Zeno Karl Schindler Award 2017 – Heather N. Bischel

"For her contributions to the development and evaluation of sustainable solutions for sanitation and resource recovery in low-income settings. Her highly interdisciplinary work is instrumental to both public health protection and consumer acceptance of a promising technology."

Humanity’s perturbation of natural phosphorous and nitrogen cycles, especially due to the production of agricultural fertilizers, has disrupted planetary equilibria. Overproduction and use of synthetic fertilizers in developed countries contrast with nutrient poor soils in many developing regions, where large quantities of human excreta also remains untreated without appropriate sanitation. An opportunity exists to link local production of fertilizers, and associated revenue generation from their sales, with improved sanitation infrastructure through the recovery of nutrients from human excreta. Human urine in particular contains the bulk of the nutrients in human excreta and can be processed into valuable liquid or solid fertilizers. Assuring human health safety in the production and application of waste-derived products is critical to market success, but the safety of these practices in urine-diversion systems remain under characterized. Through a combination of field studies, laboratory experimentation and modeling, Dr. Bischel’s research evaluated health and hygienic hazards in “source-separated” human urine and urine-derived fertilizers in Durban, South Africa and developed strategies to reduce health risks through targeted management and treatment processes. The research included a hazard assessment of urine collected from a decentralized, dry sanitation system; an evaluation of mechanisms of microbial inactivation in urine nutrient recovery reactors; and the first high-resolution quantitative microbial health risk assessment of the sanitation value chain. This work contributes to a shift in the sanitation paradigm, for which human waste can be regarded as a valuable, safe resource.