Phosphate recycling: the state of affairs

The Swiss Ministry of the Environment is taking the impending phosphate shortage seriously. A 200 page report on the state of affairs in the field of phosphate recycling is proof of this. The report shows which methods of phosphate recycling are available and examines whether they will be viable in a commercial market in the long term.
 
Leaders
The Japanese are still currently the leaders. The Japanese Unitika Group has three purification installations in operation that recover struvite (rich in phosphate) from waste water and market this successfully in the agricultural sector. Other promising technologies are those of ASH DEC (Austria), DHV (the Netherlands), Ostara (Canada) and Seaborne (Germany).
 
Centralised-decentralised
Although the recovery of struvite – as in Japan – may be the most far advanced, the decentralised operation is a disadvantage. In contrast, the ASH DEC technique, in which phosphate-rich artificial fertiliser is recovered from sludge incineration ash, can be implemented in a large central installation. The Swiss regard this as an important advantage.
 
Harmonisation
However, both techniques involve demands in terms of the manner in which phosphates are recovered. For example, an important precondition for the applicability of struvite recovery is that phosphates are removed biologically. An important precondition for the ASH DEC technique is that the sludge is incinerated.
According to the report, the fact that not all purification plants remove their phosphates biologically and that not all sludge is incinerated makes it important to harmonise the development of both techniques.

Download the complete report.