Red algae-derived activated carbon was evaluated for its ability to remove lead (Pb) from synthetic aqueous solution. The activated carbon was prepared at a constant temperature of 300°C for 1 hour using a muffle furnace. Effect of pH contact time, initial ions concentration, and activated carbon dosage as important operating variables on the reaction process were also investigated. The batch experiment was conducted for adsorption experiment. The maximum lead uptake capacity was obtained at pH 6 and operation time of 30 min. the maximum uptake capacity of Pb (II) was found to be 0.1 mg/g. This work confirms the potential use of red algae Gracilaria changii for the removal of heavy metals from wastewater. © The Authors, published by EDP Sciences, 2018.