Breathable Membrane Enclosures for Fecal Sludge Stabilization

Steven Dentel of the University of Delaware in the U.S. will test the ability of a low-cost polymeric breathable membrane liner to accelerate the drying and disinfection of fecal waste in pit latrines, while protecting surrounding groundwater from being contaminated with pathogens and chemicals. Breathable membranes are hydrophobic, allowing only air or water vapor to pass through them. In Phase I, Dentel demonstrated that containing fecal sludge within a breathable membrane enabled it to be effectively dried under different environmental conditions, and resident pathogens were trapped and subsequently inactivated. He also showed that the membranes are reusable, and could be used to physically remove the dried waste for safer cleaning. In Phase II, Daniel Cha of the University of Delaware will build mini-latrines for laboratory experiments to calculate rate limitations for water vapor flux and the energy requirements for water vaporization, as well as analyzing the ability of volatiles such as ammonia to pass through the membrane. Then he will design and run field-tests in Africa.