Lecture 10 - Environmental Pollution and Control

7/29/2019 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

Lecture 10 - Environmental Pollution and Control

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