Magnetic Polymer Microspheres In Water Treatment Applications In The Preliminary Exploration Study

Prepration of magnetic microspheres and the application in wasterwater treatment were preliminary studied in this paper.Firstly, the Fe3O4 fluids were successfully prepared by Co-precipititation in the presence of trisodium citrate solution. Secondly, Fe3O4/CS magnetic microspheres were obtained by inverse miniemulsion-chemical cross-linking method. The microstructure and properties of microspheres were characterized by IR,TEM,XRD,TG,VSM.The results showed that the Fe3O4 fluids modified by trisodium citrate were dispersed stably in water with uniform particle size (about 9nm), good crystallinity and high saturated magnetization (68.95emu/g). The prepared Fe3O4/CS magnetic microspheres were well-dispersed, well-encapsulated and its saturation magnetization value achieved 27.58 emu/g, which meet the needs of the further experiment.Setting Cu2+, Ni2+and methyl orange as the adsorption model, various factors on the adsorption properties were investigated and the adsorption mechanism was discussed. The results showed that the magnetic microspheres can decolor methyl orange with several advantages:high efficiency, quick decolorization, easy separation and regeneration. The magnetic microspheres on the adsorption of methyl orange were mainly controlled by electrostatic forces. However, according to the test results, the absorption capacity of the Fe3O4/CS magnetic microspheres for Cu2+and Ni2+need to be improved.As a result, ethylene diamine tetraacetic acid (a metal chelating agent) was chosen to decorate the surface of the Fe3O4/CS magnetic chitosan microsheres. The testing results showed that a great deal of carboxyl groups were linked to the Fe3O4/CS magnetic microspheres surface and the magnetic microspheres maintained their good properties. Compared to unmodified Fe3O4/CS magnetic microspheres, the modified Fe3O4/CS magnetic microspheres significantly accelerated the rate of adsorption and the adsorption capacity greatly increased. It conformed that the adsorption behavior of Cu2+and Ni2+obeyed to the rule of single element layer and it was surface controlled reaction.