6.4 Acid deposition

Acid deposition

Acid coming from the air

Wet deposition

Acid coming in the form of rain, snow or sleet

Dry deposition

Acid coming in the form of ash or dry particles

Acid deposition pollutants

• Sulphur dioxide, nitrogen oxides and carbon dioxide

• Forms acid rain as very soluble in water once the secondary pollutants are formed.

Sulfur trioxide (SO3)

A secondary pollutant being a gas that is produced by the burning of fossil fuels that have sulfur like coal or oil. Reacts with water vapor to form sulfuric acid (H2SO4)

Nitric acid (HNO3)

An acid which is formed by the reaction of nitrogen dioxide with water vapor in the atmosphere. Involved in the production of acid rain.

Effects of acid deposition

• Weakening tree growth, decreasing water pH, toxic effects, nutrient leeching.

• Aluminum ions disturbs fish ability to regulate amount of salt and water in body.

• Also reduces soil fertility by inhibiting nitrogen fixing bacteria.

Ways to solve acid deposition

• Replace fossil fuels with better alternatives

• Reduce electricity demand

• USe low sulphur fiels

• Use catalytic convertors

• International agreements

Clean air act (1967)

Law that seeked to regulate all sources of air emissions such as Nox, SO2, PM 10, PM 2.5, CO, VOCs, O3 and Pb

Wet scrubber

An air pollution control device that uses a liquid (water) to remove contiminants from a gas stream.

Catalytic convertor

An exhaust emission control device which converts toxic gases and pollutants into less toxic pollutants through redox reactions.