Sea mango (Cerbera odollam), a non-edible fruit which is abundantly available in Malaysia was transformed into a potential low-cost activated carbon for the removal of methyl orange (MO) (mono azo dye) from textile wastewater. The activated carbon was subjected to carbonization process at 200°C with nitrogen (N2), followed by chemical activation with phosphoric acid (H3PO4) and physical activation using microwaves at 500°C for 2 h. The Brunauer–Emmet and Teller surface area for the produced activated carbon was 1,437 m2/g. The effects of several operating parameters, such as activated carbon dosage, contact time; initial concentration, and pH at room temperature on the adsorption process of MO from simulated textile wastewater were evaluate...