The hypothesis is that the lower the degree of transparency of the plastic bottle surface, the lower the level of disinfection.

You will prepare 7 clean PET bottles, scratch the outer surface of 4 bottles to four different levels of opacity, fill all 7 bottles with an equal amount of tap water, mix each bottle with 3gm of E.Coli culture, place 5 of the bottles under sunlight for 6 hours, and place the other 2 bottles in the shade for 6 hours.

You will need 7 PET Bottles, 7 liters of Tap Water, Escherichia Coli bacteria culture, 7 Agar plates in Petri Dishes, 7 Syringes, and a sharp object, e.g. penknife, blade etc.

The results showed that the amount of bacteria increases as the degree of opacity increases. This study is important for those countries using SODIS as a method for disinfecting drinking water, as it can help eliminate or minimize diarrhea-related deaths.

This science project is interesting because it explores how sunlight can be used to disinfect water, which is a cheap and efficient way to produce water safe for drinking and is currently widely used in many third world countries.

Variations to consider include what happens if bottles made from other material are used, how to make sure the PET bottles are 100% clean before carrying out the experiment, and what controls of the experiment should be taken into consideration besides the ones mentioned above.

Hey there! Here are some awesome videos about this science project that we think you'll really like. They're not only super fun, but they'll also help you learn more about the science behind the project. So sit back, relax, and get ready to have some fun!!