soil contamination in the vicinity of the abandoned lakan lead and zinc mine was studied. the results showed that over the past decades, the environmental pollution was caused by lead, zinc tailings dam and acid mine drainage. the average of lead, zinc, cadmium, copper and nickel is 1295, 4273, 27, 185 and 92 mg/kg, respectively in the soils of tailings dam. these metals were continuously dispe...

This paper reports on the recovery of zinc, cobalt and manganese by two-step leaching of zinc-plants purification residue with sulfuric acid. The residue, hot filter press cake (HFC), contains 14 % ZnO, 4.8 % Co3O4 and 22.9 % MnO. Effects of different parameters are determined and used to optimize the process. With acid to hot filter press cake (HFC) stoichiometry of 0.85, acid concentration of...

The coordination chemistry of a series of pro-ligands ([L¹]-[L⁶]) with cobalt and zinc derivatives has been studied. All complexes have been characterized by multinuclear NMR, elemental analysis, and by single-crystal X-ray diffraction studies. Polymerization of rac-lactide takes place at 130 °C in the presence of cobalt and zinc complexes to yield polymers under solvent free conditions with co...

A DNA fragment conferring resistance to zinc and cobalt ions was isolated from a genomic DNA library of Staphylococcus aureus RN450. The DNA sequence analysis revealed two consecutive open reading frames, designated zntR and zntA. The predicted ZntR and ZntA showed significant homology to members of ArsR and cation diffusion families, respectively. A mutant strain containing the null allele of ...

Samples ( 1 and 5 liters) of filtered seawater (0.5 Jo) at its natural pH were equilibrated with several ,Gi of either carrier-free zinc-65 or carrier-free cobalt-60 and allowed to flow down individual resin columns. Retention of the ions was estimated by examining the eluate for activity; both cobalt and zinc were completely retained by the resin from both the 1 and 5 liter samples of seawater.

The extraction and separation of copper(II), zinc(II), cobalt(II), and cadmium(II) were investigated. Both copper(II) and zinc(II) formed ammine-complexes, while cadmium(II) and cobalt(II) formed hydroxide precipitates in an ammonia medium. By the addition of sodium dodecylsulfate (SDS), a copper(II) complex formed an ion-pair (copper-ammine-DS), which was extracted into the SDS phase. However,...

To determine the effects of cobalt chloride on human submandibular gland cells, HSG cells were exposed to various concentrations of cobalt chloride. Cobalt chloride induced cytotoxicity and cell death in HSG cells as determined by phase-contrast microscopy and WST-1 cell viability assay. By using the Hoechst 33342 staining, marked nuclear condensation and fragmentation of chromatin were observe...

The functions of trace elements in cellular metabolism have been emphasized by various investigators. The stimulating effect of cobalt and copper on the hematopoietic system has been recognized, and the functions of zinc in the enzyme systems have been greatly elucidated by the work of Keilin and Mann (1). Radioactive isotopes of cobalt, copper, and zinc have been used for tracer study by vario...

Metal oxide varistors (MOVs) are a type of resistor with significantly nonlinear current-voltage characteristics commonly used in power lines to protect against overvoltages. If a proper recycling plan is developed MOVs can be an excellent source of secondary zinc because they contain over 90 weight percent zinc oxide. The oxides of antimony, bismuth, and to a lesser degree cobalt, manganese, a...