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. â€œIn Uganda they can get their hands on salt, but not much more,â€ says Steve Froelicher, an engineer at GE Appliances in Louisville who helped design the system. â€œWith salt, a car battery and some solar panels you could be making clean water for years.â€
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.