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First air pollution regulation. Be it known to all within the sound of my voice, whosoever shall be found guilty of the burning of coal shall suffer the loss of his head.King Edward I, ca 1300. The solution: Particulate control devices. . Removal efficiency of particulate systems, %ESP>9
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1. The importance of the evaluation of PM10/2.5 emissions with respect to meeting forthcoming legislation Dr Lesley Sloss
Senior Environmental Consultant
2. First air pollution regulation
Be it known to all within the sound of my voice, whosoever shall be found guilty of the burning of coal shall suffer the loss of his head.
King Edward I, ca 1300
3. The solution:Particulate control devices. Removal efficiency of particulate systems, %
ESP >99-99.99
Fabric filter (baghouse) 99-99.9999
Wet particulate scrubber 90-99.9
Cyclones & multicyclones 75-99
4. Particulate emissions in Germany & Poland
5. Bonus: trace element removal for free.Overall partitioning of trace elements in a power plant
6. Were on a roll
what next? Fine particulates:
PM10 (under 10 microns in diameter)
PM coarse (PM10-PM2.5)
PM2.5 (under 2.5 microns in diameter)
PM fine (PM2.5)
PM ultra-fine (below PM1.0)
8. Emission sources of atmospheric particulate matter.
9. Why?
Over 20 major studies around the world since 1973 have indicated a link between fine particulates and early mortality.
Legislation was a foregone conclusion.
11. Cause of the health problem? Could be any or none of the following:
Size effect;
Morphology;
Chemical effect:
Acidity;
Toxin;
Transition metals
If we knew, we could refine the legislation appropriately
.
12. For the first time ever
Ambient air quality legislation has been set for a pollutant:
For which the causality is unknown; and
Without a strict chemical definition.
13. Impending legislation: Europe Stage 1: applies from 1st Jan 2005
24 hour average 50 Fg/m3
not to be exceeded more than 25 times/year
annual average 30 Fg/m3
Stage 2: applies from 1st Jan 2020
24 hour average 50 Fg/m3
not to be exceeded more than 7 times/year
annual average 20 Fg/m3
14. Impending legislation: USA PM10 (current):
24 hour average 150 Fg/m3
not to be exceeded more than once/year
99th percentile of 24 hour values in a year
averaged over three years
annual average 50 Fg/m3
averaged over 3 years
PM2.5 (impending):
24 hour average 65 Fg/m3
98th percentile of 24 hour values in a year (at highest monitor) averaged over three years
annual average 15 Fg/m3
3 year average and spacial averaging
15. Not really particles at all
Three main species within PM2.5:
Primary particles
Secondary particles (aerosols, agglomerates)
Precursor species (SO2, NOx, VOC)
16. The majority of PM2.5 matter in developed countries is secondary particulates
17. Measurement Primary particles:
Impactors
Filters
Cyclones
Secondary particles:
Dilution methods and simulation
Precursors:
Standard methods and simulation
Dilution methods and simulation
18. Modelling Atmospheric models must:
Predict the movement and spread of primary and secondary particulates and precursors;
Take into account source position, wind direction and speed and ambient conditions such as temperature and air pressure;
Take into account emissions from all other sources - human activities and natural sources
19. Global sources of aerosol particulates
20. Breakdown of PM2.5 composition in SCAB
21. Average contribution to PM2.5 from sources in the USA
22. What sources do we target?
Each source is contributing to a mix. The mixture is reactive and varies with:
location;
temperature;
other species present;
measurement method.
Legislation against a reactive mix has major limitations and problems
.
23. Complications
the emissions which lead to elevated concentrations of PM2.5 in the Pittsburgh urban area originate from Ohio River Valley sources (or beyond), far to the west and southwest of the city.
Control of emission sources only within the city would not be expected to eliminated many of the high PM2.5 episodes seen in Pittsburgh
24. So how do we reduce ambient concentrations?
Most sources of PM2.5 and precursors are natural, unavoidable or untouchable;
25. Control of primary particles?
We cannot control emissions from natural sources.
It will be years before we can reduce emissions of particles from the transport sector.
.the majority of the PM2.5 in ambient air is secondary material reaction products.
26. Control of secondary particles
Would include control of:
Sulphates;
Nitrates;
ammonia;
Organic species;
Halogens;
Trace elements
everything.
27. Control of secondary particles and precursors at large sources is possible.
Improved capture of SO2, NOx and VOC;
Multi-pollutant approaches eg
- advanced particulate systems;
- activated carbon with advanced ESP or baghouses;
- electrostatic gas cleaning systems.
28. But will it reduce localised PM2.5 concentrations?
Not necessarily
29. Will it reduce the health effects seen?
Not necessarily
30. Conclusions
Legislation has been set ahead of scientific understanding
A reduction in health effects will only be achieved if the causative agent is identified
PM2.5 legislation may lead to expensive source emission controls which may not achieve the desired effects
Much more work is required in the health studies to identify the true culprit