Portable Desalination System Designed for Use in Disaster Zones
A new system for desalination has been designed by researchers at the Massachusetts Institute of Technology (MIT). The system uses solar power to push ocean water through a permeable membrane which is capable of removing salt and other minerals. Such a portable system would be ideal for disaster-torn regions of the world which have lost access to clean water.
The MIT Field and Space Robotics Laboratory designed the system that can be deployed quickly in a crisis such as the devastating earthquake that befell Haiti. After the quake, many people lost their access to fresh drinking water, and many still suffer from dehydration. Haiti, being an island nation, is surrounded by the ocean, a resource that could prevent such a fate.
The concept of desalination is nothing new. Most desalination plants are huge plants capable of producing massive amounts of water, but also use massive amounts of energy to do so. The difference is that MIT's design is portable and self-contained. It has no need for an external power source thanks to its solar panels. Their prototype is able to produce 80 gallons of water per day, and they estimate that a larger version could provide up to 1,000 gallons per day.
Steven Dubowsky, professor at the Department of Mechanical Engineering, and his students estimate that one of the military's C-130 cargo planes can transport 24 of the larger desalination units in one trip. That number of units could provide about 24,000 gallons of water per day, enough to sustain 10,000 people.
The system is designed to be cost effective. It is made from standard parts such as PVC pipe and basic electronic components. It can be assembled and operated by local people who do not need advanced technical training. The units can also operate efficiently in a wide range of weather conditions. They have built in computers with sensors that can change certain variables if it gets cloudy. For example, the computer can adjust power going to the pump or the position of the valves to ensure the system will always produce water.
The system relies on reverse osmosis, a filtration method that removes particles such as salt by applying hydraulic pressure as the ocean water flows over the permeable membrane. The solar panels provide the electric current to power the pumps which pressurize the vessel that contains the membrane. Because of the high pressure, the water that permeates through the membrane has had the salt and other minerals removed, making the water safe for consumption.
As population grows in the world's poorest regions, access to fresh water will become more and more difficult. And if these regions are hit with a natural disaster, access can be downright impossible. A simple system that can be operated by anyone, such as the one designed by MIT, could be crucial in providing water from the planet's most abundant resource, the ocean.
Watch video of the MIT portable desalination system: http://www.youtube.com/watch?v=j2bVJxuFP4I
Photo courtesy of Melanie Gonick, MIT