Biocatalyst Based on Magnetic Nanoparticles with Cu(II), Mn(II), Zn(II) and Immobilised Catalase

This article described a process for the preparation of a Fe3O4 nanocatalyst modified with Mn(II), Cu(II) and Zn(II) ions immobilised with catalase. The effectiveness of the description of the ion sorption process was compared with four equilibrium models: Langmuir, Freundlich, Redlich-Peterson and Sips. The proposed models allow the description of both single- and multi-component sorption. The results were also verified by DFT analysis. The Langmuir model describing single-component sorption and the extended Langmuir model for multi-component systems with the best fit represented the sorption of metal ions on Fe3O4. The maximum sorption capacity values in the pseudo-second-order kinetic model were 10.76, 12.87 and 10.52 mg/g for Cu(II), Zn(II) and Mn(II) in the single-component systems and 11.79, 8.54 and 2.03 mg/g for Cu(II), Zn(II) and Mn(II) in the multi-component system, respectively. The kinetics parameters were described most accurately by a pseudo-second-order model, which suggested, along with the Extended Langmuir model, the chemical nature of the sorption. After preparation of the Fe3O4/Mn-Zn-Cu material, catalase was immobilised on the surface of the material. The final material was able to decompose hydrogen peroxide with an activity of 7130 units/g of material. Modification of the material with Mn(II), Cu(II) and Zn(II) resulted in an increase in H2O2 removal efficiency exceeding 99.9%.