Where does nickel come from? Pure nickel (Ni) is a silvery-white metal that is rarely found as a pure metal in the earth’s crust because it will oxidise when it comes into contact with oxygen. Pure nickel can be found in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside the earth’s atmosphere or in ultramafic rocks. Nickel is…
Introduction Mercury species exists in various forms: elemental (or metallic); inorganic (e.g. mercuric chloride); and organic mercury (e.g., methyl- and ethylmercury), which all have different toxic effects. Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), inhalation of mercury vapour, or by ingesting any form of mercury.…
Where does lead come from? Lead is most commonly found as lead (II) sulphide (PbS) in the mineral galenite. Cerussite (tin-lead ore), with the chemical composition lead (II) carbonate (PbCO₃), is a secondary mineral of lead formed by the chemical reaction of carbonated water with galena. A third important source of lead is anglesite (lead…
The “rotten egg” odour in some water supplies is caused by sulphide in water. Sulphide can be treated using oxidation techniques, the goal being to convert the sulphide to high oxidation state species such as sulphate to eliminate the taste and odour concerns. Traditional oxidation techniques such as ozone and chlorine can be used but…
The Problem During commissioning stages, mercury was detected in the air of a newly constructed building. Being set on a former light bulb production site, the link was quickly made between historical mercury contamination of the soil and the previous use of the site. Analyses of soil samples also showed contamination of other heavy metals,…
