Chemical Treatment of Banana Blossom Peels Adsorbent as New Approach for Manganese Removal: Isotherm and Kinetic Studies

This research aimed to investigate the potential of chemically modified banana blossom peels (BBP) as an adsorbent for removing manganese (Mn) from water. Zeta potential, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Brunauer–Emmet–Teller (BET) were used to characterise the BBP adsorbent. Batch adsorption studies were used to assess the effects of the solution pH, adsorbent dosage, initial manganese concentration, and contact time of the adsorption process. Zeta potential of BBP with a value of −9.87 to −21.1 mV and FESEM analysis revealed deeper dents and rough internal surfaces conducive to Mn deposition, whereas EDX analysis revealed the presence of C, O, and Na elements (before adsorption); C, O, and Mn (after adsorption). The presence of hydroxyl, carboxylic, and amino groups, which are responsible for the adsorption process, was discovered using FTIR analysis. Furthermore, XRD analysis revealed that the BBP adsorbent structure is amorphous. The BBP adsorbent has a BET surface area of 2.12 m2/g, a total pore volume of 0.0139 cm3/g, and an average pore diameter of 64.35 nm. The BBP adsorbent demonstrated remarkable results of 98% Mn removal under the optimum pH 7, 0.5 g (adsorbent dosage), and 10 mg/L of Mn initial concentration in 150 min of contact time. The linear Langmuir and Freundlich isotherm models best fit the adsorption isotherm data with the R2 > 0.98. In contrast, the adsorption process occurs as a function of the chemisorption as determined by linear pseudo-second-order kinetics. Using 0.1 M HCI, the maximal desorption rate of Mn was 92% in the first cycle, with a recovery rate of 94.18% Mn removal in 30 min. These findings support the use of BBP as a natural adsorbent for Mn removal as a treatment option for improving wastewater quality.