This study aims to investigate the adsorption of semi-ripe banana peel (BP) as a biosorbent for removing cationic and anionic dyes. Previous research has demonstrated the ability of fruit peels to adsorb pollutants, with a notable efficacy against cationic contaminants. Inspired by these findings BP prepared using different treatments was studied as an affordable and eco-friendly alternative for dye adsorption. Four peel preparation methods—sodium hydroxide (NaOH), hydrochloric acid (HCl), oven dried after water (H₂O), and not dried after water (H₂O) were used to prepare BP for batch adsorption of an anionic and cationic dye, allura red (AR) and methylene blue (MB), respectively. With the goal of maximizing pollutant removal efficiency by optimizing BP preparation while still maintaining environmental sustainability, the experimental design controlled peel size to reduce variability in our comparisons between findings and established literature on similar biosorbents. We found that BP prepared using NaOH had the highest percent removal. Following the pseudo second order kinetics model the peels achieved an adsorption capacity of 2.9 mg/g at equilibrium with a max percent removal of 85% after 7 hours. This suggests potential for broader application with other dyes with this preparation technique. This study contributes to the growing body of research on low-cost, renewable bioadsorbents by presenting a comparative analysis of BP treatments, with potential applications for improved wastewater treatment methods. The findings from this research could further support the utilization of waste biomass for sustainable environmental cleanup, broadening the scope of biosorbent materials used in the decontamination process.