Shear Extrusion to Treat Fecal Waste

Gary Foutch and AJ Johannes of Oklahoma State University in the U.S. propose to develop a small-scale device in which an auger forces feces and other solid wastes device through a die that results in high temperatures and pressure that dewaters the waste and destroys microorganisms. The device could reduce odor, insects, surface and ground water contamination, and the associated spread of diseases. In Phase I, they designed a laboratory-scale extruder, which is a fixed shell containing a rotating inner core driven by a motor, and an air-driven plunger to push in the material and generate pressure. They tested its performance using different operating conditions. Preliminary results revealed that their method could destroy 99 percent of parasitic worm eggs in baboon feces. In Phase II, Foutch, AJ Johannes and colleagues will develop and field test a next-generation stand-alone extruder that can effectively sanitize different types of solid sludge in the field, and is also capable of water recovery via evaporation. They will also design a sanitation module from their extruder that can be incorporated into the Omni-Ingestor technology, which is a modular system that combines sanitation with waste removal and transportation.