Meteorological Aspects of Air Pollutant Dispersion topics include: Adiabatic and environmental lapse rate, atmospheric stability and inversion, atmospheric turbulence, stack effluent dispersion theories, plume behaviour and its characteristics. Meteorological conditions are the primary factor that affects the dispersion of pollutants in the atmosphere.  Some meteorological aspects that affect air pollutant dispersion include: Wind speed: Higher wind speeds generally disperse pollutants more, resulting in lower air pollution concentrations in areas with stronger winds. Wind direction: Wind... Show more

Meteorological Aspects of Air Pollutant Dispersion topics include: Adiabatic and environmental lapse rate, atmospheric stability and inversion, atmospheric turbulence, stack effluent dispersion theories, plume behaviour and its characteristics.

Meteorological conditions are the primary factor that affects the dispersion of pollutants in the atmosphere. 

Some meteorological aspects that affect air pollutant dispersion include:
Wind speed: Higher wind speeds generally disperse pollutants more, resulting in lower air pollution concentrations in areas with stronger winds.
Wind direction: Wind direction is an important factor if there are distinct sources of pollutant emission.
Temperature: Warmer temperatures promote greater vertical mixing of the air, which helps disperse pollutants more quickly.
Humidity: Humid air traps pollutants close to the ground, preventing them from dispersing into the atmosphere.
Rainfall: Rainfall favors pollutant dispersion and removal from the atmosphere.
Atmospheric mixing layer height: This meteorological factor affects the vertical diffusion of atmospheric pollutants and water vapor concentrations.

Show less

Pollution Control Practice Test: Meteorological Aspects of Air Pollutant Dispersion

Time left 00:00

25 Questions

1. Which areas are affected by radiational inversion more so than others?

Oceanic areasLow-lying areasMountainous areasDesert areas

2. What is the wet adiabatic lapse rate in warm tropical regions?

3 times dry adiabatic lapse rateEqual to the dry adiabatic lapse rateHalf of dry adiabatic lapse rate(1/3)(Dry adiabatic lapse rate

3. What is the superadiabatic lapse rate? (ELR – Environmental Lapse Rate; DALR – Dry adiabatic lapse rate; WALR – Wet adiabatic lapse rate)

ELR > DALRELR > WALRELR < WALRELR = DALR

4. When does looping occur, when the atmosphere is unstable?

During inversionDuring subadiabatic conditionsDuring superadiabatic conditionsDuring stability

5. If the air pollutant plume size is larger than the eddy, how will the pollutants be dispersed?

Little dispersionIt will not transportIt will carry it upwindUniform dispersion

6. Which of the following is an assumption made to derive the equation for the lapse rate?

Air is assumed to be an ideal gasAdiabatic processIsochoric conditionsIsobaric conditions

7. Which is the most favourable plume behaviour to avoid ground-level pollution?

ConingLoopingFumigationLofting

8. Which of the following options correctly names the line indicated by the question mark? (DALR – Dry Adiabatic Lapse Rate, WALR – Wet Adiabatic Lapse Rate)

Environmental lapse rateSubadiabatic lapse rateSuperadiabatic lapse rateMoist adiabatic lapse rate

9. When can the downwash of the plume be avoided?

When the stack is taller than the valley rimWhen the wind speeds are lowWhen there is an inversionWhen the stack height is short

10. Fick’s molecular diffusion and Sutton’s statistical concepts are used for calculating dispersion models for which sources?

Continuous point sourcesAtmospheric stabilityLine sourcesInstantaneous point sources

11. What is meant by the effective stack height?

Sum of stack height and plume riseDifference of stack height and plume riseHeight of the plumeSynonymous with the stack height

12. Which of the following plume behaviour conditions lasts for a very short period (less than an hour)?

ConingFumigationTrappingLooping

13. What is the negative adiabatic lapse rate?

Temperature and altitude have no relationshipTemperature increases with altitudeTemperature does not change with altitudeTemperature decreases with altitude

14. What happens to the plume if its velocity is equal to the wind velocity?

Plume disperses horizontallySlow dispersionPlume does not disperse verticallyDownwashing

15. If a stack is constructed near a building, what should its height be to ensure characteristic plume dispersion?

2.5 times the height of the surrounding buildingIt should never be built near a buildingEqual to the adjacent building10 metres

16. Which plume behaviour is represented in this diagram?

LoftingFumigationFanningConing

17. What happens in the superadiabatic conditions?

The air parcel moves sidewaysThe air parcel does not moveThe air parcel rises upwardsThe air parcel moves downwards

18. Which of the following plume dispersions create the worst pollution circumstances?

FanningFumigationTrappingConing

19. How is the behaviour of the plume determined to optimise dispersion?

ModellingCalculationsFrom experienceWind tunnel testing

20. Which of the following is not a factor applied to evaluate the theories of plume rise?

Wind speedPlume temperatureStack diameterNature of the plume

21. Atmospheric turbulence is higher with rougher surfaces. Which of the following areas are categorised as having uneven surfaces?

CountrysideForestsUrban areasSuburbs

22. Which of the following is not a model used for plume rise modelling based on stability classification?

Fick’s lawASME modelPasquill modelMcElroy model

23. Fanning is associated with which of the following wind speeds?

Very high speedsModerated speedsHigh speedsVery light speeds

24. In which two kinds of plume behaviour do the air pollutants reach the ground-level?

Fanning and TrappingFanning and coningLooping and fanningLooping and coning

25. What is the condition indicated by the dotted line (question mark)?

Isothermal conditionSubadiabatic lapse rateIsochoric conditionsIsobaric conditions