GC: n
CT: Emissionsof sulfur dioxide (SO2) and nitrogen oxides (NOx) from the electric power sector in 2012 declined to their lowest level since the passage of the Clean Air Act Amendments of 1990. The decline in emissions is due primarily to an increasing number of coal-fired units retrofitted with flue-gas desulfurization (FGD), or scrubbers, to coal plants switching to lower sulfur coal, and to selective catalytic reduction (SCRs), selective noncatalytic reduction (SNCR), or low NOx burners to limit NOx emissions. In recent years the decreased use of coal for electric power generation because of cheaper natural gas has also played a significant role in the SO2 and NOx emissions declines.
S: EIA – http://www.eia.gov/todayinenergy/detail.php?id=10151 (last access: 31 December 2016)
N: 1. sulfur (n) also sulphur, c. 1300, from Anglo-French sulfere, Old French soufre “sulfur, fire and brimstone, hellfire” (13c.), later also sulphur, from Late Latin sulfur, from Latin sulphur, probably from a root meaning “to burn.” Ousted native brimstone and cognate Old English swefl, German schwefel, Swedish swafel, Dutch zwavel. The spelling with -ph- is standard in Britain, but its suggestion of a Greek origin is misleading.
dioxide (n): “The term dioxide for an oxide containing two atoms of oxygen came into use in the middle of the 19th century.”
2. Sulfur dioxide is a corrosive gas produced by the burning of fuels, such as coal and oil, that contain sulphur. It is also produced from sea spray, organic decomposition and volcanic eruptions. When combined with water in the air, it produces a weak, corrosive sulfuric acid – an ingredient of “acid rain”.
3. A colourless gas of pungent odour, found in trace quantities in the atmosphere as a result of industrial combustion and volcanic eruptions.
It combines readily with water to form sulphuric acid.
4. Sulfur dioxide affects human health when it is breathed in. It irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest. The effects of sulfur dioxide are felt very quickly and most people would feel the worst symptoms in 10 or 15 minutes after breathing it in. Those most at risk of developing problems if they are exposed to sulfur dioxide are people with asthma or similar conditions.
5. The amount of sulfur dioxide in air is at acceptable low levels in most Australian towns and cities. While sulfur dioxide levels in air are not generally a problem in Australia, fuel standards have significantly reduced sulfur levels in fuels and reduced the levels in air even further. The highest concentrations of sulfur dioxide in the air are found around petrol refineries, chemical manufacturing industries, mineral ore processing plants and power stations. Mt Isa and Kalgoorlie are the only areas where high amounts of sulfur dioxide in the air can occur and that happens only occasionally.
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=sulfur+dioxide (last access: 16.12.2016). 2. GF – http://www.greenfacts.org/glossary/pqrs/sulphur-dioxide-SO2.htm (last access: 16 December 2016). 3. GDT – http://www.granddictionnaire.com/ficheOqlf.aspx?Id_Fiche=26513891 (last access: 31 December 2016). 4 & 5. AUGOV – https://www.environment.gov.au/protection/publications/factsheet-sulfur-dioxide-so2 (last access: 31 December 2016).
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S:
CR: acid rain, air pollution, nitrogen oxide, petroleum, stratosphere, sulfuric acid.
