Hierarchy of Controls for Pollution Control
Prevention
Dispersion (dilution)
Collection and disposal
Chemical change (combustion)
Baghouse
How does it work?
Negatives?
FILTRATION- Particulates stick to the bags inside it.
Negatives- 1. temperature restrictions and 2. lose energy so the fan will have to pull harder
Cyclone
How does it work?
Negatives?
Uses centrifugal force
Negatives- 1. Can’t get respirable particles 2. Not efficient
Electrostatic Precipitator
How does it work?
Uses energy to charge particles and they are attracted to collector plates
Negatives: requires a lot of space
Settling Chamber
How does it work?
Negatives?
Particles settle
Negatives: low efficiency
Scrubber
How does it work?
Negatives?
Inertial impingement
Dry and wet scrubbers
Dry- like a sorbent tube
Wet- like a shower
Negatives: Does not get respirable particles
Venturi Scrubber
What is it?
Negatives?
cleans dirty air by squeezing it and spraying it with water
Negatives: high energy cost= expensive
Adsorber
What is it?
Negatives?
pollutants stick to the surface of a solid
Negatives: does not work at high temperatures
Absorber
What is it?
pollutants dissolve into a liquid
Condenser
What is it?
removes vapors by cooling them until they turn back into liquid and then you can collect it
Equation to determine the collection efficiency
Mass removed/ mass entering x100
PPE levels:
A- Total encapsulated suit, SCBA, boots, hard hat
B- SCBA, chemical protective suit, boots, gloves, hard hat
C- PAPR, chemical protective clothing, boots, gloves, hard hat
D- work clothing, boots, gloves, hard hat
What is the highest carbon dioxide concentration provided below that is generally considered appropriate for an office building
1000 ppm
