Using liquid gold as a resource to extract valuable phosphates is a long-time practice. For instance in 2013 the Amsterdam sewage treatment plant started a larg

Using liquid gold as a resource to extract valuable phosphates is a long-time practice. For instance in 2013 the Amsterdam sewage treatment plant started a large-scale installation to process urine. Here are some ins and outs on the hows and whys: https://www.earthmagazine.org/article/p-phosphate-could-urine-solve-fertilizer-shortage https://www.earthmagazine.org/article/p-phosphate-could-urin...