2012-10-10

Co.Exist

Table Salt and Electricity Come Together for Cheap, Clean Water

Remember your chemistry? Then you know that salt is part chlorine. Using a little ingenuity and a little electricity, you can use that chlorine to make water drinkable--and potentially save millions of lives.

Clean water in the developing world is critically important, but many systems are costly or require constant maintenance. And water is getting even more important: By the year 2020, some estimates say that as many as 135 million people will die from waterborne diseases--more than the combined total of those who die from war, HIV, and cancer each year. New technology to create clean water can help.

The story starts, like many ideas do, in a garage. Four General Electric engineers (two of them retirees) designed a water-cleaning device in a garage in Louisville, Kentucky. They were partners with a charity called WaterStep, which works to provide clean water to people in Haiti, India, Pakistan, and 23 other developing countries around the world. The organization estimates that a child dies every 20 seconds due to a waterborne illness and that 1.2 billion people, one-sixth of the planet’s total, lack daily access to safe drinking water.

In 2010, WaterStep contacted the engineers at the start of a cholera outbreak in Haiti. They were looking for a rugged, portable device made from ordinary materials that could treat 1,000 gallons of water in less than an hour. The engineers went to work, plowing through six prototypes before settling on a design that worked.

This is how it works: The device fits inside a 10-inch PVC cylinder with two plastic tubes attached at the top. It applies battery voltage across a circular membrane, pulling chlorine from salt water. The chlorine bubbles off one of the electrodes and floats to the top where the device captures it and mixes it with contaminated water. The chlorine begins to oxidize organic matter and kills the pathogens in the water, which can create 1,000 liters of clean water in an hour.

The engineers ramped up production after a flood in Pakistan and to help out a school in Uganda. Each device, they say, can be assembled from 100 parts, which can travel as checked luggage. They have been able to scale up production to 100 chlorinators per day, and they are working to reduce the amount of power the device requires to 25 watts. If that happens, it could work on solar power almost anywhere.

According to GE, Louisville has a long history with water filtration. Two centuries ago, the city was known as the Graveyard of the West and had constant outbreaks of cholera and typhoid. In 1896, the local water company figured out a way to filter water through sand rapidly and encourage particles to stick together for easy removal, processes that are still in place today around the globe.

Add New Comment

0 Comments