DOI: https://doi.org/10.55373/mjchem.v28i5.223

Keywords: Effective adsorbent, cationic dye, carcinogens, electrostatic repulsion, hydrogen bonding

Abstract

The aim of this study is to examine the adsorption behaviour of rhodamine B (Rh-B) onto mandarin orange peel (Citrus reticulata) in aqueous solutions under various conditions. Surface morphology characterisation by FESEM showed the surface is irregular, rough, and porous. The BET surface area of the orange peels was determined to be 1.2152 m²g^–1. The FTIR analysis confirmed the presence of oxygen-containing functional groups on the peel surface that promote Rh-B adsorption. Adsorption equilibrium was achieved within 20 minutes under acidic conditions (pH 3) at maximum dosage of 0.1 g adsorbent. The adsorption data aligned well with the Freundlich isotherm model and the maximum uptake (q_m) was 1.901 mgg^–1. Mandarin orange peel serves as an effective adsorbent for the removal of Rh-B from aqueous solutions.