Assessing the Removal Efficiency of Ibuprofen in an Aqueous Solution Using Acacia erioloba Nanoparticles ^†

This study highlights the adsorption efficiency of A. erioloba Seed Nanoparticles (AESNs) in the removal of ibuprofen from water. Ibuprofen is one of the most commonly used drugs in the world and often makes its way into aquatic resources through improper disposal. The AESNs (adsorbents) were extracted from the A. erioloba seed pod via dewaxing, alkali treatment, bleaching, and acid hydrolysis to obtain nanoparticles. These nanoparticles were characterized by scanning electron microscopy (SEM) analysis. An ibuprofen solution model was prepared via the dissolution of water–methanol at a ratio of 9:1. A calibration curve was prepared with a standard solution of the ibuprofen in a concentration range of 0.001–0.010 mg/L. The effect of dosage, pH, time, and temperature in each of the prepared ibuprofen concentrations was determined. Fourier–transform infrared spectroscopy (FTIR) was used to determine functional groups, and SEM was used to study the morphology, size, and surface structure of the nanoparticles. UV spectroscopy determined the concentration of ibuprofen after the interaction with the AESN in different parameters, and X-ray diffraction (XRD) was used to determine the crystal structure of the AESN. The Langmuir and Freundlich isotherm models, as well as Brunauer–Emmett–Teller (BET) methods, were applied to optimize the conditions for maximum adsorption and elucidate the surface area of AESNs and the behaviour of AESN as an adsorbent. The BET results indicate that the surface area was found to be 0.7313 m²/g and the pore size was 0.001148 cm³/g. The R² of 0.77 and 0.3710 results indicate that they do not favor both Langmuir and Freundlich isotherm models. The use of a low ibuprofen concentration, i.e., a low dosage, in this study resulted in positive results.