Chapter 19:

Air Pollution and Noise

Living and Working in a Healthy Environment

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Image from www.collegesherbrooke.qc.ca/~graphycs/martinaube.html

Sources of air pollution

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Sources of air pollutionEmissions

Anthropogenic (manmade): Fossil fuel combustion, biomass burning, industrial processes, etc.

Biogenic: Emissions from vegetation, soil, wildlife, forest fires, etc.

Other natural: Volcanos, lightning, sea salt, meteors, windblown dust, etc.

Photochemical production from other compounds in atmosphere (“secondary source”)

Transport: If considering only troposphere, then transport from stratosphere is a source

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NO

NO2

HO2

OH

CO2, etc.

CO, VOC

O3

Primary & secondary pollutants

Primary(e.g., lead)

Secondary

VOC NOx O3

Primary: Emitted directly to the atmosphereSecondary: Forms in the atmosphere

Sources of the 5 major pollutants in the U.S

Note: Historically, the 6th Major Pollutant was lead.

Source and Composition of Particulates

sulfates, ash

sea salt

meteoritic material

Soot, NOx, VOCs

Soot, organic

soot

methane, ammonia

soot

Soot, sulfates, VOCs

Minerals, clays

Emission events (Nov. 18, 2008)Textruve Plant on 2001 Sheldon Road (Channelview, TX)

Picture taken at 4:00 pm from 20 miles awayPicture taken at 6:00 pm on site

Impacts: Ozone and PM2.5 Non-Attainment

Source: U.S. EPAU.S. EPA, 2006

2002 2003 2004 2005 2006 20070

50

100

150

200

250

2002 2003 2004 2005 2006 20070

10

20

30

40

50

Year

PM

2.5 a

nnua

l ave

rage

con

c. (g

/m3)

Annual average

NAAQS (15 g/m3)

Ma

xim

um

PM

2.5 c

on

cen

tra

tion

(g

/m3 )

24hour NAAQS (35 g/m3)

Very close to non-attainment

Fine PM levels in Clinton Drive (Houston, TX)

Let’s consider those compounds that the Federal Government regulates National Ambient Air Quality Standards (NAAQS)

Secondary(1300

µg/m3)0.50 ppm3-hour Average

Primary(365 µg/m3)0.14 ppm24-hour Average

Primary(80 µg/m3)0.03 ppmAnnual Arithmetic Mean

Sulfur Dioxide (SO2)

Primary & Secondary65 µg/m324-hour Average **

Primary & Secondary15 µg/m3Annual Arithmetic Mean **

Particulate (PM 2.5) Particles with diameters of 2.5 micrometers or less

Primary & Secondary150 µg/m324-hour Average

Primary & Secondary50 µg/m3Annual Arithmetic Mean

Particulate (PM 10) Particles with diameters of 10 micrometers or less

Primary & Secondary1.5 µg/m3Quarterly Average

Lead (Pb)

Primary & Secondary(157 µg/m3)0.08 ppm8-hour Average **

Primary & Secondary(235 µg/m3)0.12 ppm1-hour Average

Ozone (O3)

Primary & Secondary(100 µg/m3)0.053 ppmAnnual Arithmetic Mean

Nitrogen Dioxide (NO2)

Primary(40 mg/m3)35 ppm1-hour Average

Primary(10 mg/m3)9 ppm8-hour Average

Carbon Monoxide (CO)

STANDARDTYPE

STANDARDVALUE *

POLLUTANT

Secondary(1300

µg/m3)0.50 ppm3-hour Average

Primary(365 µg/m3)0.14 ppm24-hour Average

Primary(80 µg/m3)0.03 ppmAnnual Arithmetic Mean

Sulfur Dioxide (SO2)

Primary & Secondary65 µg/m324-hour Average **

Primary & Secondary15 µg/m3Annual Arithmetic Mean **

Particulate (PM 2.5) Particles with diameters of 2.5 micrometers or less

Primary & Secondary150 µg/m324-hour Average

Primary & Secondary50 µg/m3Annual Arithmetic Mean

Particulate (PM 10) Particles with diameters of 10 micrometers or less

Primary & Secondary1.5 µg/m3Quarterly Average

Lead (Pb)

Primary & Secondary(157 µg/m3)0.08 ppm8-hour Average **

Primary & Secondary(235 µg/m3)0.12 ppm1-hour Average

Ozone (O3)

Primary & Secondary(100 µg/m3)0.053 ppmAnnual Arithmetic Mean

Nitrogen Dioxide (NO2)

Primary(40 mg/m3)35 ppm1-hour Average

Primary(10 mg/m3)9 ppm8-hour Average

Carbon Monoxide (CO)

STANDARDTYPE

STANDARDVALUE *

POLLUTANT

Texas Air Quality

Lecture 32Texas Air Quality

http://www.airnow.gov/index.cfm?action=airnow.national

U.S. Federal Regulation of Air Pollution

Air pollution Control Act of 1955Clean Air Act of 1963Amendment to CAA - Motor Vehicle Air

pollution Control Act of 19651970 Clean Air Amendments and formation of

the EPA. 1975 catalytic converter developed.

U.S. pollution trends since 1977

Signs that regulation works!

Stratospheric ozone—The good ozone

Types of SMOG

1.Industrial London Smog – combination of smoke and fog

- At the end of the 1800’s, 40% less sunlight in London than surrounding towns

- Health effects- Vitamin D deficiency, Rickets, Tubercolosis

2. Photochemical Smog

Consists mainly of secondary pollutants: Ozone (O3), NO2, VOCs

Forms when sunlight induces chemical changes in gases and aerosols

Causes poor visibility, burning eyes, sore lungs, worsen conditions of the heart and lungs, possible mortality.

Photochemical and Industrial Smog

“LA Smog”:Brown-air smog in Los Angeles

“London Smog or Industrial Smog”Gray-air in New York City

© Dean D. Fetterolf/ShutterStock, Inc. © Chad Littlejohn/ShutterStock, Inc.

Houston Case

• Which kind of smog do you think Houston has?

• Why is Houston different from London or LA case?

• How much do you think pollution from Houston will influence College Station?

Photochemical Smog Ozone (O3) in the Troposphere

Most problematic air pollutant in many areas of the U.S.

Ozone is not directly emitted into the atmosphere, but instead forms through a complex series of reactions.

It is largely because of this complexity that ozone is so difficult to control.

Ozone chemistry(gas-phase only)

NO2 NO

O3

HO2

RO2OH

N2O5

NO3

HNO3

VOC

HONO

hn

H2Ohn H2O2

NOx and VOC sources in the Greater Houston Area

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Ozone Non-attainment: Old standard

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Ozone Non-attainment: New standard

19.2 The Effects of Climate and Topography on Air Pollution

Air pollution levels in a region are affected by a number of factors, among them:

Temperature Sunlight Wind Other climate factors

They are also affected by the topography.

FIGURE 05a: Temperature profiles: normal pattern

FIGURE 05b: Temperature profiles: temperature inversion

The Health Effects of Air Pollution

FIGURE 6: Urban air pollution and incidence of emphysema in Winnipeg and St. Louis

Effects on Plants and Nonhuman Animals

FIGURE 7:Trees killed by acid deposition in

Pisgah Nation Forest, North Carolina

© Jerry Whaley/age fotostock

Power Plant NOx Control:Staged Combustion

Low-NOx Burners: Precisely control combustion to reduce NOx

Natural gas reburn: Creates fuel-rich zone and radicals which destroy NOx

Over-fire air: Completes the combustion

Together, can reduce NOx by ~50-75% US DOE NETL

Power Plant Sulfur Dioxide Control• Initially dispersed by

tall chimneys– “Solution to pollution is

dilution”• Low sulfur coal

– Some coals (e.g., Western U.S.) contain less sulfur

• Flue Gas Desulfurization– Sorbent such as

limestone or lime is injected to remove 80-98% of SO2

– Cobenefit of reducing mercury emissions

– Byproduct can be used in wallboard, cement

– 3-7% energy penalty

Parish Power PlantUnit 8 FGD System

Power Plant NOx Control:Selective Catalytic Reduction

(SCR)Ammonia is injected after boiler to convert NOx to N2 and water Requires catalyst Specific temperature

range

~85% NOx reduction

www.de-nox.com

Automobile Emission Controls

3-way catalytic converter Reduces NOx, oxidizes CO and hydrocarbons

Oxygen sensor: Controls air-fuel ratioDiesel particulate filters and oxidation catalystsCleaner burning fuels

Unleaded gasoline: No lead emissions; preserves catalyst

Low sulfur fuels: Preserves catalyst Added oxygenates: Reduce CO

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Catalytic ConvertersA. Reduction Catalyst:

2NO N2 + O2

B. Oxidation Catalyst: 2CO + O2 2CO2

CxHy + (x+y/4)O2 xCO2 + (y/2)H2O

CO2 is dominant component of exhaust, not significantly affected by controls 19.4 lb CO2/gal gasoline; 22.2 lb/gal diesel

Diesel Particulate Filter

Volkswagen

Electrostatic Precipitator (ESP)

Suspended particles are charged by electron field

Particles travel to collection plate

Plates are rapped to make PM fall to hoppers

~99% efficiencyceenve3.civeng.calpoly.edu/cota/ENVE411-ESP.html

19.5 Noise: The Forgotten Pollutant

Sound is characterized by loudness (measured in decibels) and pitch (how high or low it is).

How Loud is Too Loud?

Prolonged exposure to any noise above 85 decibels (dB) can cause gradual hearing loss.At higher decibel levels, hearing protection is strongly recommended.100 decibels - no more than 15 minutes prolonged exposure recommended110 decibels - regular exposure of more than one minute risks permanent hearing loss without hearing protection. www.warrencenter.org/howloud.html

www.warrencenter.org/howloud.html www.warrencenter.org/howloud.html

Indoor Air Pollution

FIGURE 14: Radon protection