Human Impact on Human Impact on Ecosystems: AcidificationEcosystems: Acidification

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Acid precipitationAcid precipitation

Rain and snow is naturally slightly Rain and snow is naturally slightly acidic with a pH of approximately acidic with a pH of approximately 5.6.5.6.

Oxides and AcidsOxides and Acids

The water vapour in the atmosphere is The water vapour in the atmosphere is reacting with the naturally-occurring reacting with the naturally-occurring carbon dioxide to form carbonic acid.carbon dioxide to form carbonic acid.

Oxides and AcidsOxides and Acids

Other naturally-occurring non-metal Other naturally-occurring non-metal oxides include carbon monoxide and oxides include carbon monoxide and nitrogen oxides and also react with nitrogen oxides and also react with water to produce acids.water to produce acids.

These can be produced by processes These can be produced by processes such as forest fires.such as forest fires.

EffectsEffects

Freshwater fish and many plants are Freshwater fish and many plants are adapted to a slightly acidic adapted to a slightly acidic environment, although chemicals in environment, although chemicals in soils such as lime (calcium oxide) soils such as lime (calcium oxide) help help neutralizeneutralize acid precipitation. acid precipitation.

Made-made Sources of OxidesMade-made Sources of Oxides

Human activities, Human activities, especially the especially the burning of fossil burning of fossil fuels, create an fuels, create an excess of non-excess of non-metal oxides metal oxides and an excess and an excess of acids in of acids in precipitation.precipitation.

EffectsEffects

We notice the effects of acid rain We notice the effects of acid rain eroding buildings and statues:eroding buildings and statues:

1908 1969

EffectsEffects

Beneath the surface of the lake, the Beneath the surface of the lake, the acid precipitation is killing fish.acid precipitation is killing fish.

LeachingLeaching

Acid precipitation also Acid precipitation also leachesleaches (removes) nutrients from soil (e.g. (removes) nutrients from soil (e.g. the calcium plants need to build cell the calcium plants need to build cell walls).walls).

LeachingLeaching

And it releases from rocks more toxic And it releases from rocks more toxic elements such as aluminum.elements such as aluminum.

Dealing with AcidificationDealing with Acidification

To try to reduce To try to reduce the amount of the amount of non-metal non-metal oxides oxides released, we released, we can use can use scrubbersscrubbers (filtration (filtration systems on systems on smokestacks).smokestacks).

Dealing with AcidificationDealing with Acidification

We can also neutralize acidic soil and We can also neutralize acidic soil and water with alkaline chemicals.water with alkaline chemicals.

Lake liming

Fossil FuelsFossil Fuels

We can also reduce our dependence We can also reduce our dependence on fossil fuels.on fossil fuels.