4. Conclusion This study was mainly focused to establish the feasibility of using spent rice biomass waste after sugar extraction as a low cost adsorbent for dyeing wastewater. The sugar extracted biomass from a cellulosic bioethanol facility required proper waste disposal which could add financial burden on the industry. The utiliza-tion of such biomass if used as adsorbent cannot only minimize its disposal cost but can also remove organic dyes from aqueous solutions. Adsorption was investigated using the statistical design of experiment to investigate the effects of experimental factors. Dye concentration appeared the most critical factor in terms of adsorption capacity and color removal. Kinetic, equilibrium and thermodynamic investigations verified the feasibility of spent rice biomass for its application as an adsorbent.