I am preparing for the Engineers Australia Oral Exam for Biomedical and Mechanical Engineering. Similar to the American PE designation. One of the topics I was given to study says:
Water spray droplets are used to scrub out Particulate Matter 2.5 in incinerators and other emission sources. Also, rain droplets are found to be effective in reducing the PM2.5 in the atmosphere.
1. Describe in detail the underlying mechanism for this scrubbing effect.
2. Perform calculations to show the effectiveness of rain droplets in removing PM2.5 under gravity. Make any assumptions as required.
3. Determine the scrubbing efficiency if the droplets are sprayed inside a chamber at high velocities.
I would appreciate guidance on how to tackle this problem. Are there books or literature on this matter that anyone could recommend? I have scoured NOAA and the EPA but not really found much.