Acid Rain

By: Marian Liwanen & Melanie Koh

What is Acid Rain??Rain made acidic by pollutants in

the air

Acid rain is a type of acid deposition

Two types of acid deposition are:Wet deposition Dry deposition

Wet DepositionRefers to acidic rain, fog, snow and

sleet and any other precipitations

It removes acids from the atmosphere

This results in the acids being delivered to the Earth’s surface and affects a variety of plants and animals

Dry DepositionRefers to acidic gases and particles

About half of the acidity in the atmosphere falls back to earth through dry deposition

The wind blows the acidic gases onto buildings, cars, homes and trees

Dry DepositionDry deposition can be washed from surfaces by rainstorms

The acids from this combined with acid rain makes the combination more acidic

How is it formed?carbon dioxide + water carbonic

acid Carbon dioxide in the air dissolves in

raindrops to form carbonic acid.

sulfur dioxide + water sulfuric acid Sulfur dioxide dissolves in rainwater to

form sulfurous acid.

How is it formed? This also reacts with oxygen in the

air to form sulfur trioxide (SO3) which dissolves in rainwater to form sulfuric acid.

nitrogen dioxide + water nitric acid Nitrogen dioxide also reacts with water to form nitric acid.

Why is it a problem?Acid rain is a major problem affecting

people, lakes and streams, buildings and forests.

Air pollution like sulfur dioxide and nitrogen oxide can cause respiratory problems or make them worse.

Nitrogen oxide causes ground-level ozone.

Why is it a problem?This ozone causes respiratory problems

such as pneumonia and bronchitis and can even cause permanent lung damage.

Acid rain is also very harmful to forests.

Acid rain that seeps into the ground can dissolve nutrients such as magnesium and calcium that trees need to be healthy.

Why is it a problem?Acid rain also causes aluminum to be

released into the soil making it harder for trees and plants to take up water.

Trees in higher altitudes are much more affected because of their exposure to acidic clouds.

Why is it a problem?Important nutrients are taken away

making it easier for insects and cold weather to damage the trees.

Lakes and streams have a pH level of about 6.5. Acid rain however has caused these levels to drop especially during heavy downpours of rain or when snow melts in the spring.

Why is it a problem?The increase of the level of acidity

affects phytoplankton, mayflies, rainbow trout and many other creatures part of the food web.

Acid rain has a corrosive effect on limestone, sandstone, marble buildings and sculptures, causing them to look worn out and old.

Worst affected places in the worldMost of the countries in the Eastern Europe

From Poland northward into Scandinavia

Eastern third of the United States

South-eastern Canada

Worst affected places in the worldChina TaiwanJapan AustraliaSouth-east AsiaGermanyLondonSwitzerlandThe Netherlands

Why are these places affected?Coal burning

Pollution-generating heating methods

Smoke

Industrial dust emissions

Why are these places affected?Power plants

Vehicles that burn diesel and gasoline

Exhaust of vehicles that release sulfur dioxide

Air pollution

What is being done???Regulations: Enforce a fixed amount of sulfur dioxide

that power plants release

Issue allowances to power plants to cover their sulfur dioxide emissions

What is being done? Minimizing pollution: Using coal that contains less sulfur “Wash” the coal to remove some sulfur Installing equipment called scrubbers –

removes sulfur dioxide from gases that leave the smokestack.

Some power plants are changing the way they burn coal to reduce the amount of nitrogen oxide produced

What is being done?

Using different energy resources:

Using renewable energy sources Solar energy Wind energy Produce energy without the use of fossil

fuels

What is being done?Vehicles – Cars and trucks: Car manufacturers are reducing the amount of

nitrogen oxides and other pollutants produced Using catalytic converter – to reduce nitrogen

oxides produced by cars Using cleaner fuels – natural gas Using low emissions vehicles