Solar Bag: Purifies Water While Walking

UNIVERSITY OF OREGON, OREGON, USA. A solar bag is a bag that holds water and hangs off the shoulders and lies on a person’s back. It uses the sun’s UV radiation to kill the bacteria in the water while the person in walking. There are many people in the world who do not have access to clean drinking water. In Africa alone, children get sick because of the bacteria in the water they drink. Some of them eventually die. This innovation can help a lot of people who need to walk several miles to get to a water source and have to carry the water back for purification. The solar bag can provide convenience and efficiency when the need for water is very urgent.

Ryan Lynch and Marcus Triest from the University of Oregon designed the solar bag as a solution to people who need clean water when they need it most especially in extreme and obscure locations (sub-Saharan Africa). They used the SODIS water purification method. This is where polyethylene terephthalate (PET) – the type of plastic used for soft drinks are filled with water. They are exposed to sunlight for up to 6 hours, allowing the UV radiation to kill most of the bacteria in the water.

Instead of using bottles, they created a 2 sided bag. The inner side is black plastic that absorbs heat. Thus, helping the UV rays to function well. The outer side is the one facing the sun when a person walks. It is made of clear plastic that allows the UV rays to enter. The bag is connected to straps that allow the water to be carried like books. It can be hung on a wall for continuous water treatment once the person arrives at his or her destination. It has a tap at the bottom to let the water out. Also, it has a squeeze balloon with filter for additional purification.

Currently, the solar bag can purify two and a half gallons of water in six hours. This is the same amount of time it usually takes other water purifying system to treat water but in lesser volume.