Articles
Desalination and Water Treatment (19443994)321
Mixed matrix membranes composed of polyvinyl alcohol (PVA) and graphene oxide (GO) were synthesized using the blending and casting method. The properties of the prepared membranes were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), tensile strength testing, and contact angle measurement. The membranes’ ability to desalinate saline solutions was investigated using the pervaporation method, focusing on two key parameters: flux and rejection. The effects of GO loading, temperature, feed solution pH and membrane thickness were studied, explained and compared with neat PVA membranes and other reported works. The results indicated that incorporating GO into PVA enhances the membrane's strength and makes it possible to use thinner membrane and finally it causes a significantly increase in flux. Desalting of different solutions containing Na+, Mg2+, Ca2+, Fe3+ and Al3+ ions, alone or together often showed the rejection values more than 99 %. Among them the best performance was achieved for a feed containing 1000 mg/L of Fe (III) at a temperature of 50°C, with an outstanding permeability value of 38.47 kg.m-²·h−1 and a rejection rate of 99.99 %. Overall, the results demonstrate these composite membranes are highly efficient and economical for water and wastewater treatment. © 2025
Journal of Food Science (00221147)90(1)
Abstract: Quercetin, a key flavonoid found in many fruits and vegetables, offers notable health benefits, including antioxidant, antiviral, and antitumor properties. Yet, isolating it from complex plant materials is challenging. This research aimed to develop a selective and efficient sorbent to clean up real sample matrices and pre-concentrate quercetin, enhancing its detection using high-performance liquid chromatography (HPLC). Several metal organic frameworks (MOFs) were synthesized and initially, their abilities to sorption of quercetin from aqueous and alcohol media were examined. Among them, HKUST-1 showed the best performance. To improve the efficiency of this MOF, its composite with graphene oxide (GO) was prepared (Fe3O4@SiO2/GO/HKUST-1) and was employed for quercetin extraction through magnetic dispersive micro solid-phase extraction. The effect of different parameters was examined and the kinetic, thermodynamic, and isotherm of the sorption process was studied. The related results showed the system followed the pseudo-second-order kinetic model, with the Temkin and Langmuir isotherm models applicable in aqueous and methanol solutions, respectively. The method enabled rapid preconcentration and clean up within 20 min, with a 99.6% adsorption efficiency using just 5 mg of sorbent. The nanocomposite demonstrated an adsorption capacity of 29.3 mg/g and effectively extracted quercetin from red onion samples, achieving recovery rates between 75% and 98% for HPLC-diode array detector analysis. Practical Application: Quercetin is a common polyphenolic compound, which is widely found in plant materials such as onions. Owing to its medicinal effects including anti-inflammatory, anti-oxidant, anti-cancer, cardioprotective, anti-bacterial, anti-viral, and anti-allergic features, it has widespread usage in pharmacology and preparation of food preservers. In this study, Fe3O4@SiO2/GO/HKUST-1 nanocomposite was synthesized for extraction and preconcentration of quercetin from an onion sample. Very low amounts of this sorbent indicated high adsorption percentage and adsorption capacity for quercetin. This method was simple, fast, cost-effective, precise, and accurate, which exhibited a potential for extraction of quercetin in a large scale. © 2025 Institute of Food Technologists.