1. Acid RainCharles Fletcher, Martyna S. Sowa, Svetlana Zusina,ACID RAIN AND ITS EFFECT ON THE ENVIRONMENT

2. 3.

What is acid rain and what is the scale of the problem?

How do we know if the rain is acid?

What causes acid rain (chemical reactions)?

Where do the acid rain precursors come from?

How does acid rain affect the environment?

What can we do to protect our planet form acid rain?

4. Acid rain, or acid deposition, is a mixture of sulphuric and nitric acids.

Wet deposition

• rain

• hail

• snow

• fog

Dry deposition

• gases and particles

5. The valid risk assessment

The net acid deposition flux

=

the total acid deposition flux

deposition flux of base cations.

6.

The acidity status of precipitation is a result of a balance between

acidifying compounds (oxides of sulfur and nitrogen) and alkaline compounds (ammonia and alkaline material in windblown soil dust).

The acidity of precipitation is measured by the concentration of hydrogen ion.

(pH value -below 5.6 is acidic).

7. Causes and chemistry

a) Acid reactions with sulphur

S + O 2->SO 2

2SO 2+ O 2->2SO 3 2-

SO 3 2-+ H 2O -> H 2 SO 4

b) Acid reactions with nitrogen

N 2 +O 2->2NO

2NO +O 2->2NO 2

4NO 2 +O 2+ 2H 2O ->4 HNO 3

8. PRECURSORS AND SOURCES

The main precursors of acid rain are emissions of sulphur dioxide (SO 2 ) and nitrogen oxides (NO x )

Fuel combustion in power plants (SO 2 )

Exhaust pipes in automobiles (NO x )

MAN MADE 9. NATURAL:

Terrestial, tidal, and nutrient-rich oceanic areas

Volcanic eruptions

Forest fires

Outgassings from anaerobic wetlands

Breakdown of amino acids in organic wastes

10. TRANSPORT OF ACID RAIN PRECURSORS

Acid rain in a certain area can be caused by pollutants from emissions that are hundreds, even thousands of kilometers away especially through wet deposition.

11. ENVIRONMENTAL EFFECTS:

Water and marine life

• Extinction of fish in lakes

Flora

• Plants, forests, crops

• • leaf necrosis, tissue damage, death of the whole tree

Soil

• Improper growth of plants and trees

Human Health

• respiratory problems

12. POLICIES AND TAKING ACTION

Strategies for mitigating acid rain

13. Liming bodies of acidified water

This process of neutralizing acidity in endangered lakes and streams is through the addition of lime (calcium carbonate and calcium hydroxide). Chemicals such as caustic soda, sodium carbonate, slacked lime and limestone help raise pH of acidified water.

Drawbacks:

Very expensive

Treatment needs to be repeated every 3-6 years

Remote lakes are inaccessible

Large pieces of lime dissolve slowly

Doesnt solve the problem for soil acidification

14. Reducing SO 2and NO xemissions

Changing from high to low sulfur coal

Moving to non-fossil fuels such as nuclear power

Using Solar, Wind or Hydro resources

COAL CLEANING

IMPROVING IN-PROCESS TECHNOLOGY

REDUCTION OF COMBUSTION TEMPERATURE (NO X )

CHANGING THE FUEL USED: 15. Policy

1979 - Geneva Convention on Long-Range Transboundary Air Pollution took place with the idea to limit sulfur and nitrogen emissions was successfully achieved

1995-1997 Title IV of the Clean Air Act was established to reduce the adverse effects of acid deposition through reductions in annual emissions of sulfur dioxide of ten million tons from 1980 emission levels.

Many policies and programs were established in the past couple of decades once governments started to become concerned with the harmful effects of air pollution. 16. Results and Conclusions

Acid rain remains an acute problem in many parts of the world and is threatened by the rapid industrial development of the developing countries

The future strategies should concentrate on both the decrease of acidifying compounds and the increase of alkaline elements

Everyone should stayed informed and educated on the matter of acid rain and lead an energy efficient lifestyle

17. Thank you! www.steelumbrellas.com