SANITARY ENGINEERING DEPARTMENT CIVIL ENGINEERING
WATER SUPPLY ENGINEERING
./
Surface Water Works ( ) ( 3-1) (3-2)
.............................................................
Intake ................................. Low Lift Pumps
................................... Raw water Sump
.................................................Flash Mixing
................................................Gentle Mixing
Sedimentation With Coagulants
............................................. Water Filtration
..................................... Disinfection of water (
)..............Clear water Tank
............................. Low Lift Pumps Raw water Sump . :-
. . ( 6 ).
() ........Sedimentation : . . . ( 7 ). ( 8 ).. ) (settleable
solids ) ( suspended solids :- . . .
V v L H v Q H Q Q v . B.H L B.L A
V.H L
V
Q B .H
Over Flow Rate=OFR= Q/A ........)Detention Time (DT : = ( ) ).(
DT=HRT=T =Q Vol = / 3 Vol. = Q/T =.m
....) ( Sedimentation with Coagulants
. ( :(Coagulants :- . Aluminum sulphate (alum), Al2(So4)3,18H2O
Coagulant + water = flocculation= flocs Flocs + suspended solids=
fast sedimentation
..............Flash Mixing 02 06 . DT=20-60 sec .
..............Gentle Mixing . 02 04 ...DT=20-40min , .
.. Design Criteria of Sedimentation Tanks )(Over Flow Rate=OFR
02-04 / / . Area=Q OFR = 2- 4 .(DT) Detention time ) Volume= Q (DT
=3- 6. 03 / . 04 , 03 . 1:4. 04 . 0543 / / .
(1) :- 000.021 : . . ( ) . 03/ 052 . . 4 06 /. :- : 04 . = . =
000.021 04 ( 06 06 42 ). = 5.55 . : 3(d2/4)d = 0.25d d=4.2 m
( ): : = 03 3 / 2 /. = 000021 03 = 0004 2 23 8 . = 6.51 61 = 052
2. 52.13 8 . 3 . = 000021 3 42 = 00051 3 . = = 00051 0004 = 57.3 .
: = 61 03 = 000021 03 06 42 = 0052 3 . = 0052 61 = 52.651 3 . 8 3
57.7 .
( ) : : ( ) = 0004 2 ( ) = 0052 3 57.3 . =57.3-50= 52.3 . = 967
. ( +) = 9674 = 6 =9674 6= 497/ D = 23 = 967 6 = 821 2 . ( ) = 8.21
.
: = 03 / ( / 3 ). = 000021 03 = 000.006.3 /. = 0063 / = 6.3 /. =
6.3 563 = 4131 . = 4131 052 = 005823 : =06 / 09 % . = 000.021 06
09.0= 0846 / = 84.6 /. 89% 2% = 423 /. = = 1 . = 4233 .
(61 ). = 52.02 3 /. 4 52.016 = 573.3 3 2 5.0 5.0 .
(6 ) = 543 /. 4 6 = 45 6 = 9 3 . 05.0 .
