Synthesis and characterization of electrospun-based composite for the remediation of pharmaceutical pollutants in wastewater

Abstract

Pharmaceutical pollutants, including non-steroidal anti-inflammatory drugs (NSAIDs) and antiretroviral drugs (ARVs), pose a significant threat to aquatic environments, necessitating effective remediation strategies. This comprehensive study delves into the efficacy of nanotechnological approaches, with a special focus on adsorption, in addressing the persistent issue of pharmaceutical pollution in wastewater bodies. The research covers the synthesis and characterization of a multi-template molecularly imprinted polymer (MIP) targeting key pharmaceutical compounds, namely naproxen, ibuprofen, diclofenac, emtricitabine, tenofovir disoproxil, and efavirenz, for extraction from contaminated water sources. Comparative analyses between the synthesized MIP and a commercial Solid Phase Extraction (SPE) cartridge showed comparative performance of the MIP and SPE cartridge in quantifying pharmaceutical compounds present in wastewater samples. The results highlighted both materials' consistent efficiency in the removal of pollutants, with selective pharmaceuticals exhibiting varying levels of removal efficiency during different treatment stages. Regressions analysis showcased high linearity (R2 values ranging from 0.9980 to 0.9999), alongside remarkable recoveries (90.9 % to 100 %) for the MIP and method detection limits (MDLs) ranging from (0.14-1.08 μg L-1) for all target pollutants. Recoveries for SPE samples ranged from (62 % to 98 %) with method detection limits at (0.7-4.68 μg L-1). The optimal conditions for efficient extraction of pharmaceutical compounds using the MIP were determined through a series of experiments, considering factors such as pH, mass, concentration, and contact time. Results showed high extraction efficiencies (>96%) and a notable adsorption capacity (>0.91 mg. g-1) for both ARVs and NSAIDs, confirming the MIP's potential for successful removal of these pollutants from wastewater. Additionally, adsorption kinetics were studied, revealing a second-order rate model and adherence to the Freundlich adsorption isotherm. Furthermore, this study incorporates synthesized MIP into the electrospinning technique, utilizing various polymer blends and optimized solvents to enhance the remediation process. The study explores the electrospun mats morphology, particularly those composed of polyvinyl alcohol (PVA) and polyethylene terephthalate (PET), examining their structural characteristics using techniques such as Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and adsorption time studies. Through merging advanced nanotechnological techniques with electrospinning methodologies, this study presents a robust framework for combating pharmaceutical pollutants in wastewater. The incorporation of the MIP into electrospun mats, coupled with in-depth material characterization and adsorption studies, emphasizes the potential of this innovative approach for environmental remediation and drug purification processes. This research contributes valuable insights into the effective removal and quantification of pharmaceutical pollutants, emphasizing the pivotal role of electrospinning technologies in addressing environmental challenges. In conclusion, this study sheds light on the potential of a multi-template MIP for the removal of ARVs and NSAIDs from contaminated water sources, showcasing its versatility and efficacy in enhancing water treatment processes, as well as its utility in drug purification and recovery processes. Overall, the research provides valuable insights into the complexities of pharmaceutical pollutant removal, emphasizing the significance of selecting appropriate extraction methodologies in wastewater treatment processes to ensure efficient and sustainable remediation practices.