Water treatment

1. Water Treatment Processes
Disinfection and removal of solids

2. 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

3. Water treatment processes
WATSAN M15 ERU 3
1.Aim of treatment

4. 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

5. 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

6. 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

7. Water treatment processes
WATSAN M15 ERU 7
2. Removal of solids in
suspension

8. 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

9. Water treatment processes
WATSAN M15 ERU 9
 Advantages: Simple, no consumption
 Disadvantages: Need of facilities, slow, limited
2. Removal of solids in suspension. Sedimentation

10. 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

11. 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

12. Water treatment processes
WATSAN M15 ERU 12
3. Disinfection

13. 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

14. 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

15. 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

16. 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

17. 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

18. Water treatment processes
WATSAN M15 ERU 18
4. Water treatment in
emergencies

19. 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

20. 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

21. Water treatment processes
WATSAN M15 ERU 21
4. Water treatment in emergencies

22. 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

23. Water treatment processes
WATSAN M15 ERU 23
4. Water treatment in emergencies

24. Water treatment processes
WATSAN M15 ERU 24
Thank you……….