ABSTRACT Coal and sugar manufacturing power generation plants are engender million tons of fly ash as waste per annum. It creates serious disposal and environmental problems. There is no alternative usage for its utilization in industries. In this regard, efforts were taken to utilize fly ash waste in the treatment of highly toxic and polluted dyes effluents. In this advanced research, characterization of fly ash properties, preparation of adsorbent, utilization for the optimum reduction of dyes effluent pollutants, determination of adsorptive capacity and study of isotherm adsorption models were accomplished. Treatment efficiency was optimized using these ashes as adsorbent at optimum dose. Sugarcane bagasse fly ash (SBFA) could reduce the higher concentration of COD (51%), color (70%), turbidity (71%) and TSS (96%) from dyes effluent. All used fly ashes could reduce higher concentration of effluent pollutants at 4 g dosing. SBFA has high porosity, which resulted in high adsorption of effluent pollutants as compared to other fly ashes. The adsorptive capacity of all used fly ash was declined on increasing adsorbent dosing. Langmuir and freundlich isotherm models were evaluated for the determination of chemical adsorption behavior of fly ashes