Removal of non-steroidal anti-inflammatory drugs (NSAIDs) from water with activated carbons synthetized from waste murumuru (Astrocaryum murumuru Mart.): Characterization and adsorption studies

Abstract

This manuscript aimed to evaluate the adsorption of ibuprofen (IBU) and naproxen (NPX) using chemically activated carbon (CAC) with ZnCl2 synthesized from the waste of murumuru (Astrocaryum murumuru Mart.). The adsorbent was characterized in terms of its textural and physicochemical properties by determining its specific surface area (SBET), pore volume (Vtotal), percentage of ash, moisture, and yield, by FT-IR spectroscopy, XRD and TGA/DTA, as well as surface functional group, surface pH, and zero-charge point (pHPZC) analyses. Batch adsorption testing was carried out to evaluate the effect of adsorbent dosage, contact time, and pH. Adsorption mechanisms and the nature of the process were elucidated through kinetics, equilibrium and thermodynamics studies. The best results of removal percentage (>70%) and adsorption capacity (>2.2 mg/g) for both adsorbates were obtained with 0.15 g CAC, pH 3.0 and 360 min. The kinetics followed the pseudo-second-order model, with external diffusion the rate-determining step. The isotherms were well fitted by the Freundlich isotherm. The thermodynamic data revealed the endothermic, physical, and spontaneous nature of the adsorption process. The results obtained in this work reveal that CAC can be used as an efficient and viable alternative adsorbent for the removal of ibuprofen and naproxen in effluent treatment processes.