Photochemical Smog
When atmosphere is loaded with large quantities of automobile exhausts, during warm sunny days with gentle winds and low level inversion, then the exausts gases are trapped by the inversion layers with stagnant air masses and simultaneously exposed to intense sunlight. Then a number of photochemical reactions involving NO2 , hydrocarbons and other organic compound and free radicals take place leading to the formation of ozone, peroxides and other photochemical oxidants in the atmosphere. This gives rises to the phenomenon of photochemical smog which is characterized by the formation of aerosols that reduced visibility, generation of brown hazy fomes that irritate eyes and lungs.
Generally, the smog which is formed by photochemical reaction is known as photochemical smog.
Smoke + Fog >> Smog
The main components of photochemical smog are unsaturated hydrocarbons, NOX, CO and some S compound.
Formation of photochemical smog/PAN
The mechanism of smog formation includes the following steps-
1. Reactive hydrocarbons (which have C=C groups) from automobile exhaust interact with ozone to form Hydrocarbon free radical (RCH2).
2. RCH2 rapidly reacts with oxygen to form another free radical RCH2O2.
3. RCH2O2. rapidly reacts with NO to produce NO2 and free radical RCH2O.
4. This new free radical next interacts with oxygen to yield a stable aldehyde RCHO and hydroperoxy radical HO2.
5. Then HO2. reacts with NO and form NO2 and free radical HO.
6. HO. Is extremely reactive and rapidly reacts with a stable hydrocarbon RCH3 to yield H2O and regenerate the hydrocarbon free radical RCH2., there by completing cycle.
This goes on and on as a chain reactions, one complete cycle yields, two molecules of NO2, one molecule of aldehyde RCHO and regenerate the free radical RCH2 to start all over again, very soon there is rapidly build up of smog product.
7. the aldehyde RCHO may initiate another root by interaction with the HO. Radical, leading to the formation of an acyl radical RC=O which then reacts with oxygen gives peroxyacyl radical (RCOOO). At last this active radical reacts with NO2 and gives peroxy acyl nitrite (PAN).
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Saturday, July 23, 2011
Effects of Photochemical Smog and Composition of Atmosphere
Effect of photochemical smog
The effects of photochemical smog are given below-
• both ozone and PAN cause irritation of eyes creating lachrymation and affect the respiratory tract of human being.
• Photochemical smog oxidizes the cellular constituents of our body and thus destroys them.
• Exposure for a period of two produces extreme fatigue and lack of CO. ordination in central nerves system.
• Inactive the enzyme.(Glucose 6 phosphate dehydrogenase).
• Free radical produced from PAN may destroy DNA.
• Exposure to PAN for several hours causes great loss of vegetation.
• Photochemical smog causes corrosion of metals, stones, building materials, textile etc.
Los Angles Smog
photochemical smog forms a serious air pollution during 1944 in some part of Los Angles, which was characterized by reduced visibility. That is why it is sometimes referred to as Los Angles Smog. It causes eye irritation and plant damage.
Composition of atmosphere
The atmosphere has three categories of constituents-
A. Major constituents-
1. Nitrogen >> 78.09 %
2. Oxygen >> 20.94 %
3. Water Vapour >> 0.1 to 5 %
B. Minor constituents-
1. Argon >> 0.934 %
2. Carbon Dioxide >> 0.0325 %
C. Trace component-
1. Ne >> 0.00182 %
2. He >> 0.000524 %
3. C2H6 >> 0.00018 %
4. Kr >> 0.00011 %
5. N2O >> 0.000025 %
6. Hydrogen >> 0.00005 %
7. CO >> 0.000012 %
8. Xe >> 0.0000087 %
9. Ozone >> 0.000002 %
10. Ammonia >> 0.000001 %
11. SO2 >> 0.0000002 %
12. NO2 >> 0.0000001 %
13. Iodine >> trace amount
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The effects of photochemical smog are given below-
• both ozone and PAN cause irritation of eyes creating lachrymation and affect the respiratory tract of human being.
• Photochemical smog oxidizes the cellular constituents of our body and thus destroys them.
• Exposure for a period of two produces extreme fatigue and lack of CO. ordination in central nerves system.
• Inactive the enzyme.(Glucose 6 phosphate dehydrogenase).
• Free radical produced from PAN may destroy DNA.
• Exposure to PAN for several hours causes great loss of vegetation.
• Photochemical smog causes corrosion of metals, stones, building materials, textile etc.
Los Angles Smog
photochemical smog forms a serious air pollution during 1944 in some part of Los Angles, which was characterized by reduced visibility. That is why it is sometimes referred to as Los Angles Smog. It causes eye irritation and plant damage.
Composition of atmosphere
The atmosphere has three categories of constituents-
A. Major constituents-
1. Nitrogen >> 78.09 %
2. Oxygen >> 20.94 %
3. Water Vapour >> 0.1 to 5 %
B. Minor constituents-
1. Argon >> 0.934 %
2. Carbon Dioxide >> 0.0325 %
C. Trace component-
1. Ne >> 0.00182 %
2. He >> 0.000524 %
3. C2H6 >> 0.00018 %
4. Kr >> 0.00011 %
5. N2O >> 0.000025 %
6. Hydrogen >> 0.00005 %
7. CO >> 0.000012 %
8. Xe >> 0.0000087 %
9. Ozone >> 0.000002 %
10. Ammonia >> 0.000001 %
11. SO2 >> 0.0000002 %
12. NO2 >> 0.0000001 %
13. Iodine >> trace amount
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Thursday, July 21, 2011
Reactions in Atmosphere
Reactions in Atmosphere
The various chemical and photochemical reactions taking place in atmosphere, mostly depends upon, temperature, composition, humidity and intensity of sunlight. Photochemical reaction take place by the absorption of solar radiations in the UV region. Absorption of photons by chemical species gives rise to electrochemically exited molecules, which can bring about cetain reactions. The electrochemically excited molecules may undergo any of the following changes-
• Reaction with other molecules on collision.
• Polymerization.
• Internal rearrangement.
• Dissociation
• De-excitation or de-activation of fluorescence.
Photochemical reaction included the following three steps-
1. absorption of radiation
2. Primary reaction
3. Secondary reaction.
Three steps of compound mainly gives photochemical reaction-
1. reaction involve in oxide of N2 (NO, NO2, NO3 etc)
2. Reaction involve in oxide of sulphuric (SO2, SO3 etc).
3. Oxidation of organic compound.
Reaction involve in oxide of Nitrogen
The oxide of nitrogen in the atmosphere are NO, NO2 and N2O. In the stratosphere N2O undergo photochemical decomposition to NO, which in turn depletes the protective ozone layer.
N2O + hv N2 + O.
N2O + O. N O. + N O.
N O. + O3 NO2 + O2
The most important photochemical reaction is dissociation of NO2
N2O + hv NO + O.
This nitric acid (NO) and pungent red-brown nitrogen dioxide (NO2) are important constituent of polluted air. The NO so formed may be O3 or more slowly by O2. thus leading to a cyclic chain reaction. The chain may be broken when the nitrogen dioxide is completely converted into HNO3 by hydration and cyclic oxidation in presence of fog or photochemical smog.
The reaction may take place are-
2NO + O2 2NO2
NO + O 3 NO2 + O2
2NO2 + O3 N2O5 + O2
4NO2 + O2 + 2H2O 4 HNO3
N2O5 + H2O 2HNO2 + O2
The HNO2 and HNO3 may also undergo photochemical dissociation as follows-
HNO3 + hv NO2 + HO.
HNO2 + hv NO + HO.
HNO2 + hv NO2 + H.
In strarosphere, NO2 may reacts with HO. And form nitric acid.
NO2 + HO. HNO3
The HNO3 so formed as acid rain or is converted into particulate nitrates due to neutralization by NH3 or particulate lime.
Reaction involves oxides of sulphur
SO2 present in the atmosphere, absorb solar radiation in the range of 300-400 nm and produces electrochemically exited ststes of SO2. This undergo oxidation to SO3 and in presence of water vapour
This converted to H2SO4.
SO2 + hv SO2.
SO2. + O2 SO4.
SO4. + O2 SO3 + O3
SO3 + H2O H2SO4
The overall reaction in the presence of sunlight and relative humidity 30-90 % may be represented as-
SO2 + O2 + H2O H2SO4
This photochemical oxidation of SO2 to H2SO4, aerosol is greatly accelerated in the presence of olefinic hydrocarbons and oxides of nitrogen which are usually present photochemically smog.
The oxidation of SO2 also take place by interaction with the free radical HO. Present in photochemical smog.
SO2 + HO. HOSO2.
HOSO2. + O2 HOSO2O2.
HOSO2O2. HOSO2O. + NO2.
In relative humid atmosphere, SO2 may also oxidize by water droplets of aerosols, which are accelerated in presence of ammonia catalysts such as oxides of Mn, Fe, Cu, Ni etc.
NH3 + SO2 + H2O NH4+ + HSO3-
NH3 + HSO3- NH4+ + SO32 –
SO2 is a pollutant responsible for smog formation, acid rain and corrosion of metals and alloys.
Reaction involves in oxidation of organic compound
Organic compounds, e.g., hydrocarbons, aldehyde, ketone, absorb solar radiations and undergo various photochemical and chemical reaction involving free radicals, some of these reactions are catalysed by sort and metal oxides-
CH4 + O2 H3C + HO.
CH4 + HO. H3C + H2O
H3C + O2 + M (third body) H3COO. + M
CH3CH CH2 + HO. CH3C.H CH2OH
RCHO + hv R. + HC.O
RCRO + hv R. + R.CO
RCOOO. + NO RCOOONO2 (peroxyacetyl nitrile PAN)
Where, R is an alkyl or aryl radical or even a H2 atom. The alkyl radical, which may reacts with oxygen to form a peroxy radical, which in turn may reacts with another oxygen atom to give O3. The peroxy radical may reacts with NO2 to give peroxy acyl nitrile(PAN), formaldehyde and various polymeric compounds which reduce visibility.
The various chemical and photochemical reactions taking place in atmosphere, mostly depends upon, temperature, composition, humidity and intensity of sunlight. Photochemical reaction take place by the absorption of solar radiations in the UV region. Absorption of photons by chemical species gives rise to electrochemically exited molecules, which can bring about cetain reactions. The electrochemically excited molecules may undergo any of the following changes-
• Reaction with other molecules on collision.
• Polymerization.
• Internal rearrangement.
• Dissociation
• De-excitation or de-activation of fluorescence.
Photochemical reaction included the following three steps-
1. absorption of radiation
2. Primary reaction
3. Secondary reaction.
Three steps of compound mainly gives photochemical reaction-
1. reaction involve in oxide of N2 (NO, NO2, NO3 etc)
2. Reaction involve in oxide of sulphuric (SO2, SO3 etc).
3. Oxidation of organic compound.
Reaction involve in oxide of Nitrogen
The oxide of nitrogen in the atmosphere are NO, NO2 and N2O. In the stratosphere N2O undergo photochemical decomposition to NO, which in turn depletes the protective ozone layer.
N2O + hv N2 + O.
N2O + O. N O. + N O.
N O. + O3 NO2 + O2
The most important photochemical reaction is dissociation of NO2
N2O + hv NO + O.
This nitric acid (NO) and pungent red-brown nitrogen dioxide (NO2) are important constituent of polluted air. The NO so formed may be O3 or more slowly by O2. thus leading to a cyclic chain reaction. The chain may be broken when the nitrogen dioxide is completely converted into HNO3 by hydration and cyclic oxidation in presence of fog or photochemical smog.
The reaction may take place are-
2NO + O2 2NO2
NO + O 3 NO2 + O2
2NO2 + O3 N2O5 + O2
4NO2 + O2 + 2H2O 4 HNO3
N2O5 + H2O 2HNO2 + O2
The HNO2 and HNO3 may also undergo photochemical dissociation as follows-
HNO3 + hv NO2 + HO.
HNO2 + hv NO + HO.
HNO2 + hv NO2 + H.
In strarosphere, NO2 may reacts with HO. And form nitric acid.
NO2 + HO. HNO3
The HNO3 so formed as acid rain or is converted into particulate nitrates due to neutralization by NH3 or particulate lime.
Reaction involves oxides of sulphur
SO2 present in the atmosphere, absorb solar radiation in the range of 300-400 nm and produces electrochemically exited ststes of SO2. This undergo oxidation to SO3 and in presence of water vapour
This converted to H2SO4.
SO2 + hv SO2.
SO2. + O2 SO4.
SO4. + O2 SO3 + O3
SO3 + H2O H2SO4
The overall reaction in the presence of sunlight and relative humidity 30-90 % may be represented as-
SO2 + O2 + H2O H2SO4
This photochemical oxidation of SO2 to H2SO4, aerosol is greatly accelerated in the presence of olefinic hydrocarbons and oxides of nitrogen which are usually present photochemically smog.
The oxidation of SO2 also take place by interaction with the free radical HO. Present in photochemical smog.
SO2 + HO. HOSO2.
HOSO2. + O2 HOSO2O2.
HOSO2O2. HOSO2O. + NO2.
In relative humid atmosphere, SO2 may also oxidize by water droplets of aerosols, which are accelerated in presence of ammonia catalysts such as oxides of Mn, Fe, Cu, Ni etc.
NH3 + SO2 + H2O NH4+ + HSO3-
NH3 + HSO3- NH4+ + SO32 –
SO2 is a pollutant responsible for smog formation, acid rain and corrosion of metals and alloys.
Reaction involves in oxidation of organic compound
Organic compounds, e.g., hydrocarbons, aldehyde, ketone, absorb solar radiations and undergo various photochemical and chemical reaction involving free radicals, some of these reactions are catalysed by sort and metal oxides-
CH4 + O2 H3C + HO.
CH4 + HO. H3C + H2O
H3C + O2 + M (third body) H3COO. + M
CH3CH CH2 + HO. CH3C.H CH2OH
RCHO + hv R. + HC.O
RCRO + hv R. + R.CO
RCOOO. + NO RCOOONO2 (peroxyacetyl nitrile PAN)
Where, R is an alkyl or aryl radical or even a H2 atom. The alkyl radical, which may reacts with oxygen to form a peroxy radical, which in turn may reacts with another oxygen atom to give O3. The peroxy radical may reacts with NO2 to give peroxy acyl nitrile(PAN), formaldehyde and various polymeric compounds which reduce visibility.
Environmental Segments
Environmental segments
The environmental segments are following below
1. Atmosphere
2. Hydrosphere
3. Biosphere
4. Lithosphere
Atmosphere
The cover of air that envelopes the earth is known as the atmosphere. It is the protective thick gaseous mantle, surrounding the earth, which sustais life on earth and save it from unfriendly environment of outer surface.
Characteristics of atmosphere
1. Weight :( 4.5 to 5) ×105 metric ton.
2. Pressure : 1 atm. to 3× 107 at 100 km above sea level.
3. Temperature:-100 to 1200 °C, depending on altitude.
4. Density : 0.0013 gm/m3
The atmosphere protects the earth from dangerous cosmic radiations. It screens the dangerous radiations from the sun (< 300 nm ) and transmit only 300 nm – 2500 nm radiations. It plays a vital role in maintaining the heat balance on earth by absorbing radiation from sun and earth.
The Atmospheric Structure
Name of the Region Height of the earth
(km) Temperature,°C Major chemical species
Troposphere 1 to 11 15 to -56 O2, N2, CO2, H2O
Stratosphere 11 to 50 -56 to -2 O3
Mesosphere 50 to 85 -2 to -92 O2+ , NO+
Thermosphere 85 to 500 -92 to 1200 O2+ , NO+, O+
Troposphere
This is the nearest region to earth’s surface and extends up to on altitude an altitude of 11 km.
Characteristics
• It is account for over 70% of the total atmospheric mass.
• The temp. of air in this region decreases exponentially with increasing altitude.
• The temperature rages 15 to -56 °C.
• The top of troposphere is troposphere, it makes temp. Inversion.
• Major chemical species are O2, N2, CO2, and H2O.
Stratosphere
The region above tropopause is called stratosphere.
Characteristics
• Height above the earth surface ranges from 11 to 50 km.
• Temperature ranges -56 to -2 °C.
• Due to its low temperature, clouds, dust and water vapor is absent in this region.
• Major chemical species O3.
• The temperature rises with increasing altitude.
• The top of stratosphere is stratopause.
Mesosphere
It is the region above the trapause , it extends up to 85 km height.
Characteristics
• Here temperature decreases with height.
• The decrease in temperature is due to low absorption of UV radiation by ozone.
• Temperature ranges from -2 to -92 °C.
• Mesosphere is the coldest region of atmosphere.
• Major chemical species are O2+, NO+, O+, and N2.
• The layer immediately above the mesosphere is mesospause.
Thermosphere
It is the region immediately above the mesospause.
Characteristics
• The Temperature rises very rapidly with increasing altitude.
• The Temperature ranges from -92 to 1200 °C.
• It extends up to 85 to 500 km.
• It has lower pressure and low density.
• Major chemical species are O2+, NO+, and O+.
The environmental segments are following below
1. Atmosphere
2. Hydrosphere
3. Biosphere
4. Lithosphere
Atmosphere
The cover of air that envelopes the earth is known as the atmosphere. It is the protective thick gaseous mantle, surrounding the earth, which sustais life on earth and save it from unfriendly environment of outer surface.
Characteristics of atmosphere
1. Weight :( 4.5 to 5) ×105 metric ton.
2. Pressure : 1 atm. to 3× 107 at 100 km above sea level.
3. Temperature:-100 to 1200 °C, depending on altitude.
4. Density : 0.0013 gm/m3
The atmosphere protects the earth from dangerous cosmic radiations. It screens the dangerous radiations from the sun (< 300 nm ) and transmit only 300 nm – 2500 nm radiations. It plays a vital role in maintaining the heat balance on earth by absorbing radiation from sun and earth.
The Atmospheric Structure
Name of the Region Height of the earth
(km) Temperature,°C Major chemical species
Troposphere 1 to 11 15 to -56 O2, N2, CO2, H2O
Stratosphere 11 to 50 -56 to -2 O3
Mesosphere 50 to 85 -2 to -92 O2+ , NO+
Thermosphere 85 to 500 -92 to 1200 O2+ , NO+, O+
Troposphere
This is the nearest region to earth’s surface and extends up to on altitude an altitude of 11 km.
Characteristics
• It is account for over 70% of the total atmospheric mass.
• The temp. of air in this region decreases exponentially with increasing altitude.
• The temperature rages 15 to -56 °C.
• The top of troposphere is troposphere, it makes temp. Inversion.
• Major chemical species are O2, N2, CO2, and H2O.
Stratosphere
The region above tropopause is called stratosphere.
Characteristics
• Height above the earth surface ranges from 11 to 50 km.
• Temperature ranges -56 to -2 °C.
• Due to its low temperature, clouds, dust and water vapor is absent in this region.
• Major chemical species O3.
• The temperature rises with increasing altitude.
• The top of stratosphere is stratopause.
Mesosphere
It is the region above the trapause , it extends up to 85 km height.
Characteristics
• Here temperature decreases with height.
• The decrease in temperature is due to low absorption of UV radiation by ozone.
• Temperature ranges from -2 to -92 °C.
• Mesosphere is the coldest region of atmosphere.
• Major chemical species are O2+, NO+, O+, and N2.
• The layer immediately above the mesosphere is mesospause.
Thermosphere
It is the region immediately above the mesospause.
Characteristics
• The Temperature rises very rapidly with increasing altitude.
• The Temperature ranges from -92 to 1200 °C.
• It extends up to 85 to 500 km.
• It has lower pressure and low density.
• Major chemical species are O2+, NO+, and O+.
Contaminant, Receptor, Sink, Treshold limit Value, Lapse Rate and Temperature Inversion
Contaminant
The unfavorable substances which do not occur in nature but are introduced by human activity into the environment (affecting its composition) are known as contaminant.
Example: Chlorine gas(Cl2) which is not present in nature but to the escaption of derailed railway tank car its occurs in nature, which is contaminant.
CFC (Chlorofluoro carbon) one of the most important contaminant is introduced in nature due to the use of the re-frigerator, circular, etc.
The process by which contaminants are introduced in our fresh environment is known as contamination.
Receptor
The medium which accept pollutants is called receptor. Human beings, plants are the example of receptor.
We can also say that the medium which is affected by pollutant is known as receptor.
Sink
The medium which retains and interacts with long live pollutants. A marbal wall will act as a sink for atmospheric sulphuric acid and ultimately get damage.
Threshold limit value
This indicates the permissible level of toxic pollutants in atmosphere to which a healthy industrial worker is exposed during an eight hour day without any adverse effect.
If an industrial environment contain 0.002 mg/m3 Be and 1.00 mg/m3 Zn, then a healthy industrial worker, worked that environment without any adverse effect. Thus the threshold limit vakue for Be is 0.002 mg/m3 and for Zn is 1.00 mg/m3 .
Lapse Rate
The change of atmosphere air temperature with attitude is called lapse rate.
Lapse rate is of two types:
1. Positive Lapse Rate
2. Negative Lapse Rate
Positive Lapse Rate
The decrease of temperature with increasing altitude is called the Positive Lapse Rate.
For example: In troposphere the temperature decreases as 15°C to -56 °C with the increase of altitude. It is positive lapse rate.
Negative Lapse Rate
The increase of temperature with increase of altitude is called negative lapse rate.
For example: In stratosphere, the temperature increases as -56 °C to -2°C as the increase of increase of altitude. Thus this negative lapse rate.
Temperature Inversion
The transition from positive lapse rate to negative lapse rate at the top is called temperature inversion. In other words, the increase of temp. with the increase of altitude is known as temperature inversion. Thus temp. inversion is also called negative lapse rate. Temperature inversion occurs in the atmosphere due to two reactions.
1. Radiation Inversion: This occurs when the air near the earth’s surface get cooled because of the loss of the heat by earth by emitting long wave radiations.
2. Subsidence inversion: This occurs when the upper layers of air subsides during a developing anticyclone.
The unfavorable substances which do not occur in nature but are introduced by human activity into the environment (affecting its composition) are known as contaminant.
Example: Chlorine gas(Cl2) which is not present in nature but to the escaption of derailed railway tank car its occurs in nature, which is contaminant.
CFC (Chlorofluoro carbon) one of the most important contaminant is introduced in nature due to the use of the re-frigerator, circular, etc.
The process by which contaminants are introduced in our fresh environment is known as contamination.
Receptor
The medium which accept pollutants is called receptor. Human beings, plants are the example of receptor.
We can also say that the medium which is affected by pollutant is known as receptor.
Sink
The medium which retains and interacts with long live pollutants. A marbal wall will act as a sink for atmospheric sulphuric acid and ultimately get damage.
Threshold limit value
This indicates the permissible level of toxic pollutants in atmosphere to which a healthy industrial worker is exposed during an eight hour day without any adverse effect.
If an industrial environment contain 0.002 mg/m3 Be and 1.00 mg/m3 Zn, then a healthy industrial worker, worked that environment without any adverse effect. Thus the threshold limit vakue for Be is 0.002 mg/m3 and for Zn is 1.00 mg/m3 .
Lapse Rate
The change of atmosphere air temperature with attitude is called lapse rate.
Lapse rate is of two types:
1. Positive Lapse Rate
2. Negative Lapse Rate
Positive Lapse Rate
The decrease of temperature with increasing altitude is called the Positive Lapse Rate.
For example: In troposphere the temperature decreases as 15°C to -56 °C with the increase of altitude. It is positive lapse rate.
Negative Lapse Rate
The increase of temperature with increase of altitude is called negative lapse rate.
For example: In stratosphere, the temperature increases as -56 °C to -2°C as the increase of increase of altitude. Thus this negative lapse rate.
Temperature Inversion
The transition from positive lapse rate to negative lapse rate at the top is called temperature inversion. In other words, the increase of temp. with the increase of altitude is known as temperature inversion. Thus temp. inversion is also called negative lapse rate. Temperature inversion occurs in the atmosphere due to two reactions.
1. Radiation Inversion: This occurs when the air near the earth’s surface get cooled because of the loss of the heat by earth by emitting long wave radiations.
2. Subsidence inversion: This occurs when the upper layers of air subsides during a developing anticyclone.
Environment/chemistry, Pollution and Pollutant
Environment
The term environment is the sum of all social, economical, biological, physical or chemical factors which is constitute of the surrounding of man, which is both creator or moulder of this environment. It is a holistic view of the world as it functions at anytime with a multitude of special elemental and social-economical systems distinguished by quality and attributes of space and mode behaviour of biotic and abotic forms.
Environmental Chemistry
Environmental Chemistry is a branch of science which deals with the environmental segments, constitutes and it sources. It is not only relates with chemicals but also non-chemist such as material science, engineering etc.
The main object of environmental chemistry is to determine the nature as well as quantity of specific pollutants in the environment.
Basic Concept of Environmental Chemistry
• Environmental Chemistry not only relates with chemist but also non-chemist such as material science, engineering etc.
• Bad effect of environmental chemistry segment on living organism and how to overcome this problem.
Importance/Objectives of Environmental Chemistry
•To determine the nature as well as quality of specific pollutants in the environment.
•To enlighten the public, particularly student about the importance of protection of conservation of our environment and need to restrain human activity which lead to indiscriminate release of pollutants into environment.
• Environmental Chemistry requires high sensitivity & accuracy in determining the environmental pollutants.
Pollution
Pollution means the addition of any foreign materials like organic/inorganic, biological or radiological or any physical change occurring in the nature which may harm or effect living organism directly or indirectly, immediately or after a long time.
The root cause of pollution has been the man’s misbehaviour with the nature.
Pollutants
The materials which cause pollution of environment are called pollutants. Pollutants may be organic/inorganic, biological or radiological unfavourable substances. Pollutants are harmful solid, liquid or gaseous substances present in nature in such concentration which tends to be injuries for the living organism.
Examples: Lead, Mercury, Sulpher-dioxide, carbon monoxide, etc.
Thus we may conclude as such types of substances which are undesirable and present in wrong place at wrong time and wrong quantity in the environment known as pollutants.
Path-ways pollutants
The mechanism by which the pollutants are distributed from its sources in to the environmental segments is known as path-ways of pollutants.
Source > Environment > Receptor
In gasoline/in automobile petrol
Pb(C2H5)4 PbCl3+ PbBr2(Air)
Auto exhausts
To food crops & Food chain PbCl2+PbBr2 (soil)
The term environment is the sum of all social, economical, biological, physical or chemical factors which is constitute of the surrounding of man, which is both creator or moulder of this environment. It is a holistic view of the world as it functions at anytime with a multitude of special elemental and social-economical systems distinguished by quality and attributes of space and mode behaviour of biotic and abotic forms.
Environmental Chemistry
Environmental Chemistry is a branch of science which deals with the environmental segments, constitutes and it sources. It is not only relates with chemicals but also non-chemist such as material science, engineering etc.
The main object of environmental chemistry is to determine the nature as well as quantity of specific pollutants in the environment.
Basic Concept of Environmental Chemistry
• Environmental Chemistry not only relates with chemist but also non-chemist such as material science, engineering etc.
• Bad effect of environmental chemistry segment on living organism and how to overcome this problem.
Importance/Objectives of Environmental Chemistry
•To determine the nature as well as quality of specific pollutants in the environment.
•To enlighten the public, particularly student about the importance of protection of conservation of our environment and need to restrain human activity which lead to indiscriminate release of pollutants into environment.
• Environmental Chemistry requires high sensitivity & accuracy in determining the environmental pollutants.
Pollution
Pollution means the addition of any foreign materials like organic/inorganic, biological or radiological or any physical change occurring in the nature which may harm or effect living organism directly or indirectly, immediately or after a long time.
The root cause of pollution has been the man’s misbehaviour with the nature.
Pollutants
The materials which cause pollution of environment are called pollutants. Pollutants may be organic/inorganic, biological or radiological unfavourable substances. Pollutants are harmful solid, liquid or gaseous substances present in nature in such concentration which tends to be injuries for the living organism.
Examples: Lead, Mercury, Sulpher-dioxide, carbon monoxide, etc.
Thus we may conclude as such types of substances which are undesirable and present in wrong place at wrong time and wrong quantity in the environment known as pollutants.
Path-ways pollutants
The mechanism by which the pollutants are distributed from its sources in to the environmental segments is known as path-ways of pollutants.
Source > Environment > Receptor
In gasoline/in automobile petrol
Pb(C2H5)4 PbCl3+ PbBr2(Air)
Auto exhausts
To food crops & Food chain PbCl2+PbBr2 (soil)
Tuesday, July 12, 2011
Microbial degradation and degradation product
Microbial degradation of some odorous substances and the degradation product
Serial No. Substrate Microorganism Degradation products
1 Phenol Pseudomonas Putida
Trichosporon Cutaneum Aldehyde and pyrovate Acetyl CoA and Succinate
2 Dimethyl sulphide Hypomicrobium SPP H2SO4, SO2, CO2
3 Pyridine, 4-methyl pyridine Pseudomonas SPP
4 Dimethyl amine Pseudomonas aminovorans Methyl amine and formaldehyde
5 Anilline Nocardia SPP Pyrocatechol
6 Benzaldehyde Acetobactor asendens Benzylalcohol and benzoic acid
7 Indole Chromobacterium violaceum Tryptophan
8 n-propyl amine Microbacterium convolutum Propionate
Serial No. Substrate Microorganism Degradation products
1 Phenol Pseudomonas Putida
Trichosporon Cutaneum Aldehyde and pyrovate Acetyl CoA and Succinate
2 Dimethyl sulphide Hypomicrobium SPP H2SO4, SO2, CO2
3 Pyridine, 4-methyl pyridine Pseudomonas SPP
4 Dimethyl amine Pseudomonas aminovorans Methyl amine and formaldehyde
5 Anilline Nocardia SPP Pyrocatechol
6 Benzaldehyde Acetobactor asendens Benzylalcohol and benzoic acid
7 Indole Chromobacterium violaceum Tryptophan
8 n-propyl amine Microbacterium convolutum Propionate
Bioremediation and Deodorization
Bioremediation
Bioremediation is the use of biological system for the reduction of pollution from air or from aquatic system. Microorganism and plants are the biological systems which are generally used. Bio-degradation with microorganism with is the most frequently occurring bioremediation option. Microorganosm can break down most compounds for their growth and energy need. Bioremediation is the microbial clean up approach. It employs biological agents to render hazardous waste to non-hazardous or less hazardous waste. Microbs can acclimatize themselves to toxic wastes and new resistant strains develop naturally. Such strains can be used for pollution control and environmental protection.
Examples
• Some of algae and bacteria can accumulate large quanties of metals. Such as pseudomonous aerugensa can accumulate Uranium and thiobacillus can accumulate silver.
• Mixture of microbes and enzymes are used to clean up chemical wastes such as detergent, pesticides, etc.
Biological deodorization
Deodorization process include physical, chemical and biological. In biological deodorization, fuel smelling compounds are decomposed by exploiting metabolic process of the microorganisms. An exhaust gas treatment system for H2S and SO2 based on Thiobacillus ferroxidan bacteria is already practice in Japan.
Bioscubbing involves scrubbing of waste effluents using microbial methods to detoxify or de-odourise certain constituents in the waste effluents. Hypomcrobium SSP can be used to oxidize the malodourous dimethylsulphide aerobically or anaerobically.
Aerobic process H2S + 2O2 H2SO4
(CH3)2S + SO2 H2SO4 + 2CO2 + 2H2O
Anaerobic process
Hypomicrobium
5H2S + 8 NaNO2 H2SO4 + 4NaSO4 + 4N2 + 4H2O
SSP
(CH3)2S + 4NaNO2 NaSO4 + 2 CO2 + 2N2 + 2NaOH + 2H2O
Bioremediation is the use of biological system for the reduction of pollution from air or from aquatic system. Microorganism and plants are the biological systems which are generally used. Bio-degradation with microorganism with is the most frequently occurring bioremediation option. Microorganosm can break down most compounds for their growth and energy need. Bioremediation is the microbial clean up approach. It employs biological agents to render hazardous waste to non-hazardous or less hazardous waste. Microbs can acclimatize themselves to toxic wastes and new resistant strains develop naturally. Such strains can be used for pollution control and environmental protection.
Examples
• Some of algae and bacteria can accumulate large quanties of metals. Such as pseudomonous aerugensa can accumulate Uranium and thiobacillus can accumulate silver.
• Mixture of microbes and enzymes are used to clean up chemical wastes such as detergent, pesticides, etc.
Biological deodorization
Deodorization process include physical, chemical and biological. In biological deodorization, fuel smelling compounds are decomposed by exploiting metabolic process of the microorganisms. An exhaust gas treatment system for H2S and SO2 based on Thiobacillus ferroxidan bacteria is already practice in Japan.
Bioscubbing involves scrubbing of waste effluents using microbial methods to detoxify or de-odourise certain constituents in the waste effluents. Hypomcrobium SSP can be used to oxidize the malodourous dimethylsulphide aerobically or anaerobically.
Aerobic process H2S + 2O2 H2SO4
(CH3)2S + SO2 H2SO4 + 2CO2 + 2H2O
Anaerobic process
Hypomicrobium
5H2S + 8 NaNO2 H2SO4 + 4NaSO4 + 4N2 + 4H2O
SSP
(CH3)2S + 4NaNO2 NaSO4 + 2 CO2 + 2N2 + 2NaOH + 2H2O
Bioinformatics and Biosensors
Bio-informatics
Bio-informatics is an interdisciplinary field which addresses biological problems using computations techniques and makes the rapid organization and analysis of biological data possible. The field may also be referred to as computational biology and can be defined as—
“Conceptualizing biology in terms of molecules and then applying informatics technique to understand and organize the information associated with these molecules on a large scale.”
Bio-informatics plays a key role in various areas such as functional genomics, structural genomcs and proteomics and forms a key component in the biotechnology and pharmaceutical sector.
Biosensor
A biosensor is an analytical gadget comprising of an immobilized layer of a biological material (Example: enzyme, antibody, hormone) inconjunction with a transducer which analyses the biological signals and converts them into an electrical signal.
Example: BOD sensor, Nitrate sensor, Ammonia sensor, sulfide ion sensor.
Bio-sensor works on the following principle
A layer of suitable biological material is immobilized on a permeable membrane which is kept in the close vicinity of a sensor. The substance to be measured passes through the membrane and interact with the immobilized material and yield a product. The product passes through another membrane to the transducer. The transducer converts into an clectrical signal which is amplified and displayed or recorder.
Bio-informatics is an interdisciplinary field which addresses biological problems using computations techniques and makes the rapid organization and analysis of biological data possible. The field may also be referred to as computational biology and can be defined as—
“Conceptualizing biology in terms of molecules and then applying informatics technique to understand and organize the information associated with these molecules on a large scale.”
Bio-informatics plays a key role in various areas such as functional genomics, structural genomcs and proteomics and forms a key component in the biotechnology and pharmaceutical sector.
Biosensor
A biosensor is an analytical gadget comprising of an immobilized layer of a biological material (Example: enzyme, antibody, hormone) inconjunction with a transducer which analyses the biological signals and converts them into an electrical signal.
Example: BOD sensor, Nitrate sensor, Ammonia sensor, sulfide ion sensor.
Bio-sensor works on the following principle
A layer of suitable biological material is immobilized on a permeable membrane which is kept in the close vicinity of a sensor. The substance to be measured passes through the membrane and interact with the immobilized material and yield a product. The product passes through another membrane to the transducer. The transducer converts into an clectrical signal which is amplified and displayed or recorder.
Biotechnology on pollution control
Biotechnology on pollution control
Biotechnology compromise of integrated application of theoretical and practical knowledge of biochemistry, microbiology, physiology, genetics and chemical engineering to exploit the properties of microbes and cultures for various beneficial technological uses. Environmental biotechnology is a very broad field which includes environmental monitoring and safety, waste treatment recovery, restoration of environment quality. Substitution of non-renewable resource-base with renewable resources, research and development of various processes for the benefit of mankind with due regard to socio-economic legal and environment safety consideration.
Important applications of biotechnology in pollution control and waste management include
A. Improvement of existing processes
Example: uses of bio-science and biochemical engineering to obtain knowledge about applicaton of mixed cultures such as-
• Improvement in sewage treatment
• Use of starter cultures for tratement processes
• Used in immobilized microbial cells in waste water treatment.
B. Treatment of toxic wastes using genetically improved organism:
Example: Genes which can bring about degradation of toxic environmental pollution(Such as toluene, chloro-organics etc.) have indentified. For degradation of toxic chemials, enzymes are encloded by specific gene present in plasmid. Such as-
• OCT plasmid degrades oxane, hexane and decame.
• XYL plasmid degrades xylenes & toluenes.
• CAM plasmid decompose camphor.
• NAH plasmid degrades naphthalene.
C. Recoveryly of useful product from waste material.
Example: Recovery of methane, metals etc. from waste material.
D. Development of new catalysts, new bioreactors, novel biosensors and automation of waste water treatment process.
Example
• Use of immobilized organisms and heavy metals as new catalyst and bioreactors.
• Use of trace of toxic organic as new sensor.
• Design of cadmium binding synthetic adsorbent.
Biotechnology compromise of integrated application of theoretical and practical knowledge of biochemistry, microbiology, physiology, genetics and chemical engineering to exploit the properties of microbes and cultures for various beneficial technological uses. Environmental biotechnology is a very broad field which includes environmental monitoring and safety, waste treatment recovery, restoration of environment quality. Substitution of non-renewable resource-base with renewable resources, research and development of various processes for the benefit of mankind with due regard to socio-economic legal and environment safety consideration.
Important applications of biotechnology in pollution control and waste management include
A. Improvement of existing processes
Example: uses of bio-science and biochemical engineering to obtain knowledge about applicaton of mixed cultures such as-
• Improvement in sewage treatment
• Use of starter cultures for tratement processes
• Used in immobilized microbial cells in waste water treatment.
B. Treatment of toxic wastes using genetically improved organism:
Example: Genes which can bring about degradation of toxic environmental pollution(Such as toluene, chloro-organics etc.) have indentified. For degradation of toxic chemials, enzymes are encloded by specific gene present in plasmid. Such as-
• OCT plasmid degrades oxane, hexane and decame.
• XYL plasmid degrades xylenes & toluenes.
• CAM plasmid decompose camphor.
• NAH plasmid degrades naphthalene.
C. Recoveryly of useful product from waste material.
Example: Recovery of methane, metals etc. from waste material.
D. Development of new catalysts, new bioreactors, novel biosensors and automation of waste water treatment process.
Example
• Use of immobilized organisms and heavy metals as new catalyst and bioreactors.
• Use of trace of toxic organic as new sensor.
• Design of cadmium binding synthetic adsorbent.
Biotechnology and pllution control
Environmental biotechnology and biotechnology
Environmental Biotechnology: The application of biotechnology in the natural environment is called environmental biotechnology .This could be primarily sustaining the environment by using eco-friendly biological process. Some of these processes could be used to solve the most demanding environment problems like enrolling air emissions and water pollution.
Bio-technology: Bio-technology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering technology medicine and other fields requiring bio-products.
The United Nations Convention on Biological Diversity (UNCBD) defines biotechnology as
“Any technological application that uses biological systems living organisms or derivatives there of to modify product or process for specific use.”
Application of biotechnology in Environment protection
The Application f bio technologies in environment protection are
1. It is used for the treatment of municipal sewage treatment plants and filters to purify town gas.
2. Bio-technological techniques to treat waste before or after it has been brought into the environment.
3. Domestic solid waste may also treated by this process.
4. Toxic waste many also be neutralize by using micro-organism.
5. Micro-organism may also be used to treat the common pollutant in Industrial effluent before discharging it into water.
For more information and suggestion : zamansgs@gmail.com
Environmental Biotechnology: The application of biotechnology in the natural environment is called environmental biotechnology .This could be primarily sustaining the environment by using eco-friendly biological process. Some of these processes could be used to solve the most demanding environment problems like enrolling air emissions and water pollution.
Bio-technology: Bio-technology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering technology medicine and other fields requiring bio-products.
The United Nations Convention on Biological Diversity (UNCBD) defines biotechnology as
“Any technological application that uses biological systems living organisms or derivatives there of to modify product or process for specific use.”
Application of biotechnology in Environment protection
The Application f bio technologies in environment protection are
1. It is used for the treatment of municipal sewage treatment plants and filters to purify town gas.
2. Bio-technological techniques to treat waste before or after it has been brought into the environment.
3. Domestic solid waste may also treated by this process.
4. Toxic waste many also be neutralize by using micro-organism.
5. Micro-organism may also be used to treat the common pollutant in Industrial effluent before discharging it into water.
For more information and suggestion : zamansgs@gmail.com
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