Phosphorus flow mapping to identify opportunities for recovery and reuse
The need to look for more local sources of phosphorus (P), such as recycling of P in waste, becomes increasingly important as rock-phosphate quality declines. Moving towards a closed P cycle has the potential to decrease cost, increase sustainability, reduce pollution, and improve local and worldwide food security through long-term access to P. In line with the EU “Roadmap to a Resource Efficient Europe” and the “Circular Economy Action Plan”, resource recycling is important to the Scottish Government’s growth strategy, resource efficiency plans and developing a closed loop circular economy.
Although there has been a significant amount of research on P flows through natural and managed water systems, the spatial patterns of P-rich waste generation, recycling opportunities, and the economic costs associated with these remain unclear. This project seeks to build on the outputs of previous studies to pilot spatial P flow maps for large Scottish catchments with contrasting land use (urban vs rural land use). Ultimately, this may be upscaled to create a regional scale map of Scotland’s P flows. This work will allow the identification of opportunities for innovation in capture and reuse of P by assessing the economic costs associated with these steps as well as locating potential links between currently untapped sources of recoverable P (e.g. wastewater treatment) and users of P (e.g. agriculture).
Previous CREW projects relevant to this project:
- Water Resource Balancing: Is a closed loop system possible that enables sustainable rural supplies?
- To what extent could water quality be improved by reducing the phosphorus content in animal feed?
- Practical measures for reducing phosphorus and faecal microbial loads from onsite wastewater treatment system discharges to the environment: A review
- Water and the circular economy: where is the greatest sustainable economic benefit for resource recovery in the water cycle?
This project aims to map out existing P flows for two Scottish catchments of contrasting land use. The project aims to develop an improved P management strategy and highlight areas where this strategy is likely to produce the most significant results.
Specific objectives include:
- Produce a short review of P flows at a Scottish level, including:
- How spatial coupling concepts (e.g. P source locations compared to P use locations) are tackled in countries where this practice is advanced (e.g. Netherlands).
- P recovery methods appropriate to Scotland’s dominant P waste sources.
- The major/minor P usage opportunities (e.g. fertiliser replacement in different sectors); products/forms available for reuse.
- Produce a P flow map for two Scottish catchments of contrasting land use.
- Analyse a number of scenarios (e.g. P recapture using different strategies, reuse in various locations) for the two catchments and identify areas that deliver best practise in P management and offer opportunities for generating value. Explicitly consider the costs associated with the proposed opportunities (e.g. transport, capture, and processing costs).
- Provide recommendations for the potential future project upscaling the results to create a P-flow map for Scotland.