Kinetics and Equilibrium of Methylene Blue Removal by Adsorbents Derived from Banana Peel

Abstract

In this work, banana peel was transformed into hydrochar (R0A), chars (BP250 and BP600), activated carbons (R2.0. R2.5 and R3.0) and hydrochar activated carbon (R2.5A). The banana peel adsorbents were characterized for specific area, surface functionalities, morphology, surface composition and pH at point of zero charge (pHPZC). The performance of adsorbents was assessed by methylene blue adsorption at different concentrations and contact times. The result shows that the R2.5 with specific area of 897 m2 g−1 yields a greater methylene blue capacity of 523 mg g−1. The experimental data obeyed pseudo−second order and Langmuir models, elucidating the monolayer accumulation of methylene blue molecules onto homogeneous adsorbent surface. It can be concluded that banana peel could be potentially valorized as effective adsorbent for environmental protection.