Efficient Removal Of Pathogenic Bacteria And Viruses By Multifunctional Amine-modified Magnetic Nanoparticles

In recent years, a lot of hazardous wastes have been discharged into the water, which can result in serious microbial contaminations. The infectious bacterial and viruses can result in not only serious threats to human health, but also widespread damages. Specifically, Escherichia coli (E.coli) O157:H7, as an enterohemorrhagic strain, can cause diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Thus, there is an urgent need to remove the pathogenic microorganisms rapidly and efficiently.The various traditional techniques which were extensively used to remove bio-organic pollutants have several important drawbacks such as high cost of equipment and operations, difficulties of adsorbents’separation and regeneration, secondary pollution, and so on. Nowadays, the functionalized magnetic nanoparticles aroused many scientists’great interests because of its smaller particle size, high specific surface area, low intraparticle diffusion rate and internal diffusion resistance. Moreover, various adsorbents coupled with different valence bonds can be widely used to remove different contaminants.Firstly, the paper introduces the treatment status of waste water which contaminated with pathogenic microorganisms, and then discusses the shortcomings of conventional removal methods in order to illustrate the background and meaning of the research. In addition, the paper presents the research status of multifunctional amine-modified magnetic nanoparticles, illustrates its modification methods, and recommends its widely applications.The aim of this paper is to prepare the novel core-shell silica-coated (Fe3O4-SiO2) and amine-functionalized (Fe3O4-SiO2-NH2) magnetic nanoparticles, which are employed to rapidly remove the pathogenic bacteria and viruses. Detailed experimental procedure is as follows:1, Prepare the Fe3O4-SiO2and Fe3O4-SiO2-NH2nanoparticles through layer-by-layer methods, which were characterized by TEM, EDS, XRD,XPS, FT-IR, BET surface analysis, magnetic property tests and zeta-potential measurements, respectively.2, The multifunctional amine-modified magnetic nanoparticles were used to non-specific remove the bacteria (Gram-positive and Gram-negative bacteria) and viruses. The specific removal of target microorganism can be realized when the nanoparticles were coupled with antibody. According to the results, the functions of different groups were detailed analyzed.3, A series of experiments were performed to discuss the optimal conditions to remove microbial pathogens using E.coli O157:H7as model microorganism, considering that the incubation time and pH of PBS may influence the capture efficiency.