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Mitreiter, I., Oswald, S.E. and Stallmach, F. (2010) Investigation of Iron(III)-Release in the Pore Water of Natural Sands by NMR Relaxometry. The Open Magnetic Resonance Journal, 3, 46-51.

has been cited by the following article:

• TITLE: Separation of Fe3O4 Nanoparticles from Water by Sedimentation in a Gradient Magnetic Field

  AUTHORS: I. Medvedeva, Iu. Bakhteeva, S. Zhakov, A. Revvo, M. Uimin, A. Yermakov, I. Byzov, A. Mysik, N. Shchegoleva

  KEYWORDS: Magnetite, Nanoparticles, Water, Sedimentation, Gradient Magnetic Field

  JOURNAL NAME: Journal of Water Resource and Protection, Vol.7 No.2, January 30, 2015

  ABSTRACT: Sedimentation dynamics of magnetite (γ-Fe3O4) nanopowders (10 - 20 nm) in water in the presence of a gradient magnetic field was studied by optical and Nuclear Magnetic Resonance (NMR) relaxometry methods. The magnetic field B ≤ 0.3 T, dB/dz ≤ 0.13 T/cm was produced by the system of permanent strip magnets. The initial sedimentation rate of the nanoparticles in water and under magnetic fields is higher for less concentrated suspensions (c0 = 0.1 g/l) than for more concentrated ones (c0 = 1 g/l). This might be connected with the formation of gel structures due to strong magnetic attraction between ferromagnetic nanoparticles. In the gravitation field, the suspensions of the particles (10 - 20 nm) remain stable for over 20 hours. The sedimentation process can be greatly accelerated by the action of a vertical gradient magnetic field, reducing the sedimentation time down to several minutes. In a gradient magnetic field enhanced by a steel grid, sedimentation of the nanopowder (c0 = 0.1 g/l) for 180 minutes resulted in reduction of the iron concentration in water down to 0.4 mg/l. In flowing water regime, the residual iron concentration in water 0.3 mg/l is reached after 80 minutes.