Water Treatment & Water Waste Management

1. DELHI JAL
BOARD
(SUMMER INTERNSHIP TRAINNING
PROGRAM)

2. FILTER HOUSE (EAST AND WEST)
 When the water is recycled from the Re-cycle pump house it is then
mixed with the raw water in bifurcation chamber.
 This water is then transferred to flash mixer where alum is mixed
with water to separate the sand from the water, from where this water is
transferred to the clariflocculator tank.
 In clariflocculator tank: - Sedimentation takes place which is a
physical water treatment process used to settle out suspended solids in
water under the influence of gravity.
Diagram of a clariflocculator tank

3.  After the clariflocculator tank the water is transferred to filter house
water chamber through a tunnel having depth of 6ft.(approx) and
breadth of 3 ft. (approx).
 This water is supplied to water beds inside the filter house which is
controlled through an inlet valve of 600 mm.
Diagram of a water filter bed in filter house
 Inside the filter house 20 filter beds are present for filtering of water
.each having a capacity of 2.5 MGD (million gallons per day) each.
20 X 2.5 MGD = 50 MGD (Per Filter House)

4.  These Water beds have different layers of stones, with layers of sand
on it.
 From these water beds the water filtered is passed through the clear
water outlet having a valve of 600mm.
 This water is then collected at the clear water chamber through the
valve. From the chamber the water is supplied to the clear Water pump
house.
Washing of Water Beds
 Water beds are backwashed after every 24 hours, as to remove the
sand collected during filtering of water .it takes about half an hour to
backwash a water bed.
Process Of Backwashing
 In this process, firstly the inlet valve is closed as to stop the water from
the clariflocculator tank, after that the water is removed from the tank
by outlet valve or drain .after that a blower is started which is attached
to every bed through blower pipes of dimension 124-150mm.there are
total 3 Nos. blowers total. The Specification of blowers is as follows:-

5. S.No. Specifications Value
1 Make Everest Transmission
2 Model LB17
3 Type HSC
4 Capacity 2910 m³/hr
5 Head 14M
6 Pressure 0.35Kg/cm²
7 Speed 1740RPM
8 Wattage 45KW
9 Voltage 415V
10 Speed 1480 RPM
11 Phase 3
12 AMB Temperature 4.5°C
13 Frequency 50Hz
14 Efficiency 92
15 Construction DELTA
Diagram of a blower

6.  This blower is operated for about 5 minutes and after 3 minutes a pump
is automatically started to pump the remaining water out of the beds
with the help of syphon pipe. After more 5 minutes the blower is
stopped and two more pumps are operated having following
specification:-
S.No. Specifications Value
Pump Details
1 Type HSC
2 Capacity 1212m³/hr3
3 Head 14M
4 Pumping Fluid Clear Water
Motor Details
1 Wattage 7.5KW/100H.P.
2 Voltage 415V
3 Speed 960RPM

7. Diagram of HSC (Horizontal Split Casing) Pump
After this process is completed the inlet valve is again opened and
filtering of water again starts.
Filter Bed
One filter bed contains
It contains 5 valves which are as follows:-
S.No. Valve Name Valve Size
1 Water Inlet Valve 600mm
2 Blower Valve 150mm
3 Clear Water Valve 500mm
4 Backwash Valve 500mm
5 Water Outlet/Drain Valve 600mm

8. Working Of Valves
1. Water Inlet Valve:-it is used to start and stop the flow of water
from the clariflocculator tank to the water beds.
2. Blower Valve:- it is used to blow air into the filter beds to blow
the sand from the surface.
3. Clear Water Chamber:- It is used to start and stop the flow of
clear water from filter bed to clear water chamber.
4. Backwash Valve:-It Is Used To Start and stop the flow of water
from Backwash Pump to Filter Beds.
5. Water Outlet/Drain Valve:- It is used to start and stop the flow
of water from filter bed to drain chamber. It is used to drain all
the water from the filter bed for backwashing.

9. Checking Of Clear Water From Clear Water Chamber
The water collected in clear water chamber is regularly checked for
that whether water is pure or no.
The main two tests for water checking in filter house are:-
1. Turbidity Check
2. pH check
 Turbidity Check:- Turbidity is the cloudiness or haziness of a fluid
caused by individual particles (suspended solids) that are generally
invisible to the naked eye, similar to smoke in air. The measurement of
turbidity is a key test of water quality.
Fluids can contain suspended solid matter consisting of particles of
many different sizes. While some suspended material will be large
enough and heavy enough to settle rapidly to the bottom of the
container if a liquid sample is left to stand (the settable solids), very
small particles will settle only very slowly or not at all if the sample is
regularly agitated or the particles are colloidal. These small solid
particles cause the liquid to appear turbid. It is measured By a Turbidity
meter.
 pH Level Test:- A water supply's pH level indicates the water's
acidity or basicity. PH is measured on a standard 1 through 14
scales, with ideal, purely neutral water falling at 7. Values above 7
are considered alkaline or basic, and values below 7 are acidic.
Water pH levels should be between 6.5 and 8.5.