31-Pollution Prevention#
Air Quality#
National Ambient Air Quality Standards (NAAQS)#
Link: https://www.epa.gov/criteria-air-pollutants/naaqs-table
Air Quality Map#
Link: https://www.epa.gov/outdoor-air-quality-data/interactive-map-air-quality-monitors
Air Data#
Click the layers and choose CO and navigate to your location.
HW:
If I worked outside and otherwise spent the whole day exposed to the air in the city of Provo, what would have been my TWA exposure to CO on 1/1/2020?
How does that value compare to the NAAQS for CO? How does it compare to the PEL for CO?
Plot the CO levels near Provo for the months of January-May 2020. Add the PEL and NAAQS levels for CO to the plot.
National Emission Standards for Hazardous Air Pollutants (NESHAP)#
188 NESHAP
standards have been established for 174 source categories. These standards limit the amount of hazardous air pollutants that may be emitted from a source. Chemicals such as benzene, mercurycompounds, selenium compounds, asbestos, vinyl chloride, and many others are regulated by NESHAP
standards.
Polution Prevention Act (PPA), 1990#
Focuses on pollution prevention (P2) as the nations primary pollution strategy. Hierarchy:
Source reduction
In process recycling
On-site recycling
Off-site recycling
Treatment
Disposal
Release
Requires P2 efforts for TRI (Toxic Release Inventory) permits. TRI permits are required for facilities that manufacture, process, or use more than a threshold amount of a listed toxic chemical. The PPA also requires the EPA to establish a P2 information clearinghouse.
In-process recycling is the reuse of materials within a process.
On-site recycling is the reuse of materials within a facility.
Off-site recycling is the reuse of materials outside a facility.
Treatment is the use of physical, chemical, or biological processes to reduce the toxicity or volume of waste.
Disposal is the final disposition of waste.
Release is the discharge of waste into the environment.
Source Reduction#
Source reduction is the reduction or elimination of waste at the source. The intent is to reduce:
energy use
raw material use
waste minimization
environmental releases
used solvents
waste water
air emissions
Reducing the amount of waste generated in a significant increase in the efficiency of the process. For example, if a process generates 1000 pounds of waste and 100 pounds of product, the process efficiency is 10% (100/1100). If the process is modified to generate 10 pounds of waste and 100 pounds of product, the process efficiency is 91% (100/110).
Case Scenario - production of nitric acid:
The production of nitric acid generates a large amount of NOx emissions.
The process can be modified to reduce the amount of NOx emissions.
Some additional specific examples of source reduction include:
LED lighting
Higher efficiency furnaces
Higher efficiency air conditioners
HW: Research a source reduction scenario and provide a brief summary.
Waste Minimization#
Substitution of less hazardous materials
Process modification
Inventory control
Equipment optimization
Fugutive emissions (Gold capture air particulate in gold processing)
Sustainability#
Sustainability means meeting the needs of today without compromising the ability of future generations to meet their needs
Life-Cycle Analysis#
Scope
Establish system boundaries
Determine functional unit (including life expectancy)
Inventory
Inputs: raw materials, energy
Outputs: products, byproducts, wastes, emissions
Impact assessment
Environmental impacts of all steps in life cycle
Improvement analysis
Generate alternatives
Consider each step
Cradle-to-grave analysis
Consider all steps in life cycle
Consider end use
Consider disposal