The activated carbon was prepared with acid digestion method using hydrochloric acid. A. fumosa seed shell was collected and it was dried without sunlight for 3 days and carbonized by using 11.0 N hydrochloric acid. The carbon was washed with distilled water until an optimum pH and dried in hot air oven at 120 °C for 24 h then placed into muffle furnace at 450 °C in 6 h for complete carbonization of the seed shell. Then the carbon was ground in ball mill to convert into desired size of the activated carbon.
Preparation of dye solution
Methylene blue dye was purchased from Merck India limited (analytical grade). 1.0 g of methylene blue dye (Molecular formula is C16H18N3SCl, formula weight is 319.85 and IUPAC name is 3,7-bis(dimethylamino)-phenothiazin-5-ium chloride; The pollution sources of MB dye: chlorine, nitrogen oxides, carbon monoxide, oxides of sulfur, carbon dioxide; source: phenyl thiazine group; safe level in water symbol: (XN)) was dissolved in 1 L of double distilled water (stock solution). Adsorption studies were conducted with desired dilution of the stock solution.