Naturally occurring Cr(VI) has recently been reported in ground and surface waters. Rock strata rich in Cr(III)-bearing minerals, in particular chromite, are universally found in these areas that occur near convergent plate margins. Here we report experiments demonstrating accelerated dissolution of chromite and subsequent oxidation of Cr(III) to aqueous Cr(VI) in the presence of birnessite, a ...

This paper examines the efficiency of electro-oxidation used as the single pretreatment of landfill leachate. The experiments were performed on three different types of leachate. The results obtained using this electrochemical method results were analyzed after seven days of treatment. The main characteristics of leachate and a diagram of the experimental apparatus are presented. The overall ob...

For commercial applications, specially formulated conversion coating treatments based on chromates and phosphates have been used extensively to prevent rapid Zn dissolution in aerospace, food processing and automobile industries. Chromate coatings are favored due to their barrier and corrosion resistance properties. Chromium deposition is obtained from hexavalent Cr salt baths, which are subjec...

The metal-catalyzed polymerization of simple olefins, such as ethylene and propylene, has been one of the transformational discoveries in chemistry of the 20th century. It is difficult to imagine today’s civilization without ubiquitous plastics, such as polyethylene and related polymers. Although often attributed to Karl Ziegler and Giulio Natta, the winners of the 1963 Nobel Prize in Chemistry...