Air pollution control technology

1. AIR POLLUTION CONTROL TECHNOLOGY
MARBLE INDUSTRY
Presented by:
Saad Farooqi, C#01
BS, 8th Semester
7/29/2018
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DEPARTMENT OF ENVIRONMENTAL AND CONSERVATION SCIENCES
UNIVERSITY OF SWAT

2. CONTENTS
 Pollution
 Air Pollution
 Marble Industry wastes
 Air pollution control technologies
 Comparison
 Control of gaseous pollutants
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3. POLLUTION
• Any undesirable change in the
 air,
 soil and
 water
which have an adversely effects on the human and
environment is known as pollution.
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4. AIR POLLUTION
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 Any undesirable particles either visible or invisible or gas found in
the air, which is not the portion of the original composition of the
atmosphere is called air pollution.
 Causing diseases, death to humans, damage to other living
organisms such as animals and food crops, or the natural or built
environment.

5. MARBLE INDUSTRY WASTES
• Many wastes are produced in the manufacturing of marble in the industries.
Some of the wastes are given below in table 1
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6. AIR POLLUTION CONTROL TECHNOLOGIES
 The marble industry can also release the toxic gases like NOx, SOx,
COx and these toxic gas stream also contain particulate matters.
 To control these gases some technologies are used to minimize such
pollutants.
 Cyclone
 Electrostatic Precipitator
 Fabric Filters
 Wet Collector
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7. CYCLONES
 Cyclones are separation devices that use the principle of inertia to
remove particulate matter from gases.
How it works
 The dirty gases are travel into the helical path.
 These gases have contain particulate matter.
 The particles hit the walls of the cyclone and stick on it.
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8. CONT,,
 Finally the gas will clean and go back in the
helical path and come out through outlet.
 Shake the cyclones and the particles will fell
down to the hopper and will discharged from
the cyclone.
 And these particles will dumped after the
discharge.
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9. CONT,,
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Advantages Disavantages
 Low capital cost
 Relative simplicity and few
maintenance problems
 Low pressure drop (ca. 2–6
w.c.)
 Dry collection and disposal
 Relatively small space
requirements
 Offer low particulate
collection efficiencies
especially for particulate
below 5 μm
 Inability to handle sticky
materials
CYCLONES

10. CONT,,
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 If the diameter increase the removal efficiency will
increase and if the diameter decrease the efficiency
will be decrease.

11. ELECTROSTATIC PRECIPITATOR
 The electrostatic precipitator is used for the trapping of fine
particulate matter.
 ESP consist of plates and bobs suspended b/w plates.
 Distance is about 3-4 inches b/w plates.
How it works
 Free electron in the gas flow, repelled by the electrode due to same
charges.
 Gas particles will positively charges, rush towards electrodes.
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12. CONT,,
 There is some kind of
hammers which is moving
mechanically and hit the
plates, this process is called
rapping.
 And the dust particle fell
down to hopper and will
discharge.
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13. CONT,,
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Advantages Disadvantages
 ≥ 99.9% for coarse
and fine particulates
 Dry collection and
disposal of dust
 Continuous operation
with minimum
maintenance
 High capital cost [ca.
U.S.$160/m2 of plate
area]
 Relatively large space
requirement
 Highly trained
maintenance
personnel required
Electrostatic Precipitator

14. FABRIC FILTERS
 Fabric filters are used for the removing of particulate matter like a
vacuum cleaner.
How it works
 Dirty gases in and passes through fabric filter bags.
 The dust particles remain in the bags.
 Shake the bags periodically.
 Similar to the sand filter, used in the management
for quality of water.
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15. CONT,,
Advantages Disadvantages
 Can be operated at high
temperatures.
 Recirculation of filter outlet air.
 Dry recovery of collected
material for subsequent
processing and disposal.
 Relatively simple operation
 Temperatures in excess of
290⁰C.
 Explosion and fire hazard of
explosive dusts.
 Respiratory protection
requirement for fabric
replacement.
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Fabric Filters

16. WET COLLECTOR
 The wet collector or spray tower is used
more efficient for larger particles.
 Water is sprayed by very high pressure .
 The dust particle are wet and fell down
to the hopper.
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17. CONT,,
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Advantages Disadvantages
 Relatively small
space
requirement.
 Ability to remove
gases as well as
particulates.
 Ability to handle
high temperature,
high-humidity gas
streams
 Potential water
disposal/effluent
treatment
problem.
 very expensive to
construct and
operate.
Wet Collector

18. COMPARISON
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 Compared on the basis of their
efficiency and the diameter of
the particulate matters.
 The graph can show the
efficiency of such technologies.

19. CONTROL OF GASEOUS POLLUTANTS
 Released air pollutants to the environment such as NOx, SOx and
COx.
Control of sulfur dioxide
 Sulfur dioxide (SO2) is a most hazardous pollutant.
 United State is the largest single source and almost in industrialized
world.
 And is the making of marble by the burning of oil and coal, which
can released SO2 and other polluted gases.
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20. CONT,,
 To reduce the emission of sulfur dioxide by.
 Change to low-sulfur fuel:
 Desulfurization:
 Tall stacks:
 SO2 is also removed from the process of dissolution flue gas in the
aqueous solution of sodium citrate of reaction.
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21. CONT,,
Control of Nitrogen dioxide
 Wet collector or spray tower absorbed NO2 and SO2 as well.
 Modifying combustion processes to prevent NOx formation.
 Treating combustion gases after flame to convert NOx to N2.
 Using ultra-low nitrogen content fuel to form less fuel NOx
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