Gel filtration chromatography using a Superose 12 HR column gave well-resolved and similar elution patterns for the maize extract, Baxtin and Polbax samples. Fractions exhibiting superoxide dismutase activity, determined by direct KO2 assay, were combined, dialysed and evaporated to dryness. The molecular weight of these fractions was approximately 30000 d. These fractions were also analyzed by...

A mutant of Escherichia coli, unable to produce manganese- or iron-containing superoxide dismutase (SOD), was found to contain modest levels of an SOD that was judged to be a copper- and zinc-containing SOD on the basis of inhibition by cyanide and inactivation by either H2O2 or diethyldithiocarbamate. Moreover, the diethyldithiocarbamate-inactivated enzyme could be reactivated with Cu(II), and...

Cyanide extraction of gold through milling of high-grade ores and heap leaching of low-grade ores requires cycling of millions of liters of alkaline water containing high concentrations of potentially toxic sodium cyanide (NaCN), free cyanide, and metal-cyanide complexes. Some milling operations result in tailings ponds of 150 ha and larger. Heap leach operations that spray or drip cyanide onto...

A mixed plating rinse wastewater containing zinc, hexavalent chromium, trivalent chromium, and cyanide with total dissolved solids of 424 mg/1 was treated by a model consisting of a sand filter and ion exchange columns. A strongly acidic cation resin in hydrogen form and a strongly basic anion resin in hydroxide form were used in the columns as cationic and anionic exchangers, respectively. The...

The recovery of valuable metals from jarosites is a topic great relevance regarding the implementation circular economy; however, these materials also contain such as arsenic and lead, which are harmful to health environment. Considering factors, it important monitor at each stage treatment used recover metals. In present work, behavior As Pb was assessed during pretreatment conducted on jarosi...