Air Quality Management

1. Air Quality Management
• Air Quality Management
• Monitoring of SPM, SOx, NOX and CO Emission
Standards
• Air sampling – Sampling Techniques – High
volume air sampler – Stack sampling
• Analysis of Air pollutants
• Air quality standards
• Air pollution control act.

2. Air Quality Management
• Air quality management refers to all the activities
a regulatory authority undertakes to help protect
human health and the environment from the
harmful effects of air pollution.
• A government institution typically establishes
goals related to air quality.
• An example is an acceptable level of a pollutant
in the air that will protect public health, including
people who are more vulnerable to the effects of
air pollution.

3. • Air quality managers need to determine how much
emissions reductions are needed to achieve the
goal.
• Air quality managers use emissions inventories, air
monitoring, air quality modelling and other
assessment tools to understand the air quality
problem fully.
• Regulated industries need training and assistance
in how to comply with rules and the rules need to
be enforced.
• The process involves all levels of government –
elected officials, national agencies like EPA, tribal,
state and local governments and WHO. Regulated
industry groups, scientists, environmental groups,
and the general public all play important roles too.

5. Suspended particulate matter (SPM)
• Suspended particulate matter (SPM) are finely
divided solids or liquids that may be dispersed
through the air from combustion processes
Or
It’s are microscopic solid or liquid matter
suspended in the Earth's atmosphere.
Particulate matter is the sum of all solid and
liquid particles suspended in air many of which
are hazardous

6. • In the atmosphere SPM reduces visibility and reacts
with other air pollutant to create new pollutants
• Particulate matter is often divided into two main
groups, based on their size
• Inhalable coarse particles: These particles range
from 2.5 micrometres to 10 micrometres in
diameter (PM10 – PM2.5)
• Fine particles: These particles are found in smoke
and haze with a size up to 2.5 µm (PM2.5)
• While Inhalable coarse particle are found near
roadways and dusty industries,
• Fine particles can be directly emitted from sources
such as forest fires, or they can form when gases
emitted from power plants, industries and
automobiles react in the air

9. Monitoring of SPM
• Various methods for monitoring of SPM are:
• Gravimetery: High volume sampler (12-24 hours) filter paper weighed
• β-guage analyser by dilution:β-rays used to note loss in weight of tape
• Piezoelectric balance: Sensitive method, change in weight is noted
• Thimble Sampling : Change in Weight of cellulose borosilic or glass ceramics filters is
measured
• Nephelometer : 0.1 – 10 micron m dia can be measured by scattering of radiation
• Lidar method : Measure reflection of light with laser beam
• Acoustical particle : In sit analysis 5 micron m bye use of changes in velocity of sound
• Transmissometer: Measure optical density, low cost, cannot detect mass
• ESP: measure particle flow

13. • Monitoring of SOX

14. Methods of Monitoring of SO2
• Reduction Method: The reduction method of
sulphur dioxide monitoring depends on the
reducing property of SO2.
• In this method, SO2 reacts with excess of KI
forming iodine.
• This liberated iodine is titrated with hypo,
which is considered as standard solution.
• The measurement of this method is highly
influenced by pollutants, organic matter and
ozone

15. • Acid Titration Method:
• The acid titration method of sulphur dioxide
monitoring depends on the acidic property of
SO2,
• In this method, SO2 is made to react with H2O2
or H2O.
• The variation in acidity is either measured
through titration or by estimating the
conductivity changes.
• The existence of NH3 highly influences by
creating negative errors

16. Monitoring of NOX
• In atmosphere we have NO and NO2 while all
other oxides get converted to NO2 by
interaction with oxygen .
NO2 + O3----------2NO + 2O2
NO + O3---------NO2+O2
NO2 + hv = NO2
• Various methods used for monitoring of
oxides of nitrogen are listed in and widely
used as method is Saltzman reaction

17. Methods of Monitoring of NO – NO2
• Colorimetric technique: Saltzman method, needs
somewhat longer time for colour development
• Chemiluminescence technique : best method for
analysis O3 is used to convert NO2 to NO
• Ion selective electrodes : Nitrate in aqueous
phase is measured
• Electrochemical transducer: Slow response time
• Non – dispersive infrared / UV spectroscopy:
Interference from SO2,H2S resonance fluorescence
show good specificity

21. Important components of NO-NO2
meter locally available
• Photo tube
• Analogue meter
• IC chips
• Gears
• Tape recorder motor
• Dry cell 9 V
• Digital display
• Tungsten lamp
• Miscellaneous components

22. Monitoring Oxides of carbon
• The best method for monitoring of CO is NDIR
i.e., (non-dispersive infrared spectroscopy)
provided water vapour is absent in sample.
• The second best method is indirect interaction of
CO on either mercuric or palladium chloride to
produce phosgene and shining metallic mercury
or palladium, which in turn can be measured by
reflectance spectroscopy.
• Silica impregnated on ammonium molybdate in
sulphuric acid is reacted with CO to give blue
coloured solution with absorption maxima at 660
nm however H2S, moisture, and organic matter
interference..

23. • The analysis of CO2 is very simple
• Carbon dioxide is absorbed in stream of excess
of alkali hydroxide and the unreacted solution
of alkali hydroxide is titrated with standard
solution of acid.
• From the amount of alkali consumed one gets
idea of amount of CO2 in the sampled air.

24. Monitoring Methods for CO,CO2
• Non – dispersive IR
• NDIR Spectrometry
• IR fluorescence method
• AAS: atomic absorption spectroscopy
(Reduction of Hgo- Hg)
• Electro catalytic method
• Electro chemical transducer
• FID (Flame ionization detector)

34. Sampling Techniques
• There are number of sampling techniques but
mostly we can use two types of samplings
they are :
• High volume air sampler
• Stack sampling
• Dust fall jar
• Particulate sampling
• Gas Sampling

35. High volume air sampler
• The high volume air sampler is a popular and
frequently used equip- ment for the determination
of suspended particulate matter (SPM) in air
• The principle involved in this method is that the
particles are filtered from known volume of an air
sample by a suction apparatus (a vacuum pump) and
the particles are made to deposit on a porous filter
paper.
• The commonly used high volume sample
(Micrometal make, Bombay and other similar
makes)

37. • Components are face plate and gasket, filter paper
(preferably what man make), and fitting assembly,
vacuum pump (air sucker) with air flow measuring
device, casing with a roof
• The filter plate provides the base for sitting the filter
paper of size200 mm x250 mm, through which air
sample is collected by creating suction in the filter
area.
• This suction is created by a vacuum pump with a flow
rate of 25 lilt pm. These conditions will permit the
sampling of ambient air for a period of 8-h. The
suspended particles of size less than 10 microns and
greater than 3 microns are retained on the filter.
• A rotameter or a manometer is provided
to measure the volume of air passed through the filter.
Generally Whatman make' filter papers are widely
used.

39. Stack Sampling
• Stack gas sampling or source sampling means
that the sampling is done at the source of
pollutants
• Generally stacks are used to discharge the
pollutants into the atmosphere hence the
sampling is done in the stacks at a specified
height (prescribed) from ground level

41. Objectives
• To determine the quantity and the type of
pollutants emitted from a specified source
• To determine the efficiency of a pollutant
control device
• To monitor the emission standards so that the
review may be made on the air quality
management programme

42. Procedure
• The stack sampling procedure consists of the
following components:
• 1. Selection of sampling position the stack
• 2.Measurement of gas flow rate
• 3. Measurement of velocity of gas in the stack,
and
• 4.Determination of temperature of gas

43. Selection of sampling position the stack
• The sample to be collected from a stack should be a
representative sample
• In practice, representative sample is obtained by
averaging the number of samples taken in a correct
location
• The location of sample should be such that it should
not get disturbances by bends ,baffles etc. and it
should be in straight portion of the stack
• For rectangular stacks the equivalent diameter is
calculated from the following equation
Equivalent diameter = 2(length x width) / length+ width)

44. Measurement of gas flow rate :
The gas flow rate through the stack is determines
by the continuity equation which are as follows:
Where:
Q = Average volumetric gas flow rate, litres per
minute
Us = Average stack gas velocity, m/s
A = Cross-sectional area of the stack, m2
Q=Us x A

45. Measurement of velocity of gas in the stack:
• Stack gas velocity is determined by a pitot-tube
in combination with a double differential
manometer
• Double pitot tube which consists of two
openings having two faces opposite to each
other
• The arrangement is connected to the incline
manometer The velocity head is estimated from
the deflections in the manometer with a known
coefficient.

47. • The velocity of stack gas is determined by this
equation is
• ΔH = Ps x Ms
Where :
ΔH = Stack height or Velocity head mm of water
Ps = Absolute pressure of the stack, mm Hg
Ms = Molecular weight of the stack gas

50. Determination of temperature of gas :
• Generally stack gases contain high
temperature because these gases are
liberated from the manufacturing processes
which involve with high temperature and
pressure
• The temperature of the gases are measured
by using mercury thermometers, thermo-
couple-pyrometers
• Thermocouple censors which consists of
probes measure temperature at all traverse
points across the cross-section of the stack

51. • The probe is selected based on the temperature
of the gas and probes used for different
temperature ranges are as follows
• Type of probe Temp range,Oc
• Chromel/ Alumel 150-1260
• Copper/Constantan 150-350
• Iron/Constantan 115-1010
• Platinum/ Platinum up to 1540