Environmental and health co-benefits for advanced phosphorus recovery

Abstract

Worldwide food production is largely dependent on rock phosphate, a finite raw material used for the production of concentrated phosphorus fertilizers. With the aim to close the biogeochemical phosphorus cycle across regions and urban–rural systems, advanced phosphorus recovery applies thermochemical and precipitation techniques to transform locally available biogenic materials into concentrated phosphorus fertilizers. Due to insufficient insights into the consequential impacts of these circular processes, opportunities to align advanced phosphorus recovery with agricultural sustainability are still widely unknown. Here we show that environmental and health life cycle impacts are often lower for phosphorus fertilizers sourced from secondary raw materials than for rock phosphate-derived products, especially in areas of high livestock and population density. Including externalities from rock phosphate extraction and avoided current-day management of biogenic materials in the comparative product life cycle severely alters the cost assessment relative to an analysis that considers only internal costs from manufacturers’ production processes. Societal costs incurred for circular products derived from sewage sludge, manure and meat and bone meal are up to 81%, 50% and 10% lower than for rock-derived superphosphate, respectively. Even without accounting for rock phosphate depletion risks, short-term and local environmental and health co-benefits might underlie the societal cost effectiveness of advanced phosphorus recovery.

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Fig. 1: Schematic representation of methodological principles and selected pathways of the life cycle assessment that applies the production and use on land of 1 kg of bioavailable P in a concentrated P fertilizer as the functional unit.
Fig. 2: Rock phosphate depletion.
Fig. 3: Conventional life cycle costing.
Fig. 4: Environmental and health impacts.
Fig. 5: External and societal life cycle costs.

Data availability

The data supporting the findings of this study are available within the paper and its supplementary information files.

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Acknowledgements

We are grateful to the manufacturers that provided primary data for the life cycle inventory. We thank P. Eder and E. Garbarino for guidance and revising previous drafts of this manuscript and A. Atkinson for language editing. The views expressed are purely those of the authors and may not in any circumstances be regarded as stating an official position of the European Commission.

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D.T. performed the environmental life cycle and cost analyses; H.G.M.S. and D.H. conceived the research and supervised the collection of primary data from manufacturers; D.T. and D.H. conceptualized the life cycle approach applied; D.H. wrote the paper with substantial contributions from D.T. and H.G.M.S. All authors interpreted the results, elaborated the structure for data presentation and developed the research conclusions.

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Correspondence to Dries Huygens.

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Tonini, D., Saveyn, H.G.M. & Huygens, D. Environmental and health co-benefits for advanced phosphorus recovery. Nat Sustain 2, 1051–1061 (2019). https://doi.org/10.1038/s41893-019-0416-x

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