Leaching and recovery of zinc and copper from brass slag by sulfuric acid

Leaching and recovery processes for zinc and copper from brass slag by sulfuric acid were carried out and iron and aluminum were also precipitated as hydroxides in addition to silica gel. The factors affecting the performance and efficiency of the leaching processsuch as agitation rate, leaching time, acid concentration and temperature were separately investigated. The results obtained revealed that zinc and copper are successfully recovered from these secondary resources, where the percent recovery amounts to 95% and 99% for zinc and copper, respectively. The experimental data of this leaching process were well interpreted with the shrinking core model under chemically controlled processes. The apparent activation energy for the leaching of zinc has been evaluated using the Arrhenius expression. Based on the experimental results, a separation method and a flow sheet were developed and tested to separate zinc, copper, iron, aluminum and silica gel from the brass slag

Synthesis, Characterization and Catalytic Activity of Cu/Cu2O Nanoparticles Prepared in Aqueous Medium

Copper/Copper oxide (Cu/Cu2O) nanoparticles were synthesized by modified chemical reduction method in an aqueous medium using hydrazine as reducing agent and copper sulfate pentahydrate as precursor. The Cu/Cu2O nanoparticles were characterized by X-ray Diffraction (XRD), Energy Dispersive X-ray Fluorescence (EDXRF), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The analysis revealed the pattern of face-centered cubic (fcc) crystal structure of copper Cu metal and cubic cuprites structure for Cu2O. The SEM result showed monodispersed and agglomerated particles with two micron sizes of about 180 nm and 800 nm, respectively. The TEM result showed few single crystal particles of face-centered cubic structures with average particle size about 11-14 nm. The catalytic activity of Cu/Cu2O nanoparticles for the decomposition of hydrogen peroxide was investigated and compared with manganese oxide MnO2. The results showed that the second-order equation provides the best correlation for the catalytic decomposition of H2O2 on Cu/Cu2O. The catalytic activity of hydrogen peroxide by Cu/Cu2O is less than the catalytic activity of MnO2 due to the presence of copper metal Cu with cuprous oxide Cu2O. © 2015 BCREC UNDIP. All rights reservedReceived: 6th January 2015; Revised: 14th March 2015; Accepted: 15th March 2015How to Cite: Badawy, S.M., El-Khashab, R.A., Nayl, A.A. (2015). Synthesis, Characterization and Catalytic Activity of Cu/Cu2O Nanoparticles Prepared in Aqueous Medium. Bulletin of Chemical Reaction Engineering &amp; Catalysis, 10 (2): 169-174. (doi:10.9767/bcrec.10.2.7984.169-174) Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.7984.169-174  </p

Synthesis and greener pastures biological study of bis-thiadiazoles as potential Covid-19 drug candidates

A novel series of bis- (Abdelhamid et al., 2017; Banerjee et al., 2018; Bharanidharan et al., 2022)thiadiazoles was synthesized from the reaction of precursor dimethyl 2,2′-(1,2-diphenylethane-1,2-diylidene)-bis(hydrazine-1-carbodithioate) and hydrazonyl chlorides in ethanol under ultrasonic irradiation. Spectral tools (IR. NMR, MS, elemental analyses, molecular dynamic simulation, DFT and LUMO and HOMO) were used to elucidate the structure of the isolated products. Molecular docking for the precursor, 3 and ligands 6a-i to two COVID-19 important proteins Mpro and RdRp was compared with two approved drugs, Remdesivir and Ivermectin. The binding affinity varied between the ligands and the drugs. The highest recorded binding affinity of 6c with Mpro was (−9.2 kcal/mol), followed by 6b and 6a, (−8.9 and −8.5 kcal/mol), respectively. The lowest recorded binding affinity was (−7.0 kcal/mol) for 6 g. In comparison, the approved drugs showed binding affinity (−7.4 and −7.7 kcal/mol), for Remdesivir and Ivermectin, respectively, which are within the range of the binding affinity of our ligands. The binding affinity of the approved drug Ivermectin against RdRp recoded the highest (−8.6 kcal/mol), followed by 6a, 6 h, and 6i are the same have (−8.2 kcal/mol). The lowest reading was found for compound 3 ligand (−6.3 kcal/mol). On the other side, the amino acids also differed between the compounds studied in this project for both the viral proteins. The ligand 6a forms three H-bonds with Thr 319(A), Sr 255(A) and Arg 457(A), whereas Ivermectin forms three H-bonds with His 41(A), Gly143(A) and Gln 18(A) for viral Mpro. The RdRp amino acids residues could be divided into four groups based on the amino acids that interact with hydrogen or hydrophobic interactions. The first group contained 6d, 6b, 6 g, and Remdesivir with 1–4 hydrogen bonds and hydrophobic interactions 1 to 10. Group 2 is 6a and 6f exhibited 1 and 3 hydrogen bonds and 15 and 14 hydrophobic interactions. Group 3 has 6e and Ivermectin shows 4 and 3 hydrogen bonds, respectively and 11 hydrophobic interactions for both compounds. The last group contains ligands 3, 6c, 6 h, and 6i gave 1–3 hydrogen bonds and 6c and 3 recorded the highest number of hydrophobic interactions, 14 for both 6c and 6 h. Pro Tox-II estimated compounds’ activities as Hepatoxic, Carcinogenic and Mutagenic, revealing that 6f-h were inactive in all five similar to that found with Remdesivir and Ivermectin. The drug-likeness prediction was carried out by studying physicochemical properties, lipophilicity, size, polarity, insolubility, unsaturation, and flexibility. Generally, some properties of the ligands were comparable to that of the standards used in this study, Remdesivir and Ivermectin