Abstract:
This study evaluates the effectiveness of two adsorbents derived from a local plant waste, biochar (via pyrolysis) and hydrochar (via hydrothermal carbonization), for the removal of Crystal Violet dye from aqueous solution. The hydrochar, with a more acidic surface (pHpzc ≈ 3.2), exhibited significantly higher adsorption capacity (148.81 mg/g) compared to biochar (16.34 mg/g). Adsorption followed the Langmuir model and fitted a pseudo-second order kinetic. Both materials showed potential for regeneration, though with decreasing efficiency. Hydrochar thus appears as a promising candidate for sustainable treatment of dye-contaminated water.