Synthesis of Novel High-Performance Adsorbent Based on Modified Polyurethane/Polysaccharides for Wastewater Treatment

Water pollution caused by harmful bacteria, heavy metals and dye is a global issue that requires strategic solutions to minimize its environmental impact. In this work, novel polysaccharide-modified polyurethanes (PS-PU) were prepared and evaluated in the removal of S. aureus, methylene blue (MB), and Cu2+ from wastewater. The PS-PU materials were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Nuclear magnetic resonance spectroscopy (H-1 NMR). The PS-PU has shown impressive antibacterial capabilities against S. aureus, while also demonstrating effective adsorption properties for MB and Cu2+. For optimizing the conditions to maximize MB and Cu2+ removal, the impacts of solution pH, adsorbent dosage, adsorption time, and temperature were investigated. The maximum adsorption of chitosan-modified polyurethane (CS-PU), chitosan and cyclodextrin-modified polyurethane (CS-PU-CD) for MB were 95.15% and 97.58% respectively in just 30 min of contact. When it comes to the removal of Cu2+, the maximum removal rates of 94.73% (CS-PU) and 96.87% (CS-PU-CD) were achieved after 40 min of absorption. The absorption behavior of this system was better described by the quasi-second-order kinetics and Langmuir isotherm model. The intraparticle diffusion demonstrated the multi-step nature of the adsorption process and the pollutants removal was associated with electrostatic adsorption. In summary, the PS-PU materials produced in this study proved to be exceptional adsorbents for treating wastewater that contains different pollutants, including S. aureus, MB, and Cu2+.