Urban Mining’s Hidden Find: Phosphorus

Are we running out of naturally occurring phosphorus, or do we just have to untap a potentially hidden amount waiting to be urban mined?

Raw sewage, in its stinkiest and most seemingly useless form, is suddenly being coveted as a harborer of the powder. With a phosphate content around 16%, phosphorus is a valuable and needed commodity in mineral fertilizer, commanding about $300 a ton.

With phosphorus reserves potentially running low and quality depleting, a solution is essential for human, animal and plant life on planet earth. Phosphorus rock reserves have been decreasing for decades, and quality of fertilizer has been greatly compromised as a result.

With just a handful of countries housing phosphorus — Morocco alone holds about 37% of the world’s reserve of the fossil treasure — acting soon is essential.

Currently, sewage treatment plants accumulate more than 2 pounds of phosphate a year per resident, usually ending up hidden in sludge. Upon heating in scorching hot kilns, the ash that is the result of two purification processes is combined with plant nutrients, creating “urban fertilizer.”

Though this extraction process is energy intensive, it is a means to untapping potentially wasted phosphorus. Already being implemented in parts of Europe, expect this technological breakthrough to spread quickly. You’ll never look at sewage sludge the same again.