Abstract:
The significant rise in the cost of conventional adsorbents used in wastewater treatment has prompted growing interest in the development of low-cost, sustainable alternatives derived from renewable resources. This study investigates the valorization of agro-waste materials—specifically potato peels and orange rinds—as bioadsorbents for the removal of methylene blue, a model cationic dye commonly found in industrial effluents.The biosorbents were evaluated in both raw and chemically activated forms (using phosphoric acid) to enhance the density of active binding sites and improve adsorption efficiency. A parametric study was conducted to assess the influence of key operational factors, including contact time, biosorbent dosage, and solution pH, on dye removal performance. Batch adsorption experiments at room temperature were performed to examine both kinetic and equilibrium aspects of the process. The results revealed that the pseudo-second-order kinetic model provided the best fit to the experimental data, suggesting a chemisorption-controlled mechanism. Furthermore, equilibrium data were best described by the Langmuir isotherm model, indicating monolayer adsorption on a homogeneous surface. These findings highlight the potential of fruit and vegetable peels as effective bioadsorbent materials for the treatment of dye-contaminated wastewater