The threat of pharmaceutical residues in natural waters is a pressing concern in both developed and underdeveloped countries. Originating mostly from municipal and farms effluents, pharmaceuticals, poorly eliminated by traditional wastewater treatments enter the environment through sewage treatment plants discharges. Their adsorption on ecological adsorptive materials such as lignin may represent an interesting remediation solution. The present study sets out the sorption capacities and properties of a newly developed lignin-based nanofibrous material for typical pharmaceutical residues (fluoxetine, venlafaxine, ibuprofen, and carbamazepine) found in surface waters. This green biomaterial showed, in addition to its high recovery yield, excellent reusability through desorption (more than 90% recovered). As an example, adsorption levels reached 78 mg/g for adsorption of fluoxetine compared to 5–10, 49 and 75–80 for unfunctionalized silica, zeolites and ion-exchange resins respectively. The innovative approach reported therein perfectly meets the concept of circular economy sought in modern societies.

Pharmaceutical residues coming from urban wastewater were recognized as a major source of pollution for the aquatic environment. Their occurrence in most municipal effluent seems to indicate that conventional wastewater treatments have only a limited ability to remove such substances from sewage. Therefore, the undesired effects caused by these emergent contaminants on the environment force the authorities to consider new measures to treat and recycle contaminated water. In this study, electrospun nanofibers made of chitosan and poly(ethylene oxide) (PEO) were used to remove the anti-inflammatory drug ibuprofen in solution. The electrospinning parameters such as the mixture solution concentration, applied voltage, distance needle-collector, and flow rate were optimized to get the best nanofiber morphology characterized by scanning electron microscopy (SEM). With the use of a high-performance liquid chromatography with ultraviolet diode array detection (HPLC-UV DAD) system, sorption tests were performed by modifying experimental conditions, e.g. pH, concentration of ibuprofen, and temperature of the tested solutions. Langmuir, Freundlich, and Dubinin-Radushkevich (DR) adsorption models were compared for the mathematical description of adsorption equilibria. Kinetic assays showed that the adsorption of chitosan nanofiber followed a pseudo-second-order model. After 20 min of exposure, 25 mg of nanofiber had removed 70% of the initial ibuprofen concentration.

Emerging contaminants present a challenge for water preservation, threatening humans' health and all ecosystems. They consist of a variety of molecules ranging from pharmaceutical and personal care products to pesticides and endocrine disruptors detectable in wastewater, sewage effluent, surface water, drinking water, and ground waters at trace level concentrations (e.g., ng/L, μg/L). Conventional wastewater treatment plants (WWTPs) possess low efficiency to remove them. Therefore, new technologies capable of removing such residues are needed. Lignin recognized as a renewable and abundant biopolymer is transformed through electrospinning into an anionic nanofibrous nonwoven adsorbent to extract those contaminants and dispose them safely. Electrospinning allows the manufacture of fibers at the micro- or nanoscale under the influence of an electric current. In this study, nanofibers of alkali lignin and a co-polymer, poly(vinyl alcohol), were developed and tested on the adsorption of a pharmaceutical contaminant (fluoxetine) in an aqueous solution. Results showed that the lignin nanofibers, of 156 nm in diameter, adsorbed 70% of fluoxetine in solution which corresponds to 32 ppm of contaminants removed in water.

Une multitude de résidus pharmaceutiques sont quotidiennement rejetés dans les eaux usées suivant une consommation humaine. Aux usines de traitement des eaux, là où ils seraient habituellement éliminés, ces résidus résistent aux procédés traditionnels et poursuivent leur chemin vers les cours d’eau [1]. Bien qu’en microtraces, ces contaminants de l’eau ont des effets néfastes tant sur l’homme que sur les écosystèmes aquatiques [2]. C’est donc pour cette raison qu’un nouveau nanomatériau écologique a été développé pour retenir par adsorption les contaminants pharmaceutiques. Son efficacité a été évaluée sur un antidépresseur, la fluoxétine (Prozac®). Sa capacité à être réutilisée sur plusieurs cycles par désorption a également été testée. Introduction