Foul Water Lab

Chase & Oliver

The Electrons Lab Report

6/14/11

Foul Water Lab

In our lab, the goal was to filter extremely foul water enough to be able to wash your hands with that same water. At the beginning of our lab we received 100 mL of extremely foul water in a glass beaker. With this water we first put it through the process of oil - water separation. This was a process where we removed the visible layer of oil with a barrel pipette. We went through this step three complete times. At first, we barely removed any oil. The second try we received more oil then the first attempt, but after this second try we realized that the mouth of the pipette was too thin to extract the thick oil from the water. In this case, we took scissors and cut the tip of the pipette so that the mouth was wide enough to get the oil out. This simple change allowed us to completely remove all visible oil from the water. Now left with 86 mL of foul water, we moved on to sand filtration. In this step, we place a damp 2 cm layer of sand in the middle of two 1 cm layers of gravel. This sand and gravel was held in a small cup with holes poked into the bottom. The goal was to have the water seep through the gravel, be naturally filtered by the sand and out the holes on the bottom of the cup. This is not what happened. In fact, the sand was so fine that it came out the holes with the water. Faced with a conflict, we decided it was best to add another step. In this step we carefully poured the water into a filter papered funnel. This method was ultimately proven too slow, so we moved on to the final step, Charcoal adsorption and filtration. We took a tea spoon of charcoal and poured it into a flask. Then we also poured the foul water into the same flask and vigorously mixed for a few seconds. While I ( Chase ) mixed the water with the charcoal, Oliver set up the funnel filter. In this, he folded filter paper and placed it in a funnel which was elevated on a ring stand. We then placed a new beaker under the funnel, the water would slowly drop into the beaker as it made its way through the filter paper. This was the longest process of all. During this step we had learned that the charcoal we had been given was of a lower quality, and because we were so far into our lab, it was too late to make any change. This played a major role on our end result, while also prolonging the step. We used glass stirring sticks to help the water through the paper. Half way into the charcoal adsorption, Dr. Forman kindly switched our filter paper with new paper. This sped up and finished our lab. At the end, we had 65 mL of yellow colored water. This water had a rubber like odor and had no oil or no solids. 

Procedure:

• First we received 100 mL of foul water
• Then we used the barrel pipette to remove the oil from the top layer of water
• First try with the pipette we barely removed any oil
• second try we received more oil than the first try
• After the second attempt we realized that the mouth of the pipette was too small
• We used scissors to cut a bigger mouth on the pipette
• On the third try we removed all visible oil from the foul water
• Then we re-measured our water in a graduated cylinder
• After the oil separation we went to sand filtration
• We received a small styrofoam cup and poked holes in the bottom using a paper clip
• In the cup we added: 1 cm of gravel on the bottom, then 2 cm of sand, and topped it with another 1 cm layer of gravel
• We then made the gravel and sand damp so that all the water was not absorbed into the sand
• The sand was so fine that it seeped through the bottom with the water
• We then added another step
• We added filter paper to a funnel and placed a clean beaker underneath 
• This stepped was proven to slow
• We then went straight to charcoal adsorption and filtration
• We received a tea spoon of charcoal and one flask
• We put the water and charcoal in the flask and mixed the two 
• While I ( Chase ) spun the flask Oliver set up the filter papered funnel in the ring stand and placed a clean beaker under to catch the water
• At this point we learned that the charcoal given to our group was a lower quality 
• But it was too late for our group to switch charcoals
• Because our lab was taking so long we used glass stirring sticks to help aid the water through the filter paper
• Towards the end of our lab Dr. Forman replaced our old filter paper with new paper
• This sped up and finished our Foul Water Lab
• We ended with 65 mL of a yellow, rubber odored, water
• 
  
• 
  
• 
  
• In our end results we were left with 65 mL of yellow water. This water was yellow because the charcoal we received was at a lower quality then other charcoal given out. However, the water was some what clear and had a rubber like odor. all visible signs of oil and any solids were removed. 
• 
  
• Data Analysis:

1. Our percent recovery of water was 65%. 

2. We lost 35 mL of foul water in our purification process.

3. 35% of the original foul water was lost during this process of purification.

4. ( Chart )

5. The largest percent recovery was 70%, and the lowest was 54%. Our classes range of percent recovery was 16.

6. The average percent recovery for our class was 64.3%

Post Lab Activities:

1. 

a. In the process of distillation, you use a distillation apparatus. This apparatus has three main sections, one round flask which holds the non pure fluid, a tube containing cool water, and another empty round flask on the other side of the tube. Under the non pure liquid is a heating plate which ( in the case of salt water ) boils the water. The water begins boiling and evaporating around 100 degrees. Sense the salt has a much higher boiling point it stays at the bottom of that flask. The vapor from the liquid then flows upward and condenses because of coming in contact with the cool water in the tube. The liquid then travels through this tube, and drops into the empty flask on the other side. Containing the pure liquid.

b. Unsure ( did not learn )

c. The liquid was left to demonstrate the difference between distilled water and un pure water.

2. The salt in salt water is able to conduct electricity. Distilled water is not a conductor, due the fact it does not contain the salt particles. This teaches us that the water samples we produced are pure if they have no electricity and not pure if the light bulb shines. Every sample in class conducted electricity, even the ones that seemed to be perfectly clear. Teaching us that even when water seems pure, there may be particles unseen to the human eye.

Questions:

1. My purified water sample was not pure because my water conducted electricity when tested.

2. Someone should judge the success of a groups purification through the amount of electricity conducted when tested by the teacher. Once you get past that pivotal step, the next place to judge would be color, odor, etc.

3. You could improve the purification procedure by making a longer time frame. Allowing more time for purification would lead to a better result.