Unit 3: Pollution

What happens at a landfill?

1. Solid waste is transported there 2. Waste is compacted by a specialized machine 3. Leachate collection system removes water and contaminants and carries them to a wastewater treatment plant 4. Methane produced in closed cells is extracted and either burned off or collected for use as fuel 4. Landfill is capped and covered with soil and then planted with vegetation

How does Pb concentration of modern humans compare to ancient ancestors?

1000x higher concentrations in bones and teeth

What was found in soils on Camels Hump Mountain, VT?

Air pollutants - spike in lead high up on slope of mountain

Nitrogen oxides (NOx)

All combustion

Give an example of noise pollution via transportation.

Boat traffic noise can terribly effect marine organisms that are sensitive to underwater sound waves (a few boats can make a big impact on a particular ecology)

Primary Pollutants (examples)

CO, SO2, VOCs, NO, NO2, CO2, most hydrocarbons, most suspended particles

EPA Air Quality National Summary - Decline Areas

CO2 Emissions and Aggregate Emissions (six common pollutants)

What does a scrubber do?

Catch toxins as they are released; operate in order to capture and slurry pollutants and deposit them into a drain where they can be disposed of (scavenge, then dropped into tank system)

What is the issue with water pollution via sediment from soil erosion?

Causes body of water to become shallower

What is the issue with coal-fired power plants?

Cheap to use but causes toxins by virtue of burning

Mercury (Hg)

Coal, oil, gold mining

Particulate matter (PM10 or PM2.5)

Combustion, land disturbance

Secondary Pollutants

Come from changes occurring in the atmosphere -- not directly from source

Examples of Nonpoint Source Pollution

DDT, urban and agricultural runoff

Describe air pollutant trends in the US between 1990 and 2008.

Downward trend mostly due to regulation

Majority of pollution from... (sulfur dioxide)

Electricity generation, fossil fuel combustion, industrial processes

Volatile Organic Compounds (VOC)

Evaporation of fuels, solvents, paints; improper combustion

Sulfur dioxide (SO2)

Fossil fuel combustion

Carbon dioxide (CO2)

Fossil fuel combustion and land clearing

EPA Air Quality National Summary - Growth Areas

GDP, vehicles miles traveled, population, energy consumption

Lead (Pb)

Gasoline, coal, oil, paint

Soil Pollution

Hazardous waste and sewage spills, non-sustainable farming practices like inorganic pesticides and fertilizers, strip mining, deforestation, household dumping and littering

Carbon monoxide (CO)

Incomplete combustion

Trends in municipal solid waste (MSW) generation in the U.S. show...

Increasing per capita and total MSW generation; mostly paper and paperboard

What were the key peaks in lead pollution historically?

Industrial revolution and expansive Roman empire (lead mines)

What is pollution generally attributed to?

Introduction by humans

Light Pollution

Large cities, infrastructure (roads, street lighting, etc.), billboards and advertising, nighttime sporting events and entertainment

Examples of Point Source Pollution

Lead and mercury pollution from smelters, coal-fired power plants, modern nuclear reactions

What caused a spike in Pb in the air?

Leaded gasoline around the 1950s (Miller et al.)

What makes a soil pollutant more problematic?

Long residence time/half life

What causes atmospheric deposition of metals?

More precipitation = more wet deposition, more cloud aerosols impact canopy, forest change from deciduous to coniferous - enhanced scavenging (more efficient surfaces on which water can condensate, i.e. pine needles)

What happens to MSW in the US?

Most is discarded, a lot is reused/recycled, and some is combusted with energy recovery

Primary Pollutants

Neutral in the environment but once they are in the atmosphere can undergo changes (e.g. in stoichiometry) that make them harmful -- directly from source

Radioactive Pollution

Nuclear power plant accidents or leakage, improper nuclear waste disposal, uranium mining

Majority of pollution from... (Nitrogen oxides)

On-road vehicles, non-road equipment, electricity generation, fossil fuel combustion, industrial processes

Majority of pollution from... (Carbon monoxide)

On-road vehicles, non-road equipment, fires

What MSW categories are the largest for recycling/composting?

Paper and paperboard, yard trimmings

What can pollution take the form of?

Pollution can take the form of substances (distributed into the environment) or energy (such as noise, heat, or light)

Point Source Pollution

Pollution originating from a source that occupies a small area and has a concentrated output, such as a pipe, ditch, or smokestack

Nonpoint Source Pollution

Pollution that cannot be defined as originating from discrete points. Areas of fertilizer and pesticide applications, atmospheric deposition, manure, and natural inputs (organic pollution) from plants and trees are types of non point source pollution.

Visual Pollution

Power lines, construction areas, billboards and advertising, neglected areas or objects such as polluted vacant fields or abandoned buildings

Thermal Pollution

Power plants, urban sprawl, air pollution particulates that trap heat, deforestation, loss of surface waters

Acid deposition

Primary to secondary pollutant; toxins undergo a transformation that leads to acid precipitation/acid rain

Pollution

Refers to the introduction of contaminants into the natural environment, resulting in adverse change

Majority of pollution from... (particulate matter)

Road dust, miscellaneous, industrial processes, electricity generation, fires, residential wood combustion, waste disposal

Secondary Pollutants (examples)

SO3, H2SO4, HNO3, O3, H2O2, most NO3- and SO42-

Water Pollution

Sediment from soil erosion, improper waste disposal and littering, industrial effluent discharge, leaching of soil pollution into water supplies, organic material decay

What is the issue with fertilizer runoff?

Source of nitrogen and phosphorous. When spiked in a watershed, it has the potential to stimulate a lot of biomass production in the water column, leading to an algal or phytoplankton bloom

Ozone (O3)

Sunlight + water + O2 + VOC + NOx

Describe the nature of soil pollution.

Things that percolate into the ground and need to be removed; one way to remediate is just get defective material out

When did lead contamination of the environment begin?

Thousands of years ago (according to Hong et al. study of the global dispersal of Pb; shows Pb content of ice)

Noise Pollution

Traffic, airports, railroads, manufacturing plants, construction or demolition, public events

Thermal inversion

Trapped zone of air pollution; cause of smog

Trends in MSW Recycling & Composting Rate have shown...

Upward trend, both in percent of generation and total MSW recycled and composted (big change in early 80's/90's when recycling programs took over)

Air Pollution

Vehicle or manufacturing exhaust, forest fires, volcanic eruptions, dry soil erosion (dust/small particulates), and other natural sources

What is the biggest problem with solid waste?

Where to put it (sheer mass)