Nickel natural source

Natural sources of airborne nickel include soil dust, sea salt, volcanoes, forest fires, and vegetation exudates and account for about 16% of the atmospheric nickel burden (Kasprzak 1987 WHO 1991 Chau and Kulikovsky-Cordeiro 1995). Human sources of atmospheric nickel — which account for about 84% of all atmospheric nickel — include emissions from nickel ore mining, smelting, and refining activities combustion of fossil fuels for heating, power, and motor vehicles ... 

Nickel is found in air, soil, water, food, and household objects ingestion or inhalation of nickel is common, as is dermal exposure. Recent estimates suggest that as much as 28,100 tons of nickel are introduced into the atmosphere each year from natural sources and as much as 99,800 tons from human activities. In the atmosphere, nickel is mostly suspended onto particulate matter. In natural waters, the dominant chemical species is Ni2+ in the form of (Ni(H20)6)2+. In alkaline soils, the major components of the soil solution are Ni2+ and Ni(OH)+ in acidic soils, the main solution species are Ni2+, NiS04, and NiHP04. 

Two thioacetates, thiofurodysin acetate (320) and thiofurodysinin acetate (209) were isolated from a Dysidea species from Sydney, Australia. They were converted by treatment with Raney nickel to a mixture containing furodysin and furodysinin respectively [214], These were the first thiol acetates isolated from natural sources. The absolute configurations of (-)-(6/ ,ll/ )-thiofurodysinin acetate (209), (-)-(6/ ,ll/ )-furodysinin disulfide (208) and (+)-(6/ ,ll/ )-methoxythiofurodysinin acetate lactone (321), isolated from a Fijian specimen of D. herbacea were determined by chemical interconversion [292]. 

Space will not be devoted here to emphasis of the vast technological importance of iron and the steels nor to the discussion of ferrous metallurgy. However, typical processes for obtaining cobalt and nickel from natural sources are outlined in Table 24-1. The process for cobalt is somewhat oversimplified, for cobalt ores often contain, in addition to iron and arsenic, nickel, silver, or copper, which must also be removed. Note that nickel is conveniently purified by conversion to its volatile carbonyl, Ni(CO)4, unstable at high temperatures Mond process). 

Nickel enters the atmosphere from natural sources (e.g., volcanic emissions and windblown dusts produced by weathering of rocks and soils), from combustion of fossil fuels by stationary and mobile power sources, from the emissions of nickel... 

In addition to natural source, nickel can be released in the environment by industries that use nickel or nickel alloys and by oil and coal burning power plants. Nickel found in soils and sediments... 

Natural sources of airborne nickel include soil dust, sea salt, volcanoes, forest fires, and... 

About 8.5 million tons of nickel enter the global atmosphere per year fiom natural sources, mainly from windblown dusts produced by weathering of rocks and by volcanic emissions [3]. More than 43 million tons are emitted into the atmosphere by anthropogenic activities per year. The main sources are residential and fuel oil combustion, nickel mining, and waste incineration [1]. 

Anodic E-i curves for nickel obtained by potentiostatic, potentiokinetic or, in earlier days, galvanostatic techniques, have been published by many workers. Unfortunately, good agreement is not always found between data from different sources. The principal reasons for the discrepancies appear to lie in the nature and amount of impurities in the metaP or in the solution -both of which may have a profound effect on the shape of the curve, and in variations in experimental procedure" . 

---