Lecture 10 - Environmental Pollution and Control
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Transcript of Lecture 10 - Environmental Pollution and Control
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Lecture 10: EnvironmentalPollution, Problems and
Measures
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Definition Environmental pollution is defined as the
undesirable change in physical, chemicaland biological characteristics of our air,land and water
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Categories of Pollutants (a) Biodegradable pollutants - Biodegradable
pollutants are broken down by the activity of micro-organisms and enter into the biogeochemical cycles.Examples of such pollutants are domestic wasteproducts, urine and fecal matter, sewage, agriculturalresidue, paper, wood and cloth etc.
(b) Non- Biodegradable pollutants - Non-biodegradable pollutants are stronger chemical bondage,do not break down into simpler and harmless products.
These include various insecticides and other pesticides,mercury, lead, arsenic, aluminum, plastics, radioactivewaste etc.
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Types of Environmental Pollution
Air
Water
Soil
Noise
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Air Pollution
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Air PollutionAir Pollution: Air is mainly a mixture of
various gases such as oxygen, carbondioxide, nitrogen. These are present in aparticular ratio. Whenever there is anyimbalance in the ratio of these gases, airpollution results.
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Sources of Air Pollution Natural; such as, forest fires, ash from
smoking volcanoes, dust storm and decayof organic matters.
Man-made due to population explosion,deforestation, urbanization andindustrializations.
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Air Pollution
According to Physical Form Air pollutants are classified as suspended particulate
matter, gases and vapours that are present in the
atmosphere in abnormally high concentrations. Particulate matter affects more people on continuing basis
than any other pollutant. The main components are coarseparticles such as soil and mineral ash or fine particles found inwood smoke or coming from engine exhausts.
Gaseous air pollutants are principally oxides of nitrogen(NOx), ozone (O3), carbon monoxide (CO), sulphur dioxide(SO2), ammonia (NH3) and volatile organic compounds.
Other air pollutants include chlorinated fluorocarbons (CFCs)
and other "greenhouse" gases, lead and other heavy metalsand radon.
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Air Pollution
According to LocationAmbient air pollution
Without proper controls, industry is a major source of air pollution. In
this way, industrial operations can affect the health of workforces,the general environment and the health of nearby (and sometimesvery far removed) populations.
Particular industries with significant health impacts include:chemical, paper and pulp, cement, glass and ceramics, iron and
steel, non-ferrous metals, leather, refining and processingpetroleum, and particularly from coal and oil burning plantsproducing electric power.
Motor vehicles account for about 30% of emissions of nitrogenoxides, 50% of hydrocarbons, 60% of lead and 60% of carbon
monoxide in cities of developed countries. In city centres the valuesrise to 95% for carbon monoxide and up to 70% for nitrogen oxides.
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Air Pollution
According to LocationIndoor air pollution
Even today, homes of the poor in developing counties are
dangerous, unhealthy places a rule of thumb states that a pollutantreleased indoors is 1000 times more likely to reach people's lungsthan a pollutant released outdoors.
Some 2000 million people throughout the world use wood or otherbiomass fuels (cow dung, crop residues and grass) for cooking and
heating. The domestic burning of these fuels is an inefficient processthat produces many pollutants, some of which may be carcinogenic.The problems are worsened in areas where people spend most oftheir time indoors.
A 20% reduction in indoor air pollution could reduce mortality from
acute respiratory infection by at least 4-8% in some populations. Coal burning for heating and cooking in developing countries resultsin indoor particle concentrations of up to 10,000 g/m, a level that ismuch higher even than ambient concentrations in polluted cities inAsia.
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Harmful Effects of Air pollution
Dirty air- affects respiratory system of living organismsand causes bronchitis, asthma, lung cancer, pneumoniaetc. Carbon monoxide (CO) emitted from motor vehiclesand cigarette smoke affects the central nervous system.
Depleted of ozone layer - UV radiation reaches the earth.UV radiation causes skin cancer, damage to eyes andimmune system.
Acid rain - caused by presence of oxides of nitrogen and
sulfur in the air. These oxides dissolve in rain water toform nitric acid and sulfuric acid respectively. Variousmonuments, buildings, and statues are damaged due tocorrosion by acid present in the rain. The soil alsobecomes acidic. The cumulative effect is the gradual
degradation of soil and a decline in forest and agriculturalproductivity. Green house gases - such as carbon dioxide (CO2) and
methane (CH4) trap the heat radiated from earth. This
leads to an increase in earths temperature.
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Air Pollution Control Combustion This technique is used when the pollutants are in the
form of organic gases or vapors. During flame combustion or
catalytic process, these organic pollutants are converted into watervapor and relatively less harmful products, such as CO2. Absorption In this technique, the gaseous effluents are passed
through scrubbers or absorbers. These contain a suitable liquidabsorbent, which removes or modifies one or more of the pollutants
present in the gaseous effluents. Adsorption The gaseous effluents are passed through porous solidadsorbents kept in suitable containers. The organic and inorganicconstituents of the effluent gases are trapped at the interface of thesolid adsorbent by physical adsorbent.
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Air Pollution Control Use of better designed equipment and smokeless fuels,
hearths in industries and at home.
Automobiles should be properly maintained and adhereto recent emission-control standards.
More trees should be planted along road side and
houses. Renewable energy sources, such as wind, solar energy,
ocean currents, should fulfill energy needs.
Tall chimneys should be installed for vertical dispersion
of pollutants.
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Air Pollution Control at Home Avoid using chemical pesticides or fertilizers in your yard and garden. Many fertilizers
are a source of nitrous oxide, a greenhouse gas that contributes to global warming.Try organic products instead.
Compost your yard waste instead of burning it. Outdoor burning is not advisable, as itpollutes air. Breathing this smoke is bad for you, your family and your neighbors.Plus, you can use the compost in your garden.
If you use a wood stove or fireplace to heat your home, it would be better to considerswitching to another form of heat which does not generate smoke. It is always betterto use sweater or warm clothing than using fireplace.
Be energy efficient. Most traditional sources of energy burn fossil fuels, causing airpollution. Keep your home well-maintained with weather-stripping, storm windows,and insulation. Lowering your thermostat can also help and for every two degreesFahrenheit you lower it, you save about two percent on your heating bill.
Plant trees and encourage other to plant trees as well. Trees absorb and storecarbon dioxide from the atmosphere, and filter out air pollution. During warmer days,trees provide cool air, unnecessary use of energy on air conditioning is avoided,hence the air pollution.
Try to stop smoking; at home, at office or at outside. Tobacco smoking not onlydeteriorates selfs health, it affects others health too.
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Air Pollution Control At the Road Keep your vehicle well maintained. A poorly maintained
engine both creates more air pollution and uses more
fuel. Replace oil and air filters regularly, and keep yourtires properly inflated.
Drive less. Walking, bicycling, riding the bus, or workingfrom home can save you money as well as reducing air
pollution. Dont idle your vehicle. If you stop for more than 30
seconds, except in traffic, turn off your engine. Dont buy more car than you need. Four-wheel drive, all-
wheel drive, engine size, vehicle weight, and tire size allaffect the amount of fuel your vehicle uses. The morefuel it uses the more air pollution it causes.
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Water Pollution
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Water Pollution Water is said to be polluted when there is
any physical, biological or chemicalchange in water quality that adverselyaffects living organisms or makes waterunsuitable for use.
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Sources of Water Pollution Sources of water pollution are mainly
factories, power plants, coal mines and oilwells situated either close to water sourceor away from sources.
They discharge pollutants directly orindirectly into the water sources like river,
lakes, water streams etc
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Causes of Water Pollution Factors that contribute to water pollution
can be categorized into two differentgroups
Point sources
Non-point sources
Point sources are the easiest to identify
and control Non point sources are ambiguously
defined and harder to control
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Point Sources Some point sources of water pollution
include Waste products from factories
Waste from sewage system
Waste from power plants Waste from underground coalmines
Waste from oil wells
They are called point sources becausethey are direct sources of water pollutionand can be reduced and monitored
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Example of a point source
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Non-point Sources The term non-point source encompasses a
large range of sources such as: when rain or snow moves through the ground and
picks up pollutants as it moves towards a major
body of water the runoff of fertilizers from farm animals and crop
land
air pollutants getting washed or deposited toearth
storm water drainage from lawns, parking lots,
and streets
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Non-point source: Agricultural
runoff
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Water Pollution Control Wastewater discharges are most commonly
controlled through effluent standards anddischarge permits. Under this system,discharge permits are issued with limits on the
quantity and quality of effluents. Water-quality standards are sets of qualitative
and quantitative criteria designed to maintain or
enhance the quality of receiving waters.Classification of bodies of water to maintainwater quality
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Water Pollution Control Sewerage and sanitation with wastewater
treatment using effluent standards Septage treatment using effluent
standards
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What is soil The physical material that covers most of
the earths land surface Generally composed of sand, silt and clay
particles, organic matter, water and airspaces
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Functions of SoilHealthy soil gives us clean air and water, bountiful crops and forests,productive rangeland, diverse wildlife, and beautiful landscapes. Soildoes all this by performing five essential functions:
Regulating water. Soil helps control where rain, snowmelt, andirrigation water goes. Water and dissolved solutes flow over the landor into and through the soil.
Sustaining plant and animal life. The diversity and productivity ofliving things depends on soil.
Filtering potential pollutants. The minerals and microbes in soil areresponsible for filtering, buffering, degrading, immobilizing, anddetoxifying organic and inorganic materials, including industrial andmunicipal by-products and atmospheric deposits.
Cycling nutrients. Carbon, nitrogen, phosphorus, and many othernutrients are stored, transformed, and cycled through soil.
Supporting structures. Buildings need stable soil for support, andarcheological treasures associated with human habitation areprotected in soils.
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Sources of Soil/Land Pollution Hazardous waste/sewage oil spills
Improper disposal of solid wastes Transfer of air pollutants to land
Transfer of water pollutants to land
Soil contamination can lead to poor growth
and reduced crop yields, loss of wildlifehabitat, water and visual pollution, soilerosion, and desertification.
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Soil/land Pollution Spills deposit pollutants to soil
Solid wastes not properly disposed makethe soil/land unsuitable for its intended use
Air pollutants emitted in the atmospherewill eventually be deposited in the soil
Water pollutants traversing land areas
have the tendency to be absorbed by soil
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Soil/land Pollution Control Treeplanting
Solid waste management
Integration with air and water pollution
control Regulating human activities and penalizing
violators
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What is Noise Unwanted sound
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Noise StandardsNOISE STANDARD (dB = Decibel)
40dB40dB35dB45dB40dB50dB40dB50dBSilence Zone
55dB65dB35dB50dB45dB55dB45dB55dBResidential Area
70dB70dB45dB60dB55dB65dB55dB65dBCommercial Area
80dB80dB70dB70dB70dB75dB65dB75dBIndustrial Area
Night timeDaytimeNight
timeDaytimeNight timeDaytimeNight timeDaytime
UNITED STATESEUROPEASIA (India)PHILIPPINESAREAS
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Sources of Noise Traffic
Airports
Railroads
Manufacturing plants Construction or demolition
Concerts/entertainment
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Health Effects of Noise sleep disturbance
cardiovascular effects
damage to work and school performance
hearing impairment including tinnitus.
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Noise Pollution Control redesigning equipment to reduce the speed or impact ofmoving parts; to install mufflers on intakes and exhausts;to replace old equipment with newer, better designed
equipment; servicing and maintaining equipment to replace worn
parts and to lubricate all moving parts; isolating equipment either by distance, by enclosures or
by barriers; damping and cushioning noise sources by using rubberpads to reduce vibration
and noise coming from metal parts; reducing the drop
height of objects falling into bins or onto belts; installing absorptive baffles in work areas to absorbsounds generated there
Creation of greenbelt