Sulfur dioxide with volcanic gases

When we consider of the heterogeneous oxidation of SO2, it has to include not only the oxidation of the SO2 within the droplet phase, but the transfer of further SO2 into the droplet and the overall depletion of the gas in the air mass as a whole. In general the overall oxidation in the remote atmosphere is rather slow and takes 2-4 d, but under some conditions it can be much faster. The depletion rates of sulfur dioxide in volcanic plumes can sometimes be very fast with residence times of as little as 15 min in moist plumes, where catalytic mechanisms similar to urban air masses probably occur. 

Sulfur dioxide, a poisonous gas, is made by burning sulfur in air. Volcanic activity, the combustion of fuels contaminated with sulfur, and the oxidation of hydrogen sulfide are the major sources of SO2 in the atmosphere. The chemical equation for the oxidation of hydrogen sulfide in the atmosphere is ... 

Acid rain is caused primarily by sulfur dioxide emissions from burning fossil fuels such as coal, oil, and natural gas. Sulfur is an impurity in these fuels for example, coal typically contains 2-3% by weight sulfur.1M Other sources of sulfur include the industrial smelting of metal sulfide ores to produce the elemental metal and, in some parts of the world, volcanic eruptions. When fossils fuels are burned, sulfur is oxidized to sulfur dioxide (SO2) and trace amounts of sulfur trioxide (SC>3)J21 The release of sulfur dioxide and sulfur trioxide emissions to the atmosphere is the major source of acid rain. These gases combine with oxygen and water vapor to form a fine mist of sulfuric acid that settles on land, on vegetation, and in the ocean. 

Volcanoes are a major source of sulfur dioxide (SO2) gas in the atmosphere. This gas is poisonous and is an irritant to the mucous membranes found in your throat, eyes, and nose. Sulfur dioxide also reacts with oxygen, sunlight, dust, and water to create S04 droplets and sulfuric acid (H2SO4), which leads to a type of smog referred to as volcanic smog, or vog. Vog can cause asthma attacks and damage the upper respiratory tract. The sulfuric acid produced can also cause acid rain. 

Large deposits of the yellow burning stone have been found in volcanic regions, such as those of Sicily, and in Texas and Louisiana, USA. Some sulfur deposits are located offshore. The sulfur that the conquistadors cut from the insides of the volcanic crater had been formed when hydrogen sulfide gas from the interior of the earth had reacted with oxidizing gases, sulfur dioxide or air. Historically, volcanic sulfur was the main source of supply. That is not the case today. 

Sulfur dioxide is a colorless, nonflammable gas with a strong suffocating odor. It is formed by burning sulfur directly or by burning sulfur-containing compounds. Sulfur dioxide is emitted during fossil-fuel combustion, especially coal, and by industry in the extraction of iron and copper from their ores. Sulfur is also emitted naturally during volcanic eruptions. 

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