Question

Module 4: Dispersion of Pollutants 1. Most equations for predicting plume rise contain two terms that account for different physical reasons for the rise. What is the nature of these two terms?

2. Is it justifiable to use a constant value for the effective plume rise for a given situation, or should one in reality, adjust for the distance downwind from the stack? Discuss.

3. Sulfur dioxide is being emitted in a rural area at a rate of 0.90 kg/s from a stack with an effective stack height of 220m. The average wind speed at stack height is 4.8 m/s and the stability category is B. Determine the short-time period, downwind, center-line concentration in micrograms per cubic meter at ground-level distances of 1.0, 2.0 and 4.0 km.

4. What is the expected short-term period ground-level concentration at 150 and 250 m away from the downwind center line for the conditions given in Problem 3?

Answer 1

1. The models are in terms of: Vs = stack exit velocity (m/s) ;d = stack diameter,(m); U = mean wind speed at top of stack(m/s) ;Qk — heat emission rate (kilocalories/sec).

in

The Holland Formula Holland14 presented the following empirical equation for predicting plume rise:

this equation says that the stack velocity, the diameter of the stack and the heat emission rate, make the plume to rise, nonetheless, the mean wind velocity makes the plume to fall.

we can gladly help you with the others but you should post them again