AcidAcid Rain ::CAUSES AND EFFECTSCAUSES AND EFFECTS::

By Priyanshu GautamPriyanshu Gautam Sec-A B.Tech Cse

Acid Deposition• Acid Rain refers to the deposition of acidic

components in either wet or dry forms• Defined by the pH of the liquid. Less than 7 pH is

acidic, more than 7 is basic• Natural acid rain can be caused by volcanic emissions

and biological processes • “Clean” rain has a natural acidity of about 5.2 on the

pH scale due to water reacting with carbon dioxide in the air to form carbonic acid

• H2O (l) + CO2 (g) → H2CO3 (aq)• 2 H2O (l) + H2CO3 (aq) <–> CO3

2− (aq) + 2 H3O+ (aq)

Areas of Highest Concern

• Current problem areas are:

• Eastern United States• South Western Canada• Eastern Europe• East Coast of China

• Potential future problem areas:

• Southern India• West Africa• Indonesia• Thailand

Human Attribution

• Human emissions of sulfur dioxide and nitrogen oxides contribute to the acidification of rain

• Emissions began during the industrial revolution, remaining unchecked until the 1970s

• Biggest contributor is the burning of coal • Annually 70Tg (1012 g) of Sulfur emissions comes

from fossil fuel burning, compared to 8Tg from volcanoes and 2.8Tg from wildfires

• Burning coal is extremely cheap and efficient but dirty, releasing sulfur dioxide which becomes sulfuric acid in the atmosphere

• Areas downwind of power plants receive heavy acid rain

• Smoke stacks built to counteract direct deposition of sulfuric acid only spread the problem

The Coal Power Plant Problem

EffectsEffects of AcidAcid Rain

• Not many things can grow in acidic conditions• Low pH and high aluminum concentrations can

damage aquatic populations• Soils can be damaged by the hydronium ion,

which mobilizes aluminum and encourages leaching of minerals such as magnesium essential for plant life

• Forests suffer from soil damage, however most food crops are unharmed because the nutrients lost are replaced in fertilizer

Other Effects• Monuments made of

Calcium Carbonate (limestone and marble) will react with acid rain to form Gypsum

• Increases the oxidation rate of metals such as copper and bronze

• Acid rain is an extremely destructive form of pollution, and the environment suffers from its effects. Forests, trees, lakes, animals, and plants suffer from acid rain.

• • ::: Trees:::• The needles and leaves of the trees turn brown

and fall off. • Trees can also suffer from stunted growth; and

have damaged bark and leaves, which makes them vulnerable to weather, disease, and insects.

How How AcidAcid Rain Affects The Rain Affects The EnvironmentEnvironment

. All of this happens partly because of direct contact between trees and acid rain, but it also happens when trees absorb soil that has come into contact with acid rain,The soil poisons the tree with toxic substances that the rain has deposited into it.

• :::Lakes:::• Lakes are also damaged by acid rain. Fish die off,

and that removes the main source of food for birds. Acid rain can even kill fish before they are born when the eggs are laid and come into contact with the acid.

• Fish usually die only when the acid level of a lake is high; when the acid level is lower, they can become sick, suffer stunted growth, or lose their ability to reproduce.

:::Buildings:::• Acid rain dissolves the stonework and mortar of buildings

(especially those made out of sandstone or limestone).• It reacts with the minerals in the stone to form a

powdery substance that can be washed away by rain.

:::Humans:::

• Humans can become seriously ill, and can even die from the effects of acid rain. One of the major problems that acid rain can cause in a human being is respiratory problems.

•• Many can find it difficult to breathe, especially people who

have asthma. Asthma, along with dry coughs, headaches, and throat irritations can be caused by the sulphur dioxides and nitrogen oxides from acid rain.

• Acid rain can be absorbed by both plants (through soil and/or direct contact) and animals (from things they eat and/or direct contact). When humans eat these plants or animals, the toxins inside of their meals can affect them. Brain damage, kidney problems, and Alzheimer's disease has been linked to people eating "toxic" animals/plants.

More Problems!!!

• Acid rain can travel long distances.

• Often it doesn’t fall where the gas is produced. High chimneys disperse (spread) the gases and winds blow them great distances before they dissolve and fall to Earth as rain.

• Eg gases produced in England and Western Europe can result in acid rain in Scotland and Scandinavia.

Acid rain disaster

• Research carried out in North America in 1982, revealed that sulphur pollution killed 51,000 people and about 200,000 people become ill as a result of the pollution.

Prevention

• Coal burning power plants use Flue gas desulfurization requiring a reaction tower that extracts the sulfuric acid by reacting it with lime or limestone slurry and removing the product with scrubbers

• Reduction in automotive emissions cuts down on nitrogen oxides

• Emissions trading put into practice to put economic incentive into cleaning industrial activities

• Sulphur dioxide can be removed from power stations chimneys but this process is expensive.

• Reduce the amount of electricity we use • turn tv’s off at the mains, don’t leave on standby .• turn off lights when a room is not in us e.• Use renewable energy like wind power, solar

panels, tidal power, HEP schemes and geothermal ener gy.

• Fit catalytic converters to vehicle exhausts which remove the nitrogen oxi des.

• Limit the number of vehicle .

THANK YOUTHANK YOU