Sorption of indium(III) and gallium(III) by iron(II) hexacyanoferrate

ABSTRACT

Iron(II) hexacyanoferrate is highly reactive to various metals, including indium and gallium. Systematic studies on the sorption process of In³⁺ and Ga³⁺cations by iron(II) hexacyanoferrate were conducted using the model system “Fe₄[Fe(CN)₆]₃∙5Н₂О – In³⁺– Ga³⁺– Н₂О.” It has been revealed that iron(II) hexacyanoferrate exhibits sorption properties concerning the studied cations. The sorption kinetics of indium(III) and gallium(III) ions were studied under static conditions, employing the limited volume method. The highest degree of sorption of In³⁺ cations at all concentrations was observed at 25°C. For a system with С_In = 50 mg/l Кс = 49%, С_In = 80 mg/L − 43%, С_In = 125 mg/L − 40% and С_In = (170–200) mg/L − 38%. Gallium(III) cations are sorbed by iron(II) hexacyanoferrate to a lesser extent. The degree of their sorption does not exceed 40–44%. Physicochemical methods (IR spectroscopy, X-ray diffraction analysis, electron microscopy) substantiate the regularities and peculiarities of the sorption process of In³⁺ and Ga³⁺cations by iron(II) hexacyanoferrate. It was found that iron hexacyanoferrate(II) exhibits preferential sorption ability with respect to In³⁺cations. The sorption of indium cations by iron(II) hexacyanoferrate follows a zeolite absorption-like process. Iron hexacyanoferrate(II) efficiently sorbs In3+ and Ga3+ ions, thus offering benefits in water purification, chemical separation, industry, and pollutant removal.

KEYWORDS:

• Iron(ii)hexacyanoferrate
• ferrocyanide
• sorption
• degree of absorption
• gallium cations
• indium cations

Acknowledgments

The work has been carried out at A.B. BekturovInstitute of Chemical Sciences JSC, within the framework of the Research Program (Agreement No. 409-PTsF-23-25, dated 15.11.23).

Disclosure statement

The authors declare that there are no conflict of interests.