) were examined. Activated carbon prepared from Gracilaria and Sargassum sp. The chromium uptake was dependent on the equilibrium pH and chromium concentration, with pH = 2.0, being the optimum pH value. The experimental adsorption data were fitted to the Langmuir and Freundlich adsorption model. The maximum efficiencies of chromium removal were 91.53% and 91.98% for activated carbon prepared of Gracilaria and Sargassum sp., respectively. A significant fraction of the total chromium (VI) uptake was achieved within 60 min. The chromium (VI) uptake by the biosorbents was best described by pseudo-second order rate model. This investigation verifies the possibility of using activated carbon prepared from algae as valuable material for the removal of chromium from aqueous solution and wastewater.