Prithvi Vijaya Simha

I research practical ways to recover resources from wastewater. My group develops and evaluates processes that convert human urine into concentrated fertilisers and other useful products, while mitigating risks from pharmaceuticals, pathogens and other micropollutants. 

I am particularly interested in ideas and technologies that can work outside controlled settings, especially in low- and middle-income countries across Southeast Asia, sub-Saharan Africa, and Latin America. Our work involves building and testing prototypes under real-world conditions, adapting them to contexts where energy, infrastructure, supply chains, or financing may be limited, and designing systems that can be manufactured locally and scaled over time. Alongside engineering, we study environmental impacts, social norms, user attitudes and experiences, regulatory pathways, business models, financing mechanisms, and institutional decision-making. 

I supervise doctoral and graduate student projects across a wide range of topics, from lab- and field-based experiments to socio-technical studies mapping nutrient flows in food systems and identifying socio-cultural barriers to recycling. Our current projects are based in Sweden, Namibia, Ethiopia, Bolivia, Madagascar and India. Students interested in thesis projects or internships are welcome to contact me. 

Ph.D. Technology, Swedish University of Agricultural Sciences

M.Sc. Environmental Sciences, Policy, & Management, Joint Degree from the University of Manchester, Lund University and Central European University.

B. Tech. Chemical Process Engineering at VIT University, India.

Simha, P., Malefors, C., van der Merwe, G., & Marais, E. (2026). Passive solar-thermal concentration of human urine for decentralised sanitation using an air-closet evaporation architecture. Desalination, 120406.

Popat, S. C., Courtney, C., Randall, D. G., & Simha, P. (2026). Making Waves: Rethinking Hydrogen Production from Human Urine Through Urea Electrolysis. Water Research, 126479.

Gregorio-Lozano, S., Senecal, J., Bijlsma, L., Pitarch, E., Celma, A., & Simha, P. (2026). Tracing pharmaceutical fate from granulated human urine-derived fertiliser through a farm-to-table food chain. Environmental Technology & Innovation, 105065.

Barton, M. A., Alrousan, D., Perez-Mercado, L. F., Dalahmeh, S. S., Vasiljev, A., Drangert, J. O., & Simha, P. (2026). Clean enough? Acceptance of urine-derived dry fertilizer and water shaped by religious and social norms in a water-scarce Islamic context. Desalination, 119804.

Rosa, L., Li, P., Shan, B., Fan, Z., Kitano, M., Zavabeti, A., Simha, P., Zhou, S. and Sutton, M.A., 2026. Reimagining ammonia for a sustainable future. One Earth, 9(4).

Mehaidli, A. P., Mandal, R., & Simha, P. (2024). Selective degradation of endogenous organic metabolites in acidified fresh human urine using sulphate radical-based advanced oxidation. Water Research, 257, 121751.

Perez-Mercado, L. F., Simha, P., Moreira, A. P., Paulo, P. L., & Vinnerås, B. (2024). Circular fertilisers combining dehydrated human urine and organic wastes can fulfil the macronutrient demand of 15 major crops. Science of the Total Environment, 951, 175655.

van der Merwe, G., & Simha, P. (2023). Approaches for bridging the sanitation delivery gap in urban informal settlements in Namibia. City and Environment Interactions, 20, 100120.

Zhou, X., Simha, P., Perez-Mercado, L. F., Barton, M. A., Lyu, Y., Guo, S., ... & Li, Z. (2022). China should focus beyond access to toilets to tap into the full potential of its Rural Toilet Revolution. Resources, Conservation and Recycling, 178, 106100.

Simha, P., Barton, M.A., Perez-Mercado, L.F., et al. (2021). Willingness among food consumers to recycle human urine as crop fertiliser: Evidence from a multinational survey. Science of The Total Environment, 765, 144438.

Senecal, J., Nordin, A., Simha, P., Vinnerås, B., 2018. Hygiene aspect of treating human urine by alkaline dehydration. Water Research, 144, 474-481.

Simha, P., Alkaline Urine Dehydration: How to dry source-separated human urine and recover nutrients? Doctoral Thesis, Sveriges lantbruksuniversitet, Acta Universitatis Agriculturae Sueciae, 1652-6880. 

Wastewater – Turning Problem to Solution. A UNEP Rapid Response Assessment Report. Nairobi, Kenya.

Simha, P., Vinnerås, B. (2022). The disruptive opportunity for mainstreaming urine recycling. IWA Source Magazine. 

Simha, P., Buckley, C., Senecal, J. (2020) We developed a simple process to recycle urine. Here’s how it’s done. The Conversation Africa. 

Simha, P., Vinnerås, B., Senecal J. (2020) We found a way to turn urine into solid fertiliser – it could make farming more sustainable. The Conversation UK.