Project Question: Project: Testing the SODIS method of disinfection to see if it will work. Question: Why is the SODIS method not directly applied? and Doesn't boiling the control group defeat the purpose?
Project Due Date: N/A | Note: I must submit a grant (due NOV 26) and I must have everything cleared up ASAP before doing so
Hello! I am doing a science project in which my partner and I will investigate the SODIS method to see if it will work. We plan to acquire three samples of water from our city and surroundings ones. Some water from each source will be put through the SODIS method of disinfection and the rest will serve as the control group. Then both samples from each source will be tested for how much pathogens they contain and the results will be compared.
Why are the bottles put under the light to simulate the process and not directly applying the method by putting it outdoors?
Why is the water in the original, dirty (control) group boiled before being tested for bacteria? Wouldn't that defeat the purpose since we're trying to see how much bacteria it contains and boiling with just kill them?
I feel like maybe our bacteria testing process might have to differ from that one. Will it?
This is a fascinating project that certainly will have useful application in many areas of the world.
You wonder why the procedure has you use UV light instead of sunlight outdoors. Look at the "make it your own" section and you will see suggestions for testing the process both with UV light and outdoors. This will allow you to compare the results from both processes!
You also suggest that boiling the water will kill the bacteria. The procedures suggest that you measure the bacteria (using the agar plates) separately for the boiled water and separately for the untreated water. This will allow you to in fact see the difference in the bacteria counts, and compare these results with the counts for the UV treated water.
Remember to replicate the experiments as indicated in the procedures, record the results, and then make a graph to show the bacterial counts for each of the processes, including the outdoors method if you want. I think that your results will be very interesting!
Good luck and be sure to let us know how you do! And ask more questions if need be!
Madeline B
Project Question: Project: Testing the SODIS method of disinfection to see if it will work. Question: Why is the SODIS method not directly applied? and Doesn't boiling the control group defeat the purpose?
Project Due Date: N/A | Note: I must submit a grant (due NOV 26) and I must have everything cleared up ASAP before doing so
Thanks for clearing that up! Judging by the information you gave, it seems as if our project deviates from it's original counterpart. We'll be directly applying the method to our water and simply measuring for bacteria in the treated halves and control halves. My only problem is whether we can follow the same bacteria testing process as described in that procedure. The bacteria testing process is still confusing me and when I searched for visuals, the best I could find was this video (https://www.youtube.com/watch?v=6-chXVgu8Z0). While it's simple and informative, I need something more in-depth (but still easy to understand).
Are tryptic soy agar plates still the type we need?
How many plates will probably be required to test one sample? (We'll be collecting a gallon of water each from 3 sources, so we'll have 3 gallons of water, each from one location. Some water from each source will have the SODIS method applied. The rest will be controls. Then, each "thing" will be tested for pathogens. In total, 6 "things"/samples will be tested.)
Are the glass stirring rods still required?
How many glass medicine droppers are required?
Sorry with the bombardment of questions. I need to send a grant in very soon and I'm still confused on things.
*Note: I'm using the words bacteria and pathogen interchangeable here, even though I'm referring to pathogens as a whole.
Hello again MustFinish_Project,
Let me start by helping you answer the second part of your last post: I suggest that a good way to figure out the number of each item of lab materials you need would be to look carefully at the Procedures
I suggest that you start by listing each experimental condition you intend to test. Don't forget to count the controls as one of the conditions. Then make a table in your lab notebook for each condition, outlining each step as described in the procedures, and write down the names and number of pieces of equipment (for example, medicine dropper, glass stirring rod, etc) used at each step.
You should repeat each table for each of the conditions which you intend to test. This will help you calculate the amount of each item needed for each test. Then multiply those amounts by the number of times each test will be repeated.
I think that following this procedure will also help you understand the bacterial testing process.
Be sure to let us know if this helped and if you have additional questions!
Madeline B
Project Question: Project: Testing the SODIS method of disinfection to see if it will work. Question: Why is the SODIS method not directly applied? and Doesn't boiling the control group defeat the purpose?
Project Due Date: N/A | Note: I must submit a grant (due NOV 26) and I must have everything cleared up ASAP before doing so
Thank you for your help! The fair was about 3 weeks ago and I would say we (my partner and I) did well. It was an emotional rollercoaster (that's the best way I can put it), but I managed to get through it. Once, again, thank you for your help! Have a great day!
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