Experiment

Experiment: Methods for removing iodine from water

· Column

· Vacuum flask

· Funnels

· Burette

· 7 conical flask

_· Cu(NO₃)₂

· Iodine

· Distilled water

· Charcoal

· Copper (II) Sulfate

· Chuck

We made an iodine solution to use for our experiment to simulate radioactive iodine, in all purposes for our lab, regular iodine will behave the same as the radioactive isotopes.

We are using the spectrophotometer to measure the concentration.

- We started out by making the solution: iodine and demineralized water

- Copper (II) sulfate solution to precipitate with the iodine solution

The first thing we did was to calibrate the spectrophotometer by using distilled water. This gave us a baseline to compare our results to. Secondly, we took a measure of the absorption of the prepared iodine solution that we made. We do not know the exact mol/L of the iodine solution, but it is not important for our investigation because we prepared only one solution that was used consistently for all of our experiments

First Test: Precipitations

Reading on the internet we found a few sources that claimed Copper Iodide to be a solid precipitate. Following this we looked for a few solutions containing copper to try and make a precipitation.

We hoped that

Instead what happened:

Cobber (II) sulfate solution + iodine solution produced a green solution. The reason for the green solution being formed is simply that when you add something blue to something yellow it will produce something green. Needless to say, there was no precipitate formed.

So instead we tried a different Copper Solution to try and force a precipitation.

Cu (NO₃)₂ + iodine = green/yellow – Once again, no precipitation

Limitation: we did not have access to the right solutions – Looking on the internet further, the ions that we needed were tin, titanium, lead, silver (I), mercury (I), and mercury (II). However, many of these ions were not available and others, especially lead and mercury, would not be appropriate solutions when speaking about drinking water.

So we tried a second method, instead of precipitates we chose to try different filtering methods.

On the internet we read that blue green algae has some adsorptive properties, so we tried to collect blue-green algae from the bay and we used a plankton net, but we found out that blue-green algae is to small so a smaller filter is needed to collect them. But they do exist in the bay. They actually have done testing on blue green algae before pertaining specifically to radiation and Japan after the atom bomb was dropped. Apparently the process is long, but it is supposed to be effective in many regards. However, we were unable to find a study on how it affected the algae.

Next, we tried to filter iodine solution trough charcoal in a burette (filter). We used charcoal that we made using a campfire and then crushed it into an activated state.

We did this in two different ways:

1: We took the green combination of the blue Cobber (II) sulfate solution and the yellow iodine solution and filtered through the burette with a vacuum. The solution that appeared in the vacuum flask was blue. Therefore the yellow iodine solution was gone. It is also interesting to note that the shade of blue was significantly diminished compared to the original suggesting that some of the copper solution was also adsorbed.

2: We took the yellow iodine solution and filtered through charcoal as in no. 1. This time the solution came out transparent with no color. We took quantitative data of this also. Using a spectrophotometer we found the absorbance of light. A spectrometer is a tool that takes light and passes it through a sample. In this case, the sample was the solution that was passed through the charcoal. The spectrophotometer can compare the amount of light that is passed and the amount of light that gets through to the other side to determine the content and sometimes concentration of a solution. In this case, we choose to compare our values to that of distilled water which in theory should have all light pass through.

We followed the same procedure for chalk to test it as a method of filtration.

Experimental Results:

Substance	Absorbance Value
Water	0.000
Iodine	0.300
Solution passed through charcoal	0.020
Solution passed through Chalk	0.029

From these we were able to work out that when passed through charcoal, 93.3% of the iodine was filtered out and when passed through chalk 90.3% was filtered out. We kept the amount of charcoal and chalk approximately constant at 7.955g and 8.015g respectively.

Conclusion:

We did not have sufficient results to warrant us making any real suggestions for the people of Japan. What we can say however, is that charcoal is a much more efficient filter than chalk in that it yielded better results and was quicker. Furthermore, we can say that because of the nature of charcoal and how we can make it easily by burning wood in a lower oxygen environment, it could be said to be a very viable solution for people simply wishing to purify small quantities of drinking water without access to any chemicals. However, on a large scale, charcoal is not a very viable solution. I would be more efficient investing in larger scale filters, especially carbon filters. Another viable option could be a precipitation reaction for a large scale operation assuming that one has access to the correct chemicals and filtering equipment. Another major issue that was raised throughout the investigation was: Where does the nuclear waste go after you have isolated it from your drinking water? True, you can now safely drink the water, but without proper facilities or equipment to handle and dispose of this kind of waste it could lead to even further problems.

(Tyrel & Ellen)

Different methods of removing radioactive compounds

We used a lot of time in researching and read a lot of scientific reports about how to remove radioactive compounds from waste water from nuclear reactors but mainly about how to do it with drinking water which is our focus. The main problems in general are that they are quite expensive or special skills are needed to be able to control the process because the waste it creates is even more radioactive than the water because it is concentrated. Usually they put the waste in landfills. But the waste will first disappear when the radioactive compounds has decayed to a stabile point which takes many, many years. It was a bit hard to understand the scientific language because it is not made for regular people to understand but made as scientific correct as possible.
What are the methods used to remove radioactive compounds from drinking water:
Most used: Absorption/filtration and through precipitation.
When working when removing radioactive compounds from water there are two main ways to do it:
Either put a reactant that will react with the radioactive compound and from a solid that will lay on the bottom on the water reserve.
Or put a absorbent agent that will absorb the radioactive compounds from the water.
The first method: Is said to be more complicated because you have to remove/scrape the solid of the bottom while with the other method it is easier to remove the absorbent.
In both cases it is hard and problematic to remove all the radioactive compounds and it is often expensive but even a little difference is better than no when we are talking radioactive contamination.
The contamination of the Japanese water comes from the meltdown of the nuclear reactors where the water that are supposed to cool the reactor down gets contaminated – and has a very high and dangerous radiation. The contaminated water is hard to control because contact with it is dangerous, eg, Beta radiation can go through the skin. And cause damage to the new skin cells that are produced.
One of the newest news is that Japan will dump some of the contaminated water in the ocean. http://www.scientificamerican.com/article.cfm?id=wrapup-4-japan-to-pump-radioactive
http://edition.cnn.com/2011/WORLD/asiapcf/03/24/japan.nuclear.workers/index.html?eref=edition_world&utm_campaign=Feed%3A+rss%2Fedition_world+%28RSS%3A+World%29

In the lab

Health Risks of Iodine-131

Iodine-131, while used in various treatments, may also pose potential health risks. While Children are potentially at risk when faced with above 100 Becquerel of radioactive iodine, the danger level for adults is approximately 300 Becquerel.
Iodine-131 particularly concentrates in the thyroid gland after entering the body. When I-131 inhabits the thyroid gland the expected biological half-life is approximately 100 days. A long-term exposure with iodine-131 may result in thyroid cancer as well as nodules.

Among those effected, children are often most vulnerable. Even small doses of iodine-131 may challenge the effectiveness of the thyroid gland. Since the thyroid hormones are highly involved in triggering essential growth such as brain development, an infant would be subject to a higher risk. In addition children who are in contact with high levels of iodine-131 have a greater chance of developing cancer later in life.

(Avikali)

sources:

http://www.epa.gov/radiation/radionuclides/iodine.html#affecthealth
http://www.cbc.ca/news/technology/story/2011/03/25/japan-nuclear-plant-core.html

http://www.businessweek.com/news/2011-03-23/tokyo-says-infants-face-health-risk-from-radiation-in-tap-water.html

http://www.news-medical.net/news/20110324/Iodine-131-exposure-during-childhood-increases-risk-of-developing-thyroid-cancer.aspx

Yesterday we made our own charcoal. We started with a normal fire, then made a box with bigger logs around the edge of the fire in an attempt to seal the bottom edges so the oxygen reaching that area was limited. Our hope was that this would produce a more concentrated carbon product. Initially we wanted to use a bucket or something more effective in limiting oxygen, but we couldn't find anything suitable. After the fire burnt out we collected the left over charcoal. We will crush this charcoal and use it in our experiment that will test how effective charcoal is in absorbing iodine from water.
[Allison]

Our Topic is regarding the crisis in Japan and our first goal is to find an appropriate narrowed research topic. Our first impression was to investigate the earthquake itself and the formation of tsunami's. The problem was that we were very unsure how we would test any of our research. So instead we thought that maybe we should do an investigation on how to survive tsunami's. However, once again the availability of data and the ability to conduct our own experiment was very limited. Finally, we came to the conclusion that we should focus on what seems to be having the longest lasting effect, that being the radiation. We decided that we should investigate in more detail about the radiation present in Japan, including what radioactive isotopes are presents, from a biological perspective what happens to a human when exposed to radiation, and finally what steps can be taken to reduce the radiation that one is exposed to, especially in a situation like Japan.

From the last question we were able to build upon this and realize the potential for an experiment. Through online research we were able to discover that in Japan currently, it is caesium 137 and iodine 131 that are causing most of the complications. Then we researched some methods for removing this, especially from drinking water. It turns out, that currently all over the world, water treatment centers have for years already used a multitude of methods to remove radioactive isotopes from water supplies. The two main methods are through absorption/filtration and through precipitation. Both of these methods are possible to test in an experiment.

So what we would like is to test different measures on their ability to remove radioactive materials. Basically we will be keeping constant the amount of solute and solvent that we use for each method, in this case likely iodine and water, and then apply a method and then measure to see the percent of the original solvent that is left.

First we would like to conduct an experiment on precipitation using non-radioactive forms of iodine and if possible caesium. The ions that will precipitate iodine are tin ion, titanium ion, lead ion, Bi3+, ag+, hg+, and hg2+. So therefore we need a few compounds that will dissociate into these ions in order to precipitate the iodine. If possible we are trying to find household compounds that contain these elements in order to make the experiment more applicable to the situation and the many people without proper access to a full chemistry lab.

The second part of the lab would be testing other filter and absorption methods. What we plan on doing is testing lime and activated charcoal. We will add both of the compound into the mixture, mix it around for a fixed period of time (likely between 5 and 10 minutes) and then use filter paper to get rid of all the added solid which has hopefully also absorbed some of the iodine/caesium. The other two things that we would like to test are a little more interesting in the sense that we can find or make them in our natural environment. Reading online, we found many claims that blue green algae has absorption like properties and that during the aftermath of Hiroshima in Japan it was tested and reportedly it reduced radioactive material in water drastically. We should be able to find some of this in the bay, or at mathieson Lake. The other material that we would like to test is normal charcoal that we would make ourselves from burning wood exposed to relatively little oxygen and then crushing it before adding it to the water. In this sense we can ensure that in our experimental results we will be able to apply it to the average person living in Japan without access to fancy lab equipment.