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1. What is air pollution?
2. Causes of Air Pollution
3. Effects of Air Pollution
4. What is the Status of Air Quality in the Country?
90 ug/Ncmannual air quality guideline value for Total
SuspendedParticulates (TSP)
The air quality of our country is still dirty but improving in
terms of TSP. For2008, TSP level is 99ug/Ncm
29% reduction from 2004 to 20085. What is the Specific Air
Quality of Metro Manila?
90 ug/Ncmannual air quality guideline value for Total
SuspendedParticulates (TSP)
The air quality of Metro Manila is still dirty but improving in
terms of TSP.For 2008, TSP level is 138 ug/Ncm
15% reduction from 2004 to 20086. How is Metro Manila Air
Quality Compared with Other International Cities?
Based on the Environmental Performance Indexfor 2008, the
Philippines ranks
5th (out of 11 countries) in the ASEAN Region,including Japan,
China and South
Korea
7. What is the Correlation between Air Quality and Health in
Metro Manila
(from 2003 to 2007)?
Data from the DOHs Field Health Survey and the EMBs air quality
monitoring
both show a downward trend from 2003 through 2007 in terms of
bronchitis
health data.
Based on DOH data on morbidity cases for Air Pollution Related
Diseases
20032007:Bronchitis: 29% (decrease)
Air Quality: 19 % (decrease)
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This downward trend is supported by the findings of a study of
the DOH under the
MMAQISDP in cooperation with the Asian Development Bank and the
World
Health Organization conducted from 2002 through 2003.
It was also found that there is a significant improvement in
blood lead levelsamong children in Metro Manila since 2000 when the
unleaded gasoline policy
has been implemented.
In 2003, only 34.6% of study children exceeding the USCDC
guideline value of
10g/dl as compared to 90.3% in 2000.
8. What are the Reasons on the Downward Trend of Air Quality in
Metro
Manila?
Completion of the MRT construction along EDSA Implementation of
the MMDAUnified Vehicle Reduction Program alongmain thoroughfares
(Color coding) i.e. EDSA Intensified antismoke belching operations
by MMDA thru MMAQISDP
(20002002), the SMOKE FREE EDSA (Oct 2003) later changed to
LINIS
HANGIN PROGRAM (Nov. 2004 up to June 2009) by DENR. Effective
July
2009, INTENSIFIED ASB OEPRATIONS OF THE METRO MANILA LGUsin
coordination with the MMASBA, LTO and LTFRB
Intensified stack emission testing program of industrial
sources/facilitieswithin the Metro Manila
Airshed(MMAQISDP)/accreditation of 3rd Party
Stack Emission Firms (2003present) Use of Alternative
FuelsConversion of gasolinefed taxis to LPG
Introduction of new CNG buses pursuant to Executive Order No.
290
[Natural Gas Vehicle Program for Public Transport (NGVPPT)]
dated 14
February 2004. To date, a total of 30 new CNG buses plying the
route of
Batangas/Sta. CruzEDSACubao & vice versa (on commercial
scale)
Intensified IEC and public awareness campaign Voluntary phaseout
of 2stroke motorcycles by the motorcycle
manufacturers in mid 2006
9. Acts and Laws
10. How air pollution is controlled
Pollution control equipment can reduce emissions by cleaning
exhaustand dirty air before it leaves the business. A wide variety
of equipmentcan be used to clean dirty air. DNR engineers carefully
study and review
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how these controls may work and the methods and requirements are
putinto a permit - a major duty performed by the DNR.
How common control equipment works is explained below:
Bag Houses or Fabric Filters Scrubbers or Wet Collectors
Adsorbers Cyclones Vapor Condensers Electrostatic Precipitators
Flares Afterburners Catalytic Oxidizers1.
In Iowa, fabric filters, commonly called baghouses, are widely
usedindustrial strength "vacuum cleaners." They remove
particulatematter found in smoke, vapors, dust or mists.
The filters remove particles from exhaust gases, leaving
theparticles on the filter while the cleaner air passes
through.Collected particulates form a "dust cake" on the filter
that isroutinely cleaned off by a blast of air in the opposite
direction or bymechanical shaking. The dust cake falls into a
hopper for disposal orreuse in the industrial process.
Filter bags hang in a sturdy house. Sometimes the house is
insulatedwhen cleaning hot gases to prevent corrosive moisture or
acid mistsfrom condensing and harming the equipment. Sometimes
dozens,even hundreds of cylindrical filters, each eight to 40 feet
long mayhang in a series of houses at one location.
Filters are made of woven cotton, wool or synthetic
materials.Some synthetic materials can withstand high temperatures
or areresistant to chemical reaction. Each baghouse must meet the
needsof the particular industry process. Gas temperature,
moisture
content and chemical reactivity decide what filter material is
used.
2.
http://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/BagHousesOrFabricFilters.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/BagHousesOrFabricFilters.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/ScrubbersOrWetCollectors.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/ScrubbersOrWetCollectors.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Adsorbers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Adsorbers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Cyclones.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Cyclones.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/VaporCondensers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/VaporCondensers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/ElectrostaticPrecipitators.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/ElectrostaticPrecipitators.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Flares.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Flares.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Afterburners.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Afterburners.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/CatalyticOxidizers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/CatalyticOxidizers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/CatalyticOxidizers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Afterburners.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Flares.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/ElectrostaticPrecipitators.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/VaporCondensers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Cyclones.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/Adsorbers.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/ScrubbersOrWetCollectors.aspxhttp://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled/BagHousesOrFabricFilters.aspx
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Scrubbers or wet collectors remove particles or gases from
theexhaust stream by using water sprays. Gases can be absorbed
ifthey are water-soluble or by adding various chemicals to the
spray.Particles of dust or soot can also be captured in microscopic
liquid
mists. Before the exhaust leaves the scrubber, the liquid mists
mustbe collected before the exhaust enters the public air.
Generally, high-powered scrubbers remove more particles but
aremore costly to operate due to added energy costs. Scrubbers
thatremove gases like sulfur oxides, nitrogen oxides or
hydrochloric aciddepend more heavily on the mechanical and chemical
engineeringdesign, not as much on power. Scrubbers are generally
better atremoving particles than cyclones, but not as good as
electrostaticprecipitators or baghouses unless operated at high
power.
3.
Activated carbon, silica gel and alumina oxide are
commonadsorbing agents. The chemical nature of the adsorbent, the
totalsurface area (how porous it is), and pore diameter are given
carefulconsideration before adsorbers are used. If the gas
containsparticulate matter, the adsorbent bed can become clogged.
Somegas is precleaned by a baghouse filter, electrostatic
precipitator orcyclone to remove particulate matter before entering
the adsorber.
How are Adsorbers Cleaned? Like squeezing a sponge for reuse,
adsorbers can be refreshed too.
There are several chemical principles that apply to how
adsorberswork. For example, as gas temperature increases,
adsorptiondecreases. As gas pressure increases, so does adsorption.
Theslower the gas moves through adsorption materials, the more
gasremoved. These same principles are used to regenerate or
refreshsaturated adsorbers.
4.
To most Iowans, the word "cyclone" refers to Iowa State
University-thehome of the Cyclones. But in air pollution control, a
cyclone is a deviceused to remove larger size particles, about 20
microns in diameter, fromthe air stream. Often, more than 80
percent of particles are removed.More efficient equipment like
baghouses or electrostatic precipitators canthen remove the smaller
particles.
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Cyclones are often found at feed mills, crushers, dryers, grain
elevators,and even high school industrial arts classrooms. Photos.
In industrial uses,cyclones are often used as precleaners for more
expensive andsophisticated control equipment such as electrostatic
precipitators orbaghouses.
5.
Condensers turn a gaseous vapor to a liquid. Any gas can be
liquefied ifthe temperature is lowered enough or if it is
pressurized. Condensers coolvapors enough to turn them into
liquid.
Dry cleaning machines may use vapor condensers to cool
evaporatedcleaning solvents such as perchloroethylene for reuse.
Without the
condenser, the chemical vapor would be lost into the air and
morechemicals purchased. Large storage tanks may use condensers to
captureevaporated gases and return them to storage. This prevents
Iowans frombreathing the vapors and allows businesses to use the
liquid for itsintended purpose, reducing emissions and sometimes
saving cost.
Condensers often act as pre-cleaners to remove gas vapors before
the airis sent to more expensive control equipment such as
incinerators oradsorbers. This reduces the volume of gas needing
treatment to reducecosts.
6.
Electrostatic Precipitators or ESPs have been used in industry
for over 60years. They can collect particles sized 0.1 to 10
microns very efficiently.They are generally more efficient at
collecting fine particles thanscrubbers or cyclones.
Electrostatic precipitators take advantage of the electrical
principle thatopposites attract. A high voltage electrode
negatively charges airborne
particles in the exhaust stream. As the exhaust gas passes
through thiselectrified field, the particles are charged. Typically
20,000 to 70,000volts are used. A large, grounded flat metal
surface acts as a collectionelectrode. Microscopic particles are
attracted to this surface where theybuild-up to form a dust cake.
Periodically, a rapper strikes the plate toknock the dust cake into
a collection hopper.
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7.
Combustion can also be used to control emissions of hydrocarbons
and
other organic vapors such as chlorine, fluorine and particulate
matter(soot). If a process emits volatile organic compounds such as
ink fumesfrom a large commercial printing operation, the fumes can
be destroyedor burned.
Flares dispose of intermittent or emergency releases of
combustible gasesfrom industrial sources. They are often found in
refineries or chemicalplants. In a flare, combustible gases are
burned in a flame. They aredesigned to do so with minimal smoke
(smoke is made up of dense
amounts of soot particulates.)
8.
Afterburners use a flame enclosed within a chamber. Combustion
by-products include water vapor and carbon dioxide gas. They are
commonlyused to destroy volatile organic compounds. Heat tolerant
refractorybricks line the chamber. Pollutant-laden gases are passed
through thechamber and burned at temperatures between 1300 to 1500
degreesFahrenheit. Because of rising fuel costs, heat recovery
systems can use
waste heat for useful purposes.
9.
A catalyst is a chemical that causes or speeds up chemical
reactionswithout the catalyst itself changing. A catalyst can speed
up the burningof organic gases or require lower temperatures to
save fuel usage andreduce costs. Platinum or palladium are two
elements often used as
catalysts. Automobile catalytic converters operate on the same
principlesto reduce tailpipe emissions.
One concern with catalytic oxidizers is contamination or
deactivation ofthe catalyst material. Particulate matter like soot
and dust can coat thecatalyst surface. Certain chemicals can
combine or react with thecatalyst to deactivate it. Sulfur in
gasoline for example, reduces the
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longevity of auto catalytic converters. The U.S. EPA is pushing
forreduced amounts of sulfur in gasoline and diesel fuel. This will
reduce the'poisoning' of catalytic converters for better emission
controls andreduced sulfur oxides in the air.
http://www.iowadnr.gov/Environment/AirQuality/HowAirPollutionIsControlled.aspx
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