Water Purification & Supply

sixcageyMécanique

22 févr. 2014 (il y a 3 années et 3 mois)

60 vue(s)



Challenges of Drinking
Water Purification & Supply
in Disaster Affected Areas

Need for Voluntary Service
s


by


Er
.
Subhash

P.
Andey

Scientist

NEERI, Nagpur




Global Water Balance
2.7 %
97.3 %
Ocean Water
Fresh water
77.2
22.4
0.35
0.04
0.01
Frozen in the polar ice cap
Ground Water & Soil Moisture
Lakes
Atmosphere
Streams
Water Availability in India

Rain 4000 BCM

Total Utilizable

Water 186 9 BCM

Surface Water 690
BCM

Ground Water 432
BCM

4% of Global Water
resource
s

14 Major River
Basins

Per Capita Water Availability

Water Management Practices

Grey water recycling

Rain water Harvesting

Groundwater Recharge

Efficient Irrigation Practice
s

Construction of check dams

Natural Disasters


These disasters include Cyclones, Floods,
earthquakes, volcanic eruptions, Drought,
and Landslides etc


Out of total deaths by Floods in the world,
(1/5) are from India. The main causes of
floods are excessive rains in river
catchments, poor natural drainage, Change
of river course, Landslide restricting river
flow, cyclone and very intense rainfall


Providing clean water is usually one of the
highest priorities in the event of an
emergency


Impacts of
Natural Disasters on Water Supply



Draught and earth quake


Shortage of water


Bacterial Contamination of water



Cyclones and floods


Contamination of water sources


Turbidity and suspended solids


Organic matter due to plan decay, animal
carcasses


Bacterial contamination




Water Supply Management During Draught

Demand assessment


How much water is needed?


Location and protection of water sources


Where are the nearest/most convenient sources of water and How can they
be protected?


Water treatment


What is the level of water treatment required for use/consumption? What
methods are available for treatment

Water distribution


Where will people collect water from?


How will the water be collected?


How will it be stored for domestic use?




Water Supply Management During Flood



Flood waters can move animal carcasses closer to intakes
which increases the chance of organic and bacteria
contaminating the drinking water supply.


The spread of bacteria also occurs when rising levels of
water cause sewage to back up into lower lying areas
such as home interiors and public throughways through
toilets and manholes.


The turbidity (cloudiness) of water can increase during
flooding as can pollution from other contaminants.

Water Supply Management During Flood



Phased action plan


Immediate measures (to sustain life)


Intermediate measures (from about 2 to 6 weeks after the
disaster, or the arrival of refugees in a camp)


Long
-
term solutions (from about 6 weeks).


Factors affecting the duration of action phases




Accessibility of the disaster area or refugee camp for local,
national, and international assistance;


The nature of the disaster


Availability of water, materials, and skilled labour


Technologies for Water
Supply During Emergency

Simple to fabricate

Easy to operate

Minimum maintenance

Light weight

Ease in transportation and
installation

Low cost




NEERI
-
ZAR


Portable Instant Water Filter

NEERI
-
ZAR : Portable Instant Water Filter


Water purification system suitable for potable water supply
particularly under emergency situation with a wide range of
flood water quality


A typical unit, with two 100 L vessels, can serve about 20
-
30 persons, when operated for 10 hours a day, on the basis
of 6
-
10
litres

per capita/day for drinking and cooking
purposes


Removes turbidity and suspended matter as well as the
micro
-
organisms .


No change in the dissolved mineral concentrations in raw
and filtered water


Can be used to treat the pond/lake water for the villages or
small colony situated at the isolated places


Operating cost Rs. 3 per 100 L






NEERI
-
ZAR : Performance


NEERI
-
Zar

produces filtered water with turbidity in the range of
1.1 to 3.8 NTU and 90


99% reduction in bacterial load from the
raw water with the turbidity in the range 10
-

300 NTU and Total
coliform

and
E.coli

counts in the range 6800

78300 CFU/100ml
and 100
-
7900 CFU/100 ml respectively.


Zooplankton species like
cyclops
,
nauplius
, daphnia,
branchionus

are also removed during filtration.


The operation of the unit includes disinfection by chemical
agent.






Installed 100 units in the
flood affected remote
areas of
Barmer

District
in October 2006

Installed 400 units in the
Aila

Cyclone affected
villages of
Sundarban

district (West Bengal) in
2009 to treat pond water

IIT
Kharagpur

Nina
Saxena

Excellence in Technology
Award


to


Er
. Subhash Andey,
Er
.
Prakash

Kelkar

and Dr.
Madan

Nanoti



for


NEERI
-
ZAR : Instant Portable Water
Filter

CSIR
-
NEERI bags 2 Prestigious International

Project Innovation Awards (PIA)


Development

instituted by International Water Association (IWA)

Winner

Honour Winner

NEERI
-
ZAR Multi Pollutant
Water Treatment Unit

Solar Energy Based Electrolytic
Defluoridation Plant

PIA entries were from various countries such as Sri Lanka, Vietnam, Lebanon, Brazil,
Republic of Korea (South Korea), China, Tanzania, South Africa, Kenya, Philippines,
Jordan besides India


The awards were presented in the Ceremony held during the 2
nd

IWA Development
Congress and Exhibition in Kuala Lumpur, Malaysia on 23
rd

November, 2011



Pot Chlorinator for Disinfection of Dug Well and
Storage Tanks Waters


Single Pot system




Single Pot system Suitable for Community dug
wells and storage tanks of 9000 to 13000 L
capacity


Earthen pot of 7 to 8 L capacity is used in the
system


Dry mixture of 1.5 kg bleaching power (BP) and 3
kg coarse sand is placed in the pot over the pea
gravel


Addition of sodium
hexametaphosphate

(5% of BP)
helps in prolonging the chlorination period


Pot is lowered in the well/tank and kept 0.9 to 1.2 m
below water level with the help of rope


Chlorine residual : 0.2 to 1.0 mg/L for 15 to 20 days


One pot is enough for daily drawl of 900 to 1300 L
(40
-
50 people per day)


With higher drawl rates two pots are necessary per
well




Pot Chlorinator for Disinfection of Dug Well and
Storage Tanks Waters


Double Pot system




Suitable for household dug wells of 4000
L or less capacity having withdrawal rate
of 360 to 450 L of water per day Unit
consist of two cylindrical pots, one
inside the other


Moist mixture of 1 kg bleaching power
(BP) and 2 kg of sand is kept in the inner
pot with 0.6 cm diameter hole above the
level of sand and BP mixture


Pot is lowered in the well and kept 0.9 to
1.2 m below water level with the help of
rope


Chlorine residual : 0.15 to 0.5 mg/L for 15
to 20 days


Technologies for Safe Water
Supply


Defluoridation Technology


Electrolytic Defluoridation Technique


Removal of fluoride by active species of hydroxide of
aluminium

produced by passing DC power through
aluminium

electrode


Process is effective to remove excess fluoride and also
bring down the bacterial load of the raw water


Simple to fabricate, easy to operate with minimum
maintenance


Suitable for treatment of raw water with fluoride
concentration
upto

10 mg/L


Produces potable water with palatable taste as against
the other available chemical treatment methods


Quantity of sludge produced is much less (60
-
70%)
than conventional treatment methods


Simultaneous reduction in bacterial contamination in
treated water


Treatment cost
upto

Rs. 20 per 1000 L


Electrolytic Defluoridation Plants
working in the field





Dongargaon
,
Chandrapur

Dist. (Maharashtra)


Installation year 2002


Working on Solar power


Capacity
-

600 lit / Batch


Usaravara

village,
Durg

district (Chhattisgarh)

and
Sargapur

village
Seoni

Dist.(M.P.)


Installation year 2010


Working on Solar power


Capacity
-

2000 lit / Batch


UNICEF provided funds for installation of 16
plants in Madhya Pradesh


DST
-
Lockheed Martin India Innovation Growth Award

Solar Energy Based Electrolytic
Defluoridation Plant

NEERI
-
ZAR : Domestic Iron Removal Unit



Oxidation of iron by KMnO
4

and removal of
precipitated iron by sand filtration


The dose of KMnO
4

required is about 50%
of the iron concentration in the water


Suitable for remote places such as reserve
forest, police /military camps


20 plants are installed in Tadoba Tiger
Reserve Forest, Maharashtra for supply of
water to forest guards


NEERI
-
ZAR : Domestic Fluoride Removal Unit



Process involves formation of insoluble
fluoride complex with salts of calcium
and phosphorous and filtration through
sand filter


Reduces the fluoride concentration in
water to <1 mg/L


Suitable for treating the water
upto

fluoride concentration of 10 mg/L


Taste of the treated water is palatable


Installed 60 demonstration units at
Sakhara

village in Maharashtra


Cost of treatment Rs. 0.30 per liter




NEERI
-
ZAR : Domestic Arsenic Removal Unit



Process involves formation of insoluble
arsenic complex with Chemical A and B
and filtration through sand filter


Reduces the arsenic concentration in
water below 0.01 mg/L


Suitable for treating the water
upto

arsenic concentration of
100 to 3000 ppb


Taste of the treated water is palatable


Installed 5 demonstration units at C.G.





Hand Pump Attachable Iron Removal Plant




Continuous

operation

system


1 cu m/hour hydraulic loading


40
Ipcd

and 10 hours daily operation
assumption



250 population


Based

on

contact

bed

aeration

system

in

aeration

chamber



Cylindrical

body



Collection / flocculation chamber



Sedimentation chamber



Filter chamber



Plant Dimensions


Diameter,

cm

:

135


Height,

cm

:

150



240 plants were installed at Assam during
water Mission in 1992


Construction cost about Rs. 50,000


Principle:


Aeration (Gas transfer)


Oxidation


Precipitation


Sedimentation


Filtration