Stanford Radio

The Future of Everything with Russ Altman: E130 | Will Tarpeh: How to take the waste out of wastewater The very notion of wastewater, and what we choose to do with it, could change dramatically if this Stanford chemical engineer has his way. Once the bathwater is drained, the toilet flushed or the laundry done, few give a passing thought to the wastewater that leaves our homes. But chemical engineer Will Tarpeh might change your mind, if you give him the chance. Tarpeh says that that water is a literal mine of valuable chemicals. Chemicals like nitrogen, phosphorus and potassium make great fertilizers. Lithium can be used in lithium ion batteries. And even pharmaceuticals could be recovered and reused. In fact, Tarpeh points out that if we could harvest all the world’s urine, it could supplant 20–30% of our nitrogen needs — and in some places can be cheaper to do than existing production and transport methods. Waste, Tarpeh says, is just a state of mind. His “pipe dream,” he says, is to develop next-gener