Fabrication of Novel Magnetic Nanoparticles of Multifunctionality for Water Decontamination

Efficient and powerful water purifiers are in increasing need because we are facing a more and more serious problem of water pollution. Here, we demonstrate the design of versatile magnetic nanoadsorbents (M-QAC) that exhibit excellent disinfection and adsorption performances at the same time. The M-QAC is constructed by a Fe3O4 core surrounded by a polyethylenimine-derived corona. When dispersed in water, the M-QAC particles are able to interact simultaneously with multiple contaminants, including pathogens and heavy metallic cations and anions, in minutes. Subsequently, the M-QACs along with those contaminants can be easily removed and recollected by using a magnet. Meanwhile, the mechanisms of disinfection are investigated by using TEM and SEM, and the adsorption mechanisms are analyzed by XPS. In a practical application, M-QACs are applied to polluted river water 8000-fold greater in mass, producing clean water with the concentrations of all major pollutants below the drinking water standard of China. The adsorption ability of M-QAC could be regenerated for continuous use in a facile manner. With more virtues, such as low-cost fabrication and easy scaling up, the M-QAC have been shown to be a very promising multifunctional water purifier with rational design and to have great potential for real water purification applications.