AIR POLLUTION CONTROL

 AIR POLLUTION CONTROL

Review 1

Part I: Short answer

1. A power plant of 500 MW is operating at 50% efficiency, what is the amount of natural gas needed per day? 
2. Convert SO2 concentration of 1 ppm to mg/m3, under STP.
3. What is the half-hour point of impingement criterion of SO2 in Ontario?
4. What are the two parameters in lognormal distribution of aerosols?
5. Lognormal distribution of particles.  d₅₀= 7 mm, d_84.1=13 mm, and d_15.9= 4 mm, calculate geometric standard deviation.
6. Dry adiabatic rate.
7. How is atmospheric stability determined using temperature profile?
8. How is atmospheric stability class determined?
9. List at least two assumptions of the Gaussian Plume Model used in class.
10. How to use a Gaussian Plume Model to get worse case ground level concentration due to a nearby point source?
11. How to use a Gaussian Plume Model to estimate annual ground level concentration at a receptor due to a nearby point source?
12. Two APCs are in a series. The removal rate of the first one is 70%.  In order to achieve 90% overall removal efficiency, what should be the penetration rate of the second APC?
13. List three advantages and three disadvantages of settling chambers.
14. List three advantages and three disadvantages of cyclones.
15. How to design a setting chamber?  

Part II: True/false questions

1. Acid rain is an air pollutant.
2. According to the CDI equation, if the time of an individual exposed to vinyl chloride doubles, the risk will double.  
3. Gaussian Plume Models assume the plume in y-direction is always symmetric to X-axis.
4. Gaussian Plume Models assume the plume in z-direction is always symmetric to a horizontal plane of z=H.
5. Gaussian Plume Models assume constant wind speed and direction during the distance of plume travel.
6. Gaussian Plume Models can be used to estimate annual average concentration due to two or more sources.
7. Using Gaussian Dispersion Models to estimate concentration, one has to adjust the wind speed to stack height.
8. Effective stack height increases with wind speed. 
9. Using Gaussian Dispersion Models, the POI concentration will double if the emission double.
10. Using the Gaussian Dispersion Model, a 10 min average concentration is lower than a 30 min average.
11. It is not recommended to use Gaussian Dispersion Models to predict concentration at x>10 km. 
12. The measurements, from surface to 2 km, indicated environmental lapse rate of    –9^oC/km, the atmospheric boundary layer was stable. 
13. Summer noon at Toronto, ON, strong winds, overcast, the stability class is A. 
14. PM >10 mm are more important from a human health stand point.
15. It is easier to get geometric mean and geometric standard deviation using cumulative size distribution.
16. If the particles are measured in mm, the unit of geometric standard deviation will be mm.
17. Particles in an air stream experience gravity. 
18. The drag coefficient is a function of Reynold’s number.
19. The Reynold’s number is NOT a function of the density of the particles. 
20. Mean free path is a property of the air stream and the particles. 
21. Cunning Correction Factor should be close to 1.0 under STP. 
22. One can always assume Cunning Correction Factor is 1.0.
23. With the same size, the aerodynamic diameter of a lead particle is the same as that of a sawdust.
24. To increase removal efficiency of a cyclone, one can increase inlet velocity.