Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal
ions from aqueous solutions. In this study, the batch removal of nickel (II) ions from aqueous solution under
different experimental conditions using activated carbon prepared of red alga Gracilaria was investigated in
this study. The nickel (II) uptake was dependent on initial pH and initial nickel concentration, with pH 5 being
the optimum value. The equilibrium data were fitted using Langmuir and Freundlich isotherm model, with the
maximum nickel (II) uptake of 99.03% determined at a pH of 5. At various initial nickel (II) concentrations
(30-70 mg/L ), If the adsorption is design correctly, it will be attractive. sorption equilibrium was attained
between 15 and 120 min. The nickel (II) uptake by activated carbon was best described by Pseudo-second order
rate model. This study, shows the usage of activated carbon as a valuable material for the removal of Ni from
aqueous solution wastewater and a better substitute to be used in activated marine red algae.