Apriyana, Khamariah2021-10-192021-10-192021-03wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10269The aim of this study was to utilize fly ash boiler waste as an adsorbent for the absorption of methylene. Fly ash boiler adsorbent was made by physical activation method using microwave at 100 watts of power with time variations (1; 2; 3; 4 and 5 minutes). The optimum time of microwave irradiation and adsorption efficiency were tested by adsorbing the methylene blue (10, 20 and 30 ppm). Nonactivated and activated fly ash at the optimum time were characterized using SEM. The result indicated that the adsorption efficiency increased in the existence of activation using microwave irradiation and the optimum time of activation was 3 minutes, with a percentage value of 99.94% adsorption efficiency. The activation process could lead to pore unveiling. Thus, it has proved that fly ash activation using microwave irradiation can increase the absorption ability of methylene blue and adsorption efficiency.enadsorptionfly ashmicrowaveArticle