Phosphate Recovery From Sewage

In this blog (see "Dwindling Phosphorus Supplies") I talked about the world’s dwindling phosphate supplies, and how the key to sustainability of phosphate supplies would be recycling. But who among us has even thought about how we might recycle the gram and a half of precious phosphate we excrete in urine every day?

Well, a researcher at the University of British Columbia did, and then he set out to do something about it. Today, a phosphate recovery system based on his design is producing about a ton of slow-release phosphate fertilizer every day from a sewage treatment facility serving Portland, Oregon. The fertilizer is in such high demand that the recovery system will pay for itself in less than five years. Other recovery plants are planned, including larger ones to recover the waste from dairy and pig farms.

So if you live in Portland, Oregon, count yourself lucky; you already ARE recycling your phosphate! (Or at least somebody is.)

Reference: Tweed, Katherine. Sewage’s Cash Crop. Scientific American Nov. 2009, p. 28.