Adsorption of malachite green from synthetic wastewater using banana peel adsorbents

The adsorption of malachite green (MG) from synthetic wastewater on banana peel adsorbent was studied in batch experiments. Two species of banana peel adsorbents (Musa x paradisiaca, ABB and Musa acuminate, AAA) with two maturation stages (2 and 6) were studied. The best efficiency of MG removal (97.64%) was obtained using the powder of ripe ABB banana peel (stage 6) as the adsorbent under the optimal conditions of pH 5, 12 h equilibrium time, initial dye concentration of 25 mg/L, adsorbent particle size of 0.150-0.212 mm at the dose of 1 g/L, 30 °C, and shaken at the speed of 150 rpm. The experimental results were best described by the Freundlich isotherm model and the pseudo-second-order kinetic model. Thermodynamic results of the adsorption revealed that it was a random, endothermic, and spontaneous process under the investigated temperature range