Intakes, sedimentation principles, gorund water quality and quantity ...

choppedspleenMechanics

Feb 22, 2014 (4 years and 22 days ago)

125 views

VARDHAMAN COLLEGE OF
ENGINEERING

DEPARTMENT OF CIVIL ENGINEERING


ENVIRONMENTAL ENGINEERING





By

M. Rajasekhar

Assistant Professor

1

2


OBJECTIVES
:


On the completion of this topic, you will be able to
know:





The importance of different units in water treatment plant for
purification water
.





3

Treatment of water



Objectives:


To remove




Pathogens



Dissolved gases and solids.



Objectionable ,unpleasant odour.



Taste and colour



To make the water suitable for the domestic and


Industrial purposes.

C 504.28

4


5



Click on the stage
number to view the
contents


1


3


4


6

7

8

2

Fig.1
C 504.28

5

SOURCES OF WATER

Ponds, Lakes, Streams, Rivers and Impounding Reservoirs

Fig.2
6

PRELIMINARY TREATMENT

The

first

operation

encountered

in

preliminary

treatment

of

water

is

called

as

screening
.


A

screen

is

a

device

with

uniform

openings

used

to

retain

floating

solids

in

the

raw

water

by

mechanical

straining

action
.

PRE
-
CHLORINATION

Addition

of

Chlorine

to

raw

water

before

treatment

in

sedimentation

tanks

and

filter

beds

is

called

Pre
-
Chlorination
.

7

8

Coagulation and Flocculation

The Process of adding certain chemicals for accelerating sedimentation process

and effective removal of very fine and colloidal particles is known as Coagulation

Fig.3

9

FILTRATION

The

process

of

passing

the

water

through

a

filter

media

consisting

of

thick

layer

of

sand

to

remove

impurities

is

called

Filtration
.

Fig.4

POST
-
CHLORINATION ( DISINFECTION)

10

Application

of

chlorine

gas

or

its

compounds

like

bleaching

powder

for

disinfecting

water

is

known

as

Chlorination
.


Addition

of

chlorine

after

filtration

is

called

Post
-
Chlorination
.

11

SEDIMENTATION

The

Process

of

settling

the

suspended

solids

by

virtue

of

gravity

is

called

Sedimentation
.

Fig.5

12

The

treated

water

has

to

be

supplied

to

the

people

in

required

quantities

at

the

point

of

consumption

through

network

of

pipes

is

called

as

Distribution

System
.

Clear
Water

Point of
Consumption

Distribution System

Fig.6

13


Treatment of water


Major units in water treatment plant are:




Aeration



Plain Sedimentation



Sedimentation with coagulation



Filtration



Disinfection