Issues Investigation - Is ‘low Sulfur Coal’ the Best Answer to Sulfur Pollution?”

Sulfur pollution has become a universal issue and it is essential to take this topic into concern as sulfur pollution harms the environment in many ways. Sulfur dioxide is a major contributor of Acid rain. It destroys the flora and fauna including marine ecosystems and man-made structures and buildings. Human and animal health is also severely affected by this occurrence. There are many different ways to address sulfur pollution and some of them are using Low sulfur coal, scrubbing, Flue Gas Desulphurisation and using renewable sources of energy such as solar, wind and water.

Sulphur dioxide is emitted from combustion of fossil fuels, particularly coal which contains a large amount of sulphur. Industrial processes such as metal extraction from sulphide ores as well as volcanic activity in nature cause the sulphur emissions.

Burning of fossil fuels:

S(in compounds) + O2(g) SO2(g)

2SO2(g) + O2 2SO3(g)

Compounds of sulphur react with oxygen to form sulphur dioxide which reacts with oxygen in the atmosphere to form sulphur trioxide.

Burning of Zinc Sulphide:

2ZnS(s) + 3O2(g) 2ZnO(s) +2SO2(g)

Oxides of sulphur are the major contributors in acid rain formation. When sulphur dioxide and sulphur trioxide react with water present in the atmosphere they form the chemicals, sulphurous acid and sulfuric acid that are harmful.

SO2(g) + H2O H2SO3(aq)

SO3(g) + H2O(l) H2SO4aq)

(Source 2, 4)

Any precipitation that is less than 5.6 on the pH scale is considered as an acid rain and is damaging to the environment. When acid rain falls on the soil, it dissolves all the nutrients and the minerals in the soil and speed up the process of leaching of the toxic metals such as aluminium which adversely affects the vegetation’s growth. Acid rain destroys marine or aquatic ecosystems as the natural pH of the aquatic-systems is disrupted, i.e. the pH drops hence acidifying them. It harms the biotic as well as abiotic factors of the marine systems, thus affecting the biodiversity of the earth. Apart from this, it also harms man-made structures or materials. Many structures dissolve in it which might be a part for a country’s cultural heritage and thus are very expensive to replace or repair. Sulfuric acids react with limestone to form calcium sulphate and also corrode metals such as iron, zinc and aluminium, hence destroying them.

CaCO3(s) +H2SO4 (aq) CaSO4 (aq) + CO2(g) + H2O(l)

Fe(S) + 2H+(aq) Fe2+(aq) + H2(g)

(Source 1, 3)

One way to address sulphur pollution is by is by using low sulfur content