The scientists looked at how to break down harmful chemicals (BTEX) found in water using light and hydrogen peroxide. They tested two types of light, and they found that you need 250 mg of hydrogen peroxide for UV-185 light and 300 mg for UV-254 light to clean 100 mg of the chemicals in the water. Combining the lights didn't improve the cleaning process. When the water was acidified (pH 3), UV-185 light with hydrogen peroxide removed more BTEX than UV-254 light with hydrogen peroxide. In acid conditions, 90% of the chemicals were cleaned by UV-185 light and hydrogen peroxide. Over time (around 140 minutes), the amount of waste in the water decreased by about a quarter to a third.