Atmospheric pollutants alloying elements

These low-alloy steels have improved corrosion resistance in outdoor atmospheres in rural areas, or in areas having relatively low pollution levels. The protective action of copper and other alloying elements is due to a resistant form of oxide that forms a protective coating imder atmospheric conditions, but has little or no favorable effect when immersed continuously in water or when exposed to severe industrial corrosive conditions. 

Nano-photosynthesis can produce sugar and starch for food and further synthesis of cellulose can produce paper and wood to avoid clear-cutting forests. Carbon retrieved from the atmosphere and recycled from existing wastes by MNT will be used to make carbon nano-tubes, with superior properties to steel. Carbon will be the most common structural and functional element for a MNT-based civilization [32,33]. A carbon-based MNT material production model is conceptualized as in Fig. 9. If there is a specific need for metal, a nano-factory with trillions of nano-assemblers will synthesize steel, copper, and alloys in order to skip mining and refining [32,33]. Therefore, industrial wastewater, hazardous wastes and air pollution will all vanish. 

In the production of lead, this element enters into the atmosphere from the metallurgical plant in the form of particles of sizes between 0.001 and 100 fim. The particles present in the smoke are of sizes between 0.01 and 2 m. Besides the air, they also pollute the soil and water, since larger particles sediment on areas adjacent to the works. The production of lead-containing alloys contributes about 2% to the total air pollution with lead. 

A rapid development of certain specialized industries such as the production of computers, beryllium ceramics, nuclear power engineering, rocket techniques and other complex technologies give rise to the possibility of occupational exposure to beryllium effects. In the vicinity of works producing beryllium, its alloys or salts, and also in coal combustion (where as much as 100 g of beryllium may be present in one ton of certain types of coal), the atmosphere is polluted with this toxic element, which thus leads to the exposure of the population in these localities. The maximal permissible beryllium concentration is as low as 0.002 mg m. ... 

---