ME3003 - Module Two part two.pdf

8/14/2019 ME3003 - Module Two part two.pdf

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Notes for ME3003 - Environmental Studies for Mechanical

Engineers

Module 2 part 2

Topics covered: Water Pollution Causes and Effects, Marine

Pollution, Soil Pollution.

References used

Book 1 : [1] Environmental Studies, by Mr. Benny Joseph.

Book 2 : [2] Environmental Engineering and Management, by

Mr. Suresh. K. Dhameja.


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Water pollutionCauses and Effects

Presence of impurities (organic, inorganic, biological, radiological) and foreign

substances in such quantities which cause health hazards by lowering the quality

of water and making it unfit for use.

Causes Effects

1

Bacteria, virus, parasitic worms (enter

water from domestic sewage).

sickness, disease, death.

2

Oxygen demanding waste - organic waste

which if present in large quantities, will

deplete oxygen from water because it is

decomposed by oxygen-consuming-

bacteria.

fish and other aquatic life

die.

Ref [1]


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Causes Effects

3

Inorganic plant nutrients - water soluble

phosphate and nitrate compounds.

cause excessive growth of

algae etc. which die, decay

resulting in oxygen depletion.

cause death of aquatic life.

4

Water soluble organic chemicals - Acids, salts,

toxic metal (Pb, Hg) compounds.

make water unfit for drinking,

harm aquatic life, reduce crop

yields, promote corrosion in

equipment using this water.

5

Radioactive substances - water soluble radio

isotopes, ionizing radiation etc. cause birth defects, cancer etc.

6

Heat of hot water from power plants, cooling

towers, which is discharged into water.

decreases dissolved oxygen

and increases water

temperature.

Water pollutionCauses and Effects Ref [1]


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Water pollutionSources

Sources of water pollution

Non-point sources

e.g. run-offs from agricultural /

industrial land, roads etc. getdischarged into ground and surface

waters and pollute them.

Point sources

e.g. Pipe, sewage treatment plants,

factories, ditches, offshore oil wells,

coal mines etc. These are easy to be

identified, regulated and monitored.

Ref [1]

Ground water pollution

caused by waste disposed on land.


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Water pollutionDrinking water qualityPotable drinking water should be

Colorless, odorless, clear, without suspended solids and turbidity, free from toxic

substances etc.

Dissolved inorganic solids (in moderate quantity).

Non-corrosive (pH between 7 and 8.5) .

Aesthetically pleasant, should not cause stains in clothes.

Effects of water pollution (Health hazards from water pollution)

Phosphate, nitrate in fertilizers, detergents etc. pollute surface water bodies.

These are nutrients and encourage algae growth which consume oxygen which

reduces DO (dissolved oxygen) levels.

Arsenic, Cd, Pb etc. harm aquatic life and also reach humans through these.

Organic pollutants (coming from petroleum refineries, paper mills etc.) provide

nutrition to microorganisms that decompose organic matter, consume oxygen

resulting in reduced DO levels, leading to death of aquatic organisms.

Ref [2]

Ref [1]


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Effects of water pollution (Health hazards from water

pollution)

Non-biodegradable pesticides reach humans through food chains and

get accumulated in the fatty tissues and harm nervous systems .

Typhoid, Cholera etc. caused due to drinking of contaminated water.

Fluoride-containing pollutants cause dental problems, gastro-

intestinal, neuro-muscular respiratory disorders.

Thermal pollution reduces DO levels reduces survival of aquatic life.

Oil pollutants cause death of aquatic life.

Radioactive pollutants (from Uranium mining/refining areas, nuclear

power plant etc.) reaching humans through food chain get

accumulated in liver, muscles, blood, thyroid gland etc.

Ref [1]


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Marine Pollution

Introduction of energy / substances into the marine envt resulting in

harms / hazards to living organisms, and affect quality of sea water.

Natural causes like earthquake on ocean floor etc. are not included as

causes. Marine pollution refers to pollution caused as a result of human

activity only.

Causes originate from land or sea.

Type of pollutant Source / Cause Effects

1 Nutrients

Sewage, run-off from

farming, air-borne nitrogen

oxide from cars etc.

cause blooming of algae,

oxygen depletion, death of

marine life.

2 Plastics Fishing nets, beach litter. cause harm to marine life.

3 Pathogens Sewage and livestock.

spread cholera, typhoid and

other diseases.

Causes and Effects of Marine Pollution

Ref [1]


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Type of pollutant Source / Cause Effects

4 Sediments

Due to erosion, byforestry, mining.

Hinder photosynthesis, clog gills

of fish. Contains excess ofnutrients and toxins.

5

Persistent toxins

(DDT, PCB, heavy

metals)

Industrial discharge,

wastewater discharge,

pesticides from farms.

Contaminate seafood. Fat soluble

toxins are harmful.

6

Oil - crude and

refined petroleum

(fuel oil, gasoline

etc.)

From land (industry and

cars), accidents at sea,

offshore drilling etc.

Oil spills (have long lasting

effect). In low levels, cause

disease of marine life. Volatile

hydrocarbons in oil destroy corals

and harm marine organisms.

Natural insulation or buoyancy of

marine organisms affected by oil.

Causes and Effects of Marine Pollution Ref [1]


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Control of Marine Pollution

Improve sewage disposal facilities. Each house can have

septic tanks. Better use of municipal sewage systems.

Better coastal & marine planning and management.

Ref [1]


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Soil Pollution

Soil is made up of organic and inorganic layers.

Organic formed by decaying of plants and animals.

Inorganic rocky layers .

Pollution of soil is caused when / substances / energy / biological

organisms enter soil and harm its quality.

Causes of Soil Pollution

Accidents involving vehicles carrying fuels, resulting in their

spilling.

Toxic chemicals due to solid waste disposal.

e.g. garbage from homes, industries result in respiratory and nervous problems.

Hazardous substances from industries (Chemical,

petroleum and metal related).

Ref [1]


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Control of Soil Pollution

Restricting construction in certain sensitive areas.

Use 3 Rs(Reduce, Reuse and Recycle) so that it results inlesser fertilizer and pesticide use.

Treatment (Physical, chemical and biological) of industrial

wastes.

Bioremediation

A treatment process that uses fungi / bacteria / yeast etc. to

degrade / breakdown hazardous substances to non-toxic /

less toxic substances. (like CO2, H2O etc.)

Ref [1]


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Control of Soil Pollution

Types of Bioremediation

Biostimulation - stimulating biological activity.

Bioaugmentation Inoculating soil with microbes.

BioventingInjecting air / nutrients into unsaturation zone.

Biospraying Injecting air / nutrients into unsaturated and

saturated zones.

Ref [1]


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ME3003 - Module Two part two.pdf

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