Montmorillonite clays and biomass have noticeable metal sorption capacity. Clays or biomass are difficult to separate from the solution when used as sorbent materials. A methodology to retain biomass and improve separation processes is to generate clay biopolymers matrices from fungal biomass grown on a natural Montmorillonite (MMT). The objective of this study is to generate and characterize clay biopolymers matrices and evaluate their uranium adsorption capacity. The generated clay biopolymers (BMMTs) were characterized through X-ray diffraction, measurement of the apparent diameter of particles, and electrophoretic mobility. Some BMMTs showed greater Uranium-specific adsorption capacity than that found for MMT. The X-ray diffraction analysis indicated that the Uranium was located partially in the clay interlayer. The BMMT surfaces were more negatively charged than the MMT surface, thus favoring their uranium uptake. Also, immobilization of the biomass and better coagulation of the system were achieved. These preliminary studies indicate that BMMTs have a great potentiality for uranium uptake processes.

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We have investigated the magnetism of 0.5 at. % Fe3+-doped CuO samples by Mössbauer spectroscopy and magnetization studies. The Curie–Weiss-type behavior observed for low-field-magnetization measurements at temperatures higher than 220 K is interpreted as an uncompensation of moments enhanced by the doping. The results are compared with 1.2 at. % Zn2+-doped CuO magnetization results and previous ones for samples doped with divalent ions. Trivalent ion doping produces an increase in the susceptibility with a peak at TN. The magnetic coupling of Fe2+ ions to the magnetic lattice is found to be about four times stronger than that of Fe3+.

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