UAU212F Spring 2012 Throstur Thorsteinsson ([email protected]) 1 Sustainable Energy Options UAU212F ENVIRONMENTAL IMPACT Throstur Thorsteinsson [email protected]Pollution: refers to the occurrence of an unwanted change in the environment caused by the introduction of harmful materials - introduced through a) Point Sources b) Area Sources c) Mobile Sources Contamination: making something unfit for a particular use through the introduction of an undesirable material. Toxicity: Materials that are poisonous to living things. Carcinogen: a type of toxin that increases the risk of cancer. Synergism: the interaction of different substances resulting in a total effect greater than the sum of the effects of the separate sources. Terminology ⇨ Infectious Agents ⇨ Toxic Heavy Metals ⇨ Organic Compounds ⇨ Radiation ⇨ Thermal Pollution ⇨ Particulates ⇨ Asbestos ⇨ Electromagnetic Fields ⇨ Noise Pollution Categories of Pollutants ⇨ High atomic weight ⇨ Mercury, Lead, Cadmium, Nikkel, Gold, arsenic, selenium, chromium, tallium ⇨ Been around since the stone age ⇨ Stored in living tissue – accumulate over time ⇨ biomagification in tissue. ⇨ 10% of energy moved, but 100% of THM. Toxic Heavy Metals ⇨ Biomagnifications: the accumulation or increase in concentration of a substance in living tissue (e.g. fatty tissue) as it moves through a food web. ⇨ Body burden: the quantity of metals that is toxic to humans. ⇨ Drinking water inorganic mercury Maximum contaminant level: 2 ppb (0.002 mg/L) Toxic Heavy Metals ⇨ Pathways: ⇨ Cadmium from burning coal. ⇨ is absorbed by plants from ash. ⇨ Concentration increases from ash to plant to humans ⇨ Mercury from burning coal, processing metals ⇨ Goes into waterways and is methylated by bacteria ⇨ creating Methyl mercury (CH3HG). ⇨ Absorbed by fish ⇨ Concentration increases up food chain Biomagnification
14
Embed
Sustainable Energy Options - University of Iceland · Primary vs. Secondary ... ⇨London Smog: original meaning of smog; mixture of smoke, sulfurous particles and ... Sustainable
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
calculating the concentration of a pollutant at a certain point.
⇨ Describes the transport and mixing of the pollutants.
⇨ It assumes dispersion in the horizontal and vertical direction will take the form of a normal Gaussian curve with the maximum concentration at the center of the plume.
⇨ High smokestacks emit SO2 into higher layers – becomes transboundary
⇨ Acid rain originates from sulfur dioxide and nitrogen oxide particles – that become sulfate or nitrate particles
⇨ Travel long distances on wind currents ⇨ By combining with water vapor, these particles form
acids which fall to the earth as acid rain. ⇨ “Acid rain” includes both wet and dry acidic deposits ⇨ Precipitation with a pH lower than 5.6 is considered
⇨ Natural (91%) Most released naturally by volcanic eruptions, fires, bacteria,
⇨ (9%) Poorly running automobiles emit large amounts by incomplete burning
⇨ Extremely toxic – causes heart disease long-term, or death within an hour if concentration is 1600 ppm or more - chemical suffocation
⇨ Hemoglobin in the blood is 200 times more attracted to carbon monoxide than oxygen (leading to oxygen starvation of the body)
⇨ Most hazardous to human health of all criteria pollutants
NOX
⇨ NO and NO2 ⇨ Sources: Emitted from burning of fossil
fuels (nearly all) ⇨ The impact of NOx is mostly as being a
primary pollutant that acts as a secondary pollutant through its acting as a precursor to acid rain – and as a major contributor to urban smog as it facilitates the creation of ozone.
⇨ Other impacts: respiratory effects
VOC
(Volatile organic compounds)
⇨ E.g. hydrocarbons, entirely made of carbon and hydrogen atoms
⇨ Examples include methane, butane, propane, and octane
⇨ Most emitted naturally by plant and animal emissions and decomposition (84%)
⇨ Industrial activities (used as solvents)/automobiles are a source of anthropogenic VOCs (16%)
⇨ Toxic, carcinogens, they react with other substances to form brown smog
Ozone and other
Photochemical Oxidants
⇨ At the earth’s surface, ozone (O3) is a pollutant - it irritates the respiratory system and damages plants - Impact depends on the dose
⇨ A secondary pollutant ⇨ Created from atmospheric interactions between
sunlight and NOx NO2 split to NO and O, reacting with O2 creating O3
VOC’s facilitate the reaction by enabling creation of additional NO2
⇨ In certain meteorological conditions ⇨ Stable air, not much wind ⇨ Sufficient emissions ⇨ Downwind distance ⇨ Amount of mixing due to Inversion layer ⇨ Sunlight
Inversion layer (IL)
⇨ Atmospheric inversion ⇨ Usually temps decline with increased height ⇨ IL is when warmer air is found above cooler air
⇨ High pressure areas ⇨ Warm air moving down, trapping colder air ⇨ Mountain effect traps the pollutants
⇨ Cooler air cannot rise ⇨ Polluted air gets trapped
⇨ Also possibly due to valley effect, cloud cover, humidity