Phosphorus recovery from wastewater: needs, technologies and costs

Abstract

Phosphorus is an essential, yet limited resource, which cannot be replaced by any other element. This is why there are increasing efforts to recycle phosphorus contained in wastewater. It involves the recovery of phosphorus and, normally, the separation of phosphates from harmful substances. Phosphorus can be recovered from wastewater, sewage sludge, as well as from the ash of incinerated sewage sludge, and can be combined with phosphorus removal in most cases. The phosphorus recovery rate from the liquid phase can reach 40 to 50% at the most, while recovery rates from sewage sludge and sewage sludge ash can reach up to 90%. There are various methods which can be applied for phosphorus recovery. Up to now, there is limited experience in industrial-scale implementation. The costs for recovered phosphate exceed the costs for phosphate from rock phosphate by several times. For German conditions, the specific additional costs of wastewater treatment by integrating phosphorus recovery can be estimated at euro2-6 per capita and year.

Phosphorus recycling and food security in the long run: a conceptual modelling approach

“…This is where recycling technologies, like struvite production from urban waste waters, attain their essential role. Currently new technologies are under development or in the implementation phase (Cornel and Schaum 2009). Hence, in what follows I will assume that the recycling sector can produce suitable fertilizers that are perfect substitutes for fertilizers from rock phosphates.…”

“…As yet P recycling from urban wastes, such as for example 1 Ulrich and Frossard (2014) provide a historical perspective on the current debate on P scarcity. struvite production from urban waste waters (Cornel and Schaum 2009), is too expensive to be worthwhile, and fertilizers from recycled P cannot compete with rock phosphates on the market (Molinos-Senante et al 2011). The importance and, indeed, the urgency of the phosphorus problem stem from the fact that there is no substitute for P fertilizers.…”

“…Cordell et al (2011) provide an overview of options for P reuse and recovery. As yet P recycling from urban wastes, such as for example struvite production from urban waste waters (Cornel and Schaum 2009), is too expensive to be worthwhile, and fertilizers from recycled P cannot compete with rock phosphates on the market (Molinos-Senante et al 2011).…”

ZeroWasteWater: short-cycling of wastewater resources for sustainable cities of the future

“…Fertilizer prices for urea, ammonium nitrate and ammonium sulphate ranged up to 0.88 to 1.48 EUR kg −1 N mid 2008 (Apodaca, 2010). j Since about 90% of the P ends up in the sludge (Cornel and Schaum, 2009), this was assumed as recovery percentage. Fertilizer prices for triple superphosphate and diammonium phosphate in 2010 were 1.1 and 1.6 EUR kg −1 P, respectively (The World Bank, 2010).…”

“…The amount of phosphorus excreted in sewage and kitchen waste is 0.9 and 0.7 kg P IE −1 year −1 , respectively (Table 1), which is in most cases precipitated or incorporated into sludge through biological and/or chemical reactions, and subsequently dumped in landfills either directly or after incineration (Cornel and Schaum, 2009). In contrast to the main resource for nitrogen fertilizer production, the resource for phosphorus fertilizer production, i.e.…”