Jackfruit Leaf–Based Natural Adsorbent for the Efficient Removal of Auramine O Dye

Adsorbents synthesized from jackfruit leaves are efficient and economical for the removal of dyes and contributed to waste minimization as well as the reuse and recovery of water. Adsorption characteristics of Auramine O (Basic Yellow 2) dye by jackfruit leaf powder (JLP) were investigated in this study. The study was performed at different impregnation ratios of orthophosphoric acid (JLP/H 3 PO 4 = 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3) and activation temperature (500, 600, and 700 °C) during the synthesis of adsorbent. A batch study was employed to evaluate the effect of various parameters such as pH, adsorbent dosage, initial dye concentration, temperature, and contact time. The adsorbent was characterized by Brunauer–Emmett–Teller analysis, particle size analysis, and scanning electron microscope. The experimental data were successfully fitted with Freundlich, Langmuir, Temkin, Dubinin-Radushkevich, Sips, Redlich-Peterson, and Toth isotherm models. The kinetic models, pseudo-first- and pseudo-second-order equations, and Weber and Morris kinetic models were selected to determine the kinetics and rate-determining step during the adsorption process. The activated jackfruit leaf powder (AJLP) was following pseudo-2nd-order kinetics and best fitted in Langmuir isotherm. The BET surface area for the prepared AJLP was observed to be 500.15 m 2 /g. In addition, AJLP showed a maximum monolayer adsorption capacity of 79.36 mg/g of Auramine O dye. The present study suggests using AJLP as an eco-friendly adsorbent for Auramine O dye removal up to 99.69%. Overall, the promising results indicate that AJLP could be used as an effective green adsorbent for the removal of Auramine O dye. Our prepared adsorbent has an advantage over other adsorbents based on better specific surface area and higher adsorption capacity. Therefore, this study proved our novelty among all the currently available adsorbents for removing Auramine O dye remarkably. Graphical Abstract