Magnetite Fe-Al-Zr ternary composite filled dialysis membrane tubes (DMT-FeAlZr): A modified technique for phosphate desorption study from acid soil

Most soils cannot supply sufficient amounts of P to the plant due to various factors such as P fixation. To this effect, the development of a composite to monitor soil P supplies over time helps with fertilization recommendations. For this purpose, Fe-Al-Zr ternary composite adsorbent with 70%, 25%, and 5% of Fe, Al, and Zr, respectively, was synthesized by co-precipitation method. The as-synthesized adsorbent was characterized by X-ray diffraction (XRD), infrared spectroscopic (FTIR), atomic absorption spectroscopic (AAS) and scanning electron microscopy-energy dispersive spectroscopic (SEM-EDX) techniques. The study was conducted on four soil samples collected from West Wollega Zone, Oromia, Ethiopia, and incubated at 0, 50, 100, and 150 mg/kg phosphate. The amount of phosphate desorbed was higher at Nedjo (N) soil with 150 mg/kg treatment ranging from 4.51-32.62 mg/kg and lower in the control (1.42-15.591 mg/kg at all levels of extraction time for all soil types. The present study suggests that the dialysis membrane tube filled with the ternary composite DMT-Fe-Al-Zr method can serve as an analytical tool to assess the availability of residual P in soils. However, assessment of the reliability of this method at greenhouse and field levels is important to check the universality of this method. KEY WORDS: Desorption, Dialysis membrane tubes, Fe-Al-Zr mixed oxide, Phosphorus, Two-component first order model Bull. Chem. Soc. Ethiop. 2025, 39(5), 817-831. DOI: https://dx.doi.org/10.4314/bcse.v39i5.2