Cactus goo purifies water

From Washington, D.C., at a meeting of the American Chemical Society

WATER FILTER. This nopal cactus could help Mexican communities purify drinking water. Alcantar

Many Mexican communities have drinking water laced with unsafe levels of arsenic and unappealing amounts of sand and other solids. To make the water cleaner, Norma Alcantar, a chemical engineer at the University of South Florida in Tampa and her colleagues are working on an environmentally benign filtering process based on a plant found all over Mexico: the nopal cactus or prickly pear.