SOUTHERN JOURNAL OF SCIENCES

A new phase of the (CuAlSe₂)_1-x(TaSe)_x alloy system was synthesized by the melt and annealingtechnique and studied by SEM, DTA, and XRPD techniques. Its structure has been refined by the Rietveld methodusing X-ray powder diffraction data. The new alloy corresponds with the stoichiometry Cu_0.4Al_0.3TaSe₂. Thiscompound crystallizes in the hexagonal space group 𝑃6ത𝑚2 (Nº 187) with a MoS₂-type structure, and unit cellparameters a = 3.455(2) Å, c = 13.423(4) Å, V = 138.7(1) Å3, Z =2. The crystal structure is based on the MoS₂-type of stacking of TaSe₂ layers with a partial ordering of Cu and Al cations over the tetrahedral sites. The powderpattern was composed of 63.1% of the principal phase Cu_0.4Al_0.3TaSe₂ and 29.9% of CuAlSe₂, 7.0% of TaSe₃, asthe secondary phases. 

Background: Industrial wastewater contains pollutants that are detrimental to human health in varied proportions. Among the pollutants are heavy metals, including Zn2+, Pb2+, and Cu2+ found in a characterized pharmaceutical wastewater. Several techniques have been proposed for the heavy metal sequester. However, they are with attendant challenges. The adsorption techniques using clay-metal oxide modified adsorbent/composite such as silver-clay adsorbent is considered suitable for an effective sequestering process. Aims: To develop and characterize Ag/clay adsorbent for pharmaceutical wastewater treatment. Methods: The Ag nanoparticles were synthesized using Parkia biglobossa aqueous leaves extract in an optimization study. The raw clay was beneficiated and doped with silver nanoparticles via the wet impregnation method. The silver-clay adsorbent was characterized using FTIR, XRD, SEM, and EDS characterization tools. The developed adsorbent was used for the batch adsorption process of the heavy metal ion removal from the wastewater. Results and Discussion: The phytochemical analysis and FTIR results of the P. biglobosa showed that the leaf contains phenol, tannin, and flavonoids which acts as reducing, capping, and stabilizing agent required for synthesizing the silver nanoparticles. The prepared silver nanoparticles modified clay adsorbent Ag/clay, have evenly distributed stacks of pseudo-hexagonal plates, are rich in silica, possess silver nanoparticles in the frameworks, and contain functional groups suitable for binding heavy metals. The adsorptions of Zn2+, Pb2+, and Cu2+ from pharmaceutical wastewater onto the silver-modified clay were studied as a function of adsorbent dosage and contact time. The percentage removal results obtained showed that the adsorbent had up to 99.96%, 99.5%, and 99.44% removal efficiency for Zn2+, Pb2+, and Cu2+, respectively, which are better compared with previous studies. The adsorption process was feasible, spontaneous, and exothermic, with Langmuir and Pseudo-second-order models as best fits for the process. Conclusions: The adsorption of selected heavy metal ions onto the green synthesized silver-modified clay adsorbent (Ag/clay) was feasible, spontaneous, and exothermic in the order Zn2+>Pb2+>Cu2+ with Langmuir and Pseudo-second-order model best fitted for the process. These show that the synthesized silver oxide nanoparticles supported on local clay can be used as a potentially low-cost adsorbent to remove heavy metal ions from industrial wastewater.

Sugar beet is a crop able to resist high levels of soil salinity after emergence and establishment. Considering the significant difference in the effect of nitrogen forms on sugar beet performance under normal conditions, the form of nitrogen may affect the performance of sugar beet plants under abiotic stress, particularly salinity. Additionally, exploring the most appropriate type of nitrogen for sugar beet could mean optimizing sucrose content. Therefore, here using two lines, sugar beet was grown in pots (filled with 4 kg soil), salt-resistance (line 7233- p.29 x Mst), and salt-sensitive (line 3929-21939), the effect of two different forms of nitrate in the form of calcium nitrate (1 g per pot) and ammonium in the form of ammonium sulfate (1 g per pot) under normal and salt stress condition (40 Millimoles per liter sodium chloride) were evaluated. The result revealed the positive influence of nitrate over ammonium by indicating higher dry weight in both sensitive line: 19.2 and 13.6 g, and tolerance line: 20.4 and 13.6 g, respectively alone and in combination with salinity stress. Similarly, root yield levels positively influenced by nitrate treatment either alone or under salinity stress (sensitive line: 194.5 and 243.2 g and tolerance line: 207 and 249.5 g). The outcomes additionally showed the accumulation of proline aerial parts in both lines, and however, the proline accumulation of sensitive line was higher (3.9 mg/g dry weight). Moreover, induction of proline aggregation was considerably higher in nitrate nitrogen-treated sensitive line (9.3 mg/g dry weight). The absence of significant difference was obseved between nitrogen treatments in terms of extractable sucrose and root molasses sugar. Also, the root impurities increased in those treated with nitrate-nitrogen and salinity. It can be concluded that nitrate-nitrogen has improved the performance of both sugar beet lines against salinity stress, and its practical application is adviseable.