The Future of Everything Best of: How to take waste out of wastewater
Nov 28, 2025
William Tarpeh, a chemical engineer and MacArthur Fellowship recipient, dives into the fascinating world of wastewater, viewing it as a modern mine. He shares innovative methods to extract valuable nutrients like nitrogen and phosphorus from waste. Tarpeh discusses the potential of urine to supply substantial fertilizer globally and the environmental benefits that come with it. He also emphasizes the need for decentralized sanitation solutions to tackle global challenges and highlights his initiatives in Senegal to convert waste into local products.
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Wastewater As A Renewable Resource
- Wastewater functions as a constantly renewing ‘modern mine’ containing recoverable elements like nitrogen, phosphorus, and potassium.
- Treating wastewater as a resource enables local, ongoing extraction rather than one-time disposal.
Selective Separation Is The Core Method
- Selective separation isolates specific ions or molecules from complex wastewater mixtures using designed materials and electrochemistry.
- Choosing the target element, the wastewater type, and the desired product defines the recovery process.
Urine Could Supply Significant Fertilizer
- Collecting global urine could supply roughly 20–30% of current nitrogen fertilizer demand.
- Recovering that nitrogen reduces energy-intensive industrial fertilizer production and related emissions.