Известия Томского политехнического университета: Инжиниринг георесурсов (Aug 2019)
MAGNETITE WITH MODIFIED SURFACE FOR WATER TREATMENT
Abstract
Relevance. Recently, interest in the synthesis of magnetite nanoparticles has been growing, which is due to the possibility of using it as a sorbent for protecting environment, such as, for purifying wastewater from organic compounds, drugs and inorganic heavy metals. The necessity to improve the efficiency of sorption and study mechanism of sorption makes this problem urgent. The main aim of the research is to determine the sorption possibility of inorganic and organic ions, as well as drugs on magnetite powders with a modified surface obtained by a chemical method for further use in water purification. Object: magnetic nanopowders based on Fe3O4 with modified surface with citrate ions and dioxide silica. Methods: X-ray phase analysis, inductively coupled plasma atomic emission spectrometry, method of thermal desorption of nitrogen, indicator method. Results. Magnetic powders based on magnetite Fe3O4 with a surface coated with сitrate ions (MNP) and silicon dioxide (MNP/SiO2) were obtained for sorption of organic and inorganic compounds from aqueous media. Their composition and magnetic properties were studied. It is shown that the obtained composition of magnetite coated with dioxide silica corresponds to the crystalline phase of Fe3O4 and amorphous phase of SiO2. Furthermore, the saturation magnetization Ms and average surface diameter of particles were determined. The sorption isotherms of organic and inorganic compounds on the surface of obtained nanopowders were described by the Langmuir equation, which indicates the formation of a monomolecular layer on the surface of the sorbents. The maximum sorption capacity of Ni2+ , methylene blue and doxorubicin on silicon dioxide-coated magnetite powders was determined, it is 22,3, 14,7 and 18,8 mg/g, respectively. The charge of surface active centers of the magnetite was determined by the indicator method. The obtained results make it possible to simulate sorption of organic, inorganic substances and drugs in water purification and utilization of chemical compounds in pharmaceutical plants and cancer centers.
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