This study aimed at investigating the feasibility of using jackfruit peel (JFP), a solid waste, abundantly
available in Malaysia, for the adsorption of methylene blue, a cationic dye. Batch adsorption studies were
conducted to evaluate the effects of contact time, initial concentration (35–400 mg/L), pH (2–11), and
adsorbent dose (0.05–1.20 g) on the removal of dye at temperature of 30 ◦C. The experimental data were
analyzed by the four different types of linearized Langmuir isotherm, the Freundlich isotherm and the
Temkin isotherm. The experimental data fitted well with the type 2 Langmuir model with a maximum
adsorption capacity of 285.713 mg/g. Pseudo-first and pseudo-second-order kinetics models were tested
with the experimental data, and pseudo-second-order kinetics was the best for the adsorption of MB
by JFP with coefficients of correlation R2 ≥ 0.9967 for all initial MB concentrations studied. The results
demonstrated that the JFP is very effective for the adsorption of methylene blue (MB) from aqueous
solutions.