What is the connection for SO2

Sulfur dioxide - SO 2


Sulfur dioxide (SO2) is a colorless gas that is very soluble in water and has an acidic character. With its pungent odor it irritates the respiratory tract.

It is created when fossil elements such as coal or oil are burned. The sulfur contained in the fuel as an impurity oxidizes to sulfur dioxide (SO2) and, to a lesser extent, sulfur trioxide (SO3).

Source of pollution

The emissions of sulfur dioxide are closely linked to the use of fuels containing sulfur, but there are also other sources such as the production of sulfuric acid or metal processing, in which sulfur in mineral form is used as sulfide. Volcanoes can also be an important natural source of sulfur dioxide.

In Wallonia, most emissions (61% in 2014) come from the industrial sector. After that, the residential sector ranks with 25% of emissions and the energy sector with 7%. The share of the transport sector (1.6%) is low compared to other pollutants such as nitrogen oxides.

The emissions of sulfur dioxide decrease continuously: -91% between 1990 and 2014. This improvement is due to several factors: the gradual abandonment of sulfur-rich fuels (coal, heating oil) in favor of clean fuels (natural gas), the limitation of the sulfur content of fuels, the most important The role of nuclear energy in energy production, more rational use of energy, advances in waste treatment and, admittedly, the decline of heavy industry in the Walloon industrial landscape.

Health effects

Sulfur dioxide irritates the mucous membranes and eyes. It causes breathing difficulties in susceptible individuals (people with asthma or chronic respiratory diseases, etc.) that can lead to an increase in hospital admissions. At high doses, it is responsible for bronchoconstriction, bronchitis and tracheitis and, in the long term, chronic bronchitis. In connection with high particle concentrations, we can even observe an increase in mortality, as was the case during the Engis 1930 or London 1952 incidents.

In the atmosphere, sulfur dioxide can turn into sulphates and thus be indirectly involved in particulate matter pollution.

Impact on the environment

Sulfur dioxide can change plant growth and disrupt ecosystems. In the atmosphere, it turns into sulfuric acid, which is deposited on the ground and in the vegetation, thereby contributing to the acidification and impoverishment of the natural environment. In the past, it was therefore considered to be the main cause of acid rain and forest death. Finally, it also contributes to the destruction of the materials used in construction and, in particular, accelerates the deterioration of buildings that are part of our historical heritage (limestone is particularly vulnerable).

The situation in Wallonia

After the sharp drop in emissions, we can now say with certainty that sulfur dioxide pollution is under control in our regions and that European standards in force and the recommendations of the World Health Organization are largely observed.

Measurement method

Sulfur dioxide is measured continuously and in real time using monitoring devices based on the principle of UV fluorescence.

Learn more: http://www.awac.be/index.php/2017-03-28-09-19-01/emission-de-sox