Air (on Final)

Question 1

What Is the first recorded control of air pollution?

Answer 1

13th century when London prohibited the use of coal

Question 2

What are types of air samples?

Answer 2

• indoor
• Ambient (outdoor)
• air from stacks
• emission exhausts

Question 3

What are the four types of air quality decisions

Answer 3

1) determination of effects
2) identification of pollutants causing effects
3) source attribution
4) emission control

Question 4

Explain what determination of effects means as

An air quality decision?

Answer 4

Perceiving a problem exists and is cause by constituents in the atmosphere.

• the air quality affects human respiration, impairs visibility, causes damage to plants and wildlife or is a nuisance
• observations determine the existence of a problem

Question 5

Explain identification of pollutants causing effects as a air quality decision

Answer 5

Atmospheric constituent must have the chemical and physical properties and be present in sufficient quantities to cause an unacceptable effect.

Classification as a pollutant is based on measurements that establish a cause and effect relationship

Question 6

Explain source attribution as an air quality decision

Answer 6

Can only reduce exposure to air pollutants by going to their sources

• many sources exists so decisions must be made with respect to contributions from each source.
• based on emissions, meteorological and ambient air measurements

Question 7

Explain emission control as an air quality decision

Answer 7

Many alternatives exist for reducing emissions. We need measurements of the control efficiency and the assumption that a reduction in emissions will be accompanied by a proportional reduction in ambient concentrations

Question 8

What categories do air samples taken from the env fall into?

Answer 8

1) ambient
2) indoor
3) emission samples(cars,incinerator stacks)
4) soil atmosphere (landfills,contaminated soil from spills)

Question 9

What % of air pollutants are organic?

Answer 9

90

Question 10

What does collection of a

Representative air sample require?

Answer 10

1) knowledge of pollutants present
2) pollutants behaviour
3) pollutants properties

Question 11

What is used to classify air pollutants

Answer 11

1) chem comp of pollutants (organic or not)
2) chem properties (water solubility, polarity and reactivity)
3) physical properties (density and vapour pressure)

Question 12

What are the activities for air pollutants

Answer 12

1) vvoc- >15 Kpa
2) voc - >1.010^-2 kpa
3) svoc - 10^-2 to 10^-8
4) nvoc-<1.010^-8

Question 13

What does vvoc Stand for? What is it’s common physical state? What is it’s vapour pressure?

Answer 13

• very volatile organic compound
• gases
• > 15kpa

Question 14

What does voc stand for?

What’s is common physical state?

What’s its saturation vapour pressure?

Answer 14

• volatile organic compound
• > 1.0*10^-2
• gas

Question 15

What’s svoc?

Saturation vapour?

Physical state?

Answer 15

• semi volatile organic chemicals
• 10^-2 to 10^-8
• gasses and aerosols

Question 16

What’s nvoc?

Saturation pressure?

Physical state?

Answer 16

Non volatile organic chemicals

<1.0 *10^-8

Mostly aerosols

Question 17

What to consider when selecting a sampling site

Answer 17

• source of contamination
• air flow/direction/velocity
• density of contaminants
• intensity of sunlight
• time of day
• presence of obstructions (trees/buildings)
• traffic
• site access/amenities

Question 18

Meteorological effect to consider when air sampling

Answer 18

• wind direction/speed
• temp
• atmospheric stability/pressure
• precipitation

Question 19

What are the 4 collection methods in air sampling?

Answer 19

1) absorption/Adsorption
2) filtration
3) whole air sampling
4) cryogenics

Question 20

Explain absorption/adsorption as a collection method

Answer 20

• analytes adhered to a physical material
• absorption occurs when the analyte is permanently affixed to a physical substrate
• substrate removed and analyzed
• adsorption is when analyte sticks to substrate and then is stripped for specific analysis
• stripping by chemical of thermal methods

Question 21

What are sorbet cartridges used for?

What collection method are they apart of?

Answer 21

Used to extract and concentrate both voc’s and scocs from air. Air drawn through cartridge containing solid cartridge. Voc’s retained on surface of cartridge packing

Question 22

What does a breakthrough mean in regards to sorbet cartridges

Answer 22

Is when the front adsorbent portion is overloaded with the analyte and unretained analyte passes through

Question 23

How many adsorbent portions do most sorbent cartridges have?

Answer 23

2 to prevent breakthroughs

Question 24

Why are there two sorbent chambers in a sorbent cartridge?

Answer 24

So the analyst can see if the first chamber has had a break through but seeing if any analyte made it to the second chamber

Question 25

Explain filtration as a collection method?

Answer 25

High volume air sampler draws air through quartz or glass fibre filters.

T air collected = flow rate * sampling time

Drawback: no break down of samples particle distribution by size

Filter pore size dictates the amount and type of particles collected

Question 26

Explain whole air sampling as a collection method

Answer 26

Stainless steel canister used to collect samples. Air pumped in preevacuated container and pressurized to a few atmospheres

Analysis done by measuring volume of air and focusing it cryogenically

Question 27

Explain cryogenics as a collection method

Answer 27

Preferred when dealing with voc’s

Sensitive

Under vacuum and extreme cold sample of air is passed through. Analytes condense upon cooking and can be analyzed