Term
|
Definition
| Colloidal sized atmospheric particle |
|
|
Term
|
Definition
| 1 to 1x10-3 μm in diameter |
|
|
Term
| How are aerosols characterized? |
|
Definition
| Characterized by the way they are formed. |
|
|
Term
| What are the 7 types of atmospheric particles? |
|
Definition
1) aerosol
2) Condensation aerosol
3) dispersion aerosol
4) Fog
5) Haze
6) Mists
7) Smoke |
|
|
Term
| Define Condensation aerosol |
|
Definition
| Formed by condensation of vapors or reaction of gases |
|
|
Term
| Define dispersion aerosol |
|
Definition
| Formed by grinding of solids, atomization of liquids or dispersion of dusts. |
|
|
Term
|
Definition
| Term denoting high level of water droplets |
|
|
Term
|
Definition
| Denotes decreased visibility due to the presence of particles |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Particles formed by incomplete combustion of fuel |
|
|
Term
| What are the effects of particles? |
|
Definition
1) Reduced visibility
2) Provide an active surface for chemical reactions
3) Effect weather and air pollution
4) Nucleation body
5) Respiratory Irritation |
|
|
Term
| What are the particle restrictions set in place by the 1978 clean air act? |
|
Definition
| Restriction on particulate matter <10μm or <2.5μm in diameter(more recent) |
|
|
Term
| What detrimental health effect do particle of <10μm or <2.5μm in diameter have? |
|
Definition
| Particulate build up in cilia making it harder to keep lungs clean. |
|
|
Term
Define radioactive particles
(with respect to atmospheric particles) |
|
Definition
| Daughter products of Radon |
|
|
Term
| What are the problems in connections with radon? |
|
Definition
| Radioactivity originating from uranium mine tailings that have been used in some areas as back fill, soil conditioner and a base for building foundations. |
|
|
Term
| What are the decay products of the 2 isotopes of radon and what is there half life. |
|
Definition
222Rn->218Po+42He2+ (t1/2=3.8days)
220Rn->216Po+42He2+ (t1/2=5.4secs) |
|
|
Term
|
Definition
| Non-gaseous particle that will adhere to an atmospheric particle. This can then get stuck in your lungs a decay 7 more times to lead. |
|
|
Term
|
Definition
-Radioactive noble gas
-t1/2=10.3yrs
-non-regulated
-released in nuclear reactors and fuel reprocessing
-biota cannot concentrate this chemically unreactive element |
|
|
Term
| What are the 5 ways to control particulate emission |
|
Definition
1)Sedimentation chamber
2)Inertial mechanism
3)Fabric filters
4)Venturi scrubbers
5)Electrostatic precipitators |
|
|
Term
| Describe sedimentation chamber |
|
Definition
-Low collection efficiency, particularly for small particles
-Particles removed from stream of gas by gravitational settling over time
-Spontaneous coagulation of particles overtime, thus making them larger, enhances gravitational settling |
|
|
Term
| Describe inertial mechanisms |
|
Definition
-good for heavy particles
-particle of high inertial mass cannot turn corners rapidly and collide w/ container walls and are removed when they fall to the bottom of the container. Cleaner air then leaves through another port. |
|
|
Term
| Describe Fabric filters (bag house) |
|
Definition
1) Gas flows into bag house and particulate in the gas clogs the fabric walls. Walls bow out.
2)Pressure reversed w/ vacuum, bowing wall in.
3)Alternate positive and negative pressure flaps particulate free from bag
4)Cleaner gas passes through fabric of bag |
|
|
Term
| Describe venturi scrubbers |
|
Definition
-any aerosol that is water soluble is effectively scrubbed
1)Pass gas through a device with a converging section(throat)
2)Inject liquid at right angle into throat, which breaks into droplets
3)Droplets scavenge particles in gas(warm section)
4)Stream enters reduced pressure area leading to expanding and therefore cooling.
5)Cooling leads to condensation, and particles are collected in condensed liquid |
|
|
Term
| Describe electrostatic precipitator |
|
Definition
Effective for ionizable and polar particles
1) pass gas through electric field
2)particles obtain charge from negative discharge electrode
3)Charged particles are attracted to ground(positive) walls and later removed |
|
|
Term
| What two vapor forms of mercury might be found in the atmosphere? |
|
Definition
|
|
Term
| Why are aerosols in the 0.1-1.0 micrometer size especially effective in scattering visible light? |
|
Definition
| particles have size similar to wavelength of visible light |
|
|
Term
| What are the five major classes of material making up the composition if atmospheric aerosol particles? |
|
Definition
1)Metal oxides and glasses
2)carbonaceous material
3)dissolved ionic species
4)ionic solids
5)water |
|
|
