Use of Rice Hull as a Biomass Sorbent for Organic Pollutant Removal: Adsorption Isotherms and Thermodynamic

The present study describes the adsorption of textile dye on rice hull. The adsorption parameters were obtained from Langmuir and Freundlich isotherms utilizing linear regression plots to fit the data. The results showed that Langmuir equation was more suitable than the Freundlich one to predict the experimental adsorption isotherms, indicating that the adsorption of dye molecules is localized in a monolayer on the surface of the adsorbent. Thermodynamic parameters such as Ha, Sa and Ga were determined in this work. The heat evolved during adsorption is endothermic. The maximum sorption capacity of rice husk was satisfactory when compared to capacities of other low-cost adsorbent materials.