Lab Report

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER

Introduction (Will) :

Which activated carbon filtration material leads to the clearest water. Alina, Amanda, Uriel and Will
The City College of New York

Clean water is a necessity for survival. It is used in countless everyday tasks such as showering, washing clothes/dishes and most importantly drinking. In order for water to be clean enough to drink, it must be free of impurities. Water is filtered and purified by many different methods but one of the most common ways is by use of a carbon filter. Activated carbon or activated charcoal is a very porous form of carbon. As stated by Lohner (2019), the porous characteristic of activated carbon is what makes the compound serve as a good material for water filtration. The porous structure of the compound results in it having an extremely large surface area to volume ratio. “About five teaspoons (10 grams) of granular activated carbon has a surface area that is approximately the area of a football field.” (Lohner, 2019). When water passes through the porous structure of the activated carbon, impurities in the water bind to the carbon by the process of adsorption.​ “An adsorbent attracts other liquids or gases onto its surface only. However, the “surface” can also include internal surfaces, like pores and capillaries. Highly porous substances, like activated carbon, are great adsorbents.” (McGrath, 2012).​ As stated by McGrath (2012), the covalent bonds and weak molecular interactions of van der Waals forces are what keep the impurities bound to the carbon structure. The principle driving characteristic of this process of adsorption is the amount of surface area that the activated carbon in solution has

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER 2
for impurities to bind. The greater surface area to volume ratio that the activated carbon possess leads to a larger area of the carbon exposed to the water that is able to bind impurities. Another factor that is important for the carbon’s ability to bind impurities in the amount of time that the water is exposed to the carbon.

In this experiment the filtration efficiency of two different particle sizes of activated carbon will be examined. Water will be filtered with a granulated form of activated carbon and a powdered form of activated charcoal. The hypothesis is that the powdered activated charcoal will be more efficient at purifying the water than the granulated activated carbon. The justification behind this hypothesis is that since the powdered form of activated carbon is a smaller particle size and thus has a larger surface area to volume ratio, it will have a larger area of binding sites exposed to the water in the solution for the same amount of carbon and should therefore be able to bind more impurities in the same amount of time.

Materials and Methods (Alina) :

Plastic cups, Food color (green, blue or red).Spoon,Rubber bands, Measuring cup,paper towels,permanent markers, Lab Notebook.

Methods:

We have to prepare a total of 21 cups, 3 cups with different food color solutions and 9 cups with no powdered carbon and 9 filtration cups and empty cups with filter paper attached. In step 1 we have to prepare the water samples that we are going to filter. Then we need to use food coloring that needs to be removed from the water. Prepare three food color solutions and each solution with a different concentration.After preparing three food colour solutions label these

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER 3
three cups with a permanent marker. Than measure 2 cups (about 500 mL) of tap water into each plastic cup using the measuring machine. After this we have added food color to two of the three cups. Then we have two cups of liquid in each of the cups. After this add 4 drops of food colour to the label cup A, 10 drops of food colour to the cup of liquid that you labeled as B. Stir each of the solutions with a clean spoon to mix the food color.

Then prepare activated carbon for your filter. We tested activated carbon and no activated carbon for different concentrations. As you will test all dye concentrations, we labeled 3 cups for each form of carbon we test. We labeled Cup A and Cup B.

Our label tells us which kind of concentration and what dye concentration we used. At the end, we should have 9 labeled cups. Use a measuring machine to weigh out 3 grams of granular activated carbon into each cup that you labeled with cup A. Next, we set up filters for the different forms of activated carbon and dye concentrations. Label 9 cups in total, one for each testing condition. Again, make sure that your label is specific to the type of activated carbon and the dye concentration that you are going to test. Take 4 coffee filters and stack them into each other press the filters into the top of a cup, fold their edges.and bind them with a rubber band. Repeat step for the remaining filtration cups. Before you start with your filtration experiment, prepare a data table such as Table 1 in your lab notebook. You will rate the color of your water samples on a scale from 0–10, where 0 and 10 is the darkest you will have to choose a number to assign to the intermediate cup, which may vary slightly depending on the type or color of food color you used Within a specific dye concentration, they should all look the same.

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER 4

Then take a picture of all your solutions. For the filtration experiment using no activated carbon, pour each of the prepared water samples onto the filtration cups. At the end, write down your observations about the collected water samples after filtration in your lab notebook.

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER 5Results (Amanda) :

We wanted to figure out which filtration material would provide the cleanest water to drink. From out experiment our answer is no doubt the powdered charcoal per the result tables down below. In the data tables it might look repetitive in the columns but those are base levels for our “contaminants” in the water.

Carbon type: No carbon		Color rating after treatment
Dye concentration (drops/cups of liquid)	Color rating before treatment
0	0	0
2	7	7
5	10	10

Figure A

Carbon type: Granulated		Color rating after treatment
Dye concentration (drops/cups of liquid)	Color rating before treatment
0	0	0
2	7	5
5	10	8

Figure B

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER 6

Carbon type: Powdered		Color rating after treatment
Dye concentration (drops/cups of liquid)	Color rating before treatment
0	0	0
2	7	0
5	10	0

Figure C
The tables depict the amount of contaminant (first column) that was put into every filter

for each material. The second column is what the contaminant level before filtration. 1 being the lowest and 10 being the highest. The final column is the contaminant level after filtration. *Water not tested in lab therefore the results can be a little skewed or abstract.
*Treatment – the filtration

The results for the No carbon filter is exactly what is expected. No filter material the water will just go straight through. That is why the columns the numbers are the same. The results for the granulated carbon filter was what is expected. Larger grain size helps water go down easier but it doesn’t filter the water. As we can see by the results, the concentration of contaminate only lightened you but did not clear all the way through. The results for the powdered carbon was exactly what is expected. Sediments that are less porous filter water substantially better. Although it takes the most time for filtration to happen you get the cleanest water. The water being filtered through the powder took approximately 4 minutes longer to filter than it’s other two counterparts.

Filtration through carbon or activated charcoal is not the only way to filter tap water. There is reverse osmosis, UV-disinfection, and ozone treatment among other options. (Boutilier,

WHICH ACTIVATED CARBON FILTRATION MATERIAL LEADS TO THE CLEAREST WATER 7
2014) which means we can’t say for certain which is a better filtration method to get clean water. While the carbon produced clean water by color does not mean there are other contaminants besides the food coloring in the tap water. Boutilier writes, “controlling water quality at the point-of-use is often most effective due to the issues of microbial regrowth, byproducts of disinfectants, pipeline corrosion, and contamination in the distribution system”. The experiment done here can not possibly test for all other contaminants. Without a proper lab to see how particles bond and how those bonds work in filtration.

Discussions and Conclusion (Uriel) :

Throughout our procedure and results collected, we were able to conclude that our hypothesis was in fact correct after all. The only filtration system that was most effective during the procedure was the powdered carbon. When the water w/ contaminant (green dye) came into contact with powdered charcoal, it was sucked up by the charcoals binding particle sites. This is due to the fact that powdered charcoal has a very small particle size so its surface area was very large, allowing it to be able to consume all contaminants as a whole. On the other hand, the granulated charcoal was just swept away by the water in the cup as we poured in the water and water with contaminants. This is because of the larger size of the granulated charcoal particles possibly not being able to suck up the water properly because of its binding sites and low surface area.

A common question that could be brought up from this is how would the experiment change if warm water was used. Would warm water dissolve any of the charcoal types, causing a different result when it came into contact with the contaminant? These conclusions and results

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may also be compared to theoretical ideas of how charcoal overall works. Some may believe that all charcoal works the same, no matter the texture and the size. However, each charcoal type may change based on the temperature of water being used. This then can change the purpose of the charcoal being used, hence changing the result that it can give.

References :

Boutilier, M. S. H., Lee, J., Chambers, V., Venkatesh, V., & Karnik, R. (2014). Water Filtration Using Plant Xylem. PLoS ONE, 9(2), e89934. Retrieved from https://link-gale-com.ccny-proxy1.libr.ccny.cuny.edu/apps/doc/A478792267/HWRC?u=cuny_cc ny&sid=HWRC&xid=299c6f1a

Lohner, S. (2019, July 16). ​Which Filtration Material Leads to the Best Drinking Water? ​Science Buddies.​ Retrieved from

https://www.sciencebuddies.org/science-fair-projects/project-ideas/Chem_p108/chemistr

y/which-filtration-material-leads-to-the-best-drinking-water#background

McGrath, J. (2012, April 10). How are adsorbents used for environmental cleanup? ​How Stuff Works. ​Retrieved from

https://science.howstuffworks.com/environmental/green-science/adsorbents-for-environm ental-cleanup.htm