Magnetite nanoparticles Fe3O4 synthesized by chemical precipitation were used for the magnetic extraction of tungsten(VI) ions (CW0=0.5 mg/L) from aqueous solutions. At the first stage, tungsten ions were sorbed by magnetite particles. Then the sorbent was removed from aqueous solutions by magnetic filtration. We studied the pH of the solution, Fe3O4 concentration, and the contact time between the target ions and the added MNP effect on the efficiency of tungsten ions magnetic extraction from aqueous solutions. The tungsten removal was strongly dependent on pH of the aqueous solution. The magnetic extraction maximum value (0.0005 mg/L) was observed at pH 5, 20 mg/L magnetite concentration and within 1 hour contact time. The maximum adsorption capacity of Fe3O4 was 270 mg/g at pH 5. The obtained value of adsorption capacity is 6 times higher than that known in the literature for other sorbents. This is probably due to the MNP large specific surface area. It was shown that tNaCl addition did not significantly change the efficiency of tungsten ions extraction, as well as Na2SO4 presence in aqueous solution the extraction efficiency. These results can be explained by a change in the MNP surface charge in the presence of anions in aqueous solutions. This method of tungsten(VI) ions magnetic extraction from aqueous solutions satisfies to modern principles of “green technologies” and ensures effectiveness and simplicity of implementation.
Keywords: magnetite, tungsten ions, water purification, adsorption, magnetic separation
Article published in number 4 for 2025 DOI: 10.25750/1995-4301-2025-4-114-122
ISSN 1995-4301
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