Sulphur dioxide Causes

SO2
Causes and Source and effect of health

1. Sulphur Dioxide ( SO₂ ) Z a m e e r A h m e d C h e m i cal E n g ineer

2. Introduction Sulfur Dioxide (SO2) is a colorless gas, belonging to the family of gases called sulfur oxides (SOx). It reacts on the surface of a variety of airborne solid particles, is soluble in water and can be oxidized within airborne water droplets.

3. Introduction It is the chemical compound with the formula SO2. It is a toxic gas with a pungent, colorless irritating smell, that is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel. It is used to preserve foods. It is one of a group of sulfiting agents, used in wine, on many dried fruits and in numerous other foods. Sulfur dioxide is formed when sulfur-containing fuels, such as coal and oil, are burned.

4. Natural Sources   Natural sources of sulfur dioxide include releases from volcanoes, oceans, biological decay and forest fires. The most important man-made sources of sulfur dioxide are fossil fuel combustion, smelting, manufacture of sulfuric acid, conversion of wood pulp to paper, incineration of refuse and production of elemental sulfur. Coal burning is the single largest man-made source of sulfur dioxide accounting for about 50% of annual global emissions, with oil burning accounting for a further 25 to 30%

5. Sources of Sulfur dioxide Sulfur dioxide, SO2, is a colorless gas or liquid with a strong, choking odor. It is produced from the burning of fossil fuels (coal and oil) and the smelting of mineral ores (aluminum, copper, zinc, lead, and iron) that contain sulfur. Sulfur dioxide dissolves easily in water to form sulfuric acid. Erupting volcanoes can be a significant natural source of sulfur dioxide emissions.

6. Sources of SO 2  emissions Source of sulfur dioxide emissions (data for electric utilities and point sources are from the 2009 Minnesota Emissions Inventory; other data are from the 2005 inventory)The  Minnesota Criteria Pollutant Emissions Inventory  includes emissions from four principal sources: Nonpoint sources:  Smaller stationary sources such as dry cleaners, gasoline service stations and residential wood burning. May also include diffuse stationary sources such as wildfires and agricultural tilling.

7. Sources of SO 2  emissions On-road vehicles:  Vehicles operated on highways, streets and roads. Point sources:  Large, stationary sources with relatively high emissions, such as electric power plants and refineries. Non-road sources:   Off-road vehicles and portable equipment powered by internal combustion engines. Includes lawn and garden equipment, recreational equipment, construction equipment, aircraft and locomotives. Point sources are estimated annually, while the other categories are estimated every three years.

8. Health Effects The major health concerns associated with exposure to high concentrations of sulfur dioxide include effects on breathing, respiratory illness, alterations in pulmonary defenses, and aggravation of existing cardiovascular disease. In the atmosphere, sulfur dioxide mixes with water vapor producing sulfuric acid. This acidic pollution can be transported by wind over many hundreds of miles, and deposited as acid rain.

9. Health Effects Sulfur dioxide affects the respiratory system, particularly lung function, and can irritate the eyes. Sulfur dioxide irritates the respiratory tract and increases the risk of tract infections. It causes coughing, mucus secretion and aggravates conditions such as asthma and chronic bronchitis.

10. Health Effects Sulfur dioxide affects the respiratory system, particularly lung function, and can irritate the eyes. Sulfur dioxide irritates the respiratory tract and increases the risk of tract infections. It causes coughing, mucus secretion and aggravates conditions such as asthma and chronic bronchitis.

11. Environmental effects When sulfur dioxide combines with water and air, it forms sulfuric acid, which is the main component of acid rain. Acid rain can: cause deforestation acidify waterways to the detriment of aquatic life corrode building materials and paints. In Queensland, there is less heavy industry than in Europe or North America, where the potential for forming acid rain from sulfur dioxide emissions is higher. Our weather conditions and low sulfur content of fuels reduce the potential for acid rain.

12. Air quality standard The recommended air quality standards for sulfur dioxide are: 0.20 parts per million (ppm) for a 1-hour exposure period 0.08ppm for a 24-hour exposure period 0.02ppm for an annual exposure period. These standards are designed to protect sensitive individuals, such as children and asthmatics. Significant concentrations of sulfur dioxide are only measured in Queensland near large industrial sources.

13. Emissions Control Technologies The two major emissions control methods are sorbent injection and flue gas desulfurization: Sorbent injection involves adding an alkali compound to the coal combustion gases for reaction with the sulfur dioxide. Typical calcium sorbents include lime and variants of lime. Sodium-based compounds are also used. Sorbent injection processes remove 30–60% of sulfur oxide emissions. Flue gas desulfurization may be carried out using either of two basic FGD systems: regenerable and throwaway. Both methods may include wet or dry processes. Currently, more than 90% of utility FGD systems use a wet throwaway system process.

14. Sulfur dioxide analyser

15. Measuring sulfur dioxide A sulfur dioxide analyzer. The sample (shown by the path of the blue dot) is drawn into the analyser by means of the vacuum pump, firstly through a filter to remove particles, and then through a scrubber to remove interfering gases, such as hydrocarbons. The scrubbed sample passes into a reaction chamber where it is irradiated with ultraviolet (UV) light at 214nm (nanometers) generated by a zinc discharge lamp and a UV band pass filter.

16. Measuring sulfur dioxide Sulfur dioxide absorbs UV radiation at wavelengths between 200nm and 240nm. Emission of fluorescence (light-producing) photons at higher wavelengths (around 350nm) follows this absorption of UV radiation by the molecule. This fluorescence is measured perpendicular to the beam using a photomultiplier (PM) tube and the signal converted to a concentration value. The measured fluorescence is directly proportional to the concentration of sulfur dioxide in the sample.