Unit VIII

Pollution

Air Pollution

Atmospheric Structure

• Essentially it is a thin sea of air that

supports life

• Weight and Pressure

Atmospheric Structure

Outdoor Air Pollution

• Primary Air Pollution

– Harmful substances emitted directly into the atmosphere

• Secondary Air Pollution

– formed when primary air pollutants combine with each other or with a substance normally found in the atmosphere.

Outdoor Air Pollution

Outdoor Air Pollution

Outdoor Air Pollution • PM

– Different liquid or solid particles suspended in

the air

– Can be toxic/carcinogenic

• NOx

– Greenhouse gas

– Produced by chemical interactions between N

and O at high temperatures

Outdoor Air Pollution • SOx

– Causes acid deposition

– Produced by chemical interactions between S

and O at high temperatures

• COx

– Greenhouse gases

• CO and CO2

Outdoor Air Pollution • Hydrocarbons

Outdoor Air Pollution • O3

– Troposphere

– Stratosphere

Sources of Outdoor Air Pollution

Urban Air Pollution • Photochemical Smog

Effects of Outdoor Air Pollution • Low Level Exposure

• Can develop into chronic respiratory disease

Controlling Air Pollution

• Electrostatic Precipitator

Controlling Air Pollution

• Scrubbers

Clean Air Act • Authorizes EPA to set limits on certain pollutants

• Tragedy of the Commons

Clean Air Act

1970-2006

Ozone Depletion • The “ozone hole” is a seasonal thinning

• >160 consumer products break down by UV radiation and release Cl atoms

• CFC emissions are continuing to decrease

• Satellite pictures in 2000 indicated it was recovering – Full recovery isn’t expected until 2050

Ozone Depletion • Effects of increased UV exposure:

– skin cancer

– eye cataracts

– weakened immunity

– increased acid deposition

– increased smog

– lower crop yield

– reduction in phytoplankton

– degradation of plastics, paints, and other

exposed materials

Acid Deposition

• SOx and NOx react with H2O in atmosphere

to form acidic compounds

• Industries & Power Plant Emissions

• Acid Deposition

Acid Deposition

Acid Deposition • Acids and Animals

– harmful to most living organisms

– thins egg shells

– enzymes for digestion stop functioning, respiratory

tissues decay, organisms die

• Acids and Trees

– can stress & weaken trees in forests

– decrease soil productivity

Acid Deposition

Outdoor Air Pollution

Indoor Air Pollution • EPA studies show many common pollutants

Indoor Air Pollution • Asbestos

• CO, NO2, O3

• Cigarette Smoke

• Lead Based Cleaning Solvents

Indoor Air Pollution • Mold

• Formaldehyde

• Radon

Water Pollution

Water Pollution • No standard checklist to define healthy water.

• Different nations have different standards.

• US - all levels of government monitor using a variety of techniques.

Sewage

• Enrichment/Eutrophication

• Increase in Biological Oxygen Demand (BOD)

Disease-Causing Organisms

• Infectious organisms that cause diseases that originate in wastes

• Common diseases:

Disease-Causing Organisms

• Monitored by testing for presence of E. coli in water – Fecal coliform testing

Sediment Pollution

• Excessive amounts of suspended soil particles

Inorganic Nutrients

• Primarily N and P – Primary sources

– Causes

Organic Compounds

• Chemicals that contain C

Organic Chemicals

• VOC Distribution in the US

Inorganic Chemicals

• Contaminants that contain elements other than carbon

• Do not degrade easily

Radioactive Substances

• Contain atoms of radioisotopes that emit radiation

Thermal Pollution

• Heated water produced during industrial processes

Agricultural Pollution

• Agriculture is leading source of water pollution

• Nearly all streams and rivers in US are polluted w/ agricultural pesticides

Municipal Water Pollution

Industrial Wastes

• Food processing plants

• Paper Mills

• Some industries recover toxins before discharge

Groundwater Contamination

Drinking Water Purification

• Majority of municipal water supplies treated in US

• Treated water distributed to customers

Drinking Water Purification

• Cl

• Fluoridation

Sewage Treatment

• Sewer lines bring sewage to treatment plants

Sewage Treatment

• Primary Treatment – Removal of suspended and floating particles by

mechanical processes and filters.

• Secondary Treatment – Treatment through aerobic bacteria to decompose suspended organic

materials

• Sewage Sludge – Solids remaining after 1°& 2°treatment

Sewage Treatment

• Tertiary Treatment – Advanced treatment methods sometimes employed before discharge.

• Bleaching – Used on all effluent***

Sewage Treatment • Septic Tanks

– used primarily for household wastes

– relies on breakdown of wastes through bacteria

– discharges into nearest water body or a drainfield

Sewage Treatment • Septic Tanks

Water Pollution Regulation • Clean Water Act - NPDES

– Point Sources

– Limits set by models determining how much pollution a water body can endure.

Water Pollution • Clean Water Act – TMDL

– Non-Point Sources

Water Classifications In Florida…

• Class I – potable water

• Class II – shellfish harvesting

• Class III – recreational usage

• suitable for swimming and fishing

• Class IV – agricultural irrigation

• Class V – navigation only

Solid & Hazardous

Waste

Solid Waste

• US generates more solid waste per capita

than any other country

– 2.1 kg per person per day

Composition of Municipal Solid Wastes

Disposal of Solid Waste

• Three methods

– Sanitary Landfills

– Incineration

– Recycling

Sanitary Landfill

• Compacting and burying waste under a

shallow layer of soil

• Most common method of disposal

• Problems

– Methane gas production by microorganisms

– Contamination of surface water & ground water

by leachate

– Not a long-term remedy

– Few new facilities being opened (NIMBY)

– Closing a full landfill is very expensive

Sanitary Landfill

Incineration

• Volume of solid waste reduced by 90%

• Produces heat that can make steam to

generate electricity

• Byproduct

Composting

• Municipal Solid Waste Composting

• Reduces yard waste in landfills

• Can be sold or distributed to community

Waste Prevention

• Four Goals

– (1)

– (2)

– (3)

– (4

Reducing Waste

• Source reduction

• Dematerialization

Reusing Products

• Refilling glass beverage bottles

• Japan reuses almost all bottles

Recycling Materials

• Every ton of recycled paper saves:

– trees

– gallons of water

– kwatt-hrs of energy

– cubic yards of landfill space

• Recycle

– Glass bottles, newspapers, steel cans, plastic

bottles, cardboard, office paper

Recycling

• Recycling Paper

• Recycling Glass

Recycling

• Recycling Aluminum

• Recycling Metals other than Aluminum

Recycling

• Recycling Plastic

– % of all plastic was

recycled in 2007

– % of PET was

recycled in 2007

Recycling

• Recycling Tires

– Few products are made from old tires

• Playground equipment

• Trashcans

• Garden hose

• Carpet

• Roofing materials

– % of tires are currently recycled to make

other products

Love Canal Toxic Waste Site

Hazardous Waste

• Any discarded chemical that threatens

human health or the environment

• Types of Hazardous Waste

Hazardous Waste

Management of Hazardous Waste

• Current Management Policies

– Resource Conservation and Recovery Act (1976,

1984)

– Comprehensive Environmental Response,

Compensation, and Liability Act (1980)

Superfund Program

• Cleaning up existing

hazardous waste:

• Must be cleaned up

Management of Hazardous Waste

• Superfund National Priorities List

– States with the greatest number of sites

Management of Hazardous Waste

• (1)

• (2)

• (3)

Case Studies • Love Canal, NY

– Leaking chemicals from abandoned dump site

– Contaminated entire town

• Renamed Black Creek Village

– Sparked creation of Superfund Act

• Bhopal, India

– World’s worst industrial accident

– Explosion at Union Carbide Pesticide Plant

• Released methyl isocyanate into atmosphere

• Covered 78 km2