Which Physical Filtration Material Leads to the Best Drinking Water?

Abstract:

This experiment investigated how different physical filtration materials affect how clean a sample of water is. This is important to know because, for us humans to live a healthy life, we need to first make sure we are drinking pure and filtered water, so we avoid developing diseases that can make us sick. In order to prevent sickness, we first needed to find out which filtration material works the best to purify the dirty water. Therefore, I tried 4 different filtration methods: activated carbon + paper filter, just paper filter, activated carbon + nylon filter and just the nylon filter. I also made one sample of just the dirty water with no filter and one sample of clean tap water in order to compare. Then I added the dirty water into each filter and found that the activated carbon + paper filter worked the best to clean the water. Although, it didn’t completely clean it, it was pretty close and was a beige/yellowish color compared to brown. Also, the dirt smell went away as well as the sediment and rocks that were in the water. Therefore, activated carbon and a paper filter are the best to use when filtering water at home. However, just the two materials aren’t enough to have clean and purified drinking water, so more ingredients would need to be added to make it 100% drinkable. 

 

Introduction:

Clean water is essential for humans and prevents us from developing diseases or becoming sick. That is why it is important that what we drink is always filtered to remove unwanted particles like dirt, sediment, bacteria, and chemicals. Filtration is a process in which a filter medium (ex. Sand, activated carbon, gravel) allows the fluid to pass through, and instead blocks the particles from entering. These particles can enter through the pores of the filter medium due to the pressure difference driven normally by gravity. This process can be biological, chemical, physical or mechanical. In this experiment, we will perform both the chemical and physical filtration methods. Generally, chemical filtration uses processed carbon that absorbs and removes smaller contaminants. On the other hand, physical filtration is where there is a physical filter, normally made of paper, that removes the larger contaminated particles and allows the water to go through. 

 

This experiment aimed to test 5 different filter combinations– coffee filter (paper), nylon filter, no filter (constant), coffee filter (paper) + coconut shell activated carbon and nylon filter + coconut shell activated carbon. I hypothesize that the paper filter and activated carbon will work the best to clean the dirty water, to provide the cleanest drinking water because the paper filter has very small pore sizes, ranging from 10-20 micrometers, which prevent more small, harmful particles from passing through. On the other hand, nylon/cloth filters have pores from between 15-50 micrometers which are much larger and can’t block the smaller particles. As well, activated carbon has a high surface area and a high degree of surface reactivity that allows it to finish the cleaning job after the physical filtration process. 

 

Methodology:

 

Materials:

1. Coconut shell activated carbon

2. Scissors

3. 2 Coffee Filters

4. 2 Nylon Filters

5. Sharpie

6. Dirty water (dirt+tap water)

7. Teaspoon

8. 5 Plastic cups

9. Paper towels (optional but it may get messy)
   
   
   
   
   
   
   
   
    

 

To begin, I made the dirty water by grabbing dirt that contained a few rocks and pebbles from my backyard and I combined ⅓ dirt and ⅔ tap water (room temperature) into a measuring cup that was 800 mL full. I also cut the nylon fabric and made 2 filters that were round and the same size as the coffee filters.

Then I layed out all 5 cups and labeled them as followed:

*NF=no filter, PF=paper filter, NyF=nylon filter, AC=activated carbon




 

 

I placed the 2 paper filters, 2 nylon filters, and put the 3 teaspoons of activated carbon on one of the nylon filters and on one of the paper/coffee filters:








 

 

Then I slowly poured some of the dirty water into each filter and waited for the filter to absorb some of the dirty water. I kept adding the dirty water to each filter until there was none left. (I tried to add similar amounts of dirty water to each cup, but it doesn’t need to be exactly the same). Next I waited around an hour for the filters to finish their job of cleaning and purifying the water.

 

Then I shook each cup because a lot of the dirt/sediment that was still there had settled to the bottom. Then I took down observations about color, odor, clarity and if there was sediment at the bottom or not. I also filled up a cup with the same tap water that I originally used to make the dirty water in order to compare each cup’s color of water to the normal drinking water color. 

Results:

I noticed that overall the coffee filter + activated carbon worked the best to clean the water. Although it wasn’t perfect, I noticed that it didn’t have much sediment lying at the bottom and it was a beige/clear/light yellow color. From looking at the top of both the paper filter +activated carbon and the paper filter, I noticed that the clarity of the PF+AC was better and I could see more through the water to the bottom of the cup. The paper filter overall worked pretty good and was also a beige/yellow color, but not as clear as mentioned before. Also, I noticed that the PF+AC had no smell compared to just the PF that has a slight dirt smell.

 

The nylon filter by itself didn't do that great of a job and looked nearly identical to the no filter trial because it was a light peanut brown color and had sediment build up at the bottom and wasn’t clear. However, I did notice that the nylon filter did remove some of the bigger rocks and sediment which worked well. It still also had a dirt smell.

 

The nylon filter with activated carbon also had sediment laying at the bottom and was a brownish color and looked almost more beige/medium brown. Overall, I believe it did a slightly better job than just the nylon filter, but it barely made any difference other than having no dirt smell.










 

 

 

 

 

 

Conclusion:

Overall, I would recommend using the paper filter and activated carbon as a way to clean water at home compared to any other methods. However, this method isn't enough to get it fully purified enough to drink, but if you want to get a partially clean, this would be the best method to do so, but I would advise against drinking the water as it is not safe for consumption.

For future research, it would be interesting to see if I tried different types of contaminants besides dirt such as ink or coffee to see if I would still get the same results. It would also be helpful to try out different brands of filtration systems that have technology and chemicals that purify water to see if I can get the water to be drinkable. 

 

References (APA):

1. Filtration - membrane, adsorption, centrifugation | britannica. (n.d.). https://www.britannica.com/science/filtration-chemistry/Filter-types 

2. Coconut Shell Activated Carbon. Coconut Shell Activated Carbon | Carbon Activated Corporation. (n.d.). https://activatedcarbon.com/products/coconut-shell-activated-carbon 

3. Cloth filter: Filter technology. Royal Brinkman International - Global Specialist in Horticulture. (n.d.). https://royalbrinkman.com/knowledge-center/technical-projects/water-filter-technologies-horticulture/cloth-filter 

4. Giles, A. (2024, February 14). Water filtration stages: Which water filter removes the most contaminants?. Brio Water. https://briowater.com/blogs/blog/which-water-filter-removes-the-most-contaminants?srsltid=AfmBOorgvafj_TfxCYKNGpJy95IYSeivru2PvEHp5l6qE_iuxXOypMya 

5. Water, A. (2025, April 30). Six types of water filters and their benefits. APEC WATER. https://www.apecwater.com/blogs/water-quality/six-kinds-of-water-filters-and-their-benefits?srsltid=AfmBOoouSbFoPwsnpvvzwEAdD5sIBrkLAIiaJOfTPEDfyXz5OYxHSELj 

6. Agrawal, V., & Bhalwar, R. (2009, July). Household water purification: Low-cost interventions. Medical Journal, Armed Forces India. https://pmc.ncbi.nlm.nih.gov/articles/PMC4921383/ 

7. Hawach. (2026, January 8). A brief introduction of Filter Paper. https://www.hawach.com/news/a-brief-introduction-of-filter-paper.html