Tsai’s process involves using a CD’s flat surface as a platform on which to grow zinc oxide. Later, when illuminated with UV light in a prototype water treatment device, the zinc oxide acts a photo-catalyst, breaking down organic pollutants in sewage water that’s filtered in by a hose.
In a test, the researchers found that “over 95 percent of the contaminants had broken down after just 60 minutes. That's about 150 ml of waste water per minute.” For comparison, a typical bottle of water contains 500 milliliters.
Tsai said the device could be used on a small scale to clean water that is polluted with domestic sewage, urban run-off and farm waste.
Globally, 884 million people don’t have access to safe drinking water. And the number one of cause of illness and death worldwide is diarrhea, 88 percent of which is caused by lack of access to sanitation facilities and unsafe drinking water.