Investigating the Adsorption Efficiency of Banana Pseudo-Stem Derived Biochar for Polyethylene Microplastic Removal from Aqueous Solutions

Microplastic pollution, particularly from polyethylene terephthalate (PET), has emerged as a significant environmental concern due to its persistence and toxicity in aquatic systems. This study evaluates the use of banana pseudo-stem (BPS) biochar as a low-cost, sustainable adsorbent for removing PET microplastics from water. Biochar was synthesized at 450°C, 550°C, and 650°C using slow pyrolysis. PET microplastics (<150 μm) were prepared from plastic waste and used to create stock solutions. Batch adsorption experiments were conducted under varying pH (4, 7, 9), dosage (2, 4, 6 mg), and contact times (30–90 min). Characterization via TGA, FTIR, and CHNS revealed that higher pyrolysis temperatures enhanced the aromaticity, surface area, and carbon content of the biochar. The highest adsorption efficiency was recorded at 650°C, with 6 mg of biochar at pH 9. These findings support the potential of BPS biochar as an environmentally friendly and effective solution for microplastic removal and valorization of agricultural waste.