UNIT 6- NONRENEWABLE RESOURCES AND AIR POLLUTION (copy)

Renewable energy sources

those that can be replenished naturally at or near the rate of consumption and reused

EX) HYDROPOWER

Nonrenewable energy source

FIXED amounts and involve energy transformation that cannot be easily replaced

EX) COAL

BIOMASS

wood and charcoal

charcoal

made by cooking wood in a low 02 environment and can take days

used in areas where electricity is widespread

How is biomass formed

produced in an earth-mound kiln in developing nations

Primary pollutants from biomass

emitted directly from burning of that material:

• Co2 and CO

• NO2

• PM/SPM (Suspended particulate matter)

  • dust, soot

• VOCs (volatile organic compounds)

  • Gases emitted into the air from products/processes

PEAT

surface organic layer of a soil that consists of partially decomposed organic matter

what is peat derived of

mostly from plan material which has accumulated under conditions of waterlogging, oxygen deficiency, high acidity and nutrient deficiency

BOGS

type of wetland but receive their moisture from precipitation (unlike swamps, which receive their moisture from rivers and streams)

where is peat formed?

• Tropical rainforests, Boreal forests, and subartic regions

• Where low temperatures (below freezing for long periods during the winter) reduce the rate of decomposition, peat is formed mainly from mosses, herbs, shrubs, and small trees

• Tropical rainforests

• Where it is derived mostly from leaves, branches, trunks, and roots under near constant annual high temperatures

Industrial peat harvesting?

Involves huge tractors that scrape peat from the surface of BOGS

• scraped peat is then collected into bricks

• Wet bricks of raw peat are pressed to force out water. They are then used as fuel mostly for heating homes and businesses

  • precursor to COAL

How does peat contribute to air pollution?

Emits more C02 than coal and nearly 2x as much as natural gas

CO2, CO, NO2, SO2, PM, SPM, and Hg (Mercury) are emitted directly into the atmosphere

Peat contribution to air 2

secondary pollutants- form as a result of reactions between primary pollutants and other components of atmosphere

• No2+UV light= photochemical smog

• SO2+h2O=UV light= Acid Rain

Coal

Hard blackish substance formed from organic matter (woody plant material) compressed under very high pressure to form dense, solid carbon structures

• Very little decomposition occurs to the starting organic material

• world’s most abundant fossil fuel

How is coal formed

• Solid fossil fuel burned mostly to produce electricity, heat, pressure, and depth matters in the formation of coal

how is coal formed 2

Formed in swamps= anaerobic environment and acidic (C02 is converted carbonic acid)

• Lignite

• Bituminous (most abundant in the U.S.)

• anthracite (highest quality, highest heating value)

Strip mining

method of mining shallow HORIZONTAL deposits in which layers of soil and rock are removed to exposure to the resource

• after each extraction, each strip is refilled with the overburden

Overburden

overlying soil and rock that is removed by heavy machinery

• NO toxic components

Subsurface mines

mines that access deep pockets of minerals through shafts and tunnels that follow deposits

Subsurface mine techniques

• MOST DANGEROUS FORM OF MINING

• Dynamite blasts

• Gas explosions

• Collapsed tunnels

• Toxic fumes + coal dust

Mountaintop removal

When the resource occurs in seams near the top of a ridge/mountain it can be accessed by mountaintop removal

Process in which several hundred vertical feet of mountaintop are removed to allow recovery of entire seams of a resource

Done in Appalachain mountains

“Valley filling’

practice of dumping excess rock and debris into valleys

Mining effects

• destroys natural communities/ecosystems over large areas

  • Deforestation

  • Removes forests and nutrient-rich topsoil

  • Contributes to habitat fragmentation

  • Loss of biodiversity

  • Triggers erosion because of loss of vegetation

  • Noise pollution

Primary pollutants of coal to air pollution

Co2 and Co

NO2

SO2

SPM- Suspended particulate matter and soot and ash

Trace amounts of mercury and other radioactive materials

Tailings

Materials left over after resources have been extracted at a processing plant/mill

• contain arsenic, lead, and cadmium that leaches into water supplies and contaminate soil

• As more accessible resources are mined to depletion, mining operations are forced to access lower grade ores

• Requires increased use of resources that can cause increased waste and pollution

Coal contribute to water pollution

Waste water is stored in large reservoirs called SURFACE IMPOUNDMENTS

• Breaches of surface impoundments can have massive environmental impacts (groundwater contamination)

Acid mine drainage

Leakage of water containing toxic materials from coal and metal mines

• leach metals from rock

• leachate is toxic to many animals

• Accelerated by mining

Coal ash slurry spills

coal ash is mixed with water and stored in surface impoundments (ponds)/landfills

can leak into groundwater or spill into waterways

mercury, arsenic, and cadmium

Secondary pollutants: acid rain

Acid deposition

Acid rain, regional air pollution problem

Formation of acid deposition

Natural causes (volcanism) and anthropocentric (industrial emissions)

Nitrogen oxides and sulfur oxides are released into the atmosphere

• from motor vehicles and coal burning power plants

Mixed with water vapor

• rain, snow, mist and fog

Corrodes buildings (limestone)

SOIL CHEM OF ACID DEPOSITION

Calcium, limestone, or even marble are able to neutralize acids

Basic soils can be fixed when farmers “lime” their fields to buffer the soil

Ecosystem sensitivity to acidification

• areas where soil if not rich in limestone, the acid rainwater accumulates in the bodies of water in the area

• NE US bc the bedrock is primarily granite

Prevention of acid deposition

1) Reduce energy use and thus air pollution by improving energy efficiency

2) Switch from coal to cleaner-burning natural gas

3) Removes sulfur from coal before it is burned

4) Burn low-sulfur coal

5) Removes SO2 particles, particulates, and nitrogen oxides from wet scrubbers

6) Remove nitrogen oxides from morot vehicle exhaust

Reducing coal use is economically and politically difficult

Job losses, updating infrastructure is expensive, etc

Clean-up approaches are expensive and mask symptoms without treating causes

• add lime to neutralize acidified lakes and soil

• add phosphate fertilizer to neutralize acidified lakes (runoff and algal blooms)

Clean coal technologies

technologies, equipment, and approaches to remove chemical contaminants while generating electricity from coal

Clean coal continued

Scrubbers chemically convert/remove pollutants

Clean the gases passing through the smokestack of a coal-burning power plant

Remove sulfur dioxide or nitrogen oxides

Reduces formation of acid rain

Oil and formation

All the oil and gas we use today began as microscopic algae and plankton living in OCEANS millions of years ago

Buried under layers of sediment and subjected to heat and pressure

Largest reserves- tells us about geologic history

Oil and gas

collects in pore spaces of rock and are trapped by impermeable layers of rock (above and below)

organic matter in the source rock is subjected to heat and pressure over time, changing to oil and gas which collects in the reservoir rock above it

Oil and gas extraction

Oil rigs on land

• Roads have to be built to bring materials to and from

• drill down at least 1 mile

• Once the drill hits the oil, it’ll gush out because pressure is released

• replace the drill with a steel pipe to pull out the oil

• oil is then pumped out

Shallow offshore drilling

rigs have been used for decades

Industry is moving into deeper and deeper waters

poses increased danger like hurricanes and tsunamis

farther from shore= long amount of time to get to accidents

Oil primary pollutants to air pollution

CO

CO2

NOx

SO2

PB (unless unleaded gasoline)

Oil secondary pollutants to air pollution

O3

• Tropospheric ozone

• MAJOR component of photochemical smog

• Photochemical smog: O3+NO2+VOCs+ UV light

Photochemical smog

produced by combustion engines and industrial fumes that react with sunlight to produce secondary pollutants

Photochemical smog details

• Created from nitrogen dioxides O3+NO2+VOCs+sunlight

  • NO2 produced in the AM, O3 conc peaks in the afternoon

• Occurs in hot, dry climates and particularly on sunny days with a lot of cars on the road

Thermal / Temperature inversion

a layer of cool air occurs beneath warm air

Inversion layer

the band of air where temperature rises with altitude

• denser, cooler air at the bottom of the layer resists mixing

• Inversions trap smog and particulates close to the ground

  • typically in cities surrounded by mountains

Oil contributions to water pollution

cannot dissolve in H20 and forms a thick sludge:

• suffocates fish

• Gets caught in the feathers of marine birds, stopping them from flying and can cause them to drive

• Blocks light from photosynthetic awuatic plants

• Increases turbidity, reduces, DO, disrupts food chain

Natural gas

methane (CH4) and other volatile hydrocarbons (mixture of gases)

• more than half is CH4

• Cleaner because it burns more completely than oil

• emits fewer pollutants than oil

• 50% less CO2 released compared to coal

• doesn’t produce ashes after energy release

• inexpensive

• no odor until added

Formation of natural gas

• Methanogenic organisms in marshes and bogs decompose organic material (anaerobic respiration)

• Thermogenic gas is created when organic matter is heated and compressed deep underground (much slower process)

Where is natural gas found

Plankton decomposes into natural gas and oil, while plants become coal so areas once covered by ancient seas

Top global reserves:

• Russia

• Iran

• Qatar

• US

Hydraulic fracturing

breaking rock formations to release oil/gas trapped in impermeable shale

• concern as the choice between financial gain and impacts to health and drinking water (surface and GROUNDWATER SUPPLIES)

Primary pollutants of natural gas contributions to air pollution

CO and CO2

CH4 (Methane)

NOx

SO2

VOCs

SPM (very low)

secondary pollutants

ground level ozone

Reclamation

Restoration that aims to bring a site to a condition similar to its pre-mining condition

removes structures, replace overburden, replant vegetation

What is reclamation?

Where mining companies will restore mined alnd to beneficial use

• open space (golf courses)

• Wildlife habitat (The Wilds)

• Agriculture

• Residential and commercial development

• erosion control, slope stabilization, and repairing wildlife habitat

Reclamation difficulty

• reclaimed soil is weak

• compressible and compacted

• many years of stabilization

• limited to shorter buildings due to unstability