Cellulose-based waste structure and chemical composition impact on the adsorption of pharmaceuticals

In an attempt to reuse fibrous textile waste, and at the same time to reduce its quantity, waste hemp and flax fibers, and cotton yarn were used as cheap and sustainable adsorbents for the removal of pharmaceuticals from water. In order to improve their adsorption properties, waste fibers, and yarn samples were modified using 18% NaOH solution. Morphology, surface chemistry, and structural characteristics were examined through scanning electron microscopy, Fourier transform infrared spectroscopy, degree of surface crystallinity, and crystallinity index. Adsorption properties were analyzed through the determination of iodine sorption and water retention, as well as, the adsorption of selected sedatives. Modification with 18% NaOH increased the content of amorphous areas in examined fibers and yarn samples, improving their adsorption characteristics. Utilization of both unmodified and modified samples enables fast and highly efficient removal (adsorption efficiency ranging from 75 to 100%) of sedatives from water, making waste hemp and flax fibers and cotton yarn samples promising adsorbents for water treatment.