Potential Application of Propionic Acid Modified Sugarcane Bagasse for Removing of Basic and Acid Dyes from Industrial Wastewater

Raw sugarcane bagasse modified with propionic acid (RBMPA) was used as an efficient, low cost and eco-friendly adsorbent for the removal of methylene blue (basic) and orange II (acid) dyes from aqueous solutions. The effect of different system variables, namely contact time, dye concentration, adsorption dose, pH and particle size were investigated and optimal experimental conditions were ascertained. A greater percentage of dye removal was observed in acidic medium (pH=2) in case of orange II whereas in (pH=7) in case of methylene blue dyes and increases with the increase of the dosage of adsorbent. Maximum dye removal was attained after 60 min. Equilibrium isotherms were analysed by the Langmuir and Freundlich models of adsorption and it was found that the Langmuir isotherm provides a good model for the adsorption of methylene blue whereas the Freundlich isotherm is fit for the adsorption of orange II. The kinetics of the adsorption of both dyes was consistent with pseudo second-order kinetics with a good correlation (R2 > 0.99). Furthermore, the amounts of dye adsorbed at equilibrium, qe (mg g-1) for methylene blue and orange II were 59.5 and 25.5, respectively.