Adsorption Behavior of Methylene Blue, Cd 2+ , and Pb 2+ Onto Raw Bamboo Shoot Brown Powder: Kinetic, Isotherm, Thermodynamic, and Regeneration Studies

ABSTRACT Textile wastewater containing synthetic dyes and toxic heavy metals poses a serious environmental concern. This study investigated raw bamboo shoot brown powder (BSBP) as a low‐cost biosorbent for the removal of methylene blue (MB), Cd 2+ , and Pb 2+ from aqueous solution. Batch adsorption experiments were performed by varying pH (2–9), adsorbent dosage (0.25–6.0 g), contact time (5–240 min), initial concentration (10–200 mg L −1 ), and temperature (25°C–35°C). Maximum removal efficiencies of 98% for MB, 85% for Cd 2+ , and 80% for Pb 2+ were achieved at pH 6 using 2.0 g of adsorbent. Equilibrium was attained within 180 min for MB and 120 min for Cd 2+ and Pb 2+ . The adsorption kinetics were best described by the pseudo‐second‐order model, while isotherm analysis indicated heterogeneous adsorption behavior. FTIR and SEM analyses supported the role of functional groups and porous morphology in adsorption. Overall, findings suggest BSBP is a sustainable and promising adsorbent for wastewater treatment.