Water Purification

This exercise was developed by Dr. Michael Hotz, Wyandotte High Science Teacher and Lead Teacher at the KCK Saturday Science and Math Academy



Lab Activity: Simulated Drinking Water Treatment Plant


WARNING: THE WATER USED IN THE EXPERIMENT IS NOT SUITABLE FOR DRINKING AT ANY STAGE IN TREATMENT. HENCE, DO NOT CONSUME TH WATER UNDER ANY CIRCUMSTANCES. Begin by familiarizing yourself with the lab procedures. It is important that you know the steps well as mistakes may cause you to have to repeat a process.


CONTAIMINATED WATER--Cap and shake the container of contaminated water, and pour 1.5 L into one of the empty two liter bottles. Rank the appearance and odor of the water. * Scale: Apperarance 1-5 with 1 being clear. Odor 1-5 with 1 having no odor.


1 2 3 4 5
Appearance:






Odor:














STEP 1: Aeration -- Cap the two liter bottle and aerate the water aby shaking it vigorously for 30 seconds. Pour the water into one of the cut-off two liter bottles, and then pour the water back and forth between the cut-off two-liter bottles five times. Once you are done, rank the appearance and odor of the water. * Scale: Apperarance 1-5 with 1 being clear. Odor 1-5 with 1 having no odor.


1 2 3 4 5
Appearance:






Odor:






STEP 2: Coagulation--The water should be in one of the cut-off two-liter bottles. Add 20 grams (1 teaspoon of alum crystals to the container and stir gently for 5 minutes. The alum wil act as a coagulant and bind with the particles suspended in the water. Describe what happens to the appearance of the water during the 5 minutes. *




STEP 3: Sedimentation--Leave the container undistrurbed for 20 minutes, and record the observations of the water's appearance at 5 minute intervals. *


STEP 4: Filtration--Construct the filter apparatus as directed(go back to the top under Constructions). Pour approximately 1 liter of clean water through your filter to clean it.(Be sure to have a collecting container under the filter before you do this.) Pour this water down the drain. Carefully and slowly pour off the top two thirds of the water in the container into a clean beaker(or cut off bottle). It is important that you do not disturb the sediment when pouring, so take a great deal of care during this step. Allow the water to settle, and then pur 400 ml of water from the beaker into the filter aparatus. The water will percolate through the sand and pebbles and collect in the beaker beneath the apparatus. Describe the appearnace and odor of the water after it has been filtered. Pour the remaining water and sediment in the two liter bottle into the 5 gal white bucket. * Scale: Apperarance 1-5 with 1 being clear. Odor 1-5 with 1 having no odor.


1 2 3 4 5
Appearance:






Odor:






STEP 5: Disinfection: The final step in the process, the elimination of any remaining microorganisms, WILL NOT BE DONE in this exercise. This is normally an important step in the process, but as the water is not to be consumed and disinfection methods can be dangerous outside of controlled conditions, this step will not be done.
ANALYZING RESULTS: Appearance--Rank the appearance through out the treatment process. * Scale: Apperarance 1-5 with 1 being clear. Odor 1-5 with 1 having no odor.


1 2 3 4 5
Contaminated Water






Aeration






Coagulation






Sedimentation






Filtration






ANALYZING RESULTS: Odor--Rank the odor through out the treatment process. * Scale: Apperarance 1-5 with 1 being clear. Odor 1-5 with 1 having no odor.


1 2 3 4 5
Contaminated Water






Aeration






Coagulation






Sedimentation






Filtration






Did the appearance change from the begining to the end? *
  • Yes
  • No
  • Stayed the same.
Did the odor change from the begining to the end? *
  • Yes
  • No
  • Stayed the same
How well would you say this filtration process worked? *





What suggestions do you have for making this experience better. *


Go to EPA website for instructions



Teacher's notes


YouTube Video



Water Purification