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An ingenious invention is set to bring clean water to the third world and while the science may be cutting edge, the materials are extremely down to earth.
A. Tony Flynn, a materials scientist from Australian National University (ANU), developed a simple new way of making water filters with commonly available materials, and these water filters can be fired on the ground using cow manure as a source of heat, without the need for a kiln. The filters have proved the ability to remove common pathogens (disease-producing organisms) such as E-coli. Unlike other water filtering devices, these filters are simple and inexpensive to make. “They are very simple to explain and demonstrate and can be made by anyone, anywhere, ”says Flynn “They don't require any advanced technology. All you need is terracotta clay, a compliant cow, and a match.”
B. The production of the filters is extremely simple: take a handful of dry, crushed clay and mix it with a kind of organic material such as used tea leaves, coffee grounds, or rice hulls, and add enough water to make a stiff biscuit-like mixture and form a cylindrical pot with one end closed, and let it dry in the sun. According to Flynn, used coffee grounds have given the best result to date. Next, surround the post with straw, placing them in a pile of cow manure. Then light the straw and top up the burning manure as required. In less than an hour, the filters are ready. The walls of the finished pot should have the thickness similar to that of an adult index finger. The properties of cow manure are vital as the fuel can reach a temperature of 700 degrees and above in half an hour, peaking at 950 degrees after another 20 to 30 minutes. The manure makes a good fuel because it is very high in organic material that burns readily and quickly; the manure only works when it is dry and is best used exactly as found in the field; there is no need to change its form or process further.
C. “For one thing, a potter's kiln is an expensive item. For another, it could take up to four or five hours to get up to 800 degrees. Besides, to make it work, fuel that is expensive or scarce such as gas or wood will be needed, plus the experience to run it. With no technology, no insulation and nothing other than a pile of cow manure, and a match, none of these restrictions apply,” Flynn says.
D. One of the reasons why manure is a desired material to be used in making these filters is because cow dung is so readily available in most areas of the planet. “A cow is a natural fuel factory. My understanding is that cow dung as a fuel would be pretty much the same wherever you would find it. ”Just as using manure as a fuel for domestic uses is not a new idea, the porosity of clay is something that potters have known about for years, and something that, as a former ceramics lecturer in the ANU School of Art, Flynn is well aware of. The difference is that rather than viewing the porous nature of the material as a problem, it must be viewed as a solution - after all, not many people want a pot that won't hold water; his filters capitalise on this property.
E. Now with Flynn's method, the filtration process is simple but effective. The basic principle is that there are passages through the filter that are wide enough for water droplets to pass through, but too narrow for pathogens. For example, tests with the deadly E-coli bacterium have shown that the filters will remove 96.4% to 99.8% of the pathogens, which is certainly within the safe levels. The use of organic material which burns away leaving cavities after firing helps produce the structure in which pathogens will become trapped. This overcomes the potential problems of finer clay that may not let water through or the problem that cracks are too large to filter pathogens. Much like clay and cow dung, organic material is universally available.
F. This invention was spawned from a World Vision project involving the Manatuto community in East Timor. The charity wanted to help set up a small industry manufacturing water filters, but initial research found the local clay to be too fine - a problem solved by the addition of organic material. Although the problems of producing a working ceramic filter in East Timor were eventually overcome, the Timor solution was based on the use of a kiln and materials that were only native to Timor. Manure firing with no requirement for a kiln has made this zero technology approach available anywhere it is needed. With all the components being widely available, Flynn, who has no plans to patent his idea, believes that there is no reason why this method couldn't be applied throughout the developing world. “Clean water should not be only accessible to a small group of people. With the help of these filters, people in any country would drink water safely,” says Flynn.
Reading Passage 3 has six paragraphs, A-F.
Which paragraph contains the following information?
Write the correct letter, A-F, on boxes 1-7 on your answer sheet.
NB You may use any letter more than once.
the unexpected value of used coffee grounds
a comment on the accessibility of the filter-making technique
a comparison on cost-efficiency in heating process
problems solved by the special structure of the water filter
a feature that is no longer disadvantageous
a water filter solution restricted by the conditions of firing
a description of bacteria-removing principle
Do the following statements agree with the information given in Reading Passage 3?
In boxes 8-14 on your answer sheet, write
|
TRUE if the statement agrees with the information FALSE if the statement contradicts the information NOT GIVEN if there is no information on this |
Flynn is known for inventing new water filters with the use of rare materials.
Kilns are made of clay.
Dry crushed clay, organic material and water are the three materials required for constructing a simple, yet an effective water filter.
Cow manure is the key for producing the heat of over 700 degrees within 30 minutes.
A potter's kiln is a more economical material than cow manure.
Local clay in East Timor was found to be unsuitable for making filters.
Flynn had revealed some future plans of gaining the legal right to exclude others from using his invention.
An ingenious invention is set to bring clean water to the third world and while the science may be cutting edge, the materials are extremely down to earth.
A. Tony Flynn, a materials scientist from Australian National University (ANU), developed a simple new way of making water filters with commonly available materials, and these water filters can be fired on the ground using cow manure as a source of heat, without the need for a kiln. The filters have proved the ability to remove common pathogens (disease-producing organisms) such as E-coli. Unlike other water filtering devices, these filters are simple and inexpensive to make. “They are very simple to explain and demonstrate and can be made by anyone, anywhere, ”says Flynn “They don't require any advanced technology. All you need is terracotta clay, a compliant cow, and a match.”
B. The production of the filters is extremely simple: take a handful of dry, crushed clay and mix it with a kind of organic material such as used tea leaves, coffee grounds, or rice hulls, and add enough water to make a stiff biscuit-like mixture and form a cylindrical pot with one end closed, and let it dry in the sun. According to Flynn, used coffee grounds have given the best result to date. Next, surround the post with straw, placing them in a pile of cow manure. Then light the straw and top up the burning manure as required. In less than an hour, the filters are ready. The walls of the finished pot should have the thickness similar to that of an adult index finger. The properties of cow manure are vital as the fuel can reach a temperature of 700 degrees and above in half an hour, peaking at 950 degrees after another 20 to 30 minutes. The manure makes a good fuel because it is very high in organic material that burns readily and quickly; the manure only works when it is dry and is best used exactly as found in the field; there is no need to change its form or process further.
C. “For one thing, a potter's kiln is an expensive item. For another, it could take up to four or five hours to get up to 800 degrees. Besides, to make it work, fuel that is expensive or scarce such as gas or wood will be needed, plus the experience to run it. With no technology, no insulation and nothing other than a pile of cow manure, and a match, none of these restrictions apply,” Flynn says.
D. One of the reasons why manure is a desired material to be used in making these filters is because cow dung is so readily available in most areas of the planet. “A cow is a natural fuel factory. My understanding is that cow dung as a fuel would be pretty much the same wherever you would find it. ”Just as using manure as a fuel for domestic uses is not a new idea, the porosity of clay is something that potters have known about for years, and something that, as a former ceramics lecturer in the ANU School of Art, Flynn is well aware of. The difference is that rather than viewing the porous nature of the material as a problem, it must be viewed as a solution - after all, not many people want a pot that won't hold water; his filters capitalise on this property.
E. Now with Flynn's method, the filtration process is simple but effective. The basic principle is that there are passages through the filter that are wide enough for water droplets to pass through, but too narrow for pathogens. For example, tests with the deadly E-coli bacterium have shown that the filters will remove 96.4% to 99.8% of the pathogens, which is certainly within the safe levels. The use of organic material which burns away leaving cavities after firing helps produce the structure in which pathogens will become trapped. This overcomes the potential problems of finer clay that may not let water through or the problem that cracks are too large to filter pathogens. Much like clay and cow dung, organic material is universally available.
F. This invention was spawned from a World Vision project involving the Manatuto community in East Timor. The charity wanted to help set up a small industry manufacturing water filters, but initial research found the local clay to be too fine - a problem solved by the addition of organic material. Although the problems of producing a working ceramic filter in East Timor were eventually overcome, the Timor solution was based on the use of a kiln and materials that were only native to Timor. Manure firing with no requirement for a kiln has made this zero technology approach available anywhere it is needed. With all the components being widely available, Flynn, who has no plans to patent his idea, believes that there is no reason why this method couldn't be applied throughout the developing world. “Clean water should not be only accessible to a small group of people. With the help of these filters, people in any country would drink water safely,” says Flynn.