Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
42 Cards in this Set
- Front
- Back
Environmental Chemistry (definition) |
Looking at the chemistry (both the processes and species) that contribute to our environment as we know it. |
|
"Sustainable" (definition) |
The industrial progress that meets the needs of the present without compromising the ability of future generations to meet their own needs. |
|
Industrial waste in the past (3 ways): |
1. Dumped on the ground 2. Drained into rivers 3. Up the smoke stack |
|
5 things we will focus on (spheres): |
1. Atmosphere - Air - 1st defense against the sun/high transport area.
2. Hydrosphere - Water - Interaction w/ atm and geosphere. High transport.
3. Geosphere - Soil and Rocks - Low transport
4. Biosphere - Life
5. Anthrosphere - Technology - Most recently defined/what we do that affects the env. |
|
Ecology (definition) |
The science that deals with the relationships between living organisms and their physical env. |
|
Pollution -- Pollutant (definition) |
Substance present in greater than natural quantities as a result of human activities that has a net detrimental effect upon its env.
** All pollutants are contaminants ** |
|
Contaminant (definition) |
Causes deviation from normal composition of an environment. |
|
Definitions:
Source
Receptor
Sink |
- Origin of pollutant (ex: factory)
- Anything affected by the pollutant (ex: atm)
- Long time repository for a pollutant (ex: ground) |
|
Physical transport (examples) |
River flow, wind, land slide, animals, runoff, precipitation, convection |
|
Chemical pathways (examples) |
Biological uptake, surface chemistry, decomposition |
|
Mass Balance (definition) |
Matter can neither be created, nor destroyed, only changed. |
|
The atmosphere (definition) |
A layer of gases that surrounds our planet
N, O, Ar, CO2, Ne, He, CH4, Kr, N2O, H2, Xe, SO2, O3, NO2, H2O, etc.
78% N2 0.9% Ar 21% O2 0.04% CO2 |
|
Components of Atmosphere (4 layers) |
1. Troposphere -- 15km 2. Stratosphere -- 50 km 3. Mesosphere -- 85 km 4. Thermosphere (ionosphere) -- 500 km |
|
What is bad in the atm today:
Hydrocarbons: |
1. Global warming (CO2, CH4) 2. Acid Rain (SO2, NO) 3. Acid Rain and Smog (NO2) 5. Health Hazards (CO)
- CH4, C2H6 |
|
Definitions:
Meteorology Weather Climate Humidity Relative Humidity |
- The study of air movement & phenomena - Short term variations in the state of the atmosphere - Localized long term variation in the atm - Vapor content in the air - % max H2O the air can hold at a given temp |
|
Dew Point |
The temperature at which water starts condensing. |
|
Inorganic Oxides Oxidants Reductants Organics Photochemically active species Acids Bases Salts Unstable intermediates |
- CO, CO2, NO2, SO2... - O3, H2O2, HO', ROO', NO3 - CO, SO2, H2S - CH4, CnH2n+2, CnH2... - NO2, CH2O - HNO3, H2SO4 - NH2 - (NH4)2SO4, NH4SO4 - NO2*, OH' |
|
3 Types of reactive things in atm: |
1. Electronically excited species (*) 2. Ions (+/-) (more cations in atm b/c of sun) 3. Radicals (') |
|
5 types of light waves: |
1. UV = (200-400nm) Break bonds, ionize, electronic excitation 2. Vis = (400-700nm) Breaking bonds, electronic excitations 3. IR = (700-10,000nm) Vibrations, rotations (heat, causes movement) 4. Microwaves = (10,000nm)Rotations (spins molecules to create energy) 5. X-rays/Cosmic rays = (>200nm) Break bonds, ionize |
|
Organic Inorganic |
- Carbon based/life, PAHs - Everything else (metals, NOx, SO2, CO2) |
|
What we have done to make particles: |
1. Coal combustion - Chemical combustion/physical grinding, mulling, etc. 2. Sulfates, Nitrates - Industry, automobiles 3. Generation of aerosols - Smaller = worse |
|
Aerosol (definition) |
Colloidal-sized (not just one, a collection) atmospheric particle |
|
Definitions:
Fog Haze Smog Mist Smoke |
- Increased H2O - Decreased visibility due to particles - A photochemically oxidizing atmosphere - Liquid particles - Incomplete combustion |
|
CO |
- 0.1 ppm, 2/3 comes from CH4 + O2 -- COH2, 20% from degradation of chlorophyls, 6% from humans - 50-100 ppm in urban areas - Above 70 ppm is hazardous - Can prevent by increasing air/fuel, which produces more CO2 instead - In atm: CO + HO' -- CO2 + H H + O2 + M -- HOO' + M - Soil micro can consume CO -- CO2 |
|
SO2 |
- Sulfur can also exist in atm as H2S, SO3, (CH3)2S, sulfates - Primary source is fossil fuels (pyrite in coal) SO2 -- SO4,2- or H2SO4 - Photochemically inert in troposphere (wavelength of light not sufficient) - Contributes to smog (hydrocarbons + NOx + UV light -- oxidation of SO2 to SO3 and SO4 - [SO2] > 1ppm can be harmful, occurs in urban areas and valleys |
|
SO2 (continued) |
- Can harm plants when dissolved in soil - Acid rain - damage to buildings & structures - Can trap SO2 by oxidizing to SO4,-2 and trap with Ca/Mg to make a salt (gas phase) - Liquid phase - make acid |
|
Nitrogen |
- N2O, NO, NO2, NO3' -- All contribute to smog, acid rain and ozone depletion |
|
N2O |
- Not very reactive N2O + O -- N2 + O2 or 2 NO O3 + hv -- O2 + O (rxn reverses at night) - Ozone depletion when O reacts with N2O instead |
|
NO and NO2 - NOx |
- Sources: Biological, lightning, cars - NO + O3 -- NO2 + O2 (depletes ozone) - Makes Smog: 2NO2 + O -- N2O5 N2O5 + H2O -- 2HNO3 HO' + NO2 - HNO3
- NO2 - health impacts - inflamed lungs, death |
|
Prevention |
1. Modify conditions to limit production - Decrease O2, lower T 2. Treat exhaust to remove NOx - Biofilters? |
|
NH3 |
- Base: NH3 + HNO3 -- NH4NO3 - React with acid to produce corrosive salts |
|
F, Cl |
- HF and F2 used in aluminum manufacturing - Highly toxic to humans - Make radicals that attack ozone - SF6 - Greenhouse gas 23,900x worse than CO2 |
|
H2S |
- Looks like H2O - Oxidizes quickly to SO2 - Very harmful to humans - Common source = natural gas wells ("sour") - Aids in oxidation of other substances |
|
What have we done to mitigate particles? |
- Fabric filter - Settling (tall smoke stacks) - Inertia - ex: centrifuge (set up spiral air motion, so they are trapped on the walls) - Electrostatic filter - Scrubbers |
|
Direct vs Indirect effects |
- Cancer vs. smog, O3 decrease, etc. |
|
3 types of hydrocarbons |
- Alkanes - CnH2n+2 - Alkenes = - Alkynes - triple bond
Can enter the atmosphere directly, or as a byproduct of incomplete combustion (unsaturated/more reactive) |
|
Things that can attack double bonds and make chemistry happen |
OH', O2, NO, NO2 |
|
Chromophores |
- A part of a molecule that absorbs light |
|
Alcohols Phenols Ethers Carboxylic Acids |
- CH3OH, C2H5OH -- Are either absorbed or reacting w/ HO' - Dissolve in H2O, react with OH' - Gas additives - Oxidize into carbonyls - Water soluble + precipitate |
|
Amine Amide Nitrile Halides/Organohalides |
- Bases, smell of rotten fish, H bonding, decrease vapor pressure - Similar to carbonyl chemistry - Rubber production - Has F, Cl, Br, I attached - Manufacturing and biological sources (ocean) |
|
Smog (definition) |
- Photochemically oxidizing atmosphere - Large conc. of oxidants - >0.15ppm oxidants that persist for 1hr+ - Hydrocarbons + UV light + NOx |
|
Harmful effects of Smog |
1. Human Health 2. Atmospheric changes 3. Plant life (acid rain) 4. Corrosion/damage to materials |