In this article engineers from MIT describe their prototype for a cheap, effective way to clean contaminated water. Find out more about their intriguing invention here:
Branching out for Safer Water
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Username: doversherborn
Chemistry is fun!
Directions for Blog Posts
Each quarter you need to read one of the recommended articles posted to this blog -- choose the one you're most interested in, read it, and post a comment. Your comment should have your first name and last initial, block (A, B, C, D, E), and answer the questions below (in complete sentences) -- these are different questions each term, so be sure to read carefully.
NOTE: comments for quarter 3 are due Friday, April 4, by 3 p.m. Check back to see if I comment on your post; if it does not meet the criteria or needs more work I will let you know.
Directions for blog post:
1. Write a sentence IN YOUR OWN words that describes the main hypothesis of the scientists described in the article, or the main function of the prototype for a device they are making.
2. Describe how the scientists in this article have gathered evidence for their hypothesis or tested their prototype -- what kinds of experiments or testing did they do?
3. Explain in your own words what questions or uncertainty are still left about the hypothesis or prototype described -- what further experiments or testing might need to be done?
4. Express your opinion -- do you think this prototype will work? Or is the hypothesis described well-supported by data? Or is it still weak or in need of many further tests? Back up your opinion with evidence from the article.
Part 2 -- Homework due by Monday, April 7, 3 p.m. -- Write a 3-4 sentence THOUGHTFUL response to someone else's comment on the blog. Agree or disagree with their opinion and discuss evidence.
YOU can recommend the next current science choices!
Each quarter we will have 2-5 articles recommended as our current science choices of the month. I've started us with 4 for quarter 1.
If you would like to see your interests reflected on this blog, you can send Ms. Memmott an email recommending an article. Provide the link to the articles and a 2-3 sentence description of why you think it would be interesting and relevant for your classmates. Use the science news websites on this blog to help you find good articles. If you can also provide an image(copyright-free!) to go with your recommendation (for posting to the blog) that will increase its chances of being picked.
Recommendations are due at least 1 week before the end of a term. If your article is chosen, you get a homework pass!
If you would like to see your interests reflected on this blog, you can send Ms. Memmott an email recommending an article. Provide the link to the articles and a 2-3 sentence description of why you think it would be interesting and relevant for your classmates. Use the science news websites on this blog to help you find good articles. If you can also provide an image(copyright-free!) to go with your recommendation (for posting to the blog) that will increase its chances of being picked.
Recommendations are due at least 1 week before the end of a term. If your article is chosen, you get a homework pass!
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Username: doversherborn
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1. At MIT, scientists are attempting to find out whether water can filter harmful out of water, creating safe drinking water.
ReplyDelete2. To test their hypothesis, the scientists cut sapwood plugs from oak & balsa trees. They then fit the plugs into tubes with contaminated water and applied pressure. They then reviewed their experiment with an electron microscope to see if the bacteria got through the wood.
3. Despite the test’s eventual success, doubts still remained about the sample size of the experiments, along with the possibility of wood being cracked or breached by viruses smaller than bacteria.
4. I think that the prototype will succeed because of its scientific corroboration. The size of the wood’s “conduits”, which act as the filter, are only 70 nanometers wide compared to the average bacteria’s 200 nanometers.
I agree with you Micah, I think it will succeed too. I think wood filters would be relatively cheap to make so people who live in poverty can have them donated by scientists with out costing them much. Although a wood filter is not as good as another type, I think in the years to come scientists will come up with more research and make them even better.
Delete1) Intrigued by the sap flow through wood, scientist Rohit Karnik uses a scanning electron microscope to find if wood slices can cheaply and effectively filter bacteria from water.
ReplyDelete2) Karnik used wooden plugs and contaminated water under pressure to first test their research. When the plugs were shaped incorrectly, they revised them and measure bacteria using the scanning electron microscope.
3) The only further testing that needs to be conducted is for maximum efficiency. For example, what types of woods work best? Also, where should the slices be taken from? The directions for use need to be clearer.
4) I think that this prototype will definitely work, as it can produce 3.5 quarts of fresh water a day, and is already shown to reduce most major bacteria. However, I think that it would be a last resort option as opposed to tried and true filters.
The research shows that the design is quite effective, but I don't think it should be used as a filtration device over more reliable options. Like you said, it should be used only as a last resort. I think that given its portability and cost-effectiveness, it would be more suited for wilderness survival and not large-scale water purification. Not only this, but it might just be something that is good to have in your car so that if it breaks down in the middle of nowhere you have a way to clean any water you might find. I think the prototype has a long way to go until it can practically be employed in the real world.
DeleteMechanical engineers from MIT are trying to find a more cost-effective and renewable way to filter bacteria out of contaminated water. Recently they've been experimenting with xylem sieves and have actually had some success in straining out bacteria such as E.coli. In vascular plants, the xylem is the living tissue that transports (primarily) water and minerals throughout the plant through microscopic tubes called conduits. These engineers, and one by the name of Rohit Karnik in particular, have discovered that these tubes and certain pits inside the tubes are exceptional at filtering out bacteria. They've tried using different types of wood and so far white-pine has proved the most effective because its natural membranes filter out any substance larger than 70 nanometers. However, Karnik knows that there is always the possibility of a better material, and he still considers his design a mere prototype. There is also the question of durability. Wood isn't the most long-lasting material out there, and if it cracks or rots the whole device (and the filtered water for that matter) becomes contaminated. In my opinion the prototype still has a long way to go before it can be employed in a real-world environment. I think that durability is more important than financial expense when it comes to something as essential as water, and so far the prototype has not exhibited an adequate level of consistency in that sense.
ReplyDeleteI agree with your opinion on this subject. This method of filtering water would I think only be used in emergency situations, and would not work well for everyday use. Wood definitely wont last more than a few weeks, and it is probably not good for the tree. I think you really nailed this on the head.
DeleteHi Riley,
DeleteNice response! I truly learned a lot of interesting facts and ideas from this. I agree that this method is not necessarily the most effective, but could be used if need be. Overall, I thought this was a great and interesting response.
1. Robert Karnik, a mechanical engineer, has developed a theory based off how sap moves through a plant. This theory is all about how a tree branch has the potential to become a efficient water filter. Karnik believed that the wood was filled with a series of conduits that almost worked like a straw.
ReplyDelete2.In order to prove this theory they took plugs made from the wood of balsa and oak trees and placed them in a tube of bacterial infected water and placed plugs on the top of the tube. They then applied pressure, they also took a microscope to watch and see if the water was flowing through.
3. The first tests were not proving this theory at all. They actually were doing the opposite. Scientists had to adjust the shape of the plugs and also the actual size of the bacterial were quite small so they were worried about how what if the were larger than that particular size, would it crack the wood?
4. I honestly feel that this will work because plants are lifeforms like us and we cannot take in certain unfiltered water so is it would make a lot of sense if this was the case.
1. Rohit Karnik, a mechanical engineer at MIT conducted tests to filter water by flowing water through certain kinds of wood to hopefully filter water without spending lots of money or using any energy.
ReplyDelete2. Karnik cut pieces of wood into plugs and closed the opening of tubs filled with contaminated water inside and added pressure. After revising the size of the plugs Karnik assessed the water by using an electron microscope to see if the bacteria escaped through the wood.
3. I believe further testing needs to be conducted to absolutely prove this point. Maybe in different quantities, wood types, temperatures, water. If this becomes a way to filter water it needs to always work otherwise people will drink contaminated water and possibly become ill depending what is in the water.
4. I believe the prototype will succeed because its already proven to remove the majority of bacteria. The wood will stop anything over 75 nanometers and bacteria is 200 nanometers. I believe because this evidence the prototype will succeed and become the future filter to save lives.
I agree with your opinion on this topic. I definitely think that there needs to be more testing done for this to be efficient. I also agree that the prototype will be successful in the future, and save lots of lives by providing clean. However, I don’t think that this design will be the most reliable compared to other ones because it uses trees. I don’t think that it’s that dependable right now, but additional testing will definitely make this prototype a great way of filtering water.
DeleteI agree with Chelsea as well. Your opinion is completely correct. Even if they have all this proof that fact of the matter is there is not enough evidence to keep it as a stable hypothesis. They have completely reasonable suspicions but they aren't back up by well thought out evidence. I also feel that there theory is correct but again as stated earlier simply requires more testing.
DeleteRobert Karnik, a mechanical engineer at MIT has discovered that trees can potentially filter water. He observed xylems and conduits to see how water and sap traveled through a plant. He then connected it to how wood can act as a filter for bacteria. In order to test his hypothesis, Karnik carved sapwood in the shape of plugs from oak and balsa trees. He took a tube of dirty water, and covered it with the plug, applying some pressure. Then, he used a scanning electron microscope to observe the water to see whether or not the wood was capable of separating the clean water from the harmful bacteria. However, this experiment was unsuccessful because he cut the conduits, which affected the results because nothing was blocking out the harmful bacteria. Even though they conducted this experiment many different ways, it is still not perfected. There are still many concerns. For example, some germs are even smaller than bacteria. Also, the wood could crack at any time, this would result in the water staying contaminated. Karnik has learned that white pine trees work the best, however, they are still other types of plants that they haven’t tested. I believe that this prototype will work after more testing. It’s already proven to remove a large amount of bacteria. Karnik needs to make it more efficient and effective. By doing so, every filter can provide enough clean water to one person per day.
ReplyDelete1. Scientists are trying to see if certain types of wood can filter bacteria out of water.
ReplyDelete2. To test the hypothesis scientists put small plugs of sapwood form oak and balsa trees. Then the scientists fitted plugs into tubes with the germs. Them they used a scanning electron microscope to see if the wood splinters stopped the bacteria.
3. I think that the scientists should try to use different amounts of bacteria and wood and constantly mix up the amounts in each test to see how much each amount effects the wood and how much bacteria goes through.
4. I think that the prototype will work, the prototype has proved that it produces about 4 liters of clean water a day. I think it is supported by well data. When the prototype didn't work at first they made adjustments to there prototype.
I agree with this opinion. The prototype has shown enough potential that there is definitely reason to try and expand on it. However, it probably won't be as reliable as man-made filters: wood is more volatile and can break with less effort. Despite this, I think that wood filters are definitely a possibility for the future.
Delete