Note: Descriptions are shown in the official language in which they were submitted.
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COMPOSITION FOR USE IN WATER TREATMENT
FIELD OF THE INVENTION
This invention relates to a water treatment composition, a method of
preparing it, as well as to methods of treating a body of water and inhibiting
the growth of a microbe in a body of water.
BACKGROUND TO THE INVENTION
Clean water is, and will continue to be, in great demand. The supply and/or
quality of the water in many storage dams and lakes is, however, currently
under threat due to increasing human population, urbanization, as well as
chemical and microbiological pollution. Furthermore, most rural communities
in developing countries do not have access to potable running water and
adequate sanitation facilities and so make use of watercourses for defecation
and urination.
The pollution of water bodies has become a serious environmental problem.
Contamination of fresh water bodies with untreated human sewage or
livestock excrement leads to an increase in the levels of microbial pathogens
such as E. coil, hepatitis and cholera. Moreover, urban storm water and
water carrying excess agricultural fertilizers into our water systems leads to
increased levels of nutrients such as phosphates and nitrates. Such
increases in biomass and nutrients result in what is known as eutrophication.
Depending on the degree of eutrophication, subsequent negative
environmental effects such as anoxia and severe reductions in water quality,
fish, and other animal populations may occur.
The process of eutrophication in fresh water bodies generally promotes
excessive plant growth and decay, favours the growth of certain weedy plant
species over others, and may cause a severe reduction in water quality. In
CONFIRMATION COPY
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aquatic environments, enhanced growth of choking aquatic vegetation (e.g.
water hyacinth) or phytoplankton and/or cyano bacteria (e.g. algal blooms)
disrupts normal functioning of the ecosystem, causing a variety of problems
such as a lack of oxygen in the water needed for original habitat plants, fish
and shellfish to survive, with a concomitant increase in invasive, often toxic
species. Algal blooms in turn limit the sunlight available to bottom-dwelling
organisms, limiting photosynthesis at lower water levels and further
decreasing the amount of available oxygen. The death of the naturally-
occurring fish and plant species further increases biomass and nutrients
upon which decomposing bacteria feed, resulting in a further decrease in
oxygen levels. Ultimately, the water becomes cloudy, changes colour to a
shade of green, yellow, brown, or red; and develops an unpleasant odour.
Eutrophication is also a common phenomenon in marine, coastal waters. In
contrast to freshwater systems, nitrogen is more commonly the key limiting
nutrient of unpolluted marine waters. Estuaries tend to be naturally eutrophic
as a result of the concentration of land-derived nutrients where run-off
enters
the marine environment in a confined channel. This process is, however,
exacerbated in the presence of pollution and contamination.
Eutrophication negatively effects farming and constitutes a health hazard.
Eutrophication of fresh water bodies complicates, and in some cases even
prevents the agricultural use of water for irrigation purposes, clogs up water
systems and may even limit the farmer's export ability as it may cause
contamination of ground water that may be transferred into crops.
Euthrophication of marine, coastal waters negatively affects fish and other
marine animal farming industries directly. Furthermore, human contact with
these algal blooms may cause illness, such as hay fever, skin rashes, eye
irritations, vomiting, gastroenteritis, diarrhoea, fever and pains in muscles
and joints.
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Current clean-up measures include removal of polluted sediment and water,
in vitro treatment of the sediment and/or water for the removal of the
pollutants contained therein, and then optionally returning the clean sediment
and/or water to the environment. This method is, however, disruptive,
expensive, and is not well suited to addressing remediation of the ecology of
the water environment. Other treatments include stepwise release of desired
bacteria into the environment capable of digesting the pollutants. The long
term environmental effects resulting from the release of such foreign live
organisms into the environment are, however, unpredictable and in many
cases undesirable.
There is therefore a need for an environmentally-friendly composition and
method of treating and rehabilitating eutrophic water in situ.
In the remainder of this specification the term "extract" shall have its
widest
meaning and shall include any substance made from a raw material or part
thereof, in this case plants or plant material, and may include essential
oils,
infusions, emulsions, suspensions, distillates and the like in liquid, solid,
powder or other suitable forms.
OBJECT OF THE INVENTION
It is an object of this invention to provide a composition and method of
treating and rehabilitating eutrophic water in situ which will at least
partially
alleviate some of the abovementioned problems.
SUMMARY OF THE INVENTION
In accordance with this invention there is provided a water treatment
composition comprising
(a) an extract from at least one plant belonging to the genus
Eucaluptus;
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(b) an extract from at least one plant belonging to the family
Poaceae; and
(c) an extract from at least one plant belonging to the genus
Carpobrotus;
the composition being in a form suitable for addition to water bodies for the
treatment and prevention of eutrophication.
Further features of the invention provide for the plant of the genus
Eucaluptus to be Eucaluptus globules and for the plant of the genus
Carpobrotus to be one or more of Carpobrotus edulis (P); Carpobrotus edulis
Carpobrotus edulis (1/40, wherein P indicates pink flowers, Y indicates
yellow flowers, and W indicates white flowers; for the composition to include
an extract from at least one of a plant from the genus Aloe and a plant from
the genus Sutherland/a, and for the plant of the genus Aloe to be Aloe ferox
and for the plant of the genus Sutherlandia to be Sutherlandia Fructecens.
Still further features of the invention provide for the water treatment
composition to be prepared from the leaves and/or stems of the plants; and
for the extracts to be prepared using a solvent, preferably water.
The invention also provides a method of preparing a water treatment
composition suitable for addition to water bodies for the in situ treatment
and
prevention of eutrophication thereof, the method including the steps of
(d) preparing an extract from at least one plant belonging to the
genus Eucaluptus;
(e) preparing an extract from at least one plant belonging to the
family Poaceae;
(f) preparing an extract from at least one plant belonging to the
genus Carpobrotus; and
(g) combining the extracts.
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Further features of the invention provide for the plant of the genus
Eucaluptus to be Eucaluptus globulus and for the plant of the genus
Carpobrotus to be one or more of Carpobrotus edulis (P); Carpobrotus edulis
(Y); and Carpobrotus edulis (1/40, wherein P indicates pink flowers, Y
5 indicates yellow flowers, and W indicates white flowers.
Still further features of the invention provide for the method to include the
step of preparing the extracts from one or both of the leaves and stems of the
plants using a suitable solvent, preferably water; for step (a) to include
processing plant material of the plant into particulate form and suspending it
in water in a ratio of about 1 part plant material to 25 parts water; for step
(b)
to include processing plant material of the plant into particulate form and
suspending it in water in a ratio of about 3 parts plant material to 100 parts
water; for step (c) to include processing plant material of the plant into
particulate form and suspending it in water in a ratio of about 1 part plant
material to 3 parts water; for step (a) and/or step (b) to include heating the
water and plant material suspension to about 55 C, cooling the suspension
and straining the suspension; and for step (d) to include combining about 1
part of the extract obtained in step (a), about 1 part of the extract obtained
in
step (b) and 1 to 1.5 parts of the extract obtained at step (c) with about 5
parts water.
Yet further features of the invention provide for the method to include the
steps of
(e) preparing an extract from at least one plant belonging to the
genus Aloe;
(f) preparing an extract from at least one plant belonging to the
genus Sutherland/a; and
(g) combining the extracts so obtained with the composition.
Further features of the invention provide for the plant in step (e) to be Aloe
ferox; for the plant used in step (f) to be Sutherlandia Fructecens; for step
(e)
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to include producing dried crystals from juice drained from the leaves of the
plant; for step (e) to further include burning the juice to form crystals; for
step
(f) to include processing plant material of the plant into particulate form
and
suspending it in water or water treatment composition in a ratio of about 1
part plant material to 200 parts water or water treatment composition.
The invention still further provides a method of treating a body of water in
order to reduce or prevent eutrophication comprising administering to the
body of water a water treatment composition as described above by spraying
the composition on the surface of the body of water or adding the
composition to the body of water. The method may include administering
about 1 part of the water treatment composition for about every 2,000,000
parts of the body of water to the body of water.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment of the invention, 25 litres of a water treatment
composition in accordance with the invention is prepared for a body of water
of approximately 50 mega litres. This implies a ratio of about 1 part water
treatment composition to 2,000,000 parts of water to be treated. The body of
water typically requires treatment as result of, for example, algal bloom
conditions such as the growth of blue-green algae. In such a situation, an
extract of Eucalyptus globulus is first prepared by suspending 20 litres of
the
leaves of the plant in 500 litres of water. It is preferred to measure the
plant
material by volume rather than weight, as a difference in water content in the
plant material may lead to incorrect weight measurements.
15 litres of leaves and/or stems from a plant belonging to the family Poaceae
is then separately processed into particulate form and suspended in 500
litres of water. It should immediately be appreciated that the processing step
may involve any suitable means including cutting, shredding, pulverising,
macerating, grating, grinding, chipping, or any other suitable means.
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An extract of either Carpobrotus edulis (P); Carpobrotus edulis (Y); or
Carpobrotus edulis (W) is then prepared by processing 500 millilitres of
leaves and/or stems into particulate form and suspending it in 1.5 litres of
water. The abbreviation P indicates that the plant has pink flowers, Y
indicates that the plant has yellow flowers, and W indicates that the plant
has
white flowers.
The Eucaluptus globulus and Poaceae suspensions are then separately
heated to 55 C, cooled, and strained. The Carpobrotus edulis suspension is
not heated but is simply left in suspension for approximately 8 hours and then
strained. The water treatment composition is then prepared by mixing
together 5 litres of the Eucaluptus globulus extract, 5 litres of the Poaceae
extract, and between about 5 and 7 litres of the Carpobrotus edulis extract.
Finally the mixture is topped up to 25 litres with water. The 25 litre water
treatment composition is then added directly to the water body and allowed to
mix into the standing water under environmental conditions. The water
treatment composition of the invention is intended to be added to a water
body requiring treatment in situ. It is, however, anticipated that
compositions
in accordance with the invention may also be used extraneously.
A second embodiment of the invention is provided for use if the body of water
to be treated contains unacceptable levels of pathogens such as E. co/i. In
such a case, two further extracts are added to the water treatment
composition before it is topped up to 25 litres with water. Firstly, an
extract
from the leaves of Aloe ferox (Group Monocot) is prepared by producing
crystals from an extract of the juice which is leached or drained from the cut
off leaves of the plant. The juices are first burned according to standard
techniques and the resulting lumps are broken up to produce the crystals.
The dry crystals are used in the ratio of 1 tablespoon of crystals to 25
litres of
water or 25 litres water treatment composition, depending on whether it is
first mixed with water or added directly to the composition.
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A second extract is prepared from the leaves and/or stems of Sutherlandia
Fructecens (Group Monocot) by processing 125 millilitres of plant material of
the plant into particulate form and suspending it in 25 litres of water, and
similarly heating, cooling and straining the suspension. One tablespoon of
the Aloe ferox extract and 125 millilitres of the Sutherlandia Fructecens
extract is then added to the water treatment composition of the invention.
Before treatment, the body of water is typically eutrophic. Upon addition of
the water treatment composition to the water body, ongoing flocculation is
almost immediate induced which reduces the total amount of suspended
solids in the water. Levels of dissolved oxygen are observed to increase,
sometimes up to 80%, and levels of ammonia are observed to decrease,
facilitating the growth and metabolism of desirable microorganisms. The
anaerobic state of the water is therefore addressed by use of the water
treatment composition, as the dissolved oxygen and nitrogen levels of the
water are substantially restored. A decrease in the mosquito population
resident in and around the water body under treatment is also often
observed.
The level of restoration is typically estimated by determining the degree of
survival of environmentally-sensitive larvae eggs such as Daphnia eggs.
Daphnia are small, planktonic crustaceans, between 0.2 and 5 mm in length
and are used in certain environments to test the effects of toxins on an
ecosystem. This makes Daphnia an indicator species, particularly useful in
that area because of its short lifespan and reproductive capabilities. In the
experiments, samples of water under treatment are placed in tanks to which
Daphnia eggs are added. The growth and reproduction of the Daphnia are
observed and noted as indicative of the restoration of the water body. A
decrease in mosquito larvae growth and reproduction was noted when the
samples of water under treatment were placed in tanks.
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The following examples illustrate the use of the composition in accordance
with the invention.
EXAMPLE 1: UILENKRAAL
In this experiment, two ponds at a feedlot located at Uilenkraal, in Darling,
Western Cape, South Africa were treated. The two ponds having a combined
volume of approximately 57.3 million litres were in a highly polluted state,
having contained therein run-off effluent from a dairy farming facility. The
ponds therefore contained raw cow-dung and over time had become rotten
and eutrophic, with bad odour, floating debris, and obvious fermentation
(bubbling).
Upon addition of 50 litres of the first water treatment composition described
above, oxidation was immediately observed. Within a week of adding the
composition, the boiling effect stabilized and the pungent smell was no longer
detectable. The contents of the pond were suitable for use as a fertilizer for
irrigation. An automatic dosing system is now being installed on the farm.
Birdlife was also seen to increase around the ponds.
EXAMPLE 2: KOI FISH
Approximately 300 Koi fish, each having a length of about 150 to 200 mm,
were kept in a 5000 litre body of water of about 800 mm deep for 6 months.
The fish were fed three times a day. The water was not changed during the
duration of the experiment, and the addition of water was limited to topping
up of the water to compensate for evaporation. The filter system used
comprised a 200 litre plastic container having filter sand at the bottom which
was covered by a layer of gravel. The water was circulated by pumping from
the bottom of the body of water to the top at about 800 litres per hour. 500
millilitres of the water composition of the invention was added to the body of
water every week.
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After 6 months, the ammonia levels were measured using standard
techniques, and were found to be 0.01 millilitres / litre, while the nitrites
were
0.02 millilitres / litre. Under normal circumstances the ammonia and nitrites
5 would have been very high, in the region of 6+ and fish would have died
as a
result. Fish are typically already endangered at levels of 0.05.
EXAMPLE 3: PANORAMA
10 In this experiment, a 2060 mega litre (about 26 hectares) dam was
treated
with 50 litres of the water treatment composition of the invention. The dam
was located in Riebeeck Kasteel on the farm Panorama, South Africa, and
was in a eutrophic state. There was rotten algal scum in the dam and the
water was turbid.
Within 4 days of the composition being sprayed onto the surface of the dam
from a boat, the rotten algal scum had decreased and the water had become
clear.
EXAMPLE 4: WELGEVONDEN
The Welgevonden farm irrigation dam in Riebeeck Kasteel, South Africa was
treated. Before treatment, brown algal problems and E. coli contamination of
about 200 counts per million was reported. After treatment, E. coli
contamination was not detectable.
EXAMPLE 5: WELGEVALLEN
University Stellenbosch Aqua culture department
The treatment of dams in Welgevallen, South Africa was conducted. Two
dams, experiment and control, each of 50 000 litres were set up under
standard supervision, and allowed to ripen to a rotting state by adding old
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rotting vegetables leaves to it during the summer season. One dam was
treated with the first water treatment composition described above, and the
other was left untreated. Fish stocks were placed in both dams.
Before treatment, algae were observed to be rapidly growing in the water.
The dam also exhibited a pungent smell. Constant aeration of the dam was
required. In addition, the treated dam had no filter system and had to rely
only on aeration, while the control dam had both a filter and aeration. An
ecological imbalance of the water was observed.
After the experimental dam was treated with the composition, no algal
blooms were noted and all fish were observed to be healthy. Since very little
aeration of the dam was required, no filter system was used. The ecology of
the water was also observed to have been rehabilitated.
EXAMPLE 6: BOSPLAAS
In this experiment, a polluted 120 mega litre dam on Bosplaas farm, Hermon,
South Africa was treated with the 50 litre composition of the invention.
Even up to a year after treatment, E. coil concentrations in the dam were
reported to be below detection levels, despite the high incidence of rain in
the
area and the fact that the water feeding into the dam from the Berg River was
reportedly highly contaminated with E. coll.
EXAMPLE 7: RUSTENBURG WINE FARM
Stellenbosch University Aqua Culture Department:
The treatment of a 68 million litre dam on Rustenburg Wine farm,
Stellenbosch, South Africa with 25 litre of the first composition of the
invention described was completed. The dam was used by the owners
thereof for the production of trout for export. Before treatment of the dam,
the
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total fish harvest for the export trout farm was rejected by customs officials
in
the European Community upon importation due to the levels of toxins
detected in the fish. The toxins were believed to be caused by an infestation
of the dam of blue-green algae. The water of the dam was observed to be
murky, and the ecology of the dam was noted to be imbalanced.
3 weeks after treatment of the dam, no blue-algae persisted in the water, and
the water became very clear, with visibility up to 2 meters below the surface
of the water. Populations of Daphnia, zoo-plankton, and bird life were
observed to reproduce and flourish, and the water ecology was rehabilitated.
The increase in Daphnia population was observed to have an enhancing
effect on the growth and total fish production of the dam. Rainbow trout
fingerlings were stocked at 250 g in May and harvested at 1.25 kg on 25
October of the same year. Fish were fed daily on artificial diets with a feed
biomass load of 1-2% of the bodyweight of the fish. The fish harvest in the
year was reported as the best harvest in terms of meat colour and fish size,
yielded by the farm in 4 years.
EXAMPLE 8: SANNITREE
An experiment was conducted on Nitida Wine farm in the Western Cape,
South Africa, where wetlands had been constructed into which the farm's
wine effluent was disposed. This effluent was reported as having a high
chemical oxygen demand (COD) which was too high to accurately measure.
Before treatment, the appearance of the body of water of the wetlands was
that of a black, stinking mess, clogged with the gels and total suspended
solids (TSS) that are typically present in wine industrial effluent.
A total of 5 litre of the first composition described according to the
invention
was added directly to the wetlands on three occasions, over a period of three
weeks. The experiment was begun in July and the first treatment was added
to the water. A week later, the COD levels had decreased to 7560, and the
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second treatment was added to the water. Approximately two weeks later,
the COD levels were decreased to 590 and the third treatment was added to
the water. An further approximately two weeks later, the COD levels were
decreased to 400. The COD test was conducted using Hanna Instruments
using a medium range and a high range reagent.
The environmentally-friendly water treatment composition of the invention
described herein, is believed to facilitate the treatment and rehabilitation
of
eutrophic water in situ, as well as the treatment of water-based effluent
derived from:
a) Mariculture and Aquaculture industries;
b) Waste water industries;
c) Industrial effluents;
d) Agricultural sectors;
e) Ornamental fish industries;
f) Parks and recreational sectors;
g) Dams holding drinking water;
h) Polluted natural water bodies such as lakes, dams, and rivers;
i) Dead zones along coastlines;
j) Eutrophic lakes;
k) Industrial treatment of corrosion on steel;
I) Industrial treatment of chlorides; and
m) Air conditioning in public places.
From the experiments conducted, the various ingredients of the composition
of the invention appear to have a lesser effect on eutrophic water if applied
individually, than when applied together in the composition. It is therefore
believed that the ingredients of the composition exhibit a synergism when
applied together that was not previously known, nor could it have been
expected.
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It should be appreciated that numerous modifications and adjustments may
be made to the water treatment composition of the invention, as well as to
the method of preparing it, the method of inhibiting or preventing the growth
of at least one microbe in a body of water, and the method of treating a body
of water using the water treatment composition of the invention, without
departing from the scope of the invention. In particular, the volume of
material in the form of leaves and/or stems of the plants that are processed
into particulate matter, as well as the volume of the water in which they are
suspended, the ratios of the extracts combined to produce the water
treatment composition, and the ratio of volume of the composition used to
treat various sizes of water bodies may be modified without departing from
the scope of the invention.
