The excessive release of color into the environment is a major concern worldwide. Adsorption process is among the most effective techniques for color removal front wastewater and fly ash has been widely used as an adsorbent. Therefore, this Study was carried Out to understand the adsorption behavior of methylene blue from aqueous systems onto fly ash using the continuous mode. Continuous mode sorption experiments were carried out to remove methylene blue from its aqueous solutions in hydrocyclone equipment. The experiments were performed at constant temperature and dimensions of hydrocyclone with variation of flows through the equipment. concentrations of methylene blue solutions and fly ash concentration, respectively. A maximum removal of 58.24% was observed at adsorbent dosage of 900 mg/l at pH 6.75 for an initial methylene blue concentration of 65 mg/l. (C) 2008 Elsevier B.V. All rights reserved.