Baobab Trust
Water purification 2009
Deletre Emilie
emiliedeletre@laposte.net
+336 63 94 01 77
4A rue Marmontel
75015 Paris
France
Water purification
Baobab Trust
P. O. Box 10587 Bamburi 80101
Mombasa, Kenya
Tel. +254 41 2101000
Email: baobab.trust@bamburi.lafarge.com
www.thebaobabtrust.com
Emilie DELETRE supervised by Dr Haller
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Baobab Trust
Water purification 2009
Introduction
Water is necessary to life but it can be unhealthy too. In general, the water quality is
poor in developing countries like Kenya. Water is a vector of diseases like yellow fever,
diarrhea… Water purification is very important in these countries but people don’t have a
lot of time to spare, they work or they are in the field and in general women must spend a
significant amount of time walking to collect water. So we need to find a quick, easy, and
economic solution that is as simple as possible. Sure enough, the numbers are frightening:
 The World Health Organization has estimated that up to 80% of all disease and
sickness in the World is caused by inadequate sanitation, polluted water or
unavailability of water.
 Waterborne diseases contribute to the death of about 4 million children in the
developing countries every year.
 About 1.6 million people are forced to use contaminated water, this is because most
of the water sources are polluted with either industrial or domestic waste, thus unfit
for use.
But there are solutions:
 Sofowora (1982) reported that Africa has 300,000 medicinal plants and Chang
(1993) reported that the world mushroom biodiversity counts 1.5 million species.
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Summary
Abstract
1_ Prior knowledge
A) Bacteria
1) Salmonella
2) Shigella
B) Salmonella Shigella Agar
C) Moringa Oleifera a very useful tree
D) The solar disinfection with PET bottle
2_ Study of different methods to purify water
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Water purification 2009
A) Water filtration
1) Study of filtration system with simple and usual things
2) Study of flocculation with Moringa seeds
B) Water purification
0) Study about contamination possibilities of the sample
1) Study of power of Moringa to purify the water
2) Test in statistic samples for using of 120 Moringa seeds per liter
3) Study of temperature effect in water purification
4) Study the complementarily of Moringa and high temperature
5) Study of using PET bottle like in the SODIS method
6) Study of complementarily of PET bottle and Moringa seeds
8) Study of a new method with Moringa seeds
3_ Argumentation about the best method
A) Criter
B) Best method
References
Appendix
Abstract
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Water purification 2009
This report describes a project which has been done throughout an internship at Baobab
Trust, Mombasa Kenya.
This project concerns the water purification project. After having some prior knowledge,
several experiments have been presented. First, experiments carried out about water
filtration with simple tools and by using the flocculation power of Moringa seeds. Each
experiment explains the principle, the protocol and the results, when it’s necessary the
results are illustrated by photos. Second, experiments carried out about water purification
with Moringa seeds, PET bottles or the boiling method. To conclude, some discussions and
suggestions are given.
This project begins without any data because there isn’t any project on the way and no
student volunteers who worked about this project before.
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Water purification 2009
I_ Prior knowledge
A) Bacteria
We choice to study Salmonella and Shigella because these bacteria are very common in
rural areas and tropical countries and they are an important cause of diseases and child
mortality with diarrhea and dysentery.
1) Salmonella
Classical classification: Kingdom Bacteria
Class Proteobacteria
Sub-class Gamma Proteobacteria
Order Enterobacteriales
Family Enterobacteriaceae
Genus Salmonella
Species of inferior rank
Salmonella are entero bacteria, bacillus, Gram-, mobiles, facultative aéroanaérobies,oxydase -, nitrate réductase +, fermentation of glucose, lactose -, H2S +, uréase -,
lysine décarboxylase + , indole-, béta-galactosidase-.
These bacteria are very contagious, responsible for gastro-entérites, toxi-infections of
food and typhoid and paratyphoid fever.
Salmonella can survive several weeks in a dry area and several months in the water.
We can frequently find them in polluted aquatic environment; these environments are often
polluted by the feces of carrier animals in an important way. Aquatic vertebra like birds and
reptiles often bring salmonella. Poultry, cows, goats, and sheep frequently contaminate, we
can also find salmonella in meat and in eggs.
Human are infected via the digestive system after drinking polluted water or eating
contaminated food. Regardless of the species, the illness can be the yellow fever or a
diarrhea. The complications are not the same, a simple diarrhea for babies and children can
cause a very severe dehydratation.
To highlight Salmonella, there are several methods. We can use different kind of
gelatinous like Salmonella-Shigella gelatinous or shining green gelatinous with different
growth environment. We can do serodiagnostics too.
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The most simple method to fight against Salmonella or try to reduce their number is
just to survey the contaminated water, to eat healthy food and to survey and treat the
infected person.
2) Shigella
Classical classification : Kingdom Bacteria
Class Proteobacteria
Sub-class Gamma Proteobacteria
Order Enterobacteriales
Family Enterobacteriaceae
Genus Shigella
Specie of inferior rank
Shigella are entero bacteria, bacillus, no moving, gram-, uréase-, désaminase -,
lysine décarboxylase-, H2S-, and acétoïne- ; no use of citrate like one source of carbon on
the enironement of Simmons. They do not have spores and capsules. They can be alone or by
two or in chain.
All Shigella are pathogens and specific of the digestive system. They are responsible
for dysentery and diarrhea. Regardless of the species, the illness can be dysentery or a
diarrhea. In tropical countries, Shigella cause severe dysentery whereas in Europe, Shigella
cause only simple diarrhea. The complications are so not the same, dysentery for babies and
children is a very important cause of death.
Shigella are not a common flora in humans, they are eliminated by feces and spread
in soils and water where they do not survive a lot of time.
Human are infected by digestive way after drinking polluted water or eating
contaminated food by infected humans with feces on their hand.
To highlight Shigella, there are not a lot of methods. For instance the growth
environment does not exist as for salmonella. We can use different kind of gels. The gels can
be unselective like the ordinary gels or it can be selective like salmonella-shigella gels or
Mac Conkey gels. We can do serodiagnostics too.
The most simple method to fight against Shigella or try to reduce their number is just
to survey the contaminated water, to eat healthy food and to survey and treat the infected
person like for salmonella.
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B) Salmonella Shigella agar
For the experiments, we will use SS Agar (Salmonella Shigella Agar) of the HIMEDIA
laboratory. The formula in grams per liter is:
Peptic Digest of Animal Tissue.................................................5 g
Beef Extract...............................................................................5 g
Lactose....................................................................................10 g
Bile Salts Mixture....................................................................8.5 g
Sodium Citrate.........................................................................10 g
Sodium Thiosulfate.................................................................8.5 g
Ferric Citrate..............................................................................1 g
Brilliant Green..................................................................0.00033 g
Neutral Red.........................................................................0.025 g
Agar..........................................................................................15 g
Final pH: 7.0 ± 0.2 at 25°C
SALMONELLA SHIGELLA AGAR (SS AGAR) is a selective and differential medium
widely used in sanitary bacteriology to isolate Salmonella and Shigella. Beef Extract, and
Enzymatic Digest of Animal Tissue provide sources of nitrogen, carbon, and vitamins
required for organism growth. Lactose (Enteric organisms are differentiated by their ability
to ferment lactose) is the carbohydrate present in Salmonella Shigella Agar. To select the
bacteria, we use Bile Salts, Sodium Citrate and Brilliant Green which inhibit Gram-positive
bacteria, most coliform bacteria, and inhibit swarming Proteus spp., while allowing
Salmonella spp. to grow. Sodium Thiosulfate and Ferric Citrate permit detection of hydrogen
sulfide (H2S) by the production of colonies with black centers. Neutral Red is the pH
indicator. Bacteria like E. coli produces pink to red colonies and may have some bile
precipitation. To summarize,
Lactose+  red colony
Lactose-  colorless or yellow colony
H2S+  colony with black center
H2S- colony without black center
Bacteria
growth
Colony color
Salmonella
Good growth
Colorless to cream, usually with black center
Proteus
Slight growth
Colorless usually with black center
Shigella
Good growth
Colorless, cream to light pink
E. Coli
Partially inhibited small pink to rose-red colonies with precipitate
Enterobacter
Slight growth
Pseudomonas Slight growth
picture
Large cream to pink
irregular
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C) Moringa Oleifera, a very useful tree
Bark: grey, thick and corky, peeling in patches
Leaves: pale green, 30-60cm, leaflets oval, thrice
compound; tip rounded, 1-2cm long
Flowers: cream, long sprays, sweet-scented, fading
to yellow; attract insect
Fruit: long, hanging, stick like capsules; up to 45
cm in length; bluntly triangular in cross-section;
split when dry to release dark brown threewinged seeds from the pith.
The Moringa Oleifera has several names like horseradish tree describing the taste of
its root, drumstick (baguette, because of the shape of the pods) tree, Mlonge (lugu), Mzunze
(Swahili). It’s an exotic tree native to Northern India and Arabia which is now grown widely
through the tropics. It is commonly planted in well drained soil on the coast or at low
altitude (500m). Moringa grows rapidly from seed or cutting, and does well even in poor
soils. So to cultivating Moringa is really easy.
The Moringa oleifera tree has a lot of uses. The leaves and the crop can be eaten by
humans and contain 15-25% digest protein, Fe, Ca, K and vitamins. We can dry the leaves
and use like food complement. The seed is use to make oil for cosmetic, food, bio carburant,
and lubricant. The leaves, the young branch and the crop can feed the livestock. A regular
consummation of leaves can increase the production of milk.
The Moringa Oleifera tree can be used to purify water with the seeds reduced in
powder. Recent studies show that a protein part has an antibacterial action, antifungal and
antivirus, it is an antimicrobial peptide called FLO. This peptide affects the membranes of the
bacteria like antimicrobial peptide in the immune system. The interaction of positive charges
on the peptide with the negatively charged bacterial membrane may occur in a stabilized
context thereby leading to the interaction of a hydrophobic kink with the hydrophobic
interior of the membrane.
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D) The solar disinfection with Pet bottle
The solar disinfection, more famously known as SODIS is a new method to purify
water with the solar energy and a PET (p) plastic bottle. SODIS is a cheap and effective
method. The SODIS method is an environmentaly friendly option too.
The UV-A (320-400nm) interfere with the metabolism of bacteria and they destroy
the cell structures of bacteria. Furthermore, they react with oxygen dissolved in the water
and produce highly reactive forms of oxygen that damage pathogens. Researchers show that
the UV-A damage the respiratory chain of bacteria and then the polarization of the cell
membrane. The damages are so severe that the bacteria cannot repair them. So after the sun
exposure, there is no re-growth of bacteria. The infrared radiations heat the water so the
disinfection process is faster. Bacteria (cholera, dysentery, diarrhea, typhoid,…) are really
sensitive to the UV-A but viruses (polio, hepatitis, diarrhea,…) parasites (fever, diarrhea,
colic,..) are less sensitive, you need much more time to kill cysts of Gardia even ten hours.
The bottle form is not really well adapted because after ten centimeters the UV-A are
stopped and the height of the bottle is near ten centimeters, so placing a dark thing like a
black plastic bag under the bottle can improve and accelerate the process because the UV-A
ray of the sun can be reflected by the dark thing.
The use of the PET bottle is really simple, you just need to fill a clean PET bottle with
water and put the roof, preferably corrugated iron. In general after six hours exposure to
the sun, the majority of pathogenic microorganisms are killed and you can drink the bottle.
With more precisions, At a water temperature of about 30°C (86°F), a threshold solar
radiation intensity of at least 500 W/m2 (all spectral light) is required for about 5 hours for
SODIS to be efficient. When there are clouds you need a longer sun exposure time.
The SODIS method is applied at the household level and is recommended by the
World Health Organization as a viable method for household water treatment and safe
storage. This method is readily accepted by the population and they spend less time and
money purifying their water. A lot of projects are already developing in several developing
countries like in India, in Africa, and in Latina America. With these projects, we can see that
in these communities that the number of diarrhea cases among SODIS users shows
reduction values of 30-80%.
Certain people are afraid that chemical products migrate in the water during the sun
exposure but a lot of studies have researched this and concluded that there is not migration
or that the level is below the standard norm.
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II_ Study of different methods to purify water
The purification of water need to be separate in two parts, the first part is the
filtration to take out the particles to improve the taste, to make easier the second part. The
second step is the water purification; it is to say to kill pathogen microorganisms like
bacteria, virus, and parasite and to be not sick after
A) Water filtration
1) Test 1: Study of filtration system with simple and usual things
In general, the population of developing countries does not have a lot of resources, so
we need to find a system which use very simple tools and that we can find in a house. The
system need to be easy and fast or else people won’t do.
Principle: utilization of fine sand for filtering solid particles, the particles bigger than sand
will be withheld, the smallest particles will pass between the spaces left by the sand.
Protocol: Close the bottle with a piece of tissue and a rubber, fill in one third of the little
bottle with sand and filter the water.
Schema of filtration demonstration and details of filtration
Result: When the water is filtered, we can’t see particles without a microscope. The diameter
of the sand is 0.3mm in average (measured thanks to a microscope) so we can say that the
particles in the filtered water are smaller than 0.3mm.
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Picture of non filtered water (left) and filtered water (right)
2) Test 2: study of flocculation with Moringa seeds
In several articles, we can read that Moringa seeds can flocculate water particles so
the filtration can be easier after adding Moringa seed powder into the water.
Principle: When the water particles are flocculated by something they are bigger so their
sedimentation velocities are faster. In this way, we can see if the product has or not the
capacity of flocculation.
Protocol: Take two bowls and put into 250mL of water in each. Add 40 grams of the same
sample of soil. In one, add one spoon of dried Moringa seeds powder. Agitate the water of
the two bowls in the same time and observe the sedimentation.
Result:
Into the bowl on the right, we added dried Moringa seeds powder and not into the
bowl on the left. The little white particles in the right bowl are the dried Moringa seeds
powder.
At 0 minute
After 1 minute
After 3 minute
After 5 minute
After 10 minute
After 10 minute
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We can see a difference of the water color. Sure enough, the sedimentation velocity is
more important for the right bowl as the water is less dark than the left bowl. So we can say
that dried Moringa seeds powder has a flocculation capacity.
According to the literature, the proteins in the dried Moringa seeds powder are
charged negatively that’s why the particles flocculate. If we want to know exactly the
flocculation capacity of Moringa seeds, we need to compare the sedimentation velocity with
Moringa to the velocity sedimentation with chemical products whose the flocculation
capacity is known.
B_ water purification
Preparing of Petri dishes with Salmonella Shigella agar
Suspend 6.3 grams in 100ml distilled water. Heat to boiling with frequent agitation to
dissolve the medium completely. Cool to about 50°C. Mix well and pour into sterile Petri
plates.
0) Test 0: Study about contamination possibilities of the sample
Before doing the experiment you need to know if the conditions are accurate for your
experiments. The water for all experiments is taken in a fish pond where farmer animals
can drink and put their feces. This water is stagnant and so rich in bacteria and really dirty
with the mud and the fishes.
Principle: We want to demonstrate that the Petri dishes are not contaminated before
applying the sample, so we leave the Petri dishes and if no bacteria growth the medium is
valid.
Protocol: Two Petri dishes were left without sample. Took two other Petri dishes and applied
dirty water without treatment.
Results:
Without water, sample1
Without water, sample 2
Emilie DELETRE supervised by Dr Haller
With dirty water sample1
With dirty water sample 2
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We can conclude that general conditions of experiment are good because we don’t
have contaminations when we put nothing in Petri dishes. The black stains seem to be fungi
or the coloration of bacteria by the medium. So we could have a problem for the next
experiment because if we see a lot of fungi in the Petri dish with a sample of dirty water, this
mushroom could inhibit the growth of bacteria or hide the bacteria or if we see bacteria we
can have dilution problem and what kind of water we will use.
To answer of these questions, take these organisms and dilute the sample. Look at the
growth of organism and the form to know if it is bacteria or fungi.
Repiquage of precedent organisms
With this circular form, we can say these organisms are bacteria so we could have
problem of dilution for the next experiment. So to result this problem of dilution the critter
for the conclusion will be only qualitative and no qualitative.
For the control of the next experiments, we make a Petri dish with water without
treatment to see if there are bacteria in the water sample used for the experiment and
another Petri dish with water treated by aqua tabs to see what species of bacteria we take
them into count to say if the water is drinking. We can see in the continuation of this report
that there are only small white colonies in the Petri dish of aqua tabs. So we admit the
principle that we do not take this kind of colonies into count to say if the water is drinking
since with an aqua tabs pill, the water is drinking.
1) Test 1: study of power of Moringa to purify the water
We chose to study the Moringa because Kenyans think that the Moringa is a plant
which can purify the water. They use still today the Moringa to purify the water. It is
therefore an interesting plant to investigate. I was shown the local way of using Moringa
and will use this method for the experiments to see if this treatment works or not.
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Principle: We want to demonstrate that the Moringa tree has properties to purify the water.
We put different quantities of Moringa seed powder in the water and after we tried to grow
bacteria to demonstrate their presence or their absence.
Protocol: Take 15, 30, 60, 120 Moringa seeds (30 seeds = 15 grams). Take a crop of
Moringa, take out the brown protective cover and reduce the white seeds to powder. Put the
powder in the bottle, fill two thirds of the bottle of 1.5 liter in filtered water and agitate.
After waiting two hours, filter the water with a piece of fabric. Take two water samples in
bottles and pour them in prepared Petri dishes. For the control, take a water sample of non
treated water, pour it in prepared Petri dish and take one liter of filtered water, put in an
aqua tab (medicine to purify the water) and shake the bottle. Take a water sample in this
bottle and pour it into the prepared Petri dish.
Results
Essay 1
Water sample treated
Water sample treated
Water sample treated
Water sample treated
Water sample
with 15 seeds
with 30 seeds
with 60 seeds
with 120 seeds
without treatment
Water sample treated
Water sample treated
Water sample treated
Water sample treated
Water sample treated
with 15 seeds
with 30 seeds
with 60 seeds
with 120 seeds
by aqua tabs
Essay 2
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Water sample
Water sample treated
Water sample
Water sample treated
Water sample
treated with 15 seeds
with 30 seeds
treated with 60 seeds
with 120 seeds
without treatment
Water sample
Water sample treated
Water sample
Water sample treated
Water sample
treated with 15 seeds
with 30 seeds
treated with 60 seeds
with 120 seeds
treated by aqua tabs
With 60 seeds the number of bacteria decreases of noticeably manner. With 120
seeds quasi all bacteria are killed, but we can see one or two colonies of bacteria. So the
quality of water is better but it can stay pathogen bacteria so we can’t say the water is
drinking and safe. We could do an experiment with a statistic number of samples to know if
the few colonies are due to at random or if the Moringa seeds are really effective.
We need to notice that this water can’t be preserved because after few days the seeds
ferment and the smell prevent the consummation.
2) Test 2: statistic test for using of 120 Moringa seeds per liter
We need to do an experiment with a statistic number of samples to know if the few
colonies, found in the last experiment, are due to at random or if the Moringa seeds are
really effective.
Principle: A statistic sample counts thirty samples. With thirty water samples we can say that
there is no round and we can do average and conclude about the efficiency of Moringa seed
powder.
Protocol: Make the same protocol that for the test 1 but take 30 bottles for 30 samples with
120 seeds of Moringa reduce in powder in each bottle. For the control, take a water sample
of non treated water, pour it in prepared Petri dish and take one liter of filtered water, put
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an aqua tabs and shake the bottle. Take a water sample from this bottle and pour it in
prepared Petri dish.
Result
samples After 24h
After 30h
1
notes
O1818 18
N
2
N
19
N
3
N
20
O
4
O
21
O
5
N
22
O
6
N
23
N
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7
O
24
N
8
N
25
O
9
N
26
O
10
N
27
N
11
O
28
O
12
N
29
N
13
N
30
O
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Water purification 2009
N
Without
O
treatment
1
15
N
Without
O
treatment
2
16
N
17
N
Aquatabs
N
We can see that the samples 1, 4, 7, 11, 20, 21, 22, 25, 26, 28, and 3o involve pathogen
bacteria. So eleven samples on thirty involve that the water is not safe, even if in general the
number of bacteria decreases compared with the number of bacteria in the water sample
without treatment. So in 36,6 % of cases it stay pathogen bacteria, this is can’t due to only at
random. We can conclude that the Moringa seeds decrease only the number of bacteria and
sometimes the number decrease up to zero.
The water is not suitable to drinking water, it’s not completely safe but the quality of
the water is better.
3) Test 3: study of temperature effect in water purification
A lot of populations boil water to purify the water and this method is really famous
in lot of countries.
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Principle: We want to demonstrate that the high temperatures kill bacteria thus purifying
the water. We want to boil the water for different lengths of time during different to see if
the time of heating is related to a decrease in the number of bacteria.
Protocol: After filtering the water, boil one liter of water. Take a sample of water after 1, 2, 5,
and 10 minutes of ebullition and pour them into prepared Petri dishes. For the control, take
a water sample of non treated water, pour it in prepared Petri dish and take one liter of
filtered water, put an aqua tabs and shake the bottle. Take a water sample from this bottle
and pour it in prepared Petri dish.
Results
Water sample after Water sample after Water sample after Water sample after
1min of ebullition
2min of ebullition
5 min of ebullition
10min of ebullition
Water sample
treated by aqua tabs
We can see that boiling water for just one minute is effective. We arrive at the same
level of water quality as using the medicinal aqua tabs. So we can conclude that the dirty
water is suitable for drinking water after one minute of ebullition.
4) Test 4: study the complementarily of Moringa and high temperature
For the next experiment, the Moringa seeds can be heated so we want to see how the
Moringa seeds are after high temperature and if the Moringa seeds prevent the high
temperature to kill bacteria.
Principle: We wanted to see if using the two methods together would obtain better results.
So the best results obtained with Moringa seeds are with 60 and 120 seeds and the best
results for high temperature are with a time of 1 second and 1 minute. We have four cases:
60seeds-1second, 60seeds-1minute, 120seeds-1second and 120seeds-1minute to see if
there is any interactions. Furthermore, we can see if the smell and the taste remain as good if
the Moringa seeds are baked.
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Protocol: Repeat the Moringa protocol (test 1) of with 60 or 120 seeds but before taking
water samples, boil the water for 1 second and 1 minute. For the control, take a water
sample of non treated water, pour it in prepared Petri dish and take one liter of filtered
water, put an aqua tabs and shake the bottle. Take a water sample from this bottle and pour
it in prepared Petri dish.
Results
Water sample for
Water sample for
Water sample for
Water sample for
Water sample
60seeds-1second
120seeds-1second
60seeds-1minute
120seeds-1minute
without treatment
Water sample for
Water sample for
Water sample for
Water sample for
Water sample
60seeds-1second
120seeds-1second
60seeds-1minute
120seeds-1minute
treated by aqua tabs
We can see that this method is effective just after one second of boiling. The smell
and the taste are good even after Moringa seeds boiling.. The Moringa powder becomes like
the white baked egg when the water boils.
5) Test 5: study of using PET bottle like in the SODIS method
There are several articles about SODIS (solar disinfection) so we can perform
experiments using this knowledge:
“Complete inactivation of total Coli forms was observed in 6h when solar radiation
exceeded 500W/m2. Moderate turbidity did not reduce the inactivation efficiency, but
slightly enhanced it. No regrowth of microorganisms was observed after 24h following solar
disinfection.”
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“The effect of SODIS on two important entheric pathogens, Shigella flexneri and Salmonella
typhimurium. The respiratory chain of enteric bacteria was identified to be a likely target of
sunlight and UVA irradiation. Futhermore, during dark storage after irradiation, the
physiological state of the bacterial cells continued to deteriorate even in the absence of
irradiation: apparently the cells were unable to repair damage. Storage of bottles after
irradiation does not allow regrowth of inactivated bacteria cells.”
Principle: Take water samples at different hour in the PET bottle to see if the recommended
time is good and if the PET bottle is effective.
Protocol: Put water into the PET Bottle. Put the bottle under the sun on a dark thing like a
black plastic bag to reflect better the sun. Then take samples after 4h, 5h, 6h, and 7h of
exposure to the sun. For the control, take a water sample of non treated water, pour it in
prepared Petri dish and take one liter of filtered water, put an aqua tabs and shake the
bottle. Take a water sample from this bottle and pour it in prepared Petri dish.
Result:
Water sample after
Water sample after
Water sample after
Water sample after
Water sample without
4h of sun exposure
5h of sun exposure
6h of sun exposure
7h of sun exposure
treatment
Water sample after
Water sample after
Water sample after
Water sample after
Water sample
4h of sun exposure
5h of sun exposure
6h of sun exposure
7h of sun exposure
treated by aquatabs
We can see after 6h of sun exposure all salmonella and shigella are killed so PET
bottles are effective after 6h for these bacteria. Just after the exposure we can’t drink directly
the water because the water is warm even hot, you need to put in shade few time before
drinking.
6) Test 6: study of complementarily of PET bottle and Moringa seeds
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In an article we can read this sentence: “This research show that a number of lowcost additives are capable of accelerating SODIS. These additives included 100-1000mM
hydrogen peroxide, 0.5-1% lemon and lime juice, and copper metal or aqueous copper plus
ascorbate, with or without hydrogen peroxide.” So if we put Moringa seeds in PET bottle, the
process can be accelerated.
Principle: Put Moringa seeds in the PET bottle and we can take water sample before the
effective time to see if the Moringa seeds accelerate the purification process.
Protocol: Put 60 and 120 Moringa seed reduced in powder in each PET bottle. Put water into
the PET Bottle. Put the bottle under the sun. After 5h and 6h (the effective time)sun exposure
take sample into each PET bottle and filter this sample before pouring them in prepared Petri
dishes. For the control, take a water sample of non treated water, pour it in prepared Petri
dish and take one liter of filtered water, put an aqua tabs and shake the bottle. Take a water
sample from this bottle and pour it in prepared Petri dish.
Result:
Test 1
Water sample with
Water sample with
Water sample with
Water sample with
Water sample
60 seeds after 5h
120 seeds after 5h
60 seeds after 6h
120 seeds after 6h
without treatment
sun exposure
sun exposure
sun exposure
sun exposure
Water sample with
Water sample with
Water sample with
Water sample with
Water sample treated
60 seeds after 5h
120 seeds after 5h
60 seeds after 6h
120 seeds after 6h
by aquatabs
sun exposure
sun exposure
sun exposure
sun exposure
Test 2
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Water sample with
Water sample with
Water sample with
Water sample with
Water sample
60 seeds after 5h
120 seeds after 5h
60 seeds after 6h sun
120 seeds after 6h
without treatment
sun exposure
sun exposure
exposure
sun exposure
Water sample with
Water sample with
Water sample with
Water sample with
Water sample
60 seeds after 5h
120 seeds after 5h
60 seeds after 6h sun
120 seeds after 6h
treated by aquatabs
sun exposure
sun exposure
exposure
sun exposure
Test1: we can see that there was a problem of sterility. Sure enough the Petri dish
with the water sample treated by aqua tabs is contaminated because there are the black
bacteria that we consider like pathogen which are normally destroy by the medicine. So we
can conclude nothing for this test because of this problem. We need to make again the
experiment.
Test 2: we have again a problem of sterility for one bottle (120seeds-5h) otherwise we can
conclude for the other samples that the Moringa seeds accelerate the process since soon as
5h with 60 seeds the water seems to be without pathogen bacteria. Just as with 120 seeds
after 5H of exposure we can’t see pathogen bacteria.
We can conclude that to add Moringa seeds in PET bottle accelerate the process, thus
we can win one hour. But we need to spend time to reduce the Moringa seeds in powder
whereas when the bottle stays one hour in more on the sun, we can spend our time
somewhere else.
7) Test 7 : study of a new method with Moringa seeds
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The literature describes another method to use the Moringa seeds, different than the
use uses by the Kenyan people. This method could permit to purify bigger quantity water
than the other method and the user could spend less time at this activity.
Principle: Take water samples to see if this new use is effective or not to kill bacteria.
Protocol: Take 100 seeds of Moringa cut them in little pieces and place them any sun to dry
them during two days or until they are dried after reduce them in little powder. It’s really
easy because the Moringa seeds break down in powder almost without helping. Take ¼ litre
of filtered water and add into the bottle two spoons of dried Moringa seeds powder. Shake a
little and filter. Add the filter into 20L of water. Shake a little and wait for taking water
samples 10 minutes. This water is normally purified.
Result:
Water sample
Water sample
Water sample
Water sample
Water sample
treated by aqua tabs
without treatment
treated by Moringa
treated by Moringa
treated by Moringa
seed powder
seed powder
seed powder
We can see that there are pathogen bacteria in the water treated by dried Moringa
seeds powder whereas there are not pathogen bacteria in the Petri dish with the water
sample treated by aqua tabs. So this new use of Moringa seeds is not efficient.
Maybe that when we put the Moringa seeds powder on the sun, the efficient
molecular is destroyed by the sun so the bacteria are not killed.
III_Argumentation about the best method
A) Critters
Remind us the future users of these different methods are poor populations of
developing countries so for our critters we need to take their social and economic level and
their environment.
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All kept critters are kills germs, taste, ease of use, used tools, cost, adequacy of water
supply, and time. We want to see the efficiency of the method with killed germs but not
only. The taste is important because if the taste is bad populations prefer drinking dirty
water. The method need to be easy or else populations don’t do the method or not in whole.
The tools need to be very simple and used every day because in general these poor
populations do not have lot of things only the usual thing. The cost is very important
because in general poor populations drink very dirty water and they do not have enough
money to buy mineral water or chemical products like chlorine to purify their water. Their
waters are not current; in general women walk a long time before taking water in a little
pond and their days are already busy for the others chores so they do not have a lot of time
to spend for purifying the water.
B) Best method
Summarize the different methods in a board and classify them to know which one is
the best.
Kills germs
taste
Ease of use
Used tools cost
Adequacy of water supply
time
total
Moringa 1
3
2
3
2
1
2
3
16
Boiling
1
4
2
4
4
4
4
23
Pet bottle
2
1
1
1
3
3
1
12
Moringa 2
4
3
4
3
1
1
2
18
The SODIS method with the Pet bottle seems to be the best. This method kills all
studied bacteria. It does not improve the taste but it is not worse too. The use and the tools
are really simple and the preparation time is really short you can do your other and forget
your bottles and they finished the water is purify. The cost is really cheap because one bottle
costs only 15-20 Ksh for a bottle of two liters. The biggest problem is to supply the bottles in
very far and isolate village but they can get the bottle themselves by going in a shop. In more
you cannot purify a big quantity of water but it is enough for all the household drinking
water needs.
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The biggest problem of the boiling method is its cost because it is really expensive. In
more you cannot purify a big quantity of water. The water taste is worse, the smoke from the
fire give the water a bad taste. You need a lot of time for doing this method because you
need to go and collect a lot of firewood. But this method is really efficient for killing
bacteria.
The Moringa methods are really cheap and we do not spend a lot of time for these
methods. The biggest problem for these method is that the first on is not completely efficient
for killing bacteria and the second one is not efficient. Moreover, the taste is really bad after
few days because the seeds ferment but at the beginning the taste of the water is a vegetable
taste so it’s a little better. With the first method you cannot purify a big quantity of water
instead of the second one.
Conclusion
At the beginning my research relies on the use of Moringa Oleifera to purify water.
In the course of my research, I find a better method for purifying water: the SODIS method.
But Moringa Oleifera is a very useful plant for feeding animals and humans. The research
about a plant which can purify water is not a lost cause because some other plants like
Jatropha curcas, Hibiscus Sabdariffa, and Sclerotium of Pleurotus tuberregium are really
promising.
What could still be done by another student volunteer, it’s a study about the water
purification capacity of Jatropha Curcas because we can find this plant in the communities.
Sure enough, this plant has other properties. For instance, the green leaves can cure the skin
diseases of animals and the seeds can produce a kind of parafine.
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All results are not really reliable because they are not carried out in a sterile
laboratory. The conditions of sterility were precarious.
References
Bacteria
1) universite de laval, faculte des sciences et de genie, 2007,
www.gch.ulaval.ca/agarnier/bcm20329/lab1.gif
2) Pascal Fraperie (2007), lycée Saint Louis, Bordeaux, France
www.geniebio.ac-aix-marseille.fr/biospip (Espace collaboratif en
biotechnologies, Informations et Ressources Numériques en Biochimie Génie
Biologique)
3) (2003) Salmonella and Drinking Water from Private Wells,
www.cdc.gov/ncidod/dpd/healthywater/factsheets/pdf/salmonellosis.pdf
4) Salmonella, www.wikipedia.org/salmonella
5) Shigella, www.wikipedia.org/shigella
agar
6) BD Diagnostic system, (2005) Mode d’emploi - milieux en boite de petri prets à
l’emploi http://www.bd.com/ds/technicalCenter/inserts/SS_Agar.pdf
7) BBL™ Salmonella Shigella Agar//Hektoen Enteric Agar, SS Agar • Salmonella
Shigella Agar, 494-495, www.bbl.com/ssagar.pdf
8) Gélose SS, www.wikipedia.org/wiki/Agar-agar
9) Conda, Pronasia, SALMONELLA SHIGELLA AGAR (SS AGAR)
www.condalab.com/pdf/1064.pdf
10) Acumedia, SALMONELLA SHIGELLA AGAR (7152)
www.neogen.com/Acumedia/pdf/ProdInfo/7152_PI.pdf
11) Gélose SS (Salmonella-Shigella),
www.biologiemarine.com/qiabi/fiche/milieu%20SS.pdf
aquatabs
12) Aquatabs (2005), http://www.aquatabs.ca
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13) Sovedis, Liberta communication, Cécile Bélonie, (2008), L’eau, les voyageurs et
les infections, http://www.sovedis-aquatabs.com/presse/2/fr_journal2.pdf
moringa
14) Florian Flish, Mougli Suarez, Nicolas mermod (2004), Flo antibacterial peptide
from the tropical tree Moringa oleifera: A template for novel antibacterial
agents, Lausane university, www.moringanews.org/documents/flo.pdf
15) Mougli Suarez, Marisa Haenni, Ste´phane Canarelli, Florian Fisch, Pierre
Chodanowski, Catherine Servis, Olivier Michielin, Ruth Freitag, Philippe
Moreillon, and Nicolas Mermod (2005), Structure-Function Characterization
and Optimization of a Plant-Derived Antibacterial
Peptide,www.aac.asm.org/cgi/reprint/49/9/3847.pdf
16) Kenneth Anchang Yongabi, Studies on the potential use of Medicinal Plants and
Macrofungi (Lower plants) in water and waste water purification. FMENV/ZERI
Research Centre, Abubakar Tafawa Balewa University,
www.biotech.kth.se/iobb/news/kenneth04.doc
17) Jean Michel Dupont, (2006), LE MORINGA, MORINGA OLEIFERA, UN ARBRE
TROPICAL AUX MULTIPLES USAGES ,
www.phytomania.com/phyto/moringa-oleifera.htm
18) Najma Dharani, (2002), Field guide to common trees & shrubs of east Africa,
Shruik, 320: 130-131
Sodis
19) Site sodis,(2009), www.sodis.fr
20) Solar water disinfection,
http://fr.wikipedia.org/wiki/SODIS_D%C3%A9sinfection_Solaire_de_l%27Eau
21) Franziska Bosshard, Michael Berney , Michael Scheifele, Hans-Ulrich
Weilenmann and Thomas Egli, (2007), Solar disinfection (SODIS) and
subsequent dark storage of Salmonella typhimurium and Shigella flexneri
monitored by flow cytometry, www.mic.sgmjournals.org/cgi/content/full.doc
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Appendixes
1)System of water filtration
2)Observation of black particles of dirty water kept
back by the white
sand
3)Board of open field day the 14th October 2009 :
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2) Sight of Moringa powder
3) Moringa functionally
=
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4) SODIS functionally
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