Investigation of Methylene Blue Removal from Aqueous Solutions Using Biochar Derived from Mango and Pitanga Pruning Waste

This research investigates the adsorption potential of mango and pitanga tree pruning waste biochar produced at 300 °C and 500 °C for the uptake of Methylene Blue (MB) dye. The particle size of biochar, initial MB concentration, adsorbent mass and pH of the solution were varied. Equilibrium data were modeled using Langmuir, Freundlich and Temkin equations. Increasing the temperature of the treatment resulted in a slight increase in the efficiency and adsorption capacity of the material. Finer particles (<0.25 mm) and pH (>6) were more efficient in adsorbing MB. Both materials presented similar modeled parameters for Langmuir, Freundlich and Temkin isotherm equations. The adsorption at equilibrium of MB is best described by Langmuir and Freundlich models, and the modeled maximum adsorption capacity values are 20.53 ± 5.47 mg g−1 for BTP-300 and 23.40 ± 6.41 mg g−1 for BTP-500, proving the biochar’s efficiency in the adsorption of MB and that the temperature of the thermochemical process did not affect qm.