37-48 Acid deposition and noise pollution

APES 2024

Ways to address air pollution

Ways to address air pollution

• Avoid emissions in the first place

• Use cleaner fuel

• Increase efficiency

• Control pollutants after combustion

• Regulatory practices

• Conservation practices

• Alternative fuels

Ways of controlling emissions

• Remove sulfur dioxide from coal by fluidized bed combustion

• Install catalytic converters on cars

• Use baghouse filters

• Coal burning power plants

• Use electrostatic precipitators

• Install scrubbers on smokestacks

Electrostatic precipitator

• Removes particulate matter by using an electrical charge to make particles come together so they can be removed from the
  exhaust stream

• Positive or negatively charged particles are attracted to the sides

• Common in industrial plants and coal burning power plants

In some air pollution control devices, particles are
“scrubbed” from the exhaust stream by water droplets

A water-particle “sludge” is collected and
processed for disposal

Vapor recovery nozzle on gasoline pump that prevents

fumes from escaping into the atmosphere when fueling

Catalytic converter

device for an internal combustion engine
(ICE) that converts pollutants (CO, NOx and hydrocarbons) in exhaust into less harmful molecules (CO2 , N2 , O2 and H2O)

Wet and dry scrubbers remove particulates and/or

gases from industrial exhaust streams

Municipalities have tried a number of strategies to reduce air pollution:

• Reduce gasoline spilled at the pump, restrict evaporation of dry-cleaning fluids, and the use of lighter fluid

• Reduce use of wood-burning stoves and fireplaces

• Limit automobiles to every other day use or charge user fees for roads during heavy commute times

The primary pollutants sulfur dioxide and nitrogen oxides are precursors to

acid deposition

After transformation to the secondary pollutants—sulfuric and nitric acid— dissociation occurs in the

presence of water, the resulting ions—hydrogen, sulfate, and nitrate—cause the adverse ecosystem effects of acid deposition.

Acid deposition has many harmful effects:

• Mainly affects areas downwind from coal burning power plants

• Lowering the pH of lake water

• Decreasing species diversity of aquatic organisms

• Mobilizing metals that are found in soils and releasing them into surface waters

• Damaging statues, monuments, and buildings

• Regional differences affect the impact – areas with limestone bedrock which can
  neutralize the effect of acid rain on lakes and ponds

Acid deposition occurs when

nitrogen oxides and sulfur oxides are released into the atmosphere and combine with atmospheric oxygen and water, these form the secondary pollutants nitric acid and sulfuric acid

Nitrogen oxides come from

motor vehicles and coal burning power plants

Sulfur dioxides come from

coal burning power plants

The secondary pollutants further break down into nitrate and sulfate, and hydrogen ions (H+) which cause

the acid in acid deposition

Acid deposition has been reduced in the US as a result of

lower sulfur dioxide and nitrogen oxide emissions

Noise pollution

sounds at levels high enough to cause physiological stress and hearing loss

Urban area sources of noise pollution

• Transportation

• Construction

• Domestic activity

• Industrial activit

Sounds emitted by ships and submarines can interfere with

animal communication

Especially loud sonar can negatively affect species such as

whales that rely on low-frequency, long-distance
communication

An increased awareness of noise pollution in the ocean has inspired some

ship builders to design ships equipped with quieter propellers

Noise pollution impact on animals

• Stress

• Masking of sounds used to communicate or hunt

• Damaged hearing

• Causing changes to migratory routes