Synthesis and Characterization of New Ferrite-Lignin Hybrids

The paper presents the synthesis and characterization of new cobalt ferrite-lignin hybrids. The hybrids were obtained through the combustion of cobalt nitrate and ferric nitrate, two kinds of lignin being used as combustion agents. The temperatures of calcination were 500 °C and 900 °C, respectively. The hybrids were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The magnetic properties were also assessed by vibrating sample magnetometer system (VSM). This facile synthesis method made it possible to obtain cobalt ferrite-lignin hybrids with a spinel structure. Their particle sizes and crystallite sizes have increased with an increment in the calcination temperature. A different occupancy of cations at octahedral and tetrahedral sites also occurred upon the increase in temperature. The hybrids comprising organic lignin presented the best magnetic properties.

Influence of Heavy Metals on the Environmental from Tarnita Mining Area

This paper presents aspects related to water pollution with heavy metals from the Tarnita mining area before and after the cessation of the mining activity. The impact of heavy metals on waters is important because these metals have a negative impact on both human health and aquatic ecosystems. All research data showed that, even the mining activities from this area were suspended, the sterile still pollutes the soil and water

Synthesis of Polymetallic Oxides with High Organized Structure

The synthesis and characterization of high organized and nanostructured polymetallic oxides were studied. The samples were synthesized by sol-gel autocombustion method, using glycine as chelating/fuel agent and polyacrylamide-based hydrogel as template agent. This polymer has a porous microstructure with well-individualized and regularly-dispersed pores. The asobtained samples were characterized by IR spectroscopy, XRD, SEM. The magnetic properties were studied. As-synthesized polymetallic oxides have the morphological structure given by the three-dimensional lattice structure of hydrogel used as template agent

Catalytic Property of Double Layered Perovskites A2MM’O6 for Radiolytical Split of Water

This paper deals with a study of water splitting by gamma rays in the presence of some double perovskites A2MM’O6 and also Sr2Fe1-xTa1+xO6. The irradiation is performed using 60Co as a source with 3·104 Ci activity and 8.3 kGy/h dose rate, which simulated the radioactive wastes, resulted from reprocessing of spent nuclear fuel elements much more active: 108-109 Ci. The stable products of radiolysis, as well as the other chemical species are measured by mass spectrometry. The calculated radiation yield (GH2) generally decreases in the order: Sr2Fe1-xTa1+xO6 (x=0.5; 0.4; 0.3; 0.1) > Ca2AlTaO6 > Sr2AlTaO6 > Ba2AlTaO6, under the given experimental conditions; the yield was higher in the presence of these catalysts than in their absence.