lec-14-week(12)(introduction to water treatment)

8/16/2019 Lec-14-Week(12)(Introduction to Water Treatment)

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LECTURE 13


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PURPOSE OF WATER TREATMENT

Public health protection-pathogens & heavy metal removal

Aesthetics-taste , odor, turbidity & color

Economics-softening of hard water


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NATURE OF TREATMENT

The nature of treatment will depend upon:

1. Quality of water to be treated

2. Desired quality of finished water

3. Local, provisional and / or federal regulations and

standards


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TREATMENT METHODS

Storage and plain sedimentation

Rapid sedimentation(coagulants are used) Filtration

Disinfection

Reverse Osmosis

Electro dialysis

Ion Exchange


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WATER TREATMENT PLANT

A water treatment plant is a series of units suited

to the raw quality of the water source and the

required quality of the treated water.


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TYPICAL FLOW DIAGRAM OF WATER

TREATMENT

Raw Water

Coagulation Flocculation

Disinfection

Disinfection

Sedimentation

FiltrationFlocculation


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PARTICLES IN WATER

Particles in water vary widely in origin , size andconcentration

Origin: Some particles are land based or having someatmospheric source like silt , clay etc. And some areproduced due to chemical processes in water like CaCO3

Size: Particles sizes vary from 0.005 microns to 100

microns Particles below 10 microns are called colloids, their settling

velocities are less than 10-2 m/sec.


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PARTICLES IN WATER

Concentration: of particles in water can be

measured in different ways:1. Turbidity: It is caused by the presence of

suspended matter such as clay , mud or algae etc.

2. Mass concentration: Expressed in mg/L (mostly

used)

lec-14-week(12)(introduction to water treatment)

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