Eco-friendly Biopolymer/Activated Charcoal Magnetic Nanocomposites with Enhanced Stability and Adsorption Properties for Water Treatment Applications

Despite the effectiveness of activated carbon as an adsorbent for many contaminants in water, it suffers from poor handling and regeneration along with difficulty of separation from water after application. Our research aims to develop activated carbon-based adsorbents with enhanced stability and adsorption properties through incorporating biopolymers such as xylan and pectin and coating them over magnetite. The mesoporous adsorbents, as measured by Brunauer-Emmett-Teller analyzer, successfully adsorbed the pharmaceutical emerging contaminants of fluoxetine and famotidine with respective maximum adsorption capacities of 90.9, 42.9 mg/g for the xylan-incorporated nanocomposite, and 114.9, 53.5 mg/g for the pectin-incorporated ones, which are the highest capacities reported for these drugs to date. Thermogravimetric analysis and zeta potential measurements in acidic and basic media showed superior thermal and chemical stability for the developed nanocomposites over bare activated charcoal coated magnetite. Incorporating the biopolymers improved the regenerability of the nanocomposites, as confirmed by estimating the equilibrium dissociation constants. High Performance Liquid Chromatography measurements on adsorption in binary systems of the two drugs in distilled water and spiked tap water showed a decrease in percent removal compared to single systems owing to competitive adsorption between the two drugs. [GRAPHICS]