Every person produces approximately 1.2kg/annum of phosphorous. This is typically conveyed to a wastewater treatment plant. In the United Kingdom, the annual phosphorus load from human sources which is present in wastewater is therefore approximately 72,000 tonnes. This would have a value in the region of US$168M per annum based on current market prices.
This paper examines how the Aquacritox sludge to energy process could be used in combination with Biological phosphorus removal & a fluidised bed phosphorus recovery process to recover 70% of the total influent phosphorus load to the treatment plant. The paper provides a simulated case study at a 500K PE Biological phosphorus removal plant illustrating how this could be implemented.
Phosphorus is a non renewable resource for which there is no substitute. While it is possible to substitute renewable energy for fossil fuels, no other mineral can take the place of phosphorus.
Our ability to provide enough food to feed the human population is dependent on the use of artificial fertilizers, which contain phosphorus, nitrogen and potassium. While nitrogen is abundant in the atmosphere (- it just requires the use of large amounts of natural gas to capture it), phosphorus is mined at just a handful of locations worldwide, primarily, the United States, China and Morocco. Today, Florida produces 25% of world's phosphate which makes the United States the world's largest producer of phosphate rock.
While the timing for “Peak Phosphorus” may be fifty, or even one hundred, years out, as with peak oil, it is not a question of if, but when. There are some indications that production has already peaked in terms of the readily available resources while other estimates put this 20-30 years out as is illustrated in Figure 1.