Water Filter Challenge
Define:
For this project we have been asked to design a filter that will produce water safe for release in the Pitt River. This means we needed to have safe water levels, no toxic material and proper water quality. To see what we needed to change in the water we conducted a flame test using a Bunsen burner and reference metal ions like salt and calcium chloride. To test the unfiltered water we put it through filtered paper and then tested the solids on it.
Flame Test
| Unfiltered Water | While there was some slight blue/green coloring, in the beginning, the most prominent color was orange. |
| NaCl
(Salt) |
It was orange with no other visible colors. |
| Cucl (Calcium Chloride) | It had prominent blue-green tones with a little bit of orange. The flame color was bright and seemed to flicker between green and blue. |
| SrCl (Strontium Chloride) | It was red with no other visible colors. |
| KCl (Potassium Chloride) | Light purple with some red and orange like colors. |
From these observations, we found that the dirty water we had contained salt and maybe low levels of Calcium Chloride.
We also took a Ph test before filtration, we used a petri dish, a Ph paper and some of the sample water. The outcome was an observed Ph level of 5 (on the scale of 1-14). This indicates that the water was slightly acidic. These two tests we did helped us to identify what needs to be removed from the water. From our observations, we saw that this substance that we needed to purify was liquid, translucent, slightly yellow, contained brown, black and green solids, and smelled like vinegar.
To understand what levels and requirements needed to be met for the water being poured into the Coquitlam river I looked at some information on average Ph levels in Canada, which ranged from 6.5-8.5. I also looked at a PDF from BC that talked about water guidelines and while we couldn’t necessarily test what I wanted to it increased my understanding.
Discover:
Similar projects have been conducted many times by many groups of people, specifically, the ‘bottle DIY filter’ is easy to find online. There are also many resources available to purify water in different ways that don’t rely on a plastic bottle, for example; iodine pills purify water, chlorine drops kill pathogens and bacteria, reverse osmosis and decanoic acid reduces salt content. All these ways to purify water are viable and work however we were not provided with these materials. So, while the research done on these methods increase understanding, it did not help with the creation of our specific filter. The problem of filtering water has been around for a long time, we as humans have taken many advances in the technology developed to produce clean water. Human-made water filtration dates back to over 4000 years. In the past, some solutions to this specific problem include boiling and filtration using sand and stones.
Dream:
Some ideas our group put out included things like reverse osmosis, boiling, and using different materials that we didn’t have. When we were able to recognize the materials, we were provided with we began to brainstorm different ideas like using filter paper, cotton balls and sand. We didn’t want the sand to fall into the water and create more solids in the water so we figured that we should use a filter on the bottom part to eliminate those sand grains. We also thought about how we could adjust the water to have a lower salt content and how we could balance out the Ph. To accomplish these things we tried to create a filter that would somehow get rid of salt, that included ideas like using progressively smaller rocks, stones and sand, trying to reduce the carbon dioxide (which is a large cause of Ph level change) and trying to separate the salt and the water. We were also curious about how well a sponge would work in the mouth of the bottle so using tap water we placed the sponge in the bottle and poured in water to see if it works
While all these ideas weren’t used, they were crucial to our filter making process and helped us to create our model. Our design ended up being made up to cotton, cheesecloth, filter paper, activated carbon and then we filtered it again through filter paper. We used this method because we took what we thought would work well from all of our brainstorming to create a filter that would hopefully work.
Deliver:
After we created our model, we were able to test it using the contaminated water. This resulted in the water coming the end was liquid, transparent, less yellow, contained no visible solids, and smelled less like vinegar. We then conducted another Ph test, we used a petri dish, a Ph paper and some of the filtered sample water. The outcome was an observed Ph level of 5 (on the scale of 1-14) which was the same as before the filtration. This indicates that the water is still slightly acidic.
Debrief:
Overall, I think that this project was very interesting, engaging and improved my understanding of water quality. If I were to do it again, I would change some of the elements we worked with, for example include better use of the activated charcoal. I also wish we had more time to test and research because I think that would improve the project a lot, it would allow for diving deeper into questions I have and allow for more testing to be conducted. Materials I would have liked to use include a conductivity tester, decanoic acid, and I think it would have been really interesting to work with some different materials that affect Ph levels. If I had the opportunity to use these items I would have used the conductivity tester to get a better understanding to the TDS levels before and after the filtration. For the decanoic acid, while it doesn’t really relate to a filter it sounds very interesting to work with and I would like to see if it removes salt content. The materials that could help change the Ph levels vary, from what I’ve read and researched it seems that to increase Ph level you can use many materials like lemon/lime, baking soda and even wood ash. These changes to the project, I think, would make it better.
Sites:
- https://www2.gov.bc.ca/assets/gov/environment/air-land-water/water/waterquality/water-quality-guidelines/approved-wqgs/chloride-or.pdf
- https://www.fondriest.com/environmental-measurements/parameters/water-quality/ph/
- https://www.chem.purdue.edu/jmol/cchem/aqua.html
- https://www.safewater.org/fact-sheets-1/2017/1/23/tds-and-ph
- https://www.instructables.com/id/Simple-Water-Filter-out-of-a-Waterbottle/
- https://www.chemistryworld.com/news/simple-salt-removal-to-get-fresh-water/3003646.article
- https://learn.allergyandair.com/water-filters/
- https://biologydictionary.net/semipermeable-membrane/
- https://link.springer.com/chapter/10.1007/978-3-642-67572-0_1
- https://www.coquitlamriverwatershed.ca/our-watershed/
- https://www.conserve-energy-future.com/freshwater-biome.php
- https://www.britannica.com/science/hydrosphere/River-and-ocean-waters
- https://www.onegreenplanet.org/lifestyle/diy-water-filter/
