Brine Science: How Salt and Ingenuity Purify Water for Thousands in Asia and Africa

Early last summer, Sister Mary Ethel Parrot dropped by the office of WaterStep, a Louisville charity fighting waterborne disease around the world, and picked up a pair of tote bags filled with tubing, clamps and other plastic parts. The nun took them on a plane to Uganda, where she had set up a boarding school for girls.

In Africa, Sister Mary Ethel, who is also a trained physicist, helped assemble the kits into a pair of ingenious mini water-treatment systems that look like a cross between a tea kettle and a bicycle pump. The devices use ordinary salt and electricity from a car battery to produce chlorine gas that kills germs in water for 600 African students and nuns at the Sisters of Notre Dame School and convent in rural Uganda. “In Uganda they can get their hands on salt, but not much more,” says Steve Froelicher, an engineer at GE Appliances in Louisville who helped design the system. “With salt, a car battery and some solar panels you could be making clean water for years.”

Froelicher and his colleague Sam DuPlessis led a group of GE volunteers who together with WaterStep designed the device last year. The system runs electric current between two electrodes through a water solution of sodium chloride, a.k.a. table salt. The electrolysis breaks up the salt molecules and frees bubbles of chlorine gas from the brine.

Read more about brine science at GE Reports.