Synthesis, characterization and performance of polyurethane foam nanocomposite for arsenic removal from drinking water

A new nanocomposite material is developed for arsenic removal from drinking water, in ppb concentrations, by incorporating 15-20 nm iron oxide nanoparticles (IONPs) inside a porous polyurethane foam (PU) with an open cell structure. To obtain the best removal capacity of arsenic species, the composition ratio of Polypropylene glycol (PPG) and Toluene di-isocyanate (TDI) in the PU foam, as well as, the percentage loading weight and size of the IONPs, were investigated. Scanning Electron Microscope and Energy Dispersive X-ray analysis (SEM/EDX) were used to examine the microstructure and distribution of IONPs inside the foam matrix. Atomic absorption spectrometer (AAS) analysis was conducted to measure the removal capacity of the nanocomposite foams. Sorption isotherms models were applied to determine the adsorption mechanisms and modeling parameters. It was found that the composition ratio of PPG:TDI (1:2) with 12% IONPs (15-20 nm) yields the highest affinity towards arsenic species, compared to other possible combinations, with a removal capacity of 40% using single stage batch analysis. Multi-stage setup and applications can increase the removal capacity significantly. Polyurethane nanocomposite adsorbents provide low-cost solutions to water filtration applications with high versatility and potentials.