Research 289: Phosphorus from wastewater: Novel technologies for advanced treatment and re-use

Authors: Katrina A. Macintosh, Jason Chin, Daren McHugh, Jasmine Connolly, Juan Castilla Archilla, José Antonio Pícon, Pia McAleenan, John P. Quinn, Panagiotis Manesiotis, Vincent O’Flaherty, and John W. McGrath.

Summary: This project reviewed the current state of the art with respect to Phosphorus (P) removal and recycling, assessed the potential of novel removal and recovery systems, and facilitated an All Island Phosphorus Sustainability Workshop.

Research 289

Published: 2019

ISBN: 978-1-84095-854-6

Pages: 40

Filesize: 1,820 KB

Format: pdf


Identify Pressures

Phosphorus (P) is a non-renewable commodity that plays an essential role in the global food web. Europe’s P production is minimal. Globally, finite reserves are being rapidly depleted, with supplies coming predominantly from Morocco, the USA, China and Russia. As a P importer, Ireland and the wider European community, which has for many years seen itself as a food-secure region, now recognises its high vulnerability to P scarcity. Paradoxically, eutrophication, caused by freshwater P enrichment, constitutes an important threat to good water quality. This research sought to address the two contrasting issues of P sustainability and the pollution of receiving waters by:

  • reviewing the current state of the art with respect to commercial processes for P removal and recovery from wastewater;
  • dissecting the scientific basis of three novel P removal and recovery systems through assessment of their robustness, scalability and effectiveness as P recycling technologies;
  • capturing perspectives from relevant stakeholders from across the regulatory, wastewater, academic and agri-food sectors in relation to P reuse, recovery and recycling, as well as future directions for P sustainability and research on the island of Ireland.

Inform Policy

The findings from this research suggest that legislation needs to move away from “removal” only and towards “recovery”, to stimulate the adoption of the P circular economy on the island of Ireland. P reuse and recovery needs to be incentivised and value chains need to be developed to promote uptake. Further research is needed to develop markets and value chains for recovered P products. The current market situation for primary sources of P means that recovery processes are economically viable only at large scale. This could, however, be offset by factors around security of supply, future EU legislation around permissible cadmium levels in fertiliser products, and the production of “blended” fertilisers, which contain a proportion of recycled P product. Ireland should consider setting a target (in terms of both percentage reduction and date) for reducing P imports. The findings suggest a robust justification for the establishment of an Irish Nutrient Sustainability Platform (, to engage the public and private sectors in the development and implementation of nutrient (and co-recoverable resource) management and value chain development.

Develop Solutions

Research is required on the agronomic value of recycled P products across the Irish agricultural sector and on methodologies to stabilise nutrient levels in agri-food wastes to produce new innovative fertiliser products that perform, in terms of yield, comparably to traditional chemical fertilisers. The development of alternative formulations of slow-release fertiliser encapsulated with recovered P and nitrogen should also be considered. In utilising recovered products as fertilisers (or other commercial products), the presence of microbiological, chemical and physical contaminants requires evaluation. Increased on-farm soil testing, adoption of nutrient management tools and uptake of recovered product fertilisers across the agricultural community should be encouraged by working in association with regional farmer’s unions and associations, both assisting, and learning from, the farming community with respect to nutrient management and the improvements that could be made therein. Knowledge transfer with regard to P loss mitigation practices across the Irish farming sector is key. Finally, investment in both research into and the application of anaerobic digestion-based biorefinery processes is needed to deliver “value-added products” in addition to methane.