Water Waste Managemnt [Compatibility Mode]

8/13/2019 Water Waste Managemnt [Compatibility Mode]

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By

SHIWANI


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What is Wastewater?

Water is used for many purposes.

Water that has been used and contains domestic,

industrial, institutional and commercial waste

products is called wastewater.


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Where does wastewater come from?

Residences (kitchen, bathroom, brushing teeth,

washing utensils and cloths, and cooking food)

Industrial Institution (water containing Industrial

wastes and chemical.)


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What is wastewater treatment

Process of removing pollutants from waste waterbefore it enters water bodies or is reused iscalled treatment of water.

Usually refer to sewage treatment, or domestic

wastewater treatment


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SEWAGE

Sewage is wastewater that flows down thedrain of houses, industries, hospitals, offices,fields etc.

Rainwater that runs down the streets duringstorm or heavy rain also adds to the sewage.

The dissolved and suspended solid impuritiespresent in sewage are called contaminants.


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CONTAMINANTS PRESENT IN SEWAGE

Organic Impurities

Inorganic Impurities

Nutrients

Bacteria

Other Microbes

Human and Animal waste, oil,pesticides and herbicides usedin fruit and veg. peels.

Various metals, nitrates andphosphates

Nitrogen and phosphorus

Causing water-related diseases

such as cholera and typhoid

Causing diseases like dysentery


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HARMFUL EFFECTS OF

UNTREATED OR INADEQUATELY TREATED SEWAGE

Untreated sewage is major source of groundwater and surface water

pollution.

Stagnant sewage from leaking sewer pies sometimes enters the drinking

water pipes and pollutes it.

It acts as a breeding ground for various disease causing organism such as

mosquitoes and flies, which leads to diseases like cholera, diarrhea,

jaundice and dysentery.

Soaps and detergents contain phosphates. When wastes contain soaps

and detergents are released into rivers and ponds, the favour algal

growth. Growing algae consume a lot of oxygen and thus oxygen level in

water decreases. The algae compete with aquatic plant and animals for

oxygen and affect the aquatic life.


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To produce waste stream (effluent)

To produce solid waste (sludge)

To discharge or reuse them back

into the environment


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WASTEWATER TREATED

Clean water is basic need of alhuman being, plants andanimals.

To make drinking water availableto people, wastewater has to betreated to remove all impurities.

The clean water that can beconsumed is called potablewater.


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WASTEWATER TREATMENT PLANT

Wastewater treatment is process of removing

contaminants from wastewater.

It includes removal of physical, chemical and

biological contaminants using physical,chemical and biological processes.

It involves the removal of solid waste or sludge

from sewage and discharging the treated

water into water bodies.

After treatment, the solid part of the sewage

can be used as fertilizer for crops.


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Where is wastewater treated?

All sources ofwastewater in a SewageService Area areconnected to sewers,

which join together toform a network called acollection system.

The collection system

leads to a WaterPollution Control Plant(WPCP).


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How does it get there?

Water flows downhillbecause of gravity, so theWPCP is usually locatedat a low point in theservice area.

If the force of gravityisnt enough, pumpingstations are used to

boost wastewaterthrough forcemains(pressurized sewers) tothe WPCP.


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Preliminary Treatment:

Wastewater is passed

through parallel bar screen.

This remove materials like

rags, sticks, cans, plasticetc.

The wastewater is than

passed through grinder

where solid waste is

reduced in size so that it

does not clog up the plant.


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GRIT AND SAND REMOVAL PROECSS

Wastewater is then

allowed to enter Grit &

sand removal tant.

Here, the spped of

wastewater is reduced

in order to allow sand,

grit and pebbles to

settle down.


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WATER CALRIFIER

Wastewater then goes to largetank called water clarifier.

The tank sloped towards themiddle to allow organic materiallike faeces to settle at its bottom.

The sludge is removed withscrapers.

Here floatable solids like oil andgrease are also removed with

skimmer.

The cleared water, so obtained, iscalled clarified water.


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DIGESTION

Sludge is solid material removed fromprimary sedimentation tanks andsecondary clarifiers.

The sludge is transferred to separate

tank where anaerobic bacteria act onit and convert it into methane, carbondioxide and humus like material.

This process is called digestion. Thedigested sludge is dried by spreadingon sand beds and used as fertilizer.

Air is the pumped through clarifiedwater. Aerobic bacteria grow inpresence of air and consume theremaining waste.


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Stages of wastewater treatment:


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BETTER HOUSEKEEPING PRACTICE

Solid wastes such as used tea leaves,

food remains, plastic bags, soft toys,

cotton and sanitary towels should not

thrown down the drain.

Various chemical products such as

medicnes, motor oils, paints, grease,

machine oils and insecticides may kill

water purifying microorganism and

hamper the degradation process. These

should not be thrown down the drain


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SANITATION AND SEWAGE DISPOSAL

Septic tanks can bebuilt for hospitals, forgroups of 4-5 housesand other isolated

buildings. Using on site human

waste disposaltechnology, excretafrom the toilet seatscan directly be sent to

a biogas plant throughcovered drain. Thebiogas so producedcan be used as sourceof energy.


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Water Waste Managemnt [Compatibility Mode]

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