WASH cholera / AWD EP&R training Key responses – Water Water treatment and Priorities in Different...
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Transcript of WASH cholera / AWD EP&R training Key responses – Water Water treatment and Priorities in Different...
WASH cholera / AWD EP&R training
Key responses – Water
Water treatment and Priorities in Different Settings
Session 3.2WASH Cholera / AWD EP&R training
WASH cholera / AWD EP&R training
Learning Objectives
By the end of the session the participants• specify water treatment during a cholera / AWD
outbreak• describe basic principles of chlorination, its
limitations and advantages • suggest solutions to provision of water for
different settings at different stages of cholera / AWD response
WASH cholera / AWD EP&R training
IMPORTANT
During a cholera outbreak it is
advisable to use chlorinated water
only for drinking and cooking!!!
WASH cholera / AWD EP&R training
Bulk vs. household water treatment
• .
WASH cholera / AWD EP&R training
Work in pairs
Discuss advantages and
disadvantages of household and bulk
water treatment
10 min
WASH cholera / AWD EP&R training
Bulk vs. household treatment
+ -Bulk water treatment
• Can supply to large numbers of people
• Can provide drinking water quickly
• Can control water quality
• Can monitor changing water needs
• Not useful for dispersed populations
• High Operation & Maintenance inputs
• Water can be contaminated post - treatment (at source, during transport and storage)
Household water treatment
• More control by users
• More sustainable (if appropriate to situation)
• Less risk of contamination post treatment
•Good for dispersed populations
• Training needed for effective use
• More difficult to supply for large numbers of people
• Limited control on effective use
• Might be difficult to introduce quickly to communities if no prior knowledge
WASH cholera / AWD EP&R training
Water Treatment Chlorination
Most common water treatment is
chlorination because…..
1. It is easy to use and monitor
2. it is readily available
3. It has a residual effect
4. It is effective against most pathogens
WASH cholera / AWD EP&R training
Chlorination Limitation
• Chlorination works most effectively with low turbidity <5 NTU (max 20 NTU)
• Chlorination will require 30 minutes contact time under the conditions that:– pH<8– turbidity <5 NTU– temperature approx 20oC
• If pH higher, temp lower, turbidity higher then processes need to be adjusted
WASH cholera / AWD EP&R training
Chlorine Source Available Chlorine %
Remarks
High Test Hypochlorite (HTH ) Granules
70 Preferable for high chlorine content & stability.
Let the deposit settle & use only supernatant.
Strict air transport regulations.
Sodium Dichloro-isocyanurate (NaDCC)
60% powder
1g tablets
Preferable for high chlorine content & stability.
Completely soluble.
Usually more expensive than HTH.
Chlorinated Lime (Bleaching Powder)
30 Let the deposit settle & use only supernatant.
Sodium Hypochlorite Concentrate
15 Only use if manufactured very recently (<3 months) and if stored away from heat & light.
Sodium Hypochlorite (Bleach)
5 Only use if manufactured very recently (<3months) and if stored away from heat & light.
Antiseptic Solution – e.g. Milton, Javel
1 Keeps for a very short time after being opened
WASH cholera / AWD EP&R training
Handling & Storage of Chlorine
• Metal consumes chlorine - do not store chlorine solutions in metallic containers
• When in contact with air and especially humidity, HTH, chlorinated lime and NaDCC produce corrosive and toxic chlorine gas heavier than air. Stores should be ventilated at the bottom of the walls.
• Both powdered and liquid forms of chlorine reduce in strength over time. Store dry chlorine in sealed containers, away from heat & out of sunlight and keep liquid solutions in dark coloured bottles.
• Chlorine in corrosive – handle with care, avoid skin contact and when mixing chlorine solution, wear protective clothes and gloves, protect eyes and do not inhale fumes. In case of contact, rinse thoroughly with water.
WASH cholera / AWD EP&R training
Chlorination – important points
1. Training & on-going monitoring – check correct use regularly
2. Care when agencies using different makes - different instructions, package size and strengths
3. Check instructions – they can vary even for same product
4. Turbidity & type of water affects use – test samples & residuals before distribution
5. Work closely with hygiene promotion staff - ensure effective communication (e.g. why used, how used, taste) with users, training and support
Bucket Chlorination
WASH cholera / AWD EP&R training
Picture MSF
WASH cholera / AWD EP&R training
Bucket Chlorination
Water is treated with chlorine generating product at water
source at each individual water container
There are some issues you need to consider…….• Different sizes of water containers need different dose • Requires recruitment, training and close support
supervision of “chlorinators” • Could be expensive if there are many water points to
cover • Short term solution only • Effective and fast method if properly implemented
WASH cholera / AWD EP&R training
Exercise
Calculate how much HTH (70%) active
chlorine you will need to make 1 litre of 1%
solution.
WASH cholera / AWD EP&R training
Answer Exercise
PREPARATION OF A 1% SOLUTION
• 1% chlorine solution contains 10g of active chlorine per litre
• HTH is not 100% active chlorine but 70%
Calculation: calcium hypochlorite (HTH) at
70% active chlorine : 10 x (100/70) = 14.2 g
(which is about 14 g / l of solution)
WASH cholera / AWD EP&R training
16
Instructions for group work
In your groups discuss what would be your water prioritiesin this setting during the- First two weeks of a cholera / AWD outbreak response - After first two weeks up to 2 months - Beyond 2 months
Time 25 min
Make notes on your handouts. Choose who will to presentyour priorities in plenary
WASH cholera / AWD EP&R training
17
Nomadic communities
WASH cholera / AWD EP&R training
18
Rural area - spring
WASH cholera / AWD EP&R training
19
Peri Urban area
WASH cholera / AWD EP&R training
20
Urban formal setting with broken infrastructure
WASH cholera / AWD EP&R training
21
Established IDP Camp
WASH cholera / AWD EP&R training
22
New IDP camp
WASH cholera / AWD EP&R training
23
Rural setting - open wells
WASH cholera / AWD EP&R training
24
Urban informal settings
WASH cholera / AWD EP&R training
Learning Objectives
By the end of the session the participants
• specify water treatment during a cholera / AWD outbreak
• describe basic principles of chlorination, its limitations and advantages
• suggest solutions to provision of water for different settings at different stages of cholera / AWD response