IRFP: Inactivation of Pathogens and Fate of Pharmaceuticals in Novel Treatment Processes for Source-Separated Urine in Durban, South Africa

Bischel Heather N, Stanford CA

Investigators

Abstract

The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award is co-funded by the Office of International Science and Engineering and by the Environmental Engineering Program in the Chemical, Bioengineering, Environmental, and Transport Systems Division. This award will support a twenty-four-month research fellowship by Dr. Heather N. Bischel to work with Dr. Tamar Kohn at École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland and University of KwaZulu-Natal, Durban, South Africa. In this project, the inactivation of pathogens and removal of select trace organic chemicals of concern (TrOCs) are assessed to evaluate the safety and optimize design parameters of urine recycling systems. The primary goals of urine recycling systems are to increase access to sanitation, recover valuable nutrients for revenue generation, and protect human and environmental health. Several technologies to collect and treat stored urine from urine-diverting dry toilets (UDDTs) to produce fertilizers are under development through the "VUNA" project, a collaborative effort between the Swiss Federal Institute of Aquatic Science and Technology (Eawag) in Switzerland and eThekwini Water and Sanitation (EWS) in Durban, South Africa. This International Research Fellowship Program award will support Dr. Heather N. Bischel to work with Dr. Tamar Kohn at École Polytechnique Fédérale de Lausanne (EPFL). Research will be conducted at EPFL, with field components in Durban in coordination with the University of KwaZulu-Natal. The project leverages technological expertise from VUNA to develop an understanding of pathogen inactivation and trace organic contaminant removal processes and to model the fate of contaminants in urine recycling systems and urine-derived fertilizers. Field analysis for pilot-scale urine recycling reactors operating in Durban will be conducted for comparison to laboratory-modeled contaminant removal processes. As an alternative to an expanded centralized sewerage system, the municipality that serves Durban installed approximately 90,000 UDDTs in the city's peri-urban areas. Currently these UDDTs separate urine at the source for diversion to soak pits, and feces are collected in vaults for drying following the addition of ash or sand. For this system, however, separately collected urine could be processed, rather than disposed, to recover nutrients and produce urine-derived fertilizers. In addition to introducing a potential source of revenue, recovery of nutrients for reuse also lowers phosphorous and nitrogen concentrations in the waste stream, thus reducing environmental contamination. Pathogens and TrOCs in the urine-derived fertilizer and reactor effluent may impact the quality, or perceived quality, of end products. Ultimately, this project will contribute to the design of improved urine recycling technologies to achieve the best possible hygiene standards.