Ancient cultures, from Greece to Asia, have used urine as a fertiliser to provide nutrients to their crops. Is recycling our urine a radical solution to global food security and saving our waterways?

Green Home Guide
Fresh fruits and vegetables Image: Stuart Humphreys
© Australian Museum

Urine contains important nutrients that plants need to grow, including nitrogen, potassium and phosphorous. Global reserves of phosphorus are quickly running out and are expected to be depleted in the next 100 years. Since plants need phosphate to grow, this poses an enormous challenge for global food production in the future — a shortage of phosphate could potentially result in worldwide famine.

Approximately 14.9 million tons of phosphate ore is mined worldwide. Of this, 3.5 million tons of phosphate ends up in our food, and eventually, three million tons of phosphates are released through human waste. Since urine is such an important source of phosphates, can we afford to be flushing it down the toilet?

Not only are the nutrients from our urine being wasted, but their presence in wastewater released into the environment can cause harmful algal blooms in waterways and pose problems to coastal waters and ecosystems.
The solution to both those problems: recycle our urine. Urine Diversion Technology (UDT) recycles urine by using special toilets designed to separate urine from solid matter, storing it for a period of time to kill off bacteria and then recovering the nutrients in the urine by means of crystallisation for use as fertiliser. This also diverts urine from the waste stream, reducing water pollution.

UDT has been trialled in Sweden, Germany, the Netherlands, Switzerland, China and now in Australia at the Currumbin Eco-village in Queensland, in Kinlake West in Victoria and at University of Technology in Sydney. Read article.

So what are your thoughts? Do you think UD toilets will be replacing our traditional toilets in the near future? Can our urine save the planet from large-scale famine?