ME 6403- Environmental Science and Engineering

ENVIRONMENTAL POLLUTION

Prepared by

V.NaveenPrabhu

Assistant Professor

Sri Eshwar college of Engineering

Coimbatore

2

PollutionPollution is the introduction of contaminants into an

environment that causes instability, disorder, harm ordiscomfort to the ecosystem .

e.g. Industry

Automobiles

Nuclear Reactors etc,.

Types of pollutants

Biodegradable

Non-degradable

Types of pollution

Air pollution

Marine (Water) pollution

Land or soil pollution

Noise pollution

Thermal pollution

Nuclear pollution

AIR POLLUTION

Air pollution is the “presence of contaminants

in atmosphere in quantities such that it is

injurious to human, plant animal life and

property”.

Sources of air pollution

Natural sources : Volcanic eruption, forest fires,

biological decay.

Manmade sources :thermal power plant ,fuel

burning, agriculture activities.

Classification of Air pollutants

1.Primary air pollutants.

Emitted directly in the atmosphere. E.g. CO,NO

& SO2

INDOOR AIR POLLUTANTS

Radon gas emitted from building materials like

bricks,concrete,tiles etc.,

It is present in natural gas and ground water.

burning of fuel in the kitchen, cigaratte,

smoke.

2.Secondary air pollutants

Primary pollutant may react with one

Sulphur dioxide:

The combustion of sulphur containing fuels such as

coal and oil.

It can be converted into sulphuric acid.

Human Sources :

Coal burning in power plant (88%)

Industrial processes (10%)

Environmental effects :

In humans : it causes eye irritation, cough, lung

diseases including lung cancer and asthma

In plants: it causes damage of leaves, bleaching of

chlorophyll which turns leaves brown, damage to

crops and to growth of plants.

Carbon monoxide

Sources:

Cigarette smoking,incomplete burning of fuels.

Automobile exhaust- carbon monoxide is formed

during the combustion of fuel such as petrol.(77%)

Industries: carbon monoxide is released by industries

such as iron and steel and petroleum .

CO2 + C ------- 2CO

2CO2 --------- 2CO + O2

Effects:

In humans:

When the atmosphere is polluted with carbonmonoxide, on inhalation, CO combines withthe hemoglobin to form car boxy hemoglobinand hence oxygen carrying capacity of theblood decreases.

This causes, headache, dizziness,unconsciousness.

When inhaled for a long duration it may causeeven death.

In environment :

it increase globe temp.

Lead

Sources

Paint, metal refineries, storage battteries…..

Effects

In humans

Mental retardation, health problems even leads

to cancer.

In environment

Harms wild life

Control of air pollution Source Control:

Use only unleaded petrol.

Use petroleum products and other fuels that have lowsulphur and ash content.

Reduce the no. of private vehicles

Ensure the houses, schools are not located on busystreets.

Plant trees along busy streets to reduce particulates,CO and noise.

Industries should be situated outside the city

Use catalytic converters to control CO&hydrocarbons

Control measures in industries

The emission rates should be restricted to

permissible levels by industries.

Air pollution control equipments must be

made mandatory.

Continuous monitoring of the atmosphere

for the pollutants, to know the pollution

levels.

EQUIPMENTS USED TO CONTROL AIR

POLLUTION

Use sufficient supply of oxygen in combustion chamber, so that the combustion is complete.

Use mechanical devices such as

scrubbers, cyclones, bag houses and electro-static precipitators to reduce particulate pollutants

Electrostatic precipitator

Bag house filter/cyclone separator

Wet scrubber

WATER POLLUTION

“The alteration in

physical, chemical or

biological properties of

water, as well as the

addition of any foreign

substance makes it unfit

for health and which

decreases the utility of

water” is known as water

pollution.

Main sources of water pollution are:

Domestic and municipal sewage

Industrial waste

Agricultural waste

Radioactive materials, etc.,

POINT AND NONPOINT SOURCESTwo types of water pollutants exist;

Point source

Point sources of pollution occur when harmfulsubstances are emitted directly into water.

e.g.,Oil spill

Nonpoint source.

A non-point source delivers pollutants indirectlythrough environmental changes.

e.g., Fertilizer from a field is carried into a stream byrain

Point Sources

Non Point Sources

Types of water pollutant:

1.Infectious agents: Bacteria, viruses, protozoa

source : animal waste.

Effect : variety of diseases

2.Oxygen demanding waste:

Dissolved oxygen (DO) is the amount of oxygendissolved in given quantity of water at a particularP and T. The saturation point 8-15mg/lit.

Sources: Sewage, paper waste, food processingwaste.

Effects: affect the water quality, affect fishsurvival and migration.

3.Inorganic chemicals : Acids, pb, arsenic, selenium,

sodium chloride and fluorides.

Sources : surface runoff, effluents

Effects: Cause skin cancer, damage nervoussystem,harm to fish and aquatic life, lower cropyields.

4.Organic chemicals:Oil, gasoline,plastics,

solvents ,detergents.

Sources: Industrial efflents, surface runoff forms.

Effects: Causing effect nervous system ,cancer,harm fish and wild life.

5.Plant nutrients:

Nitrate, phosphate and ammonium ions

Sources: sewage, runoff water from agriculture, fertillizer.

Effects: Excessive growth of algae, lower the oxygen carrying capacity.

6.Sediment: Soil

Source: Land erosion.

Effects: Can reduce photosynthesis, Affect aquatic food webs.

Testing of water

Dissolved oxygen (DO)

Amount of oxygen dissolved in water at a

particular pressure and temp.

Bio chemical oxygen demand (BOD)

Oxygen required for biological decomposition

of organic matters.

Chemical oxygen demand (COD)

Oxygen required for chemical oxidation of

organic matters

Control measures of water pollution:

Avoid Pesticides and fertilizers on sloped land areas.

The nutrient rich water can be used as fertilizer in the

fields.

Separate drainage of sewage and rain water should be

provided to prevent overflow of sewage with rain water.

Planting more trees.

Use nitrogen fixing plants to supplement the use of

fertilizers.

Sewage treatment

Main objective is to convert harmfulcompounds into harmless compounds.

In primary treatment, the suspended solidsand floating objects are removed using coarsescreens and sieves.

In secondary treatment, the maximumproportions of the suspended inorganic/ organicsolids are removed from the liquid sewage. Theliquid material passes into the sedimentationtank and finely suspended particles are allowedto settle by adding coagulants like Alum.

Tertiary treatment

Remove detergents, metal ions, nitrates andpesticides, as these are not removed in theearlier treatments.

The phosphates are removed as calciumphosphates by adding calcium hydroxide at pH10-11. At this pH, ammonium salts are alsoconverted into ammonia.

The effluent is chlorinated to removepathogenic bacteria's and finally passedthrough activated charcoal to absorb gases.

SOIL POLLUTIONSoil pollution is caused by the presence of human-

made chemicals or other alteration in the natural soil

environment.

This type of contamination typically arises

from,

Application of pesticides and fertilizers

Percolation of contaminated surface water to

subsurface strata, oil and fuel dumping.

Discharge of industrial wastes to the soil. The

most common chemicals involved are

petroleum hydrocarbons, solvents, pesticides,

lead and other heavy metals.

Effects of soil pollution:

Chronic exposure to chromium, lead and other

metals, petroleum, solvents, and many pesticide

and herbicide formulations can be carcinogenic.

Chronic exposure to benzene leads to

leukemia.(blood cancer)

Mercury and cyclodienes are known to induce

higher incidences of kidney damage.

Sewage sludge has many types of bacteria, viruses

and worms which cause types of diseases and also

emits toxic vapours.

Radioactive fallout cause abnormalities .eg.,

Strontium-90 instead of calcium gets deposited

in the bones.

Effects occur to agricultural lands which have

certain types of soil contamination.

Alteration of metabolism of endemic

microorganisms.

N & P from fertilizer in soil reach water bodies

with agricultural runoff cause Eutrophication.

Chemicals contaminates ground water

resources.

Acids, alkalis, heavy metals affect soil fertility.

Inhibit non target organism like flora, fauna

and soil productivity.

Control of soil pollution :

Effluents should be properly treated beforedischarging on the soil.

Solid waste should be properly collected anddisposed off by appropriate method.

From the waste, recovery of useful productsshould be done.

Cattle dung should be used for methanegeneration.

Microbial degradation of biodegradablesubstance for reducing soil pollution.

NOISE POLLUTIONDefinition: Noise Pollution can be defied as unwanted or

unpleasant sounds that causes discomfort for all living

things.

The various sources of noises are associated with urban

development; road-air and rail transport; Industrial noise.

In our country, indiscriminate use of loud speakers,

generator sets and firecrackers has given new dimensions

to the noise pollution problem.

The commonly used parameter for noise is the sound

level in decibel(dB). Human ears are sensitive in the

frequency range of 20Hz to 20000Hz

Major Noise Sources:

1. Road Traffic:

Road traffic noise is one of the most

widespread and growing environmental problems in

urban area. The impact of road traffic noise on the

community depends an various factors such as road

location and design, land use planning measures,

building design, Vehicle standards and deriver

behavior. Motor vehicle ownership in India has

increased substantially over the last 30 years and

general levels of road traffic noise throughout India

have increased through out the period.

2. Air Traffic:

The extend of aircraft noise impact dependson the type of aircraft flown, the number of flightsand flight paths. The increase in number of flights, animportant factor is overall noise levels, the led to anincrease in general noise levels associated with airtraffic.

3. Rail Traffic:

The two main sources of noise and vibrationrelating to the operation of the rail network is

1. The operation of trains and the maintenance

2. Construction of rail infrastructure.

4.Neighborhood & Domestic Noise:

Other significant source of noise

annoyance is car alarms, building construction

and household noise,Celebrations- religious

function,social and elections.

5.Noise generated by noise levels of 125dB as

per Environmental rules 1999.

Effects:

1. Noise can disturb out work, rest, sleep and

communication.

2. It can damage our hearing and evoke other

psychological, physiological and possibly

pathological reactions.

3.It effects health efficiency and behaviour. It

may cause damage to heart, brain,kidneys and

liver.

4.It causes muscles to contract leading to

nervous breakdown, tension.

5.Change in hormone content of blood, whichturn increase the rate of heart beat.

6.Recently it has been reported that blood is alsothickened by excessive noise.

7. Hearing damage : it can cause permanenthearing loss.

8.Interferences with man’s communication :Innoise area communication is affected.

Sound Source Sound Level

dB

Subjective Feeling

of Human Beings

Rockets and missiles,

heavy explosives

160 Unbearable

Jet Planes and cannons,

explosives

140 Unbearable

Aircraft Propeller and

Machine Guns

130 Unbearable

Diesel, steam engine and

ball mills, crackers

120 Unbearable

Electric saws and looms,

heavy trucks

110 Unbearable

The CPCB-The central pollution control board recommended noise

levels.

CONTROL MEASURES OF NOISE POLLUTION:

1.REDUCTION IN SOURCE OF NOISE : Heavy vehicles and oldvehicles may not be allowed in populated areas.

2. Noise making machines should be kept in containers withsound absorbing media.

3. Proper oiling will reduce the noise from the machinery.

4. Use sound absorbing silencers: Silencers can reducenoise by absorbing sound.

5. Planting more trees having broad leaves.

6. Through law:

sound production is minimized at various

social function.

7. The use of fireworks or fire crackers shall not be

permitted except between 6.00a.m and

10.00p.m.No fireworks or fire crackers shall be

used between 10.00p.m and 6.00a.m.

8. Silence zone in area comprising not less than

100meters around hospitals, educational

institutions ,courts and religious places.

THERMAL POLLUTION

Thermal pollution is the degradation of water quality byany process that changes ambient water temperature.

A common cause of thermal pollution is the use of wateras a coolant by power plants and industrial manufacturers.

Energy is the basic necessity for the economicdevelopment of a country.

The electrical energy is produced in power plants orgenerating stations. The conventional power plants are:

- Steam or Thermal Power station,

- Hydro-electric Power station,

- Nuclear Power station

Steam or Thermal Power station

In the thermal power station, the steam is

produced in the boiler, using the heat released

by the combustion of coal, oil or natural gas.

The steam is used to rotate the steam turbine

(impulse/ reaction).

The steam turbine drives the alternator, which

converts mechanical energy into electrical

energy.10-16oC higher than initial temp.

Hydro-electric Power station

Hydroelectricity is the term referring to

electricity generated by hydropower.

The production of electrical power through the

use of the gravitational force of falling or

flowing water.

It is the most widely used form of renewable

energy.

Once a hydroelectric complex is constructed, theproject produces no direct waste, and has a considerablylower output level of the greenhouse gas & carbondioxide (CO2).

Nuclear Power station

Nuclear power is produced by controlled

(i.e., non-explosive) nuclear reactions.

Commercial and utility plants currently

use nuclear fission reactions to heat water to

produce steam, which is then used to generate

electricity.

Effects of thermal pollution

Elevated temperature typically decreases the levelof dissolved oxygen (DO) in water.

Thermal pollution may also increase themetabolic rate of aquatic animals.

Fish migration is affected due to formation ofvarious thermal zones.

Discharge of hot water near the shores coulddisturb and even kill young fishes.

Toxicity of pesticides ,detergents and chemicalsinto the effluent increases with increase in temp.

The composition of flora and fauna changes.

Control of thermal pollution

Thermal pollution from industrial sources is generated

mostly by power plants, petroleum refineries, pulp and

paper mills, chemical plants, steel mills and smelters.

Cooling ponds, man-made bodies of water designed for

cooling by evaporation, convection, and radiation.

Cooling towers, which transfer waste heat to the

atmosphere through evaporation and/or heat transfer.

Cogeneration, a process where waste heat is recycled

for domestic and/or industrial heating purposes.

RADIO ACTIVE OR NUCLEAR POLLUTION

The uncontrolled distribution of radioactivematerial in a given environment.

Radioactive contamination is typically theresult of a spill or accident during theproduction or use of radionuclide(radioisotopes), an unstable nucleus which hasexcessive energy.

Contamination may occur from radioactivegases, liquids or particles

Effects

Radioactive contamination can enter the bodythrough ingestion, inhalation, absorption, orinjection that causes discomfort, diarrhea,nausea or vomiting, and burns skin and hairloss.

The cumulative damage can cause serioushealth problems long term, such as cancer,especially leukemia and Thyroid Cancer.

For this reason, it is important to use personalprotective equipment when working withradioactive materials.

Control methods:

It includes the stoppage of leakage from the

radioactive materials including the nuclear

reactors, industries and laboratories.

The disposal of radioactive material must be

safe and secure.

The protective garments must be worn by the

workers who work in the nuclear plants.

The natural radiation must be at the permissible

limits and they must not cross it.

SOLID WASTE MANAGEMENT:

Each household generates garbage or wasteday in and day out. There are different types ofsolid waste depending on their source

Types of solid waste: Solid waste can beclassified into different types depending ontheir source: Household waste is generallyclassified as,

Municipal waste

Industrial waste as hazardous waste

Biomedical waste or hospital waste

E waste-Electronic waste

SOURCES OF URBAN AND INDUSTRIAL

WASTE:

Waste from homes: polyethylene bags, cans,

glass bottles, waste paper, cloth, food waste,

empty metal.

Waste from shops: Cans, bottles, waste paper,

tea leaves, packaging material.

Biomedical waste : discarded medicines,

chemical wastes, disposable syringes, swabs,

bandages and body fluids.

Construction waste :wood, concrete, cement .,

Industrial waste :Packaging meterial,organicwaste, acid,alkali and metals.

Solid waste: Rubber,plastic,paper,glass,wood,oils,paints, dyes,heavy metals, asbestos.

Effects of solid waste :Physicochemical and chemical characteristics

affecting productivity of soils.Toxic substance contaminate the ground water.Burning of materials produce dioxins, furans

causes cancer.

TYPES INVOLVED SOLID WASTE

MANAGEMENT:

1.REDUCE,REUSE,RECYCLE:

a.Reduce the usage of raw materials:

If usage is reduced,generation of waste also

reduced.

b.Reuse of waste materials:

1.Refillable containers can be reused

2.Discarded cycle tubes can be made into rubber

rings.

c.Recycling of materials:

1.Old Al cans and bottles are melted and recast

into new cans and bottles.

2.Preparation of cellulose insulation from paper

3.Preparation fuel pellets from kitchen waste.

Methods of disposal of solid waste:

a. Landfill :

The bottom is covered with several layers of

clay,plastic & sand –protects ground water

contamination.

• Landfill is covered with clay, sand & gravel.

• Methane gas is collected and used to produceelectricity.

b. Composting:

The biodegradable waste is allowed todecomposed into oxygen rich medium andquality rich environment is formed whichimproves soil fertility rate.

c. Incineration :Burning of waste at hightemp(2800-3200 F) in combustion chamberand used to produce electricity andincinerate100-150tonnes per hour.

Role of individual in prevention of

pollution

Individuals can, however, play an important role inabatement of air, water, soil or noise pollution in thefollowing simple manners:

Use low-phosphate, phosphate-free orbiodegradable dishwashing liquid, laundrydetergent, and shampoo.

Use manure or compost instead of commercial

inorganic fertilizers to fertilize gardens and yard

plant.

Use biological methods or integrated pest

management to control garden, yard, and household

pests.

Don't pour pesticides, paints, solvents, oils, or otherproducts containing harmful chemicals down drainor on the ground.

Recycle old motor oil and antifreeze at an autoservice center that has an oil recycling program.Test water for lead, nitrates, trihalomethanes, radon,volatile, organic compounds and pesticides.

Support ecological land-use planning in yourcommunity.

Get to know your local water bodies and formwatchdog groups to help monitor and protect.

“THINK GLOBALLY ACT LOCALLY”

Flood

Flood

Definition: Whenever the magnitude of waterflow exceeds the carrying capacity of thechannel within its bank, the excess of water overflows on the surroundings causes floods.

Causes of flood

1.Slow kinds: Runoff from sustained rainfall2.Rapid kinds: snow melt exceeding the capacityof a river's channel.

3.Fast kinds: sudden release of water from dam,landslide, or glacier.

Effects of flood

1.Primary effects

2.Secondary effects

1.Primary effects

Physical damage – Can damage any type of

structure, including bridges, cars, buildings,

sewerage systems, roadways, and canals.

2.Secondary effects

Water supplies – Contamination of water. Clean

drinking water becomes scarce.

Diseases – Unhygienic conditions. Spread of water-

borne diseases.

Crops and food supplies – Shortage of food crops can

be caused due to loss of entire harvest.

Trees – Non-tolerant species can die from suffocation.

Transport - Transport links destroyed.

Flood management:

1.Diverting excess water through channel or canals

like river ,lake.

2.Satelite pictures of pre-flood, flood and post

flood with other information.

3.River networking .

4.Flood warning given by central water

commission.

Cyclone

Definition:

“A cyclone is an area of closed, circular

fluid motion rotating in the same direction as the

Earth”

Most large-scale cyclonic circulations are centered on

areas of low atmospheric pressure.

Cyclones are powerful destructive and active from days

to weak and speed varies 180-500km/hr.

A broad area of low pressure rotating "counter-

clockwise" (cyclonically) is also a cyclone.

Different names of cyclone

Hurricanes - Atlantic, USA

Typhoons – western pacific, Japan

Cyclones – Bangladesh, India

Willy willies - Australia

Occurrence:

1.Tropical cyclone in the warm oceans are formed,

because of heat and moisture.

2. Sea surface temperature must below 25Oc .

3.It move like spinning top at the speed of 10-

30km/hr.

4.Indian cyclone occurs during oct-dec or April –

may.

Effects:

Tropical cyclones are responsible for large

amounts of damage to human life, crop, roads,

transport, tanks wherever they strike.

Slow down the developmental activities.

Control:

Boarding up homes and businesses, strategically

placing sand bags, and building more wind

resistant structures.

Cyclone management:

Satellite images are used by meteorological

department.

Radar system is used to detect the cyclone and

for cyclone warning.

For observing exact location of cyclone ,every

half an hour satellite picture are analyzed.

Its difficult to stop the formation of cyclone,

but the effect could be minimized by planting

more trees.

Earthquake

An earthquake is a sudden vibration caused on

the earth’s surface due to the sudden release of

tremendous amount of energy stored in the rocks

under the earth’s crust.

Causes

Volcanic eruptions, rock falls, landslides, and

explosions ,hydrostatic pressure of manmade water

bodies.

Under ground nuclear testing.

Decrease under ground water level.

Its measures by Richter scale.

less than 4 – insignificant,4-4.9 – minor,5-5.9-

damaging,6-6.9 – destructive,7-7.9 – major, more

than 8 – severe damage.

Effects

Earthquakes produce deformation of ground

space.

This includes damage to buildings and in worst

cases the loss of human life.

The effects of the rumbling produced by

earthquakes usually leads to the destruction of

structures such as buildings, bridges, and dams.

They can also trigger landslides.

Control:

To prevent an earthquake hazard the building

should be properly designed.

Do not construct houses on high risk prone areas.

In case of an earthquake move out of the

building and came in the open but not panic.

Do not use lifts in case of an earthquake.

Tsunami

Tsunami is a series of water waves caused bythe displacement of a large volume of a body ofwater, usually an ocean.

Causes :

Earth quake ,landslide

Deformatiaon of the sea floor due to themovement of plates.

Ordinary wave – 100,tsunami – 500km.

It travels across the deep sea at very high velocity of at around 800-900km/hr.

Velocity decreases ,the height and energy of wave increases.

Its height near the sea shore ranges from 15-65m

Effects:

The effects of the tsunami on the country during

this period range from destruction damage, death,

injury, millions of dollars in financial loss, and long

lasting psychological problems for the inhabitants of the

region.

Tsunami management :

Under the water, the bottom of sea is monitored by sensors.

If any changes, sensor send information.

The information will be passed through earth stations.

Warning system are warned of the danger approaching.

Land slidesLand slides are the process of large

differential movement of two land portion.

OR

A landslide or landslip is a geological

phenomenon which includes a wide range of

ground movement.

Causes:

Down hill movement of earth caused by rain,

forces either increasing top materials.

Movement of heavy vehicles.

Earthquake ,shocks, vibrations, cyclone creates

landslides.

Erosion in the hilly tract due to runoff water.

Underground caves, underground mining

operation.

Effects

Property damage,

Injury,

Death,

adversely affect a variety of water supplies,

fisheries,

sewage disposal systems,

forests, dams, and roadways

Control measures

Soil Conservation: Ways to reduce soil erosion:

Terracing: Terracing reduces soil erosion on steep slopesby concerting the land into a series of broad, levelterraces. This retains water for crops at each level andreduces soil erosion by water run off.

Contour Farming: This method is adopted for gentlysloped land. This involves planting crops in rows acrossthe contour of gently sloped land.

Agro forestry: In this method crops are planted togetherin strips or alleys between trees and shrubs that canprovide fruits and fuel wood. The trees and shrubsprovide shade which reduce water loss by evaporationand preserve soil moisture.

Wind Breaks : Wind breaks and shelter belts or trees areestablished to reduce wind erosion and also for retainingsoil moisture

Unloading the upper parts of the slope.

Concrete support.

Draining the surface and subsurface water fromsloppy region.

Soil stabilization by using quick lime in weakareas.