A Circular Economy Strategy for Mitigating Pharmaceutical Contamination

Addressing pharmaceutical contamination in urban wastewater involves more than enhancing wastewater treatment plant operations. Addressing contamination at its source remains the gold standard in environmental remediation, enabling more efficient and targeted mitigation efforts [1]. Effective management of risks associated with transformation by-products requires interventions at the contamination source, alongside innovative applications of adsorption technology within a circular economy framework [2]. This study aims to fill gaps in the literature by exploring the potential of desorbing and recovering adsorbates, specifically focusing on granular activated carbon's adsorption of two commonly used iodinated contrast media (ICMs): the non-ionic iopamidol (IOP) and the ionic diatrizoate (DTA), essential pharmaceuticals of environmental significance as contaminants of emerging concern [3]. Our methodology includes initial adsorption onto granular activated carbon followed by separation and extraction of the pharmaceuticals from the spent adsorbent material. We employ a combination of physical and chemical techniques to enhance removal and recovery processes, ultimately developing a robust extraction protocol for these contrast agents. To ensure practical relevance, experiments were conducted using both ultrapure water solutions of pure ICM and a laboratory-simulated artificial urine matrix. The artificial urine matrix represents a more complex and realistic aqueous environment, aiming to simulate scenarios where ICMs are extracted from patients' urine post-imaging procedures. From this complex matrix, upwards of 83.14 ±8.46% pharmaceutical recovery could be achieved with the best available methods.

[1]     F. Russo, L. Nemer, M. Martuzzi e F. Zambon, «Keeping our water clean: the case of water contamination in the Veneto Region, Italy,» World Health Organization, Copenhagen, DK, 2017.
[2]     S. E. Duirk, C. Lindell, C. C. Cornelison, J. L. Kormos, T. A. Ternes, M. Attene-Ramos, J. Osiol, E. D. Wagner, M. J. Plewa e S. D. Richardson, «Formation of Toxic Iodinated Disinfection By-Products from Compounds Used in Medical Imaging,» Environmental Science & Technology, vol. 45, pp. 6845-6854, 2011. 
[3]     A. Sengar e A. Vijayanandan, «Comprehensive review on iodinated X-ray contrast media: Complete fate, occurrence, and formation of disinfection byproducts,» Science of the Total Environment, vol. 769, 2021.