Water Treatment Processes

lameubiquityMechanics

Feb 21, 2014 (3 years and 8 months ago)

95 views

Water Treatment Processes

Disinfection and removal of solids

Water treatment processes

WATSAN M15 ERU

2

Contents

1.
Aim of treatment

2.
Removal of solids in suspension

3.
Disinfection

4.
Water treatment in emergencies


Water treatment processes

WATSAN M15 ERU

3

1.
Aim of treatment

Water treatment processes

WATSAN M15 ERU

4


Multiple options of treatment


Safe water supply:



All people have safe and equitable access to a sufficient quantity of
water for drinking, cooking and personal and domestic hygiene.






Water is palatable, and of sufficient quality to be drunk and used for
personal and domestic hygiene without causing significant risk to
health










(The Sphere Project, Chap.2, Norms 1 y 2 )

1.
Aim of the treatment process

Water treatment processes

WATSAN M15 ERU

5


Pathogen free


Chemically safe


Without dirt solid matter


Aesthetically acceptable


WHO Guidelines

National Regulation

1.
Aim of the treatment process

Water treatment processes

WATSAN M15 ERU

6


The treatment process starts in the water extraction




Source selection (surface water/groundwater)




Means of water extraction (strainer)




The treatment process ends in the distribution



Storage and distribution



Jerry cans for the beneficiaries



Re
-
contamination risks

1.
Aim of the treatment process

Water treatment processes

WATSAN M15 ERU

7

2. Removal of solids in
suspension

Water treatment processes

WATSAN M15 ERU

8



Why?


-

aspect



-

efficiency of disinfection


Control parameter:


Gravity analysis






Turbidity (NTU)


Aim: < 5 NTU


Methods



Sedimentation

Flocculation

Filtration

2.
Removal of solids in suspension

Water treatment processes

WATSAN M15 ERU

9


Advantages: Simple, no consumption


Disadvantages: Need of facilities, slow, limited

2.
Removal of solids in suspension. Sedimentation

Water treatment processes

WATSAN M15 ERU

10


Advantages: Removes colloids, time, equipment


Disadvantages: Chemicals, factor control (temp. time, dosage)

2.
Removal of solids in suspension. Flocculation

colloids

coagulation

dosage and mixture

flocculation

sedimentation

polyelectrolyte

Water treatment processes

WATSAN M15 ERU

11


Advantages: No chemicals, modules, possible sterilization


Disadvantages: Material (means of filtration) and facilities


Absortion

Active carbon

Filtration + Back washing

2.
Removal of solids in suspension. Filtration

Water treatment processes

WATSAN M15 ERU

12

3. Disinfection

Water treatment processes

WATSAN M15 ERU

13


To destroy the germs present in the raw water



To destroy the germs introduced in the treatment and
distribution systems (pipeline and storage)

3.
Disinfection: Aims

Water treatment processes

WATSAN M15 ERU

14


Properties of disinfection agents


Physical agents: heat, UV radiation


Chemical agents: chlorine, ozone, iodine, salts of
ammonium…


Chlorination


Calcium hypochlorite HTH 70 % of active chlorine


3.
Disinfection: Procedures

Water treatment processes

WATSAN M15 ERU

15

3.
Disinfection: Chlorination dosage

Residual chlorine mg/l

Applied chlorine mg/l

Maximum quantity of
combine chlorine

Break point

Free chlorine

Residual combine chlorine

Water treatment processes

WATSAN M15 ERU

16


Dosage: Chlorine request test


Contact time


pH and temperature


Final ranges: 0.4
-

0,8 mg/l


Shock chlorine

3.
Disinfection: Chlorination

Water treatment processes

WATSAN M15 ERU

17

DIAGRAMME

INPUT TANK

PREOXIDATION

CARBON FILTER

COAGULATION

FLOCCULATION

SEDIMENTATION

SILEX FILTER

FINAL
CHLORINATION

OUTPUT

DRINKING WATER

SLUDGE

DRINKING WATER

WASTE WATER

WASTE WATER

RAW WATER

COAGULANT

FLOCULANT

Water treatment processes

WATSAN M15 ERU

18

4. Water treatment in
emergencies

Water treatment processes

WATSAN M15 ERU

19

Pumping water from


the water source


Water storage in an onion tank (30,000 l.)

Water pre
-
treatment
with flocculent

Submersible pump


WATER TREATMENT PLANT

Silex filter

Carbon filter

Rapid mixer

Pressure

group

Residual Chlorine

Bladder tanks (10,000 litres)
to store drinking water

Water distribution

Water distribution: Taps

Chlorine

& Alum

Flocculation

tank

Water treatment processes

WATSAN M15 ERU

20



Specialized water production



FLOCCULATION



pre
-
treatment in the tank




treatment in the sedimentation

tank in the WTP


CHLORINATION



in the WTP (shock & residual
)

4.
Water treatment in emergencies

Water treatment processes

WATSAN M15 ERU

21

4.
Water treatment in emergencies

Water treatment processes

WATSAN M15 ERU

22



Mass water production


FLOCCULATION



in the tank as chlorination


pre
-
tretament



CHLORINATION



in the tank

4.
Water treatment in emergencies

Water treatment processes

WATSAN M15 ERU

23

4.
Water treatment in emergencies

Water treatment processes

WATSAN M15 ERU

24

Thank you
……….