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Title: Killing Coli formsObjective: To determine if two different methods listed below will kill coli forms in contaminated water.
Boiling for ten minutesChlorine
Hypothesis: I think that the two methods will kill all the coli forms in the water to a level considered safe for consumption because they are all well known methods of sanitation.
Materials:
Approx. 28 grams of feline fecesTwo and a half liters of room temperature water [68 degrees F. to 72 degrees F.]
3 four liter milk containers labeled A B, C, with caps with pin sized holes to allow venting of Carbon Dioxide
Permanent marker to label milk containers
A funnel
Testing materials to perform 3 tests
Cheesecloth
Four pairs of latex gloves
A pair of safety glasses
A cloth for clean up
Sanitizing spray for clean up
A pot to boil sample water with a lid
A counter top
Measuring syringe
A pencil with an eraser for data collection
Two sheets of paper for data collection
Variable(s):
Independent - The two methods of sanitation:Boiling for ten minutesChlorine
Dependent - Whether or not each method kills the coli forms to an acceptable level.
Control - All samples and tests are kept in the same temperature and all coli forms tests are performed in the same manner at the same time from the same sample batch.
All measuring syringes, milk containers will be sanitized between uses with bleach then thoroughly rinsed with hot water [160 degrees F.]Procedure:
Step A: Growing Coli Forms Samples:1. Grow a coli form culture by adding feline feces to two and a half liters of water at room temperature [68 degrees F. to 72 degrees F.] into milk container A, while using safety glasses and latex gloves.2. Allow the culture to incubate in a room temperature environment [68 degrees F. to 72 degrees F.] for a period of five days.
3. Pour the samples water though the cheesecloth from milk container A to milk container B using a funnel to remove most of the particulate.
4. Test sample water using a test kit to verify that there are live coli forms present in the water.
Step B: Preparing For Testing:
1. Transfer one liter samples from container B to container C, and to the pot.2. Heat the pot to a boil and boil covered for ten minutes, set aside over night until cooled to room temperature.
3. Measure out 4 drops of chlorine with the measuring syringe, and add to container C, and shake well, set aside over night.
Step C: Testing Treated Samples:
1. Read test kits instructions.2. Perform test according to instructions on the treated samples from the pot.
3. Collect data.
4. Perform test according to instructions on the treated samples from container C.
5. Collect data.
Step D: Clean Up:
1. Properly dispose of all sample material.2. Sanitize all equipment that was used.
3. Recycle all three milk containers.
4. Properly dispose of all leftover chemicals.
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