Preparation of activated carbon from Enteromorpha prolifera and its use on cationic red X-GRL removal

► Detailed activation procedures to prepare activated carbon. ► Activated carbon with the high surface area of 1722 m2/g. ► Excellent dye adsorption capacity (263.16 mg/g) of activated carbon. ► Spontaneous and endothermic adsorption process. ► Langmuir isotherm indicates a monolayer adsorption behavior.